;; x86-64 instruction selection and CLIF-to-MachInst lowering.
;; The main lowering constructor term: takes a clif `Inst` and returns the
;; register(s) within which the lowered instruction's result values live.
(decl lower (Inst) InstOutput)
;; A variant of the main lowering constructor term, used for branches.
;; The only difference is that it gets an extra argument holding a vector
;; of branch targets to be used.
(decl lower_branch (Inst MachLabelSlice) InstOutput)
;;;; Rules for `iconst` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(rule (lower (has_type (fits_in_64 ty)
(iconst (u64_from_imm64 x))))
(imm ty x))
;; `i128`
(rule 1 (lower (has_type $I128
(iconst (u64_from_imm64 x))))
(value_regs (imm $I64 x)
(imm $I64 0)))
;;;; Rules for `bconst` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `b64` and smaller.
(rule (lower (has_type (fits_in_64 ty)
(bconst $false)))
(imm ty 0))
(rule (lower (has_type (fits_in_64 ty)
(bconst $true)))
(imm ty 1))
;; `b128`
(rule 1 (lower (has_type $B128
(bconst $false)))
(value_regs (imm $B64 0)
(imm $B64 0)))
(rule 1 (lower (has_type $B128
(bconst $true)))
(value_regs (imm $B64 1)
(imm $B64 0)))
;;;; Rules for `f32const` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (f32const (u64_from_ieee32 x)))
(imm $F32 x))
;;;; Rules for `f64const` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (f64const (u64_from_ieee64 x)))
(imm $F64 x))
;;;; Rules for `null` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type ty (null)))
(imm ty 0))
;;;; Rules for `iadd` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
;; Add two registers.
(rule -5 (lower (has_type (fits_in_64 ty)
(iadd x y)))
(x64_add ty x y))
;; Add a register and an immediate.
(rule -4 (lower (has_type (fits_in_64 ty)
(iadd x (simm32_from_value y))))
(x64_add ty x y))
(rule -3 (lower (has_type (fits_in_64 ty)
(iadd (simm32_from_value x) y)))
(x64_add ty y x))
;; Add a register and memory.
(rule -2 (lower (has_type (fits_in_64 ty)
(iadd x (sinkable_load y))))
(x64_add ty
x
(sink_load_to_gpr_mem_imm y)))
(rule -1 (lower (has_type (fits_in_64 ty)
(iadd (sinkable_load x) y)))
(x64_add ty
y
(sink_load_to_gpr_mem_imm x)))
;; SSE.
(rule (lower (has_type (multi_lane 8 16)
(iadd x y)))
(x64_paddb x y))
(rule (lower (has_type (multi_lane 16 8)
(iadd x y)))
(x64_paddw x y))
(rule (lower (has_type (multi_lane 32 4)
(iadd x y)))
(x64_paddd x y))
(rule (lower (has_type (multi_lane 64 2)
(iadd x y)))
(x64_paddq x y))
;; `i128`
(rule 1 (lower (has_type $I128 (iadd x y)))
;; Get the high/low registers for `x`.
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1)))
;; Get the high/low registers for `y`.
(let ((y_regs ValueRegs y)
(y_lo Gpr (value_regs_get_gpr y_regs 0))
(y_hi Gpr (value_regs_get_gpr y_regs 1)))
;; Do an add followed by an add-with-carry.
(with_flags (x64_add_with_flags_paired $I64 x_lo y_lo)
(x64_adc_paired $I64 x_hi y_hi)))))
;;;; Rules for `sadd_sat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (multi_lane 8 16)
(sadd_sat x y)))
(x64_paddsb x y))
(rule (lower (has_type (multi_lane 16 8)
(sadd_sat x y)))
(x64_paddsw x y))
;;;; Rules for `uadd_sat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (multi_lane 8 16)
(uadd_sat x y)))
(x64_paddusb x y))
(rule (lower (has_type (multi_lane 16 8)
(uadd_sat x y)))
(x64_paddusw x y))
;;;; Rules for `iadd_ifcout` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; N.B.: the second output of `iadd_ifcout` is meant to be the
;; `iflags` value containing the carry result. However, we plan to
;; replace this with a bool carry flag, and all consumers of `iflags`
;; remain in the handwritten pattern-matching code and explicitly
;; match on the flags producer. So we can get away with just
;; using an invalid second output, and the reg-renaming code does the
;; right thing, for now. For safety, we assert elsewhere that no one
;; actually uses the register assigned to the SSA `iflags`-typed
;; `Value`.
(decl output_ifcout (Reg) InstOutput)
(rule (output_ifcout reg)
(output_pair reg (value_regs_invalid)))
;; Add two registers.
(rule 0 (lower (has_type (fits_in_64 ty)
(iadd_ifcout x y)))
(output_ifcout (x64_add ty x y)))
;; Add a register and an immediate.
(rule 1 (lower (has_type (fits_in_64 ty)
(iadd_ifcout x (simm32_from_value y))))
(output_ifcout (x64_add ty x y)))
(rule 2 (lower (has_type (fits_in_64 ty)
(iadd_ifcout (simm32_from_value x) y)))
(output_ifcout (x64_add ty y x)))
;; Add a register and memory.
(rule 3 (lower (has_type (fits_in_64 ty)
(iadd_ifcout x (sinkable_load y))))
(output_ifcout (x64_add ty x (sink_load_to_gpr_mem_imm y))))
(rule 4 (lower (has_type (fits_in_64 ty)
(iadd_ifcout (sinkable_load x) y)))
(output_ifcout (x64_add ty y (sink_load_to_gpr_mem_imm x))))
;; (No `iadd_ifcout` for `i128`.)
;;;; Rules for `isub` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
;; Sub two registers.
(rule -3 (lower (has_type (fits_in_64 ty)
(isub x y)))
(x64_sub ty x y))
;; Sub a register and an immediate.
(rule -2 (lower (has_type (fits_in_64 ty)
(isub x (simm32_from_value y))))
(x64_sub ty x y))
;; Sub a register and memory.
(rule -1 (lower (has_type (fits_in_64 ty)
(isub x (sinkable_load y))))
(x64_sub ty x
(sink_load_to_gpr_mem_imm y)))
;; SSE.
(rule (lower (has_type (multi_lane 8 16)
(isub x y)))
(x64_psubb x y))
(rule (lower (has_type (multi_lane 16 8)
(isub x y)))
(x64_psubw x y))
(rule (lower (has_type (multi_lane 32 4)
(isub x y)))
(x64_psubd x y))
(rule (lower (has_type (multi_lane 64 2)
(isub x y)))
(x64_psubq x y))
;; `i128`
(rule 1 (lower (has_type $I128 (isub x y)))
;; Get the high/low registers for `x`.
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1)))
;; Get the high/low registers for `y`.
(let ((y_regs ValueRegs y)
(y_lo Gpr (value_regs_get_gpr y_regs 0))
(y_hi Gpr (value_regs_get_gpr y_regs 1)))
;; Do a sub followed by an sub-with-borrow.
(with_flags (x64_sub_with_flags_paired $I64 x_lo y_lo)
(x64_sbb_paired $I64 x_hi y_hi)))))
;;;; Rules for `ssub_sat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (multi_lane 8 16)
(ssub_sat x y)))
(x64_psubsb x y))
(rule (lower (has_type (multi_lane 16 8)
(ssub_sat x y)))
(x64_psubsw x y))
;;;; Rules for `usub_sat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (multi_lane 8 16)
(usub_sat x y)))
(x64_psubusb x y))
(rule (lower (has_type (multi_lane 16 8)
(usub_sat x y)))
(x64_psubusw x y))
;;;; Rules for `band` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `{i,b}64` and smaller.
;; And two registers.
(rule 0 (lower (has_type (fits_in_64 ty) (band x y)))
(x64_and ty x y))
;; And with a memory operand.
(rule 1 (lower (has_type (fits_in_64 ty)
(band x (sinkable_load y))))
(x64_and ty x
(sink_load_to_gpr_mem_imm y)))
(rule 2 (lower (has_type (fits_in_64 ty)
(band (sinkable_load x) y)))
(x64_and ty
y
(sink_load_to_gpr_mem_imm x)))
;; And with an immediate.
(rule 3 (lower (has_type (fits_in_64 ty)
(band x (simm32_from_value y))))
(x64_and ty x y))
(rule 4 (lower (has_type (fits_in_64 ty)
(band (simm32_from_value x) y)))
(x64_and ty y x))
;; SSE.
(decl sse_and (Type Xmm XmmMem) Xmm)
(rule (sse_and $F32X4 x y) (x64_andps x y))
(rule (sse_and $F64X2 x y) (x64_andpd x y))
(rule -1 (sse_and (multi_lane _bits _lanes) x y) (x64_pand x y))
(rule 5 (lower (has_type ty @ (multi_lane _bits _lanes)
(band x y)))
(sse_and ty x y))
;; `{i,b}128`.
(rule 6 (lower (has_type $I128 (band x y)))
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1))
(y_regs ValueRegs y)
(y_lo Gpr (value_regs_get_gpr y_regs 0))
(y_hi Gpr (value_regs_get_gpr y_regs 1)))
(value_gprs (x64_and $I64 x_lo y_lo)
(x64_and $I64 x_hi y_hi))))
(rule 6 (lower (has_type $B128 (band x y)))
;; Booleans are always `0` or `1`, so we only need to do the `and` on the
;; low half. The high half is always zero but, rather than generate a new
;; zero, we just reuse `x`'s high half which is already zero.
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1))
(y_lo Gpr (lo_gpr y)))
(value_gprs (x64_and $I64 x_lo y_lo)
x_hi)))
;;;; Rules for `bor` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `{i,b}64` and smaller.
;; Or two registers.
(rule 0 (lower (has_type (fits_in_64 ty) (bor x y)))
(x64_or ty x y))
;; Or with a memory operand.
(rule 1 (lower (has_type (fits_in_64 ty)
(bor x (sinkable_load y))))
(x64_or ty x
(sink_load_to_gpr_mem_imm y)))
(rule 2 (lower (has_type (fits_in_64 ty)
(bor (sinkable_load x) y)))
(x64_or ty y
(sink_load_to_gpr_mem_imm x)))
;; Or with an immediate.
(rule 3 (lower (has_type (fits_in_64 ty)
(bor x (simm32_from_value y))))
(x64_or ty x y))
(rule 4 (lower (has_type (fits_in_64 ty)
(bor (simm32_from_value x) y)))
(x64_or ty y x))
;; SSE.
(decl sse_or (Type Xmm XmmMem) Xmm)
(rule (sse_or $F32X4 x y) (x64_orps x y))
(rule (sse_or $F64X2 x y) (x64_orpd x y))
(rule -1 (sse_or (multi_lane _bits _lanes) x y) (x64_por x y))
(rule 5 (lower (has_type ty @ (multi_lane _bits _lanes)
(bor x y)))
(sse_or ty x y))
;; `{i,b}128`.
(decl or_i128 (ValueRegs ValueRegs) ValueRegs)
(rule (or_i128 x y)
(let ((x_lo Gpr (value_regs_get_gpr x 0))
(x_hi Gpr (value_regs_get_gpr x 1))
(y_lo Gpr (value_regs_get_gpr y 0))
(y_hi Gpr (value_regs_get_gpr y 1)))
(value_gprs (x64_or $I64 x_lo y_lo)
(x64_or $I64 x_hi y_hi))))
(rule 6 (lower (has_type $I128 (bor x y)))
(or_i128 x y))
(rule 6 (lower (has_type $B128 (bor x y)))
;; Booleans are always `0` or `1`, so we only need to do the `or` on the
;; low half. The high half is always zero but, rather than generate a new
;; zero, we just reuse `x`'s high half which is already zero.
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1))
(y_lo Gpr (lo_gpr y)))
(value_gprs (x64_or $I64 x_lo y_lo)
x_hi)))
;;;; Rules for `bxor` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `{i,b}64` and smaller.
;; Xor two registers.
(rule 0 (lower (has_type (fits_in_64 ty) (bxor x y)))
(x64_xor ty x y))
;; Xor with a memory operand.
(rule 1 (lower (has_type (fits_in_64 ty)
(bxor x (sinkable_load y))))
(x64_xor ty x
(sink_load_to_gpr_mem_imm y)))
(rule 2 (lower (has_type (fits_in_64 ty)
(bxor (sinkable_load x) y)))
(x64_xor ty y
(sink_load_to_gpr_mem_imm x)))
;; Xor with an immediate.
(rule 3 (lower (has_type (fits_in_64 ty)
(bxor x (simm32_from_value y))))
(x64_xor ty x y))
(rule 4 (lower (has_type (fits_in_64 ty)
(bxor (simm32_from_value x) y)))
(x64_xor ty y x))
;; SSE.
(rule 5 (lower (has_type ty @ (multi_lane _bits _lanes) (bxor x y)))
(sse_xor ty x y))
;; `{i,b}128`.
(rule 6 (lower (has_type $I128 (bxor x y)))
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1))
(y_regs ValueRegs y)
(y_lo Gpr (value_regs_get_gpr y_regs 0))
(y_hi Gpr (value_regs_get_gpr y_regs 1)))
(value_gprs (x64_xor $I64 x_lo y_lo)
(x64_xor $I64 x_hi y_hi))))
(rule 6 (lower (has_type $B128 (bxor x y)))
;; Booleans are always `0` or `1`, so we only need to do the `xor` on the
;; low half. The high half is always zero but, rather than generate a new
;; zero, we just reuse `x`'s high half which is already zero.
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1))
(y_lo Gpr (lo_gpr y)))
(value_gprs (x64_xor $I64 x_lo y_lo)
x_hi)))
;;;; Rules for `ishl` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(rule -1 (lower (has_type (fits_in_64 ty) (ishl src amt)))
(x64_shl ty src (put_masked_in_imm8_gpr amt ty)))
;; `i128`.
(decl shl_i128 (ValueRegs Gpr) ValueRegs)
(rule (shl_i128 src amt)
;; Unpack the registers that make up the 128-bit value being shifted.
(let ((src_lo Gpr (value_regs_get_gpr src 0))
(src_hi Gpr (value_regs_get_gpr src 1))
;; Do two 64-bit shifts.
(lo_shifted Gpr (x64_shl $I64 src_lo amt))
(hi_shifted Gpr (x64_shl $I64 src_hi amt))
;; `src_lo >> (64 - amt)` are the bits to carry over from the lo
;; into the hi.
(carry Gpr (x64_shr $I64
src_lo
(x64_sub $I64
(imm $I64 64)
amt)))
(zero Gpr (imm $I64 0))
;; Nullify the carry if we are shifting in by a multiple of 128.
(carry_ Gpr (with_flags_reg (x64_test (OperandSize.Size64)
(RegMemImm.Imm 127)
amt)
(cmove $I64
(CC.Z)
zero
carry)))
;; Add the carry into the high half.
(hi_shifted_ Gpr (x64_or $I64 carry_ hi_shifted)))
;; Combine the two shifted halves. However, if we are shifting by >= 64
;; (modulo 128), then the low bits are zero and the high bits are our
;; low bits.
(with_flags (x64_test (OperandSize.Size64) (RegMemImm.Imm 64) amt)
(consumes_flags_concat
(cmove $I64 (CC.Z) lo_shifted zero)
(cmove $I64 (CC.Z) hi_shifted_ lo_shifted)))))
(rule (lower (has_type $I128 (ishl src amt)))
;; NB: Only the low bits of `amt` matter since we logically mask the shift
;; amount to the value's bit width.
(let ((amt_ Gpr (lo_gpr amt)))
(shl_i128 src amt_)))
;; SSE.
;; Since the x86 instruction set does not have any 8x16 shift instructions (even
;; in higher feature sets like AVX), we lower the `ishl.i8x16` to a sequence of
;; instructions. The basic idea, whether the amount to shift by is an immediate
;; or not, is to use a 16x8 shift and then mask off the incorrect bits to 0s.
(rule (lower (has_type ty @ $I8X16 (ishl src amt)))
(let (
;; Mask the amount to ensure wrapping behaviour
(masked_amt Reg (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty))))
;; Shift `src` using 16x8. Unfortunately, a 16x8 shift will only be
;; correct for half of the lanes; the others must be fixed up with
;; the mask below.
(unmasked Xmm (x64_psllw src (mov_rmi_to_xmm masked_amt)))
(mask_addr SyntheticAmode (ishl_i8x16_mask masked_amt))
(mask Reg (x64_load $I8X16 mask_addr (ExtKind.None))))
(sse_and $I8X16 unmasked (RegMem.Reg mask))))
;; Get the address of the mask to use when fixing up the lanes that weren't
;; correctly generated by the 16x8 shift.
(decl ishl_i8x16_mask (RegMemImm) SyntheticAmode)
;; When the shift amount is known, we can statically (i.e. at compile time)
;; determine the mask to use and only emit that.
(decl ishl_i8x16_mask_for_const (u32) SyntheticAmode)
(extern constructor ishl_i8x16_mask_for_const ishl_i8x16_mask_for_const)
(rule (ishl_i8x16_mask (RegMemImm.Imm amt))
(ishl_i8x16_mask_for_const amt))
;; Otherwise, we must emit the entire mask table and dynamically (i.e. at run
;; time) find the correct mask offset in the table. We use `lea` to find the
;; base address of the mask table and then complex addressing to offset to the
;; right mask: `base_address + amt << 4`
(decl ishl_i8x16_mask_table () SyntheticAmode)
(extern constructor ishl_i8x16_mask_table ishl_i8x16_mask_table)
(rule (ishl_i8x16_mask (RegMemImm.Reg amt))
(let ((mask_table SyntheticAmode (ishl_i8x16_mask_table))
(base_mask_addr Gpr (x64_lea mask_table))
(mask_offset Gpr (x64_shl $I64 amt
(imm8_to_imm8_gpr 4))))
(amode_imm_reg_reg_shift 0
base_mask_addr
mask_offset
0)))
(rule (ishl_i8x16_mask (RegMemImm.Mem amt))
(ishl_i8x16_mask (RegMemImm.Reg (x64_load $I64 amt (ExtKind.None)))))
;; 16x8, 32x4, and 64x2 shifts can each use a single instruction, once the shift amount is masked.
(rule (lower (has_type ty @ $I16X8 (ishl src amt)))
(let ((masked_amt Reg (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty)))))
(x64_psllw src (mov_rmi_to_xmm masked_amt))))
(rule (lower (has_type ty @ $I32X4 (ishl src amt)))
(let ((masked_amt Reg (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty)))))
(x64_pslld src (mov_rmi_to_xmm masked_amt))))
(rule (lower (has_type ty @ $I64X2 (ishl src amt)))
(let ((masked_amt Reg (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty)))))
(x64_psllq src (mov_rmi_to_xmm masked_amt))))
;;;; Rules for `ushr` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(rule -1 (lower (has_type (fits_in_64 ty) (ushr src amt)))
(let ((src_ Gpr (extend_to_gpr src ty (ExtendKind.Zero))))
(x64_shr ty src_ (put_masked_in_imm8_gpr amt ty))))
;; `i128`.
(decl shr_i128 (ValueRegs Gpr) ValueRegs)
(rule (shr_i128 src amt)
;; Unpack the lo/hi halves of `src`.
(let ((src_lo Gpr (value_regs_get_gpr src 0))
(src_hi Gpr (value_regs_get_gpr src 1))
;; Do a shift on each half.
(lo_shifted Gpr (x64_shr $I64 src_lo amt))
(hi_shifted Gpr (x64_shr $I64 src_hi amt))
;; `src_hi << (64 - amt)` are the bits to carry over from the hi
;; into the lo.
(carry Gpr (x64_shl $I64
src_hi
(x64_sub $I64
(imm $I64 64)
amt)))
;; Nullify the carry if we are shifting by a multiple of 128.
(carry_ Gpr (with_flags_reg (x64_test (OperandSize.Size64) (RegMemImm.Imm 127) amt)
(cmove $I64 (CC.Z) (imm $I64 0) carry)))
;; Add the carry bits into the lo.
(lo_shifted_ Gpr (x64_or $I64 carry_ lo_shifted)))
;; Combine the two shifted halves. However, if we are shifting by >= 64
;; (modulo 128), then the hi bits are zero and the lo bits are what
;; would otherwise be our hi bits.
(with_flags (x64_test (OperandSize.Size64) (RegMemImm.Imm 64) amt)
(consumes_flags_concat
(cmove $I64 (CC.Z) lo_shifted_ hi_shifted)
(cmove $I64 (CC.Z) hi_shifted (imm $I64 0))))))
(rule (lower (has_type $I128 (ushr src amt)))
;; NB: Only the low bits of `amt` matter since we logically mask the shift
;; amount to the value's bit width.
(let ((amt_ Gpr (lo_gpr amt)))
(shr_i128 src amt_)))
;; SSE.
;; There are no 8x16 shifts in x64. Do the same 16x8-shift-and-mask thing we do
;; with 8x16 `ishl`.
(rule (lower (has_type ty @ $I8X16 (ushr src amt)))
(let (
;; Mask the amount to ensure wrapping behaviour
(masked_amt Reg (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty))))
;; Shift `src` using 16x8. Unfortunately, a 16x8 shift will only be
;; correct for half of the lanes; the others must be fixed up with
;; the mask below.
(unmasked Xmm (x64_psrlw src (mov_rmi_to_xmm masked_amt)))
(mask_addr SyntheticAmode (ushr_i8x16_mask masked_amt))
(mask Reg (x64_load $I8X16 mask_addr (ExtKind.None))))
(sse_and $I8X16
unmasked
(RegMem.Reg mask))))
;; Get the address of the mask to use when fixing up the lanes that weren't
;; correctly generated by the 16x8 shift.
(decl ushr_i8x16_mask (RegMemImm) SyntheticAmode)
;; When the shift amount is known, we can statically (i.e. at compile time)
;; determine the mask to use and only emit that.
(decl ushr_i8x16_mask_for_const (u32) SyntheticAmode)
(extern constructor ushr_i8x16_mask_for_const ushr_i8x16_mask_for_const)
(rule (ushr_i8x16_mask (RegMemImm.Imm amt))
(ushr_i8x16_mask_for_const amt))
;; Otherwise, we must emit the entire mask table and dynamically (i.e. at run
;; time) find the correct mask offset in the table. We use `lea` to find the
;; base address of the mask table and then complex addressing to offset to the
;; right mask: `base_address + amt << 4`
(decl ushr_i8x16_mask_table () SyntheticAmode)
(extern constructor ushr_i8x16_mask_table ushr_i8x16_mask_table)
(rule (ushr_i8x16_mask (RegMemImm.Reg amt))
(let ((mask_table SyntheticAmode (ushr_i8x16_mask_table))
(base_mask_addr Gpr (x64_lea mask_table))
(mask_offset Gpr (x64_shl $I64
amt
(imm8_to_imm8_gpr 4))))
(amode_imm_reg_reg_shift 0
base_mask_addr
mask_offset
0)))
(rule (ushr_i8x16_mask (RegMemImm.Mem amt))
(ushr_i8x16_mask (RegMemImm.Reg (x64_load $I64 amt (ExtKind.None)))))
;; 16x8, 32x4, and 64x2 shifts can each use a single instruction, once the shift amount is masked.
(rule (lower (has_type ty @ $I16X8 (ushr src amt)))
(let ((masked_amt Reg (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty)))))
(x64_psrlw src (mov_rmi_to_xmm masked_amt))))
(rule (lower (has_type ty @ $I32X4 (ushr src amt)))
(let ((masked_amt Reg (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty)))))
(x64_psrld src (mov_rmi_to_xmm masked_amt))))
(rule (lower (has_type ty @ $I64X2 (ushr src amt)))
(let ((masked_amt Reg (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty)))))
(x64_psrlq src (mov_rmi_to_xmm masked_amt))))
;;;; Rules for `sshr` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(rule -1 (lower (has_type (fits_in_64 ty) (sshr src amt)))
(let ((src_ Gpr (extend_to_gpr src ty (ExtendKind.Sign))))
(x64_sar ty src_ (put_masked_in_imm8_gpr amt ty))))
;; `i128`.
(decl sar_i128 (ValueRegs Gpr) ValueRegs)
(rule (sar_i128 src amt)
;; Unpack the low/high halves of `src`.
(let ((src_lo Gpr (value_regs_get_gpr src 0))
(src_hi Gpr (value_regs_get_gpr src 1))
;; Do a shift of each half. NB: the low half uses an unsigned shift
;; because its MSB is not a sign bit.
(lo_shifted Gpr (x64_shr $I64 src_lo amt))
(hi_shifted Gpr (x64_sar $I64 src_hi amt))
;; `src_hi << (64 - amt)` are the bits to carry over from the low
;; half to the high half.
(carry Gpr (x64_shl $I64
src_hi
(x64_sub $I64
(imm $I64 64)
amt)))
;; Nullify the carry if we are shifting by a multiple of 128.
(carry_ Gpr (with_flags_reg (x64_test (OperandSize.Size64) (RegMemImm.Imm 127) amt)
(cmove $I64 (CC.Z) (imm $I64 0) carry)))
;; Add the carry into the low half.
(lo_shifted_ Gpr (x64_or $I64 lo_shifted carry_))
;; Get all sign bits.
(sign_bits Gpr (x64_sar $I64 src_hi (imm8_to_imm8_gpr 63))))
;; Combine the two shifted halves. However, if we are shifting by >= 64
;; (modulo 128), then the hi bits are all sign bits and the lo bits are
;; what would otherwise be our hi bits.
(with_flags (x64_test (OperandSize.Size64) (RegMemImm.Imm 64) amt)
(consumes_flags_concat
(cmove $I64 (CC.Z) lo_shifted_ hi_shifted)
(cmove $I64 (CC.Z) hi_shifted sign_bits)))))
(rule (lower (has_type $I128 (sshr src amt)))
;; NB: Only the low bits of `amt` matter since we logically mask the shift
;; amount to the value's bit width.
(let ((amt_ Gpr (lo_gpr amt)))
(sar_i128 src amt_)))
;; SSE.
;; Since the x86 instruction set does not have an 8x16 shift instruction and the
;; approach used for `ishl` and `ushr` cannot be easily used (the masks do not
;; preserve the sign), we use a different approach here: separate the low and
;; high lanes, shift them separately, and merge them into the final result.
;;
;; Visually, this looks like the following, where `src.i8x16 = [s0, s1, ...,
;; s15]:
;;
;; lo.i16x8 = [(s0, s0), (s1, s1), ..., (s7, s7)]
;; shifted_lo.i16x8 = shift each lane of `low`
;; hi.i16x8 = [(s8, s8), (s9, s9), ..., (s15, s15)]
;; shifted_hi.i16x8 = shift each lane of `high`
;; result = [s0'', s1'', ..., s15'']
(rule (lower (has_type ty @ $I8X16 (sshr src amt @ (value_type amt_ty))))
(let ((src_ Xmm (put_in_xmm src))
;; Mask the amount to ensure wrapping behaviour
(masked_amt Reg (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty))))
;; In order for `packsswb` later to only use the high byte of each
;; 16x8 lane, we shift right an extra 8 bits, relying on `psraw` to
;; fill in the upper bits appropriately.
(lo Xmm (x64_punpcklbw src_ src_))
(hi Xmm (x64_punpckhbw src_ src_))
(amt_ XmmMemImm (sshr_i8x16_bigger_shift amt_ty masked_amt))
(shifted_lo Xmm (x64_psraw lo amt_))
(shifted_hi Xmm (x64_psraw hi amt_)))
(x64_packsswb shifted_lo shifted_hi)))
(decl sshr_i8x16_bigger_shift (Type RegMemImm) XmmMemImm)
(rule (sshr_i8x16_bigger_shift _ty (RegMemImm.Imm i))
(xmm_mem_imm_new (RegMemImm.Imm (u32_add i 8))))
(rule (sshr_i8x16_bigger_shift ty (RegMemImm.Reg r))
(mov_rmi_to_xmm (RegMemImm.Reg (x64_add ty
r
(RegMemImm.Imm 8)))))
(rule (sshr_i8x16_bigger_shift ty rmi @ (RegMemImm.Mem _m))
(mov_rmi_to_xmm (RegMemImm.Reg (x64_add ty
(imm ty 8)
rmi))))
;; `sshr.{i16x8,i32x4}` can be a simple `psra{w,d}`, we just have to make sure
;; that if the shift amount is in a register, it is in an XMM register.
(rule (lower (has_type ty @ $I16X8 (sshr src amt)))
(let ((masked_amt Reg (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty)))))
(x64_psraw src (mov_rmi_to_xmm masked_amt))))
(rule (lower (has_type ty @ $I32X4 (sshr src amt)))
(let ((masked_amt Reg (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty)))))
(x64_psrad src (mov_rmi_to_xmm masked_amt))))
;; The `sshr.i64x2` CLIF instruction has no single x86 instruction in the older
;; feature sets. Newer ones like AVX512VL + AVX512F include `vpsraq`, a 128-bit
;; instruction that would fit here, but this backend does not currently have
;; support for EVEX encodings. To remedy this, we extract each 64-bit lane to a
;; GPR, shift each using a scalar instruction, and insert the shifted values
;; back in the `dst` XMM register.
;;
;; (TODO: when EVEX support is available, add an alternate lowering here).
(rule (lower (has_type $I64X2 (sshr src amt)))
(let ((src_ Xmm (put_in_xmm src))
(lo Gpr (x64_pextrd $I64 src_ 0))
(hi Gpr (x64_pextrd $I64 src_ 1))
(amt_ Imm8Gpr (put_masked_in_imm8_gpr amt $I64))
(shifted_lo Gpr (x64_sar $I64 lo amt_))
(shifted_hi Gpr (x64_sar $I64 hi amt_)))
(make_i64x2_from_lanes shifted_lo
shifted_hi)))
;;;; Rules for `rotl` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller: we can rely on x86's rotate-amount masking since
;; we operate on the whole register. For const's we mask the constant.
(rule -1 (lower (has_type (fits_in_64 ty) (rotl src amt)))
(x64_rotl ty src (put_masked_in_imm8_gpr amt ty)))
;; `i128`.
(rule (lower (has_type $I128 (rotl src amt)))
(let ((src_ ValueRegs src)
;; NB: Only the low bits of `amt` matter since we logically mask the
;; rotation amount to the value's bit width.
(amt_ Gpr (lo_gpr amt)))
(or_i128 (shl_i128 src_ amt_)
(shr_i128 src_ (x64_sub $I64
(imm $I64 128)
amt_)))))
;;;; Rules for `rotr` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller: we can rely on x86's rotate-amount masking since
;; we operate on the whole register. For const's we mask the constant.
(rule -1 (lower (has_type (fits_in_64 ty) (rotr src amt)))
(x64_rotr ty src (put_masked_in_imm8_gpr amt ty)))
;; `i128`.
(rule (lower (has_type $I128 (rotr src amt)))
(let ((src_ ValueRegs src)
;; NB: Only the low bits of `amt` matter since we logically mask the
;; rotation amount to the value's bit width.
(amt_ Gpr (lo_gpr amt)))
(or_i128 (shr_i128 src_ amt_)
(shl_i128 src_ (x64_sub $I64
(imm $I64 128)
amt_)))))
;;;; Rules for `ineg` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(rule -1 (lower (has_type (fits_in_64 ty) (ineg x)))
(x64_neg ty x))
;; SSE.
(rule (lower (has_type $I8X16 (ineg x)))
(x64_psubb (imm $I8X16 0) x))
(rule (lower (has_type $I16X8 (ineg x)))
(x64_psubw (imm $I16X8 0) x))
(rule (lower (has_type $I32X4 (ineg x)))
(x64_psubd (imm $I32X4 0) x))
(rule (lower (has_type $I64X2 (ineg x)))
(x64_psubq (imm $I64X2 0) x))
;;;; Rules for `avg_round` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (multi_lane 8 16)
(avg_round x y)))
(x64_pavgb x y))
(rule (lower (has_type (multi_lane 16 8)
(avg_round x y)))
(x64_pavgw x y))
;;;; Rules for `imul` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
;; Multiply two registers.
(rule -5 (lower (has_type (fits_in_64 ty) (imul x y)))
(x64_mul ty x y))
;; Multiply a register and an immediate.
(rule -3 (lower (has_type (fits_in_64 ty)
(imul x (simm32_from_value y))))
(x64_mul ty x y))
(rule -4 (lower (has_type (fits_in_64 ty)
(imul (simm32_from_value x) y)))
(x64_mul ty y x))
;; Multiply a register and a memory load.
(rule -2 (lower (has_type (fits_in_64 ty)
(imul x (sinkable_load y))))
(x64_mul ty
x
(sink_load_to_gpr_mem_imm y)))
(rule -1 (lower (has_type (fits_in_64 ty)
(imul (sinkable_load x) y)))
(x64_mul ty y
(sink_load_to_gpr_mem_imm x)))
;; `i128`.
;; mul:
;; dst_lo = lhs_lo * rhs_lo
;; dst_hi = umulhi(lhs_lo, rhs_lo) +
;; lhs_lo * rhs_hi +
;; lhs_hi * rhs_lo
;;
;; so we emit:
;; lo_hi = mul x_lo, y_hi
;; hi_lo = mul x_hi, y_lo
;; hilo_hilo = add lo_hi, hi_lo
;; dst_lo:hi_lolo = mulhi_u x_lo, y_lo
;; dst_hi = add hilo_hilo, hi_lolo
;; return (dst_lo, dst_hi)
(rule 2 (lower (has_type $I128 (imul x y)))
;; Put `x` into registers and unpack its hi/lo halves.
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1))
;; Put `y` into registers and unpack its hi/lo halves.
(y_regs ValueRegs y)
(y_lo Gpr (value_regs_get_gpr y_regs 0))
(y_hi Gpr (value_regs_get_gpr y_regs 1))
;; lo_hi = mul x_lo, y_hi
(lo_hi Gpr (x64_mul $I64 x_lo y_hi))
;; hi_lo = mul x_hi, y_lo
(hi_lo Gpr (x64_mul $I64 x_hi y_lo))
;; hilo_hilo = add lo_hi, hi_lo
(hilo_hilo Gpr (x64_add $I64 lo_hi hi_lo))
;; dst_lo:hi_lolo = mulhi_u x_lo, y_lo
(mul_regs ValueRegs (mulhi_u $I64 x_lo y_lo))
(dst_lo Gpr (value_regs_get_gpr mul_regs 0))
(hi_lolo Gpr (value_regs_get_gpr mul_regs 1))
;; dst_hi = add hilo_hilo, hi_lolo
(dst_hi Gpr (x64_add $I64 hilo_hilo hi_lolo)))
(value_gprs dst_lo dst_hi)))
;; SSE.
;; (No i8x16 multiply.)
(rule 1 (lower (has_type (multi_lane 16 8) (imul x y)))
(x64_pmullw x y))
(rule 1 (lower (has_type (multi_lane 32 4) (imul x y)))
(x64_pmulld x y))
;; With AVX-512 we can implement `i64x2` multiplication with a single
;; instruction.
(rule 3 (lower (has_type (and (avx512vl_enabled $true)
(avx512dq_enabled $true)
(multi_lane 64 2))
(imul x y)))
(x64_vpmullq x y))
;; Otherwise, for i64x2 multiplication we describe a lane A as being composed of
;; a 32-bit upper half "Ah" and a 32-bit lower half "Al". The 32-bit long hand
;; multiplication can then be written as:
;;
;; Ah Al
;; * Bh Bl
;; -----
;; Al * Bl
;; + (Ah * Bl) << 32
;; + (Al * Bh) << 32
;;
;; So for each lane we will compute:
;;
;; A * B = (Al * Bl) + ((Ah * Bl) + (Al * Bh)) << 32
;;
;; Note, the algorithm will use `pmuldq` which operates directly on the lower
;; 32-bit (`Al` or `Bl`) of a lane and writes the result to the full 64-bits of
;; the lane of the destination. For this reason we don't need shifts to isolate
;; the lower 32-bits, however, we will need to use shifts to isolate the high
;; 32-bits when doing calculations, i.e., `Ah == A >> 32`.
(rule 1 (lower (has_type (multi_lane 64 2)
(imul a b)))
(let ((a0 Xmm a)
(b0 Xmm b)
;; a_hi = A >> 32
(a_hi Xmm (x64_psrlq a0 (RegMemImm.Imm 32)))
;; ah_bl = Ah * Bl
(ah_bl Xmm (x64_pmuludq a_hi b0))
;; b_hi = B >> 32
(b_hi Xmm (x64_psrlq b0 (RegMemImm.Imm 32)))
;; al_bh = Al * Bh
(al_bh Xmm (x64_pmuludq a0 b_hi))
;; aa_bb = ah_bl + al_bh
(aa_bb Xmm (x64_paddq ah_bl al_bh))
;; aa_bb_shifted = aa_bb << 32
(aa_bb_shifted Xmm (x64_psllq aa_bb (RegMemImm.Imm 32)))
;; al_bl = Al * Bl
(al_bl Xmm (x64_pmuludq a0 b0)))
;; al_bl + aa_bb_shifted
(x64_paddq al_bl aa_bb_shifted)))
;; Special case for `i16x8.extmul_high_i8x16_s`.
(rule (lower (has_type (multi_lane 16 8)
(imul (swiden_high (and (value_type (multi_lane 8 16))
x))
(swiden_high (and (value_type (multi_lane 8 16))
y)))))
(let ((x1 Xmm x)
(x2 Xmm (x64_palignr x1 x1 8 (OperandSize.Size32)))
(x3 Xmm (x64_pmovsxbw x2))
(y1 Xmm y)
(y2 Xmm (x64_palignr y1 y1 8 (OperandSize.Size32)))
(y3 Xmm (x64_pmovsxbw y2)))
(x64_pmullw x3 y3)))
;; Special case for `i32x4.extmul_high_i16x8_s`.
(rule (lower (has_type (multi_lane 32 4)
(imul (swiden_high (and (value_type (multi_lane 16 8))
x))
(swiden_high (and (value_type (multi_lane 16 8))
y)))))
(let ((x2 Xmm x)
(y2 Xmm y)
(lo Xmm (x64_pmullw x2 y2))
(hi Xmm (x64_pmulhw x2 y2)))
(x64_punpckhwd lo hi)))
;; Special case for `i64x2.extmul_high_i32x4_s`.
(rule (lower (has_type (multi_lane 64 2)
(imul (swiden_high (and (value_type (multi_lane 32 4))
x))
(swiden_high (and (value_type (multi_lane 32 4))
y)))))
(let ((x2 Xmm (x64_pshufd x
0xFA
(OperandSize.Size32)))
(y2 Xmm (x64_pshufd y
0xFA
(OperandSize.Size32))))
(x64_pmuldq x2 y2)))
;; Special case for `i16x8.extmul_low_i8x16_s`.
(rule (lower (has_type (multi_lane 16 8)
(imul (swiden_low (and (value_type (multi_lane 8 16))
x))
(swiden_low (and (value_type (multi_lane 8 16))
y)))))
(let ((x2 Xmm (x64_pmovsxbw x))
(y2 Xmm (x64_pmovsxbw y)))
(x64_pmullw x2 y2)))
;; Special case for `i32x4.extmul_low_i16x8_s`.
(rule (lower (has_type (multi_lane 32 4)
(imul (swiden_low (and (value_type (multi_lane 16 8))
x))
(swiden_low (and (value_type (multi_lane 16 8))
y)))))
(let ((x2 Xmm x)
(y2 Xmm y)
(lo Xmm (x64_pmullw x2 y2))
(hi Xmm (x64_pmulhw x2 y2)))
(x64_punpcklwd lo hi)))
;; Special case for `i64x2.extmul_low_i32x4_s`.
(rule (lower (has_type (multi_lane 64 2)
(imul (swiden_low (and (value_type (multi_lane 32 4))
x))
(swiden_low (and (value_type (multi_lane 32 4))
y)))))
(let ((x2 Xmm (x64_pshufd x
0x50
(OperandSize.Size32)))
(y2 Xmm (x64_pshufd y
0x50
(OperandSize.Size32))))
(x64_pmuldq x2 y2)))
;; Special case for `i16x8.extmul_high_i8x16_u`.
(rule (lower (has_type (multi_lane 16 8)
(imul (uwiden_high (and (value_type (multi_lane 8 16))
x))
(uwiden_high (and (value_type (multi_lane 8 16))
y)))))
(let ((x1 Xmm x)
(x2 Xmm (x64_palignr x1 x1 8 (OperandSize.Size32)))
(x3 Xmm (x64_pmovzxbw x2))
(y1 Xmm y)
(y2 Xmm (x64_palignr y1 y1 8 (OperandSize.Size32)))
(y3 Xmm (x64_pmovzxbw y2)))
(x64_pmullw x3 y3)))
;; Special case for `i32x4.extmul_high_i16x8_u`.
(rule (lower (has_type (multi_lane 32 4)
(imul (uwiden_high (and (value_type (multi_lane 16 8))
x))
(uwiden_high (and (value_type (multi_lane 16 8))
y)))))
(let ((x2 Xmm x)
(y2 Xmm y)
(lo Xmm (x64_pmullw x2 y2))
(hi Xmm (x64_pmulhuw x2 y2)))
(x64_punpckhwd lo hi)))
;; Special case for `i64x2.extmul_high_i32x4_u`.
(rule (lower (has_type (multi_lane 64 2)
(imul (uwiden_high (and (value_type (multi_lane 32 4))
x))
(uwiden_high (and (value_type (multi_lane 32 4))
y)))))
(let ((x2 Xmm (x64_pshufd x
0xFA
(OperandSize.Size32)))
(y2 Xmm (x64_pshufd y
0xFA
(OperandSize.Size32))))
(x64_pmuludq x2 y2)))
;; Special case for `i16x8.extmul_low_i8x16_u`.
(rule (lower (has_type (multi_lane 16 8)
(imul (uwiden_low (and (value_type (multi_lane 8 16))
x))
(uwiden_low (and (value_type (multi_lane 8 16))
y)))))
(let ((x2 Xmm (x64_pmovzxbw x))
(y2 Xmm (x64_pmovzxbw y)))
(x64_pmullw x2 y2)))
;; Special case for `i32x4.extmul_low_i16x8_u`.
(rule (lower (has_type (multi_lane 32 4)
(imul (uwiden_low (and (value_type (multi_lane 16 8))
x))
(uwiden_low (and (value_type (multi_lane 16 8))
y)))))
(let ((x2 Xmm x)
(y2 Xmm y)
(lo Xmm (x64_pmullw x2 y2))
(hi Xmm (x64_pmulhuw x2 y2)))
(x64_punpcklwd lo hi)))
;; Special case for `i64x2.extmul_low_i32x4_u`.
(rule (lower (has_type (multi_lane 64 2)
(imul (uwiden_low (and (value_type (multi_lane 32 4))
x))
(uwiden_low (and (value_type (multi_lane 32 4))
y)))))
(let ((x2 Xmm (x64_pshufd x
0x50
(OperandSize.Size32)))
(y2 Xmm (x64_pshufd y
0x50
(OperandSize.Size32))))
(x64_pmuludq x2 y2)))
;;;; Rules for `band_not` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(decl sse_and_not (Type Xmm XmmMem) Xmm)
(rule (sse_and_not $F32X4 x y) (x64_andnps x y))
(rule (sse_and_not $F64X2 x y) (x64_andnpd x y))
(rule -1 (sse_and_not (multi_lane _bits _lanes) x y) (x64_pandn x y))
;; Note the flipping of operands below. CLIF specifies
;;
;; band_not(x, y) = and(x, not(y))
;;
;; while x86 does
;;
;; pandn(x, y) = and(not(x), y)
(rule (lower (has_type ty (band_not x y)))
(sse_and_not ty y x))
;;;; Rules for `iabs` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I8X16 (iabs x)))
(x64_pabsb x))
(rule (lower (has_type $I16X8 (iabs x)))
(x64_pabsw x))
(rule (lower (has_type $I32X4 (iabs x)))
(x64_pabsd x))
;; When AVX512 is available, we can use a single `vpabsq` instruction.
(rule 1 (lower (has_type (and (avx512vl_enabled $true)
(avx512f_enabled $true)
$I64X2)
(iabs x)))
(x64_vpabsq x))
;; Otherwise, we use a separate register, `neg`, to contain the results of `0 -
;; x` and then blend in those results with `blendvpd` if the MSB of `neg` was
;; set to 1 (i.e. if `neg` was negative or, conversely, if `x` was originally
;; positive).
(rule (lower (has_type $I64X2 (iabs x)))
(let ((rx Xmm x)
(neg Xmm (x64_psubq (imm $I64X2 0) rx)))
(x64_blendvpd neg rx neg)))
;;;; Rules for `fabs` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fabs x)))
(x64_andps x (imm $F32 0x7fffffff)))
(rule (lower (has_type $F64 (fabs x)))
(x64_andpd x (imm $F64 0x7fffffffffffffff)))
;; Special case for `f32x4.abs`.
(rule (lower (has_type $F32X4 (fabs x)))
(x64_andps x
(x64_psrld (vector_all_ones)
(RegMemImm.Imm 1))))
;; Special case for `f64x2.abs`.
(rule (lower (has_type $F64X2 (fabs x)))
(x64_andpd x
(x64_psrlq (vector_all_ones)
(RegMemImm.Imm 1))))
;;;; Rules for `fneg` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fneg x)))
(x64_xorps x (imm $F32 0x80000000)))
(rule (lower (has_type $F64 (fneg x)))
(x64_xorpd x (imm $F64 0x8000000000000000)))
(rule (lower (has_type $F32X4 (fneg x)))
(x64_xorps x
(x64_pslld (vector_all_ones)
(RegMemImm.Imm 31))))
(rule (lower (has_type $F64X2 (fneg x)))
(x64_xorpd x
(x64_psllq (vector_all_ones)
(RegMemImm.Imm 63))))
;;;; Rules for `bnot` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(rule -2 (lower (has_type (fits_in_64 ty) (bnot x)))
(x64_not ty x))
;; `i128`.
(decl i128_not (Value) ValueRegs)
(rule (i128_not x)
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1)))
(value_gprs (x64_not $I64 x_lo)
(x64_not $I64 x_hi))))
(rule (lower (has_type $I128 (bnot x)))
(i128_not x))
(rule (lower (has_type $B128 (bnot x)))
(i128_not x))
;; Special case for vector-types where bit-negation is an xor against an
;; all-one value
(rule -1 (lower (has_type ty @ (multi_lane _bits _lanes) (bnot x)))
(sse_xor ty x (vector_all_ones)))
;;;; Rules for `bitselect` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type ty @ (multi_lane _bits _lanes)
(bitselect condition
if_true
if_false)))
;; a = and if_true, condition
;; b = and_not condition, if_false
;; or b, a
(let ((cond_xmm Xmm condition)
(a Xmm (sse_and ty if_true cond_xmm))
(b Xmm (sse_and_not ty cond_xmm if_false)))
(sse_or ty b a)))
;;;; Rules for `vselect` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type ty @ (multi_lane _bits _lanes)
(vselect condition if_true if_false)))
(x64_blend ty
condition
if_true
if_false))
;;;; Rules for `insertlane` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (insertlane vec @ (value_type ty) val (u8_from_uimm8 idx)))
(vec_insert_lane ty vec val idx))
;; Helper function used below for `insertlane` but also here for other
;; lowerings.
;;
;; Note that the `Type` used here is the type of vector the insertion is
;; happening into, or the type of the first `Reg` argument.
(decl vec_insert_lane (Type Xmm RegMem u8) Xmm)
;; i8x16.replace_lane
(rule (vec_insert_lane $I8X16 vec val idx)
(x64_pinsrb vec val idx))
;; i16x8.replace_lane
(rule (vec_insert_lane $I16X8 vec val idx)
(x64_pinsrw vec val idx))
;; i32x4.replace_lane
(rule (vec_insert_lane $I32X4 vec val idx)
(x64_pinsrd vec val idx (OperandSize.Size32)))
;; i64x2.replace_lane
(rule (vec_insert_lane $I64X2 vec val idx)
(x64_pinsrd vec val idx (OperandSize.Size64)))
;; f32x4.replace_lane
(rule (vec_insert_lane $F32X4 vec val idx)
(x64_insertps vec val (sse_insertps_lane_imm idx)))
;; External rust code used to calculate the immediate value to `insertps`.
(decl sse_insertps_lane_imm (u8) u8)
(extern constructor sse_insertps_lane_imm sse_insertps_lane_imm)
;; f64x2.replace_lane 0
;;
;; Here the `movsd` instruction is used specifically to specialize moving
;; into the fist lane where unlike above cases we're not using the lane
;; immediate as an immediate to the instruction itself.
;;
;; Note, though, the `movsd` has different behavior with respect to the second
;; lane of the f64x2 depending on whether the RegMem operand is a register or
;; memory. When loading from a register `movsd` preserves the upper bits, but
;; when loading from memory it zeros the upper bits. We specifically want to
;; preserve the upper bits so if a `RegMem.Mem` is passed in we need to emit
;; two `movsd` instructions. The first `movsd` (used as `xmm_unary_rm_r`) will
;; load from memory into a temp register and then the second `movsd` (modeled
;; internally as `xmm_rm_r` will merge the temp register into our `vec`
;; register.
(rule 1 (vec_insert_lane $F64X2 vec (RegMem.Reg val) 0)
(x64_movsd_regmove vec val))
(rule (vec_insert_lane $F64X2 vec mem 0)
(x64_movsd_regmove vec (x64_movsd_load mem)))
;; f64x2.replace_lane 1
;;
;; Here the `movlhps` instruction is used specifically to specialize moving
;; into the second lane where unlike above cases we're not using the lane
;; immediate as an immediate to the instruction itself.
(rule (vec_insert_lane $F64X2 vec val 1)
(x64_movlhps vec (reg_mem_to_xmm_mem val)))
;;;; Rules for `imin`, `imax`, `umin`, `umax` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(decl cmp_and_choose (Type CC Value Value) ValueRegs)
(rule (cmp_and_choose (fits_in_64 ty) cc x y)
(let ((size OperandSize (raw_operand_size_of_type ty))
;; We need to put x and y in registers explicitly because
;; we use the values more than once. Hence, even if these
;; are "unique uses" at the CLIF level and would otherwise
;; allow for load-op merging, here we cannot do that.
(x_reg Reg x)
(y_reg Reg y))
(with_flags_reg (x64_cmp size x_reg y_reg)
(cmove ty cc y_reg x_reg))))
(rule -1 (lower (has_type (fits_in_64 ty) (umin x y)))
(cmp_and_choose ty (CC.B) x y))
(rule -1 (lower (has_type (fits_in_64 ty) (umax x y)))
(cmp_and_choose ty (CC.NB) x y))
(rule -1 (lower (has_type (fits_in_64 ty) (imin x y)))
(cmp_and_choose ty (CC.L) x y))
(rule -1 (lower (has_type (fits_in_64 ty) (imax x y)))
(cmp_and_choose ty (CC.NL) x y))
;; SSE `imax`.
(rule (lower (has_type $I8X16 (imax x y)))
(x64_pmaxsb x y))
(rule (lower (has_type $I16X8 (imax x y)))
(x64_pmaxsw x y))
(rule (lower (has_type $I32X4 (imax x y)))
(x64_pmaxsd x y))
;; SSE `imin`.
(rule (lower (has_type $I8X16 (imin x y)))
(x64_pminsb x y))
(rule (lower (has_type $I16X8 (imin x y)))
(x64_pminsw x y))
(rule (lower (has_type $I32X4 (imin x y)))
(x64_pminsd x y))
;; SSE `umax`.
(rule (lower (has_type $I8X16 (umax x y)))
(x64_pmaxub x y))
(rule (lower (has_type $I16X8 (umax x y)))
(x64_pmaxuw x y))
(rule (lower (has_type $I32X4 (umax x y)))
(x64_pmaxud x y))
;; SSE `umin`.
(rule (lower (has_type $I8X16 (umin x y)))
(x64_pminub x y))
(rule (lower (has_type $I16X8 (umin x y)))
(x64_pminuw x y))
(rule (lower (has_type $I32X4 (umin x y)))
(x64_pminud x y))
;;;; Rules for `trap` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (trap code))
(side_effect (x64_ud2 code)))
;;;; Rules for `trapif` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; The flags must not have been clobbered by any other instruction between the
;; iadd_ifcout and this instruction, as verified by the CLIF validator; so we
;; can simply use the flags here.
(rule (lower (trapif cc flags @ (iadd_ifcout _ _) tc))
(side_effect
(trap_if_icmp (icmp_cond_result (flags_to_producesflags flags) cc) tc)))
;; Verification ensures that the input is always a single-def ifcmp.
(rule (lower (trapif cc (ifcmp a b) tc))
(side_effect (trap_if_icmp (emit_cmp cc a b) tc)))
;;;; Rules for `trapff` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (trapff cc (ffcmp a b) tc))
(side_effect (trap_if_fcmp (emit_fcmp cc a b) tc)))
;;;; Rules for `resumable_trap` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (resumable_trap code))
(side_effect (x64_ud2 code)))
;;;; Rules for `return` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; N.B.: the Ret itself is generated by the ABI.
(rule (lower (return args))
(lower_return (range 0 (value_slice_len args)) args))
;;;; Rules for `icmp` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule -2 (lower (icmp cc a @ (value_type (fits_in_64 ty)) b))
(lower_icmp_bool (emit_cmp cc a b)))
(rule -1 (lower (icmp cc a @ (value_type $I128) b))
(lower_icmp_bool (emit_cmp cc a b)))
;; Peephole optimization for `x < 0`, when x is a signed 64 bit value
(rule 2 (lower (has_type $B1 (icmp (IntCC.SignedLessThan) x @ (value_type $I64) (u64_from_iconst 0))))
(x64_shr $I64 x (Imm8Reg.Imm8 63)))
;; Peephole optimization for `0 > x`, when x is a signed 64 bit value
(rule 2 (lower (has_type $B1 (icmp (IntCC.SignedGreaterThan) (u64_from_iconst 0) x @ (value_type $I64))))
(x64_shr $I64 x (Imm8Reg.Imm8 63)))
;; Peephole optimization for `0 <= x`, when x is a signed 64 bit value
(rule 2 (lower (has_type $B1 (icmp (IntCC.SignedLessThanOrEqual) (u64_from_iconst 0) x @ (value_type $I64))))
(x64_shr $I64 (x64_not $I64 x) (Imm8Reg.Imm8 63)))
;; Peephole optimization for `x >= 0`, when x is a signed 64 bit value
(rule 2 (lower (has_type $B1 (icmp (IntCC.SignedGreaterThanOrEqual) x @ (value_type $I64) (u64_from_iconst 0))))
(x64_shr $I64 (x64_not $I64 x) (Imm8Reg.Imm8 63)))
;; Peephole optimization for `x < 0`, when x is a signed 32 bit value
(rule 2 (lower (has_type $B1 (icmp (IntCC.SignedLessThan) x @ (value_type $I32) (u64_from_iconst 0))))
(x64_shr $I32 x (Imm8Reg.Imm8 31)))
;; Peephole optimization for `0 > x`, when x is a signed 32 bit value
(rule 2 (lower (has_type $B1 (icmp (IntCC.SignedGreaterThan) (u64_from_iconst 0) x @ (value_type $I32))))
(x64_shr $I32 x (Imm8Reg.Imm8 31)))
;; Peephole optimization for `0 <= x`, when x is a signed 32 bit value
(rule 2 (lower (has_type $B1 (icmp (IntCC.SignedLessThanOrEqual) (u64_from_iconst 0) x @ (value_type $I32))))
(x64_shr $I32 (x64_not $I64 x) (Imm8Reg.Imm8 31)))
;; Peephole optimization for `x >= 0`, when x is a signed 32 bit value
(rule 2 (lower (has_type $B1 (icmp (IntCC.SignedGreaterThanOrEqual) x @ (value_type $I32) (u64_from_iconst 0))))
(x64_shr $I32 (x64_not $I64 x) (Imm8Reg.Imm8 31)))
;; For XMM-held values, we lower to `PCMP*` instructions, sometimes more than
;; one. To note: what is different here about the output values is that each
;; lane will be filled with all 1s or all 0s according to the comparison,
;; whereas for GPR-held values, the result will be simply 0 or 1 (upper bits
;; unset).
(rule (lower (icmp (IntCC.Equal) a @ (value_type (ty_vec128 ty)) b))
(x64_pcmpeq ty a b))
;; To lower a not-equals comparison, we perform an equality comparison
;; (PCMPEQ*) and then invert the bits (PXOR with all 1s).
(rule (lower (icmp (IntCC.NotEqual) a @ (value_type (ty_vec128 ty)) b))
(let ((checked Xmm (x64_pcmpeq ty a b))
(all_ones Xmm (vector_all_ones)))
(x64_pxor checked all_ones)))
;; Signed comparisons have a single-instruction lowering, unlike their unsigned
;; counterparts. These latter instructions use the unsigned min/max
;; (PMINU*/PMAXU*) and negate the result (PXOR with all 1s).
(rule (lower (icmp (IntCC.SignedGreaterThan) a @ (value_type (ty_vec128 ty)) b))
(x64_pcmpgt ty a b))
(rule (lower (icmp (IntCC.SignedLessThan) a @ (value_type (ty_vec128 ty)) b))
(x64_pcmpgt ty b a))
(rule (lower (icmp (IntCC.UnsignedGreaterThan) a @ (value_type (ty_vec128 ty)) b))
;; N.B.: we must manually prevent load coalescing of these operands; the
;; register allocator gets confused otherwise. TODO:
;; https://github.com/bytecodealliance/wasmtime/issues/3953.
(let ((xmm_a Xmm (put_in_xmm a))
(xmm_b Xmm (put_in_xmm b))
(max Xmm (x64_pmaxu ty xmm_a xmm_b))
(eq Xmm (x64_pcmpeq ty max xmm_b))
(all_ones Xmm (vector_all_ones)))
(x64_pxor eq all_ones)))
(rule (lower (icmp (IntCC.UnsignedLessThan) a @ (value_type (ty_vec128 ty)) b))
;; N.B.: see note above.
(let ((xmm_a Xmm (put_in_xmm a))
(xmm_b Xmm (put_in_xmm b))
(min Xmm (x64_pminu ty xmm_a xmm_b))
(eq Xmm (x64_pcmpeq ty min xmm_b))
(all_ones Xmm (vector_all_ones)))
(x64_pxor eq all_ones)))
;; To lower signed and unsigned *-or-equals comparisons, we find the minimum
;; number (PMIN[U|S]*) and compare that to one of the terms (PCMPEQ*). Note that
;; there is no 64x2 version of this lowering (see below).
(rule (lower (icmp (IntCC.SignedGreaterThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(let ((max Xmm (x64_pmaxs ty a b)))
(x64_pcmpeq ty a max)))
(rule (lower (icmp (IntCC.SignedLessThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(let ((min Xmm (x64_pmins ty a b)))
(x64_pcmpeq ty a min)))
(rule (lower (icmp (IntCC.UnsignedGreaterThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(let ((max Xmm (x64_pmaxu ty a b)))
(x64_pcmpeq ty a max)))
(rule (lower (icmp (IntCC.UnsignedLessThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(let ((min Xmm (x64_pminu ty a b)))
(x64_pcmpeq ty a min)))
;; The PMIN[S|U]Q instruction is only available in AVX512VL/F so we must instead
;; compare with flipped operands (PCMPGT*) and negate the result (PXOR with all
;; 1s), emitting one more instruction than the smaller-lane versions.
(rule 1 (lower (icmp (IntCC.SignedGreaterThanOrEqual) a @ (value_type $I64X2) b))
(let ((checked Xmm (x64_pcmpgt $I64X2 b a))
(all_ones Xmm (vector_all_ones)))
(x64_pxor checked all_ones)))
(rule 1 (lower (icmp (IntCC.SignedLessThanOrEqual) a @ (value_type $I64X2) b))
(let ((checked Xmm (x64_pcmpgt $I64X2 a b))
(all_ones Xmm (vector_all_ones)))
(x64_pxor checked all_ones)))
;; TODO: not used by WebAssembly translation
;; (rule (lower (icmp (IntCC.UnsignedGreaterThanOrEqual) a @ (value_type $I64X2) b))
;; TODO: not used by WebAssembly translation
;; (rule (lower (icmp (IntCC.UnsignedLessThanOrEqual) a @ (value_type $I64X2) b))
;;;; Rules for `fcmp` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; CLIF's `fcmp` instruction always operates on XMM registers--both scalar and
;; vector. For the scalar versions, we use the flag-setting behavior of the
;; `UCOMIS*` instruction to `SETcc` a 0 or 1 in a GPR register. Note that CLIF's
;; `select` uses the same kind of flag-setting behavior but chooses values other
;; than 0 or 1.
;;
;; Checking the result of `UCOMIS*` is unfortunately difficult in some cases
;; because we do not have `SETcc` instructions that explicitly check
;; simultaneously for the condition (i.e., `eq`, `le`, `gt`, etc.) *and*
;; orderedness. Instead, we must check the flags multiple times. The UCOMIS*
;; documentation (see Intel's Software Developer's Manual, volume 2, chapter 4)
;; is helpful:
;; - unordered assigns Z = 1, P = 1, C = 1
;; - greater than assigns Z = 0, P = 0, C = 0
;; - less than assigns Z = 0, P = 0, C = 1
;; - equal assigns Z = 1, P = 0, C = 0
(rule -1 (lower (fcmp cc a @ (value_type (ty_scalar_float ty)) b))
(lower_fcmp_bool (emit_fcmp cc a b)))
;; For vector lowerings, we use `CMPP*` instructions with a 3-bit operand that
;; determines the comparison to make. Note that comparisons that succeed will
;; fill the lane with 1s; comparisons that do not will fill the lane with 0s.
(rule (lower (fcmp (FloatCC.Equal) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.Equal)))
(rule (lower (fcmp (FloatCC.NotEqual) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.NotEqual)))
(rule (lower (fcmp (FloatCC.LessThan) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.LessThan)))
(rule (lower (fcmp (FloatCC.LessThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.LessThanOrEqual)))
(rule (lower (fcmp (FloatCC.Ordered) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.Ordered)))
(rule (lower (fcmp (FloatCC.Unordered) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.Unordered)))
(rule (lower (fcmp (FloatCC.UnorderedOrGreaterThan) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.UnorderedOrGreaterThan)))
(rule (lower (fcmp (FloatCC.UnorderedOrGreaterThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.UnorderedOrGreaterThanOrEqual)))
;; Some vector lowerings rely on flipping the operands and using a reversed
;; comparison code.
(rule (lower (fcmp (FloatCC.GreaterThan) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty b a (FcmpImm.LessThan)))
(rule (lower (fcmp (FloatCC.GreaterThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty b a (FcmpImm.LessThanOrEqual)))
(rule (lower (fcmp (FloatCC.UnorderedOrLessThan) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty b a (FcmpImm.UnorderedOrGreaterThan)))
(rule (lower (fcmp (FloatCC.UnorderedOrLessThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty b a (FcmpImm.UnorderedOrGreaterThanOrEqual)))
;; Some vector lowerings are simply not supported for certain codes:
;; - FloatCC::OrderedNotEqual
;; - FloatCC::UnorderedOrEqual
;;;; Rules for `select` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; CLIF `select` instructions receive a testable argument (i.e. boolean or
;; integer) that determines which of the other two arguments is selected as
;; output. Since Cranelift booleans are typically generated by a comparison, the
;; lowerings in this section "look upwards in the tree" to emit the proper
;; sequence of "selection" instructions.
;;
;; The following rules--for selecting on a floating-point comparison--emit a
;; `UCOMIS*` instruction and then a conditional move, `cmove`. Note that for
;; values contained in XMM registers, `cmove` and `cmove_or` may in fact emit a
;; jump sequence, not `CMOV`. The `cmove` instruction operates on the flags set
;; by `UCOMIS*`; the key to understanding these is the UCOMIS* documentation
;; (see Intel's Software Developer's Manual, volume 2, chapter 4):
;; - unordered assigns Z = 1, P = 1, C = 1
;; - greater than assigns Z = 0, P = 0, C = 0
;; - less than assigns Z = 0, P = 0, C = 1
;; - equal assigns Z = 1, P = 0, C = 0
;;
;; Note that prefixing the flag with `N` means "not," so that `CC.P -> P = 1`
;; and `CC.NP -> P = 0`. Also, x86 uses mnemonics for certain combinations of
;; flags; e.g.:
;; - `CC.B -> C = 1` (below)
;; - `CC.NB -> C = 0` (not below)
;; - `CC.BE -> C = 1 OR Z = 1` (below or equal)
;; - `CC.NBE -> C = 0 AND Z = 0` (not below or equal)
(rule (lower (has_type ty (select (fcmp (FloatCC.Ordered) a b) x y)))
(with_flags (x64_ucomis b a) (cmove_from_values ty (CC.NP) x y)))
(rule (lower (has_type ty (select (fcmp (FloatCC.Unordered) a b) x y)))
(with_flags (x64_ucomis b a) (cmove_from_values ty (CC.P) x y)))
(rule (lower (has_type ty (select (fcmp (FloatCC.GreaterThan) a b) x y)))
(with_flags (x64_ucomis b a) (cmove_from_values ty (CC.NBE) x y)))
(rule (lower (has_type ty (select (fcmp (FloatCC.GreaterThanOrEqual) a b) x y)))
(with_flags (x64_ucomis b a) (cmove_from_values ty (CC.NB) x y)))
(rule (lower (has_type ty (select (fcmp (FloatCC.UnorderedOrLessThan) a b) x y)))
(with_flags (x64_ucomis b a) (cmove_from_values ty (CC.B) x y)))
(rule (lower (has_type ty (select (fcmp (FloatCC.UnorderedOrLessThanOrEqual) a b) x y)))
(with_flags (x64_ucomis b a) (cmove_from_values ty (CC.BE) x y)))
;; Certain FloatCC variants are implemented by flipping the operands of the
;; comparison (e.g., "greater than" is lowered the same as "less than" but the
;; comparison is reversed). This allows us to use a single flag for the `cmove`,
;; which involves fewer instructions than `cmove_or`.
;;
;; But why flip at all, you may ask? Can't we just use `CC.B` (i.e., below) for
;; `FloatCC.LessThan`? Recall that in these floating-point lowerings, values may
;; be unordered and we must we want to express that `FloatCC.LessThan` is `LT`,
;; not `LT | UNO`. By flipping the operands AND inverting the comparison (e.g.,
;; to `CC.NBE`), we also avoid these unordered cases.
(rule (lower (has_type ty (select (fcmp (FloatCC.LessThan) a b) x y)))
(with_flags (x64_ucomis a b) (cmove_from_values ty (CC.NBE) x y)))
(rule (lower (has_type ty (select (fcmp (FloatCC.LessThanOrEqual) a b) x y)))
(with_flags (x64_ucomis a b) (cmove_from_values ty (CC.NB) x y)))
(rule (lower (has_type ty (select (fcmp (FloatCC.UnorderedOrGreaterThan) a b) x y)))
(with_flags (x64_ucomis a b) (cmove_from_values ty (CC.B) x y)))
(rule (lower (has_type ty (select (fcmp (FloatCC.UnorderedOrGreaterThanOrEqual) a b) x y)))
(with_flags (x64_ucomis a b) (cmove_from_values ty (CC.BE) x y)))
;; `FloatCC.Equal` and `FloatCC.NotEqual` can only be implemented with multiple
;; flag checks. Recall from the flag assignment chart above that equality, e.g.,
;; will assign `Z = 1`. But so does an unordered comparison: `Z = 1, P = 1, C =
;; 1`. In order to avoid semantics like `EQ | UNO` for equality, we must ensure
;; that the values are actually ordered, checking that `P = 0` (note that the
;; `C` flag is irrelevant here). Since we cannot find a single instruction that
;; implements a `Z = 1 AND P = 0` check, we invert the flag checks (i.e., `Z = 1
;; AND P = 0` becomes `Z = 0 OR P = 1`) and also flip the select operands, `x`
;; and `y`. The same argument applies to `FloatCC.NotEqual`.
;;
;; More details about the CLIF semantics for `fcmp` are available at
;; https://docs.rs/cranelift-codegen/latest/cranelift_codegen/ir/trait.InstBuilder.html#method.fcmp.
(rule (lower (has_type ty (select (fcmp (FloatCC.Equal) a b) x y)))
(with_flags (x64_ucomis a b) (cmove_or_from_values ty (CC.NZ) (CC.P) y x)))
(rule (lower (has_type ty (select (fcmp (FloatCC.NotEqual) a b) x y)))
(with_flags (x64_ucomis a b) (cmove_or_from_values ty (CC.NZ) (CC.P) x y)))
;; We also can lower `select`s that depend on an `icmp` test, but more simply
;; than the `fcmp` variants above. In these cases, we lower to a `CMP`
;; instruction plus a `CMOV`; recall that `cmove_from_values` here may emit more
;; than one instruction for certain types (e.g., XMM-held, I128).
(rule (lower (has_type ty (select (icmp cc a @ (value_type (fits_in_64 a_ty)) b) x y)))
(let ((size OperandSize (raw_operand_size_of_type a_ty)))
(with_flags (x64_cmp size b a) (cmove_from_values ty cc x y))))
;; Finally, we lower `select` from a condition value `c`. These rules are meant
;; to be the final, default lowerings if no other patterns matched above.
(rule -1 (lower (has_type ty (select c @ (value_type $B1) x y)))
(let ((size OperandSize (raw_operand_size_of_type $B1))
;; N.B.: disallow load-op fusion, see above. TODO:
;; https://github.com/bytecodealliance/wasmtime/issues/3953.
(gpr_c Gpr (put_in_gpr c)))
(with_flags (x64_test size (RegMemImm.Imm 1) gpr_c) (cmove_from_values ty (CC.NZ) x y))))
(rule -2 (lower (has_type ty (select c @ (value_type (fits_in_64 a_ty)) x y)))
(let ((size OperandSize (raw_operand_size_of_type a_ty))
;; N.B.: disallow load-op fusion, see above. TODO:
;; https://github.com/bytecodealliance/wasmtime/issues/3953.
(gpr_c Gpr (put_in_gpr c)))
(with_flags (x64_test size gpr_c gpr_c) (cmove_from_values ty (CC.NZ) x y))))
;; Rules for `clz` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; If available, we can use a plain lzcnt instruction here. Note no
;; special handling is required for zero inputs, because the machine
;; instruction does what the CLIF expects for zero, i.e. it returns
;; zero.
(rule 2 (lower
(has_type (and
(ty_32_or_64 ty)
(use_lzcnt $true))
(clz src)))
(x64_lzcnt ty src))
(rule 2 (lower
(has_type (and
(ty_32_or_64 ty)
(use_lzcnt $false))
(clz src)))
(do_clz ty ty src))
(rule 1 (lower
(has_type (ty_8_or_16 ty)
(clz src)))
(do_clz $I32 ty (extend_to_gpr src $I32 (ExtendKind.Zero))))
(rule 0 (lower
(has_type $I128
(clz src)))
(let ((upper Gpr (do_clz $I64 $I64 (value_regs_get_gpr src 1)))
(lower Gpr (x64_add $I64
(do_clz $I64 $I64 (value_regs_get_gpr src 0))
(RegMemImm.Imm 64)))
(result_lo Gpr
(with_flags_reg
(x64_cmp_imm (OperandSize.Size64) 64 upper)
(cmove $I64 (CC.NZ) upper lower))))
(value_regs result_lo (imm $I64 0))))
;; Implementation helper for clz; operates on 32 or 64-bit units.
(decl do_clz (Type Type Gpr) Gpr)
(rule (do_clz ty orig_ty src)
(let ((highest_bit_index Reg (bsr_or_else ty src (imm_i64 $I64 -1)))
(bits_minus_1 Reg (imm ty (u64_sub (ty_bits_u64 orig_ty) 1))))
(x64_sub ty bits_minus_1 highest_bit_index)))
;; Rules for `ctz` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Analogous to `clz` cases above, but using mirror instructions
;; (tzcnt vs lzcnt, bsf vs bsr).
(rule 2 (lower
(has_type (and
(ty_32_or_64 ty)
(use_bmi1 $true))
(ctz src)))
(x64_tzcnt ty src))
(rule 2 (lower
(has_type (and
(ty_32_or_64 ty)
(use_bmi1 $false))
(ctz src)))
(do_ctz ty ty src))
(rule 1 (lower
(has_type (ty_8_or_16 ty)
(ctz src)))
(do_ctz $I32 ty (extend_to_gpr src $I32 (ExtendKind.Zero))))
(rule 0 (lower
(has_type $I128
(ctz src)))
(let ((lower Gpr (do_ctz $I64 $I64 (value_regs_get_gpr src 0)))
(upper Gpr (x64_add $I64
(do_ctz $I64 $I64 (value_regs_get_gpr src 1))
(RegMemImm.Imm 64)))
(result_lo Gpr
(with_flags_reg
(x64_cmp_imm (OperandSize.Size64) 64 lower)
(cmove $I64 (CC.Z) upper lower))))
(value_regs result_lo (imm $I64 0))))
(decl do_ctz (Type Type Gpr) Gpr)
(rule (do_ctz ty orig_ty src)
(bsf_or_else ty src (imm $I64 (ty_bits_u64 orig_ty))))
;; Rules for `popcnt` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 3 (lower
(has_type (and
(ty_32_or_64 ty)
(use_popcnt $true))
(popcnt src)))
(x64_popcnt ty src))
(rule 2 (lower
(has_type (and
(ty_8_or_16 ty)
(use_popcnt $true))
(popcnt src)))
(x64_popcnt $I32 (extend_to_gpr src $I32 (ExtendKind.Zero))))
(rule 1 (lower
(has_type (and
$I128
(use_popcnt $true))
(popcnt src)))
(let ((lo_count Gpr (x64_popcnt $I64 (value_regs_get_gpr src 0)))
(hi_count Gpr (x64_popcnt $I64 (value_regs_get_gpr src 1))))
(value_regs (x64_add $I64 lo_count hi_count) (imm $I64 0))))
(rule -1 (lower
(has_type (ty_32_or_64 ty)
(popcnt src)))
(do_popcnt ty src))
(rule -2 (lower
(has_type (ty_8_or_16 ty)
(popcnt src)))
(do_popcnt $I32 (extend_to_gpr src $I32 (ExtendKind.Zero))))
(rule (lower
(has_type $I128
(popcnt src)))
(let ((lo_count Gpr (do_popcnt $I64 (value_regs_get_gpr src 0)))
(hi_count Gpr (do_popcnt $I64 (value_regs_get_gpr src 1))))
(value_regs (x64_add $I64 lo_count hi_count) (imm $I64 0))))
;; Implementation of popcount when we don't nave a native popcount
;; instruction.
(decl do_popcnt (Type Gpr) Gpr)
(rule (do_popcnt $I64 src)
(let ((shifted1 Gpr (x64_shr $I64 src (Imm8Reg.Imm8 1)))
(sevens Gpr (imm $I64 0x7777777777777777))
(masked1 Gpr (x64_and $I64 shifted1 sevens))
;; diff1 := src - ((src >> 1) & 0b0111_0111_0111...)
(diff1 Gpr (x64_sub $I64 src masked1))
(shifted2 Gpr (x64_shr $I64 masked1 (Imm8Reg.Imm8 1)))
(masked2 Gpr (x64_and $I64 shifted2 sevens))
;; diff2 := diff1 - ((diff1 >> 1) & 0b0111_0111_0111...)
(diff2 Gpr (x64_sub $I64 diff1 masked2))
(shifted3 Gpr (x64_shr $I64 masked2 (Imm8Reg.Imm8 1)))
(masked3 Gpr (x64_and $I64 shifted3 sevens))
;; diff3 := diff2 - ((diff2 >> 1) & 0b0111_0111_0111...)
;;
;; At this point, each nibble of diff3 is the popcount of
;; that nibble. This works because at each step above, we
;; are basically subtracting floor(value / 2) from the
;; running value; the leftover remainder is 1 if the LSB
;; was 1. After three steps, we have (nibble / 8) -- 0 or
;; 1 for the MSB of the nibble -- plus three possible
;; additions for the three other bits.
(diff3 Gpr (x64_sub $I64 diff2 masked3))
;; Add the two nibbles of each byte together.
(sum1 Gpr (x64_add $I64
(x64_shr $I64 diff3 (Imm8Reg.Imm8 4))
diff3))
;; Mask the above sum to have the popcount for each byte
;; in the lower nibble of that byte.
(ofof Gpr (imm $I64 0x0f0f0f0f0f0f0f0f))
(masked4 Gpr (x64_and $I64 sum1 ofof))
(ones Gpr (imm $I64 0x0101010101010101))
;; Use a multiply to sum all of the bytes' popcounts into
;; the top byte. Consider the binomial expansion for the
;; top byte: it is the sum of the bytes (masked4 >> 56) *
;; 0x01 + (masked4 >> 48) * 0x01 + (masked4 >> 40) * 0x01
;; + ... + (masked4 >> 0).
(mul Gpr (x64_mul $I64 masked4 ones))
;; Now take that top byte and return it as the popcount.
(final Gpr (x64_shr $I64 mul (Imm8Reg.Imm8 56))))
final))
;; This is the 32-bit version of the above; the steps for each nibble
;; are the same, we just use constants half as wide.
(rule (do_popcnt $I32 src)
(let ((shifted1 Gpr (x64_shr $I32 src (Imm8Reg.Imm8 1)))
(sevens Gpr (imm $I32 0x77777777))
(masked1 Gpr (x64_and $I32 shifted1 sevens))
(diff1 Gpr (x64_sub $I32 src masked1))
(shifted2 Gpr (x64_shr $I32 masked1 (Imm8Reg.Imm8 1)))
(masked2 Gpr (x64_and $I32 shifted2 sevens))
(diff2 Gpr (x64_sub $I32 diff1 masked2))
(shifted3 Gpr (x64_shr $I32 masked2 (Imm8Reg.Imm8 1)))
(masked3 Gpr (x64_and $I32 shifted3 sevens))
(diff3 Gpr (x64_sub $I32 diff2 masked3))
(sum1 Gpr (x64_add $I32
(x64_shr $I32 diff3 (Imm8Reg.Imm8 4))
diff3))
(masked4 Gpr (x64_and $I32 sum1 (RegMemImm.Imm 0x0f0f0f0f)))
(mul Gpr (x64_mul $I32 masked4 (RegMemImm.Imm 0x01010101)))
(final Gpr (x64_shr $I32 mul (Imm8Reg.Imm8 24))))
final))
(rule 1 (lower (has_type (and
$I8X16
(avx512vl_enabled $true)
(avx512bitalg_enabled $true))
(popcnt src)))
(x64_vpopcntb src))
;; For SSE 4.2 we use Mula's algorithm (https://arxiv.org/pdf/1611.07612.pdf):
;;
;; __m128i count_bytes ( __m128i v) {
;; __m128i lookup = _mm_setr_epi8(0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4);
;; __m128i low_mask = _mm_set1_epi8 (0x0f);
;; __m128i lo = _mm_and_si128 (v, low_mask);
;; __m128i hi = _mm_and_si128 (_mm_srli_epi16 (v, 4), low_mask);
;; __m128i cnt1 = _mm_shuffle_epi8 (lookup, lo);
;; __m128i cnt2 = _mm_shuffle_epi8 (lookup, hi);
;; return _mm_add_epi8 (cnt1, cnt2);
;; }
;;
;; Details of the above algorithm can be found in the reference noted above, but the basics
;; are to create a lookup table that pre populates the popcnt values for each number [0,15].
;; The algorithm uses shifts to isolate 4 bit sections of the vector, pshufb as part of the
;; lookup process, and adds together the results.
;;
;; __m128i lookup = _mm_setr_epi8(0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4);
(decl popcount_4bit_table () VCodeConstant) ;; bits-per-nibble table `lookup` above
(extern constructor popcount_4bit_table popcount_4bit_table)
(decl popcount_low_mask () VCodeConstant) ;; mask for low nibbles: 0x0f * 16
(extern constructor popcount_low_mask popcount_low_mask)
(rule (lower (has_type $I8X16
(popcnt src)))
(let ((nibble_table_const VCodeConstant (popcount_4bit_table))
(low_mask Xmm (x64_xmm_load_const $I8X16 (popcount_low_mask)))
(low_nibbles Xmm (sse_and $I8X16 src low_mask))
;; Note that this is a 16x8 shift, but that's OK; we mask
;; off anything that traverses from one byte to the next
;; with the low_mask below.
(shifted_src Xmm (x64_psrlw src (RegMemImm.Imm 4)))
(high_nibbles Xmm (sse_and $I8X16 shifted_src low_mask))
(lookup Xmm (x64_xmm_load_const $I8X16 (popcount_4bit_table)))
(bit_counts_low Xmm (x64_pshufb lookup low_nibbles))
(bit_counts_high Xmm (x64_pshufb lookup high_nibbles)))
(x64_paddb bit_counts_low bit_counts_high)))
;; Rules for `bitrev` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I8 (bitrev src)))
(do_bitrev8 $I32 src))
(rule (lower (has_type $I16 (bitrev src)))
(do_bitrev16 $I32 src))
(rule (lower (has_type $I32 (bitrev src)))
(do_bitrev32 $I32 src))
(rule (lower (has_type $I64 (bitrev src)))
(do_bitrev64 $I64 src))
(rule (lower (has_type $I128 (bitrev src)))
(value_regs
(do_bitrev64 $I64 (value_regs_get_gpr src 1))
(do_bitrev64 $I64 (value_regs_get_gpr src 0))))
(decl do_bitrev8 (Type Gpr) Gpr)
(rule (do_bitrev8 ty src)
(let ((tymask u64 (ty_mask ty))
(mask1 Gpr (imm ty (u64_and tymask 0x5555555555555555)))
(lo1 Gpr (x64_and ty src mask1))
(hi1 Gpr (x64_and ty (x64_shr ty src (Imm8Reg.Imm8 1)) mask1))
(swap1 Gpr (x64_or ty
(x64_shl ty lo1 (Imm8Reg.Imm8 1))
hi1))
(mask2 Gpr (imm ty (u64_and tymask 0x3333333333333333)))
(lo2 Gpr (x64_and ty swap1 mask2))
(hi2 Gpr (x64_and ty (x64_shr ty swap1 (Imm8Reg.Imm8 2)) mask2))
(swap2 Gpr (x64_or ty
(x64_shl ty lo2 (Imm8Reg.Imm8 2))
hi2))
(mask4 Gpr (imm ty (u64_and tymask 0x0f0f0f0f0f0f0f0f)))
(lo4 Gpr (x64_and ty swap2 mask4))
(hi4 Gpr (x64_and ty (x64_shr ty swap2 (Imm8Reg.Imm8 4)) mask4))
(swap4 Gpr (x64_or ty
(x64_shl ty lo4 (Imm8Reg.Imm8 4))
hi4)))
swap4))
(decl do_bitrev16 (Type Gpr) Gpr)
(rule (do_bitrev16 ty src)
(let ((src_ Gpr (do_bitrev8 ty src))
(tymask u64 (ty_mask ty))
(mask8 Gpr (imm ty (u64_and tymask 0x00ff00ff00ff00ff)))
(lo8 Gpr (x64_and ty src_ mask8))
(hi8 Gpr (x64_and ty (x64_shr ty src_ (Imm8Reg.Imm8 8)) mask8))
(swap8 Gpr (x64_or ty
(x64_shl ty lo8 (Imm8Reg.Imm8 8))
hi8)))
swap8))
(decl do_bitrev32 (Type Gpr) Gpr)
(rule (do_bitrev32 ty src)
(let ((src_ Gpr (do_bitrev16 ty src))
(tymask u64 (ty_mask ty))
(mask16 Gpr (imm ty (u64_and tymask 0x0000ffff0000ffff)))
(lo16 Gpr (x64_and ty src_ mask16))
(hi16 Gpr (x64_and ty (x64_shr ty src_ (Imm8Reg.Imm8 16)) mask16))
(swap16 Gpr (x64_or ty
(x64_shl ty lo16 (Imm8Reg.Imm8 16))
hi16)))
swap16))
(decl do_bitrev64 (Type Gpr) Gpr)
(rule (do_bitrev64 ty @ $I64 src)
(let ((src_ Gpr (do_bitrev32 ty src))
(mask32 Gpr (imm ty 0xffffffff))
(lo32 Gpr (x64_and ty src_ mask32))
(hi32 Gpr (x64_shr ty src_ (Imm8Reg.Imm8 32)))
(swap32 Gpr (x64_or ty
(x64_shl ty lo32 (Imm8Reg.Imm8 32))
hi32)))
swap32))
;; Rules for `is_null` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Null references are represented by the constant value `0`.
(rule (lower (is_null src @ (value_type $R64)))
(with_flags
(x64_cmp_imm (OperandSize.Size64) 0 src)
(x64_setcc (CC.Z))))
;; Rules for `is_invalid` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Null references are represented by the constant value `-1`.
(rule (lower (is_invalid src @ (value_type $R64)))
(with_flags
(x64_cmp_imm (OperandSize.Size64) 0xffffffff src) ;; simm32 0xffff_ffff is sign-extended to -1.
(x64_setcc (CC.Z))))
;; Rules for `uextend` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; T -> T is a no-op.
(rule 1 (lower (has_type ty (uextend src @ (value_type ty))))
src)
;; I64 -> I128.
(rule -1 (lower (has_type $I128 (uextend src @ (value_type $I64))))
(value_regs src (imm $I64 0)))
;; I{8,16,32} -> I128.
(rule (lower (has_type $I128 (uextend src @ (value_type (fits_in_32 src_ty)))))
(value_regs (extend_to_gpr src $I64 (ExtendKind.Zero)) (imm $I64 0)))
;; I{8,16,32} -> I64.
(rule -1 (lower (has_type $I64 (uextend src @ (value_type (fits_in_32 src_ty)))))
(extend_to_gpr src $I64 (ExtendKind.Zero)))
;; I8 -> I{16,32}, I16 -> I32.
(rule -2 (lower (has_type (fits_in_32 dst_ty) (uextend src @ (value_type (fits_in_32 src_ty)))))
(extend_to_gpr src $I32 (ExtendKind.Zero)))
;; I32 -> I64 with op that produces a zero-extended value in a register.
;;
;; As a particular x64 extra-pattern matching opportunity, all the ALU
;; opcodes on 32-bits will zero-extend the upper 32-bits, so we can
;; even not generate a zero-extended move in this case.
;;
;; (Note that we unfortunately can't factor out the
;; insts-that-zero-upper-32 pattern into a separate extractor until we
;; can write internal extractors with multiple rules; and we'd rather
;; keep these here than write an external extractor containing bits of
;; the instruction pattern.s)
(rule (lower (has_type $I64
(uextend src @ (has_type $I32 (iadd _ _)))))
src)
(rule (lower (has_type $I64
(uextend src @ (has_type $I32 (iadd_ifcout _ _)))))
src)
(rule (lower (has_type $I64
(uextend src @ (has_type $I32 (isub _ _)))))
src)
(rule (lower (has_type $I64
(uextend src @ (has_type $I32 (imul _ _)))))
src)
(rule (lower (has_type $I64
(uextend src @ (has_type $I32 (band _ _)))))
src)
(rule (lower (has_type $I64
(uextend src @ (has_type $I32 (bor _ _)))))
src)
(rule (lower (has_type $I64
(uextend src @ (has_type $I32 (bxor _ _)))))
src)
(rule (lower (has_type $I64
(uextend src @ (has_type $I32 (ishl _ _)))))
src)
(rule (lower (has_type $I64
(uextend src @ (has_type $I32 (ushr _ _)))))
src)
(rule (lower (has_type $I64
(uextend src @ (has_type $I32 (uload32 _ _ _)))))
src)
;; Rules for `sextend` / `bextend` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(decl generic_sextend (Value Type Type) InstOutput)
;; T -> T is a no-op.
(rule 4 (generic_sextend src ty ty)
src)
;; Produce upper 64 bits sign-extended from lower 64: shift right by
;; 63 bits to spread the sign bit across the result.
(decl spread_sign_bit (Gpr) Gpr)
(rule (spread_sign_bit src)
(x64_sar $I64 src (Imm8Reg.Imm8 63)))
;; I64 -> I128.
(rule 3 (generic_sextend src (ty_int_bool_64 _) (ty_int_bool_128 _))
(value_regs src (spread_sign_bit src)))
;; I{8,16,32} -> I128.
(rule 2 (generic_sextend src (fits_in_32 src_ty) (ty_int_bool_128 _))
(let ((lo Gpr (extend_to_gpr src $I64 (ExtendKind.Sign)))
(hi Gpr (spread_sign_bit lo)))
(value_regs lo hi)))
;; I{8,16,32} -> I64.
(rule 1 (generic_sextend src (fits_in_32 src_ty) (ty_int_bool_64 _))
(extend_to_gpr src $I64 (ExtendKind.Sign)))
;; I8 -> I{16,32}, I16 -> I32.
(rule 0 (generic_sextend src (fits_in_32 src_ty) (fits_in_32 dst_ty))
(extend_to_gpr src $I32 (ExtendKind.Sign)))
(rule (lower
(has_type dst_ty
(sextend src @ (value_type src_ty))))
(generic_sextend src src_ty dst_ty))
;; Bools are stored as 0/-1 so extends must sign-extend as well.
(rule (lower
(has_type dst_ty
(bextend src @ (value_type src_ty))))
(generic_sextend src src_ty dst_ty))
;; Rules for `ireduce` / `breduce` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; T -> T is always a no-op, even I128 -> I128.
(rule (lower (has_type ty (ireduce src @ (value_type ty))))
src)
;; T -> I{64,32,16,8}: We can simply pass through the value: values
;; are always stored with high bits undefined, so we can just leave
;; them be.
(rule 1 (lower (has_type (fits_in_64 ty) (ireduce src)))
(value_regs_get_gpr src 0))
;; Likewise for breduce.
(rule (lower (has_type ty (breduce src @ (value_type ty))))
src)
(rule 1 (lower (has_type (fits_in_64 ty) (breduce src)))
(value_regs_get_gpr src 0))
;; Rules for `bint` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Booleans are stored as all-zeroes (0) or all-ones (-1). We AND out
;; the LSB to give a 0 / 1-valued integer result.
(rule (lower (has_type (fits_in_64 ty)
(bint src)))
(x64_and ty src (RegMemImm.Imm 1)))
(rule 1 (lower (has_type $I128
(bint src)))
(value_regs
(x64_and $I64 src (RegMemImm.Imm 1))
(imm $I64 0)))
;; Rules for `debugtrap` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (debugtrap))
(side_effect (x64_hlt)))
;; Rules for `widening_pairwise_dot_product_s` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I32X4
(widening_pairwise_dot_product_s x y)))
(x64_pmaddwd x y))
;; Rules for `fadd` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; N.B.: there are no load-op merging rules here. We can't guarantee
;; the RHS (if a load) is 128-bit aligned, so we must avoid merging a
;; load. Likewise for other ops below.
(rule (lower (has_type $F32 (fadd x y)))
(x64_addss x y))
(rule (lower (has_type $F64 (fadd x y)))
(x64_addsd x y))
(rule (lower (has_type $F32X4 (fadd x y)))
(x64_addps x y))
(rule (lower (has_type $F64X2 (fadd x y)))
(x64_addpd x y))
;; Rules for `fsub` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fsub x y)))
(x64_subss x y))
(rule (lower (has_type $F64 (fsub x y)))
(x64_subsd x y))
(rule (lower (has_type $F32X4 (fsub x y)))
(x64_subps x y))
(rule (lower (has_type $F64X2 (fsub x y)))
(x64_subpd x y))
;; Rules for `fmul` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fmul x y)))
(x64_mulss x y))
(rule (lower (has_type $F64 (fmul x y)))
(x64_mulsd x y))
(rule (lower (has_type $F32X4 (fmul x y)))
(x64_mulps x y))
(rule (lower (has_type $F64X2 (fmul x y)))
(x64_mulpd x y))
;; Rules for `fdiv` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fdiv x y)))
(x64_divss x y))
(rule (lower (has_type $F64 (fdiv x y)))
(x64_divsd x y))
(rule (lower (has_type $F32X4 (fdiv x y)))
(x64_divps x y))
(rule (lower (has_type $F64X2 (fdiv x y)))
(x64_divpd x y))
;; Rules for `sqrt` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (sqrt x)))
(x64_sqrtss x))
(rule (lower (has_type $F64 (sqrt x)))
(x64_sqrtsd x))
(rule (lower (has_type $F32X4 (sqrt x)))
(x64_sqrtps x))
(rule (lower (has_type $F64X2 (sqrt x)))
(x64_sqrtpd x))
;; Rules for `fpromote` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F64 (fpromote x)))
(x64_cvtss2sd x))
;; Rules for `fvpromote` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F64X2 (fvpromote_low x)))
(x64_cvtps2pd (put_in_xmm x)))
;; Rules for `fdemote` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fdemote x)))
(x64_cvtsd2ss x))
;; Rules for `fvdemote` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32X4 (fvdemote x)))
(x64_cvtpd2ps x))
;; Rules for `fmin` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fmin x y)))
(xmm_min_max_seq $F32 $true x y))
(rule (lower (has_type $F64 (fmin x y)))
(xmm_min_max_seq $F64 $true x y))
;; Vector-typed version. We don't use single pseudoinstructions as
;; above, because we don't need to generate a mini-CFG. Instead, we
;; perform a branchless series of operations.
;;
;; We cannot simply use native min instructions (minps, minpd) because
;; NaN handling is different per CLIF semantics than on
;; x86. Specifically, if an argument is NaN, or the arguments are both
;; zero but of opposite signs, then the x86 instruction always
;; produces the second argument. However, per CLIF semantics, we
;; require that fmin(NaN, _) = fmin(_, NaN) = NaN, and fmin(+0, -0) =
;; fmin(-0, +0) = -0.
(rule (lower (has_type $F32X4 (fmin x y)))
;; Compute min(x, y) and min(y, x) with native
;; instructions. These will differ in one of the edge cases
;; above that we have to handle properly. (Conversely, if they
;; don't differ, then the native instruction's answer is the
;; right one per CLIF semantics.)
(let ((min1 Xmm (x64_minps x y))
(min2 Xmm (x64_minps y x))
;; Compute the OR of the two. Note that NaNs have an
;; exponent field of all-ones (0xFF for F32), so if either
;; result is a NaN, this OR will be. And if either is a
;; zero (which has an exponent of 0 and mantissa of 0),
;; this captures a sign-bit of 1 (negative) if either
;; input is negative.
;;
;; In the case where we don't have a +/-0 mismatch or
;; NaNs, then `min1` and `min2` are equal and `min_or` is
;; the correct minimum.
(min_or Xmm (x64_orps min1 min2))
;; "compare unordered" produces a true mask (all ones) in
;; a given lane if the min is a NaN. We use this to
;; generate a mask to ensure quiet NaNs.
(is_nan_mask Xmm (x64_cmpps min_or min2 (FcmpImm.Unordered)))
;; OR in the NaN mask.
(min_or_2 Xmm (x64_orps min_or is_nan_mask))
;; Shift the NaN mask down so that it covers just the
;; fraction below the NaN signalling bit; we'll use this
;; to mask off non-canonical NaN payloads.
;;
;; All-ones for NaN, shifted down to leave 10 top bits (1
;; sign, 8 exponent, 1 QNaN bit that must remain set)
;; cleared.
(nan_fraction_mask Xmm (x64_psrld is_nan_mask (RegMemImm.Imm 10)))
;; Do a NAND, so that we retain every bit not set in
;; `nan_fraction_mask`. This mask will be all zeroes (so
;; we retain every bit) in non-NaN cases, and will have
;; ones (so we clear those bits) in NaN-payload bits
;; otherwise.
(final Xmm (x64_andnps nan_fraction_mask min_or_2)))
final))
;; Likewise for F64 lanes, except that the right-shift is by 13 bits
;; (1 sign, 11 exponent, 1 QNaN bit).
(rule (lower (has_type $F64X2 (fmin x y)))
(let ((min1 Xmm (x64_minpd x y))
(min2 Xmm (x64_minpd y x))
(min_or Xmm (x64_orpd min1 min2))
(is_nan_mask Xmm (x64_cmppd min1 min2 (FcmpImm.Unordered)))
(min_or_2 Xmm (x64_orpd min_or is_nan_mask))
(nan_fraction_mask Xmm (x64_psrlq is_nan_mask (RegMemImm.Imm 13)))
(final Xmm (x64_andnpd nan_fraction_mask min_or_2)))
final))
;; Rules for `fmax` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fmax x y)))
(xmm_min_max_seq $F32 $false x y))
(rule (lower (has_type $F64 (fmax x y)))
(xmm_min_max_seq $F64 $false x y))
;; The vector version of fmax here is a dual to the fmin sequence
;; above, almost, with a few differences.
(rule (lower (has_type $F32X4 (fmax x y)))
;; Compute max(x, y) and max(y, x) with native
;; instructions. These will differ in one of the edge cases
;; above that we have to handle properly. (Conversely, if they
;; don't differ, then the native instruction's answer is the
;; right one per CLIF semantics.)
(let ((max1 Xmm (x64_maxps x y))
(max2 Xmm (x64_maxps y x))
;; Compute the XOR of the two maxima. In the case
;; where we don't have a +/-0 mismatch or NaNs, then
;; `min1` and `min2` are equal and this XOR is zero.
(max_xor Xmm (x64_xorps max1 max2))
;; OR the XOR into one of the original maxima. If they are
;; equal, this does nothing. If max2 was NaN, its exponent
;; bits were all-ones, so the xor's exponent bits were the
;; complement of max1, and the OR of max1 and max_xor has
;; an all-ones exponent (is a NaN). If max1 was NaN, then
;; its exponent bits were already all-ones, so the OR will
;; be a NaN as well.
(max_blended_nan Xmm (x64_orps max1 max_xor))
;; Subtract the XOR. This ensures that if we had +0 and
;; -0, we end up with +0.
(max_blended_nan_positive Xmm (x64_subps max_blended_nan max_xor))
;; "compare unordered" produces a true mask (all ones) in
;; a given lane if the min is a NaN. We use this to
;; generate a mask to ensure quiet NaNs.
(is_nan_mask Xmm (x64_cmpps max_blended_nan max_blended_nan (FcmpImm.Unordered)))
;; Shift the NaN mask down so that it covers just the
;; fraction below the NaN signalling bit; we'll use this
;; to mask off non-canonical NaN payloads.
;;
;; All-ones for NaN, shifted down to leave 10 top bits (1
;; sign, 8 exponent, 1 QNaN bit that must remain set)
;; cleared.
(nan_fraction_mask Xmm (x64_psrld is_nan_mask (RegMemImm.Imm 10)))
;; Do a NAND, so that we retain every bit not set in
;; `nan_fraction_mask`. This mask will be all zeroes (so
;; we retain every bit) in non-NaN cases, and will have
;; ones (so we clear those bits) in NaN-payload bits
;; otherwise.
(final Xmm (x64_andnps nan_fraction_mask max_blended_nan_positive)))
final))
(rule (lower (has_type $F64X2 (fmax x y)))
;; Compute max(x, y) and max(y, x) with native
;; instructions. These will differ in one of the edge cases
;; above that we have to handle properly. (Conversely, if they
;; don't differ, then the native instruction's answer is the
;; right one per CLIF semantics.)
(let ((max1 Xmm (x64_maxpd x y))
(max2 Xmm (x64_maxpd y x))
;; Compute the XOR of the two maxima. In the case
;; where we don't have a +/-0 mismatch or NaNs, then
;; `min1` and `min2` are equal and this XOR is zero.
(max_xor Xmm (x64_xorpd max1 max2))
;; OR the XOR into one of the original maxima. If they are
;; equal, this does nothing. If max2 was NaN, its exponent
;; bits were all-ones, so the xor's exponent bits were the
;; complement of max1, and the OR of max1 and max_xor has
;; an all-ones exponent (is a NaN). If max1 was NaN, then
;; its exponent bits were already all-ones, so the OR will
;; be a NaN as well.
(max_blended_nan Xmm (x64_orpd max1 max_xor))
;; Subtract the XOR. This ensures that if we had +0 and
;; -0, we end up with +0.
(max_blended_nan_positive Xmm (x64_subpd max_blended_nan max_xor))
;; `cmpps` with predicate index `3` is `cmpunordps`, or
;; "compare unordered": it produces a true mask (all ones)
;; in a given lane if the min is a NaN. We use this to
;; generate a mask to ensure quiet NaNs.
(is_nan_mask Xmm (x64_cmppd max_blended_nan max_blended_nan (FcmpImm.Unordered)))
;; Shift the NaN mask down so that it covers just the
;; fraction below the NaN signalling bit; we'll use this
;; to mask off non-canonical NaN payloads.
;;
;; All-ones for NaN, shifted down to leave 13 top bits (1
;; sign, 11 exponent, 1 QNaN bit that must remain set)
;; cleared.
(nan_fraction_mask Xmm (x64_psrlq is_nan_mask (RegMemImm.Imm 13)))
;; Do a NAND, so that we retain every bit not set in
;; `nan_fraction_mask`. This mask will be all zeroes (so
;; we retain every bit) in non-NaN cases, and will have
;; ones (so we clear those bits) in NaN-payload bits
;; otherwise.
(final Xmm (x64_andnpd nan_fraction_mask max_blended_nan_positive)))
final))
;; Rules for `fmin_pseudo` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fmin_pseudo x y)))
(x64_minss y x))
(rule (lower (has_type $F64 (fmin_pseudo x y)))
(x64_minsd y x))
(rule (lower (has_type $F32X4 (fmin_pseudo x y)))
(x64_minps y x))
(rule (lower (has_type $F64X2 (fmin_pseudo x y)))
(x64_minpd y x))
;; Rules for `fmax_pseudo` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fmax_pseudo x y)))
(x64_maxss y x))
(rule (lower (has_type $F64 (fmax_pseudo x y)))
(x64_maxsd y x))
(rule (lower (has_type $F32X4 (fmax_pseudo x y)))
(x64_maxps y x))
(rule (lower (has_type $F64X2 (fmax_pseudo x y)))
(x64_maxpd y x))
;; Rules for `fma` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fma x y z)))
(libcall_3 (LibCall.FmaF32) x y z))
(rule (lower (has_type $F64 (fma x y z)))
(libcall_3 (LibCall.FmaF64) x y z))
(rule 1 (lower (has_type (and (use_fma $true) $F32) (fma x y z)))
(x64_vfmadd213ss x y z))
(rule 1 (lower (has_type (and (use_fma $true) $F64) (fma x y z)))
(x64_vfmadd213sd x y z))
(rule (lower (has_type (and (use_fma $true) $F32X4) (fma x y z)))
(x64_vfmadd213ps x y z))
(rule (lower (has_type (and (use_fma $true) $F64X2) (fma x y z)))
(x64_vfmadd213pd x y z))
;; Rules for `load*` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; In order to load a value from memory to a GPR register, we may need to extend
;; the loaded value from 8-, 16-, or 32-bits to this backend's expected GPR
;; width: 64 bits. Note that `ext_mode` will load 1-bit types (booleans) as
;; 8-bit loads.
;;
;; By default, we zero-extend all sub-64-bit loads to a GPR.
(rule -4 (lower (has_type (and (fits_in_32 ty) (is_gpr_type _)) (load flags address offset)))
(x64_movzx (ext_mode (ty_bits_u16 ty) 64) (to_amode flags address offset)))
;; But if we know that both the `from` and `to` are 64 bits, we simply load with
;; no extension.
(rule -1 (lower (has_type (ty_int_bool_ref_64 ty) (load flags address offset)))
(x64_mov (to_amode flags address offset)))
;; Also, certain scalar loads have a specific `from` width and extension kind
;; (signed -> `sx`, zeroed -> `zx`). We overwrite the high bits of the 64-bit
;; GPR even if the `to` type is smaller (e.g., 16-bits).
(rule (lower (has_type (is_gpr_type ty) (uload8 flags address offset)))
(x64_movzx (ExtMode.BQ) (to_amode flags address offset)))
(rule (lower (has_type (is_gpr_type ty) (sload8 flags address offset)))
(x64_movsx (ExtMode.BQ) (to_amode flags address offset)))
(rule (lower (has_type (is_gpr_type ty) (uload16 flags address offset)))
(x64_movzx (ExtMode.WQ) (to_amode flags address offset)))
(rule (lower (has_type (is_gpr_type ty) (sload16 flags address offset)))
(x64_movsx (ExtMode.WQ) (to_amode flags address offset)))
(rule (lower (has_type (is_gpr_type ty) (uload32 flags address offset)))
(x64_movzx (ExtMode.LQ) (to_amode flags address offset)))
(rule (lower (has_type (is_gpr_type ty) (sload32 flags address offset)))
(x64_movsx (ExtMode.LQ) (to_amode flags address offset)))
;; To load to XMM registers, we use the x64-specific instructions for each type.
;; For `$F32` and `$F64` this is important--we only want to load 32 or 64 bits.
;; But for the 128-bit types, this is not strictly necessary for performance but
;; might help with clarity during disassembly.
(rule (lower (has_type $F32 (load flags address offset)))
(x64_movss_load (to_amode flags address offset)))
(rule (lower (has_type $F64 (load flags address offset)))
(x64_movsd_load (to_amode flags address offset)))
(rule (lower (has_type $F32X4 (load flags address offset)))
(x64_movups (to_amode flags address offset)))
(rule (lower (has_type $F64X2 (load flags address offset)))
(x64_movupd (to_amode flags address offset)))
(rule -2 (lower (has_type (ty_vec128 ty) (load flags address offset)))
(x64_movdqu (to_amode flags address offset)))
;; We can load an I128/B128 by doing two 64-bit loads.
(rule -3 (lower (has_type (ty_int_bool_128 _)
(load flags address offset)))
(let ((addr_lo Amode (to_amode flags address offset))
(addr_hi Amode (amode_offset addr_lo 8))
(value_lo Reg (x64_mov addr_lo))
(value_hi Reg (x64_mov addr_hi)))
(value_regs value_lo value_hi)))
;; We also include widening vector loads; these sign- or zero-extend each lane
;; to the next wider width (e.g., 16x4 -> 32x4).
(rule (lower (has_type $I16X8 (sload8x8 flags address offset)))
(x64_pmovsxbw (to_amode flags address offset)))
(rule (lower (has_type $I16X8 (uload8x8 flags address offset)))
(x64_pmovzxbw (to_amode flags address offset)))
(rule (lower (has_type $I32X4 (sload16x4 flags address offset)))
(x64_pmovsxwd (to_amode flags address offset)))
(rule (lower (has_type $I32X4 (uload16x4 flags address offset)))
(x64_pmovzxwd (to_amode flags address offset)))
(rule (lower (has_type $I64X2 (sload32x2 flags address offset)))
(x64_pmovsxdq (to_amode flags address offset)))
(rule (lower (has_type $I64X2 (uload32x2 flags address offset)))
(x64_pmovzxdq (to_amode flags address offset)))
;; Rules for `store*` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; 8-, 16-, 32- and 64-bit GPR stores.
(rule -2 (lower (store flags
value @ (value_type (is_gpr_type ty))
address
offset))
(side_effect
(x64_movrm ty (to_amode flags address offset) value)))
;; Explicit 8/16/32-bit opcodes.
(rule (lower (istore8 flags value address offset))
(side_effect
(x64_movrm $I8 (to_amode flags address offset) value)))
(rule (lower (istore16 flags value address offset))
(side_effect
(x64_movrm $I16 (to_amode flags address offset) value)))
(rule (lower (istore32 flags value address offset))
(side_effect
(x64_movrm $I32 (to_amode flags address offset) value)))
;; F32 stores of values in XMM registers.
(rule 1 (lower (store flags
value @ (value_type $F32)
address
offset))
(side_effect
(x64_xmm_movrm (SseOpcode.Movss) (to_amode flags address offset) value)))
;; F64 stores of values in XMM registers.
(rule 1 (lower (store flags
value @ (value_type $F64)
address
offset))
(side_effect
(x64_xmm_movrm (SseOpcode.Movsd) (to_amode flags address offset) value)))
;; Stores of F32X4 vectors.
(rule 1 (lower (store flags
value @ (value_type $F32X4)
address
offset))
(side_effect
(x64_xmm_movrm (SseOpcode.Movups) (to_amode flags address offset) value)))
;; Stores of F64X2 vectors.
(rule 1 (lower (store flags
value @ (value_type $F64X2)
address
offset))
(side_effect
(x64_xmm_movrm (SseOpcode.Movupd) (to_amode flags address offset) value)))
;; Stores of all other 128-bit vector types with integer lanes.
(rule -1 (lower (store flags
value @ (value_type (ty_vec128_int _))
address
offset))
(side_effect
(x64_xmm_movrm (SseOpcode.Movdqu) (to_amode flags address offset) value)))
;; Stores of I128/B128 values: store the two 64-bit halves separately.
(rule 0 (lower (store flags
value @ (value_type (ty_int_bool_128 _))
address
offset))
(let ((value_reg ValueRegs value)
(value_lo Gpr (value_regs_get_gpr value_reg 0))
(value_hi Gpr (value_regs_get_gpr value_reg 1))
(addr_lo Amode (to_amode flags address offset))
(addr_hi Amode (amode_offset addr_lo 8)))
(side_effect
(side_effect_concat
(x64_movrm $I64 addr_lo value_lo)
(x64_movrm $I64 addr_hi value_hi)))))
;; Rules for `load*` + ALU op + `store*` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Add mem, reg
(rule 3 (lower
(store flags
(has_type (ty_32_or_64 ty)
(iadd (and
(sinkable_load sink)
(load flags addr offset))
src2))
addr
offset))
(let ((_ RegMemImm (sink_load sink)))
(side_effect
(x64_add_mem ty (to_amode flags addr offset) src2))))
;; Add mem, reg with args swapped
(rule 2 (lower
(store flags
(has_type (ty_32_or_64 ty)
(iadd src2
(and
(sinkable_load sink)
(load flags addr offset))))
addr
offset))
(let ((_ RegMemImm (sink_load sink)))
(side_effect
(x64_add_mem ty (to_amode flags addr offset) src2))))
;; Sub mem, reg
(rule 2 (lower
(store flags
(has_type (ty_32_or_64 ty)
(isub (and
(sinkable_load sink)
(load flags addr offset))
src2))
addr
offset))
(let ((_ RegMemImm (sink_load sink)))
(side_effect
(x64_sub_mem ty (to_amode flags addr offset) src2))))
;; And mem, reg
(rule 3 (lower
(store flags
(has_type (ty_32_or_64 ty)
(band (and
(sinkable_load sink)
(load flags addr offset))
src2))
addr
offset))
(let ((_ RegMemImm (sink_load sink)))
(side_effect
(x64_and_mem ty (to_amode flags addr offset) src2))))
;; And mem, reg with args swapped
(rule 2 (lower
(store flags
(has_type (ty_32_or_64 ty)
(band src2
(and
(sinkable_load sink)
(load flags addr offset))))
addr
offset))
(let ((_ RegMemImm (sink_load sink)))
(side_effect
(x64_and_mem ty (to_amode flags addr offset) src2))))
;; Or mem, reg
(rule 3 (lower
(store flags
(has_type (ty_32_or_64 ty)
(bor (and
(sinkable_load sink)
(load flags addr offset))
src2))
addr
offset))
(let ((_ RegMemImm (sink_load sink)))
(side_effect
(x64_or_mem ty (to_amode flags addr offset) src2))))
;; Or mem, reg with args swapped
(rule 2 (lower
(store flags
(has_type (ty_32_or_64 ty)
(bor src2
(and
(sinkable_load sink)
(load flags addr offset))))
addr
offset))
(let ((_ RegMemImm (sink_load sink)))
(side_effect
(x64_or_mem ty (to_amode flags addr offset) src2))))
;; Xor mem, reg
(rule 3 (lower
(store flags
(has_type (ty_32_or_64 ty)
(bxor (and
(sinkable_load sink)
(load flags addr offset))
src2))
addr
offset))
(let ((_ RegMemImm (sink_load sink)))
(side_effect
(x64_xor_mem ty (to_amode flags addr offset) src2))))
;; Xor mem, reg with args swapped
(rule 2 (lower
(store flags
(has_type (ty_32_or_64 ty)
(bxor src2
(and
(sinkable_load sink)
(load flags addr offset))))
addr
offset))
(let ((_ RegMemImm (sink_load sink)))
(side_effect
(x64_xor_mem ty (to_amode flags addr offset) src2))))
;; Rules for `fence` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (fence))
(side_effect (x64_mfence)))
;; Rules for `func_addr` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (func_addr (func_ref_data _ extname _)))
(load_ext_name extname 0))
;; Rules for `symbol_value` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (symbol_value (symbol_value_data extname _ offset)))
(load_ext_name extname offset))
;; Rules for `atomic_load` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; This is a normal load. The x86-TSO memory model provides sufficient
;; sequencing to satisfy the CLIF synchronisation requirements for `AtomicLoad`
;; without the need for any fence instructions.
;;
;; As described in the `atomic_load` documentation, this lowering is only valid
;; for I8, I16, I32, and I64. The sub-64-bit types are zero extended, as with a
;; normal load.
(rule 1 (lower (has_type $I64 (atomic_load flags address)))
(x64_mov (to_amode flags address (zero_offset))))
(rule (lower (has_type (and (fits_in_32 ty) (ty_int _)) (atomic_load flags address)))
(x64_movzx (ext_mode (ty_bits_u16 ty) 64) (to_amode flags address (zero_offset))))
;; Rules for `atomic_store` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; This is a normal store followed by an `mfence` instruction. As described in
;; the `atomic_load` documentation, this lowering is only valid for I8, I16,
;; I32, and I64.
(rule (lower (atomic_store flags
value @ (value_type (and (fits_in_64 ty) (ty_int _)))
address))
(side_effect (side_effect_concat
(x64_movrm ty (to_amode flags address (zero_offset)) value)
(x64_mfence))))
;; Rules for `atomic_cas` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (and (fits_in_64 ty) (ty_int _))
(atomic_cas flags address expected replacement)))
(x64_cmpxchg ty expected replacement (to_amode flags address (zero_offset))))
;; Rules for `atomic_rmw` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; This is a simple, general-case atomic update, based on a loop involving
;; `cmpxchg`. Note that we could do much better than this in the case where the
;; old value at the location (that is to say, the SSA `Value` computed by this
;; CLIF instruction) is not required. In that case, we could instead implement
;; this using a single `lock`-prefixed x64 read-modify-write instruction. Also,
;; even in the case where the old value is required, for the `add` and `sub`
;; cases, we can use the single instruction `lock xadd`. However, those
;; improvements have been left for another day. TODO: filed as
;; https://github.com/bytecodealliance/wasmtime/issues/2153.
(rule (lower (has_type (and (fits_in_64 ty) (ty_int _))
(atomic_rmw flags op address input)))
(x64_atomic_rmw_seq ty op (to_amode flags address (zero_offset)) input))
;; Rules for `call` and `call_indirect` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (call (func_ref_data sig_ref extname dist) inputs))
(gen_call sig_ref extname dist inputs))
(rule (lower (call_indirect sig_ref val inputs))
(gen_call_indirect sig_ref val inputs))
;;;; Rules for `get_{frame,stack}_pointer` and `get_return_address` ;;;;;;;;;;;;
(rule (lower (get_frame_pointer))
(x64_rbp))
(rule (lower (get_stack_pointer))
(x64_rsp))
(rule (lower (get_return_address))
(x64_load $I64
(Amode.ImmReg 8 (preg_rbp) (mem_flags_trusted))
(ExtKind.None)))
;; Rules for `jump` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower_branch (jump _ _) (single_target target))
(side_effect (jmp_known target)))
;; Rules for `brif` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower_branch (brif cc (ifcmp a b) _ _) (two_targets taken not_taken))
(side_effect (jmp_cond_icmp (emit_cmp cc a b) taken not_taken)))
;; Rules for `brff` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower_branch (brff cc (ffcmp a b) _ _) (two_targets taken not_taken))
(side_effect (jmp_cond_fcmp (emit_fcmp cc a b) taken not_taken)))
;; Rules for `brz` and `brnz` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 2 (lower_branch (brz (icmp cc a b) _ _) (two_targets taken not_taken))
(let ((cmp IcmpCondResult (invert_icmp_cond_result (emit_cmp cc a b))))
(side_effect (jmp_cond_icmp cmp taken not_taken))))
(rule 2 (lower_branch (brz (fcmp cc a b) _ _) (two_targets taken not_taken))
(let ((cmp FcmpCondResult (emit_fcmp (floatcc_inverse cc) a b)))
(side_effect (jmp_cond_fcmp cmp taken not_taken))))
(rule 1 (lower_branch (brz val @ (value_type $I128) _ _) (two_targets taken not_taken))
(side_effect (jmp_cond_icmp (cmp_zero_i128 (CC.NZ) val) taken not_taken)))
(rule 0 (lower_branch (brz val @ (value_type (ty_int_bool_or_ref)) _ _) (two_targets taken not_taken))
(side_effect
(with_flags_side_effect (cmp_zero_int_bool_ref val)
(jmp_cond (CC.Z) taken not_taken))))
(rule 2 (lower_branch (brnz (icmp cc a b) _ _) (two_targets taken not_taken))
(side_effect (jmp_cond_icmp (emit_cmp cc a b) taken not_taken)))
(rule 2 (lower_branch (brnz (fcmp cc a b) _ _) (two_targets taken not_taken))
(let ((cmp FcmpCondResult (emit_fcmp cc a b)))
(side_effect (jmp_cond_fcmp cmp taken not_taken))))
(rule 1 (lower_branch (brnz val @ (value_type $I128) _ _) (two_targets taken not_taken))
(side_effect (jmp_cond_icmp (cmp_zero_i128 (CC.Z) val) taken not_taken)))
(rule 0 (lower_branch (brnz val @ (value_type (ty_int_bool_or_ref)) _ _) (two_targets taken not_taken))
(side_effect
(with_flags_side_effect (cmp_zero_int_bool_ref val)
(jmp_cond (CC.NZ) taken not_taken))))
;; Compare an I128 value to zero, returning a flags result suitable for making a
;; jump decision. The comparison is implemented as `(hi == 0) && (low == 0)`,
;; and the result can be interpreted as follows
;; * CC.Z indicates that the value was non-zero, as one or both of the halves of
;; the value were non-zero
;; * CC.NZ indicates that both halves of the value were 0
(decl cmp_zero_i128 (CC ValueRegs) IcmpCondResult)
(rule (cmp_zero_i128 (cc_nz_or_z cc) val)
(let ((lo Gpr (value_regs_get_gpr val 0))
(hi Gpr (value_regs_get_gpr val 1))
(lo_z Gpr (with_flags_reg (x64_cmp (OperandSize.Size64) (RegMemImm.Imm 0) lo)
(x64_setcc (CC.Z))))
(hi_z Gpr (with_flags_reg (x64_cmp (OperandSize.Size64) (RegMemImm.Imm 0) hi)
(x64_setcc (CC.Z)))))
(icmp_cond_result (x64_test (OperandSize.Size8) lo_z hi_z) cc)))
(decl cmp_zero_int_bool_ref (Value) ProducesFlags)
(rule 1 (cmp_zero_int_bool_ref val @ (value_type $B1))
(x64_test (OperandSize.Size8) (RegMemImm.Imm 1) val))
(rule (cmp_zero_int_bool_ref val @ (value_type ty))
(let ((size OperandSize (raw_operand_size_of_type ty))
(src Gpr val))
(x64_test size src src)))
;; Rules for `bricmp` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower_branch (br_icmp cc a b _ _) (two_targets taken not_taken))
(side_effect (jmp_cond_icmp (emit_cmp cc a b) taken not_taken)))
;; Rules for `br_table` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower_branch (br_table idx @ (value_type ty) _ _) (jump_table_targets default_target jt_targets))
(side_effect (jmp_table_seq ty idx default_target jt_targets)))
;; Rules for `selectif` and `selectif_spectre_guard` ;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (selectif cc (ifcmp a b) x y))
(select_icmp (emit_cmp cc a b) x y))
(rule (lower (selectif_spectre_guard cc (ifcmp a b) x y))
(select_icmp (emit_cmp cc a b) x y))
;; Rules for `fcvt_from_sint` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 2 (lower (has_type $F32 (fcvt_from_sint a @ (value_type $I8))))
(x64_cvtsi2ss $I32 (extend_to_gpr a $I32 (ExtendKind.Sign))))
(rule 2 (lower (has_type $F32 (fcvt_from_sint a @ (value_type $I16))))
(x64_cvtsi2ss $I32 (extend_to_gpr a $I32 (ExtendKind.Sign))))
(rule 1 (lower (has_type $F32 (fcvt_from_sint a @ (value_type (ty_int (fits_in_64 ty))))))
(x64_cvtsi2ss ty a))
(rule 2 (lower (has_type $F64 (fcvt_from_sint a @ (value_type $I8))))
(x64_cvtsi2sd $I32 (extend_to_gpr a $I32 (ExtendKind.Sign))))
(rule 2 (lower (has_type $F64 (fcvt_from_sint a @ (value_type $I16))))
(x64_cvtsi2sd $I32 (extend_to_gpr a $I32 (ExtendKind.Sign))))
(rule 1 (lower (has_type $F64 (fcvt_from_sint a @ (value_type (ty_int (fits_in_64 ty))))))
(x64_cvtsi2sd ty a))
(rule 0 (lower (fcvt_from_sint a @ (value_type $I32X4)))
(x64_cvtdq2ps a))
;; Rules for `fcvt_low_from_sint` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (fcvt_low_from_sint a @ (value_type ty)))
(x64_cvtdq2pd ty a))
;; Rules for `fcvt_from_uint` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 1 (lower (has_type $F32 (fcvt_from_uint val @ (value_type (fits_in_32 (ty_int ty))))))
(x64_cvtsi2ss $I64 (extend_to_gpr val $I64 (ExtendKind.Zero))))
(rule 1 (lower (has_type $F64 (fcvt_from_uint val @ (value_type (fits_in_32 (ty_int ty))))))
(x64_cvtsi2sd $I64 (extend_to_gpr val $I64 (ExtendKind.Zero))))
(rule (lower (has_type ty (fcvt_from_uint val @ (value_type $I64))))
(cvt_u64_to_float_seq ty val))
;; Algorithm uses unpcklps to help create a float that is equivalent
;; 0x1.0p52 + double(src). 0x1.0p52 is unique because at this exponent
;; every value of the mantissa represents a corresponding uint32 number.
;; When we subtract 0x1.0p52 we are left with double(src).
(rule 1 (lower (has_type $F64X2 (fcvt_from_uint (uwiden_low val @ (value_type $I32X4)))))
(let ((uint_mask Xmm (x64_xmm_load_const $I32X4 (fcvt_uint_mask_const)))
(res Xmm (x64_unpcklps val uint_mask))
(uint_mask_high Xmm (x64_xmm_load_const $I32X4 (fcvt_uint_mask_high_const))))
(x64_subpd res uint_mask_high)))
;; When AVX512VL and AVX512F are available,
;; `fcvt_from_uint` can be lowered to a single instruction.
(rule 2 (lower (has_type (and (avx512vl_enabled $true) (avx512f_enabled $true) $F32X4)
(fcvt_from_uint src)))
(x64_vcvtudq2ps src))
;; Converting packed unsigned integers to packed floats
;; requires a few steps. There is no single instruction
;; lowering for converting unsigned floats but there is for
;; converting packed signed integers to float (cvtdq2ps). In
;; the steps below we isolate the upper half (16 bits) and
;; lower half (16 bits) of each lane and then we convert
;; each half separately using cvtdq2ps meant for signed
;; integers. In order for this to work for the upper half
;; bits we must shift right by 1 (divide by 2) these bits in
;; order to ensure the most significant bit is 0 not signed,
;; and then after the conversion we double the value.
;; Finally we add the converted values where addition will
;; correctly round.
;;
;; Sequence:
;; -> A = 0xffffffff
;; -> Ah = 0xffff0000
;; -> Al = 0x0000ffff
;; -> Convert(Al) // Convert int to float
;; -> Ah = Ah >> 1 // Shift right 1 to assure Ah conversion isn't treated as signed
;; -> Convert(Ah) // Convert .. with no loss of significant digits from previous shift
;; -> Ah = Ah + Ah // Double Ah to account for shift right before the conversion.
;; -> dst = Ah + Al // Add the two floats together
(rule 1 (lower (has_type $F32X4 (fcvt_from_uint val)))
(let ((a Xmm val)
;; get the low 16 bits
(a_lo Xmm (x64_pslld a (RegMemImm.Imm 16)))
(a_lo Xmm (x64_psrld a_lo (RegMemImm.Imm 16)))
;; get the high 16 bits
(a_hi Xmm (x64_psubd a a_lo))
;; convert the low 16 bits
(a_lo Xmm (x64_cvtdq2ps a_lo))
;; shift the high bits by 1, convert, and double to get the correct
;; value
(a_hi Xmm (x64_psrld a_hi (RegMemImm.Imm 1)))
(a_hi Xmm (x64_cvtdq2ps a_hi))
(a_hi Xmm (x64_addps a_hi a_hi)))
;; add together the two converted values
(x64_addps a_hi a_lo)))
;; Rules for `fcvt_to_uint` and `fcvt_to_sint` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type out_ty (fcvt_to_uint val @ (value_type (ty_scalar_float _)))))
(cvt_float_to_uint_seq out_ty val $false))
(rule (lower (has_type out_ty (fcvt_to_uint_sat val @ (value_type (ty_scalar_float _)))))
(cvt_float_to_uint_seq out_ty val $true))
(rule (lower (has_type out_ty (fcvt_to_sint val @ (value_type (ty_scalar_float _)))))
(cvt_float_to_sint_seq out_ty val $false))
(rule (lower (has_type out_ty (fcvt_to_sint_sat val @ (value_type (ty_scalar_float _)))))
(cvt_float_to_sint_seq out_ty val $true))
;; The x64 backend currently only supports these two type combinations.
(rule 1 (lower (has_type $I32X4 (fcvt_to_sint_sat val @ (value_type $F32X4))))
(let ((src Xmm val)
;; Sets tmp to zero if float is NaN
(tmp Xmm (x64_cmpps src src (FcmpImm.Equal)))
(dst Xmm (x64_andps src tmp))
;; Sets top bit of tmp if float is positive
;; Setting up to set top bit on negative float values
(tmp Xmm (x64_pxor tmp dst))
;; Convert the packed float to packed doubleword.
(dst Xmm (x64_cvttps2dq $F32X4 dst))
;; Set top bit only if < 0
(tmp Xmm (x64_pand dst tmp))
(tmp Xmm (x64_psrad tmp (RegMemImm.Imm 31))))
;; On overflow 0x80000000 is returned to a lane.
;; Below sets positive overflow lanes to 0x7FFFFFFF
;; Keeps negative overflow lanes as is.
(x64_pxor tmp dst)))
;; The algorithm for converting floats to unsigned ints is a little tricky. The
;; complication arises because we are converting from a signed 64-bit int with a positive
;; integer range from 1..INT_MAX (0x1..0x7FFFFFFF) to an unsigned integer with an extended
;; range from (INT_MAX+1)..UINT_MAX. It's this range from (INT_MAX+1)..UINT_MAX
;; (0x80000000..0xFFFFFFFF) that needs to be accounted for as a special case since our
;; conversion instruction (cvttps2dq) only converts as high as INT_MAX (0x7FFFFFFF), but
;; which conveniently setting underflows and overflows (smaller than MIN_INT or larger than
;; MAX_INT) to be INT_MAX+1 (0x80000000). Nothing that the range (INT_MAX+1)..UINT_MAX includes
;; precisely INT_MAX values we can correctly account for and convert every value in this range
;; if we simply subtract INT_MAX+1 before doing the cvttps2dq conversion. After the subtraction
;; every value originally (INT_MAX+1)..UINT_MAX is now the range (0..INT_MAX).
;; After the conversion we add INT_MAX+1 back to this converted value, noting again that
;; values we are trying to account for were already set to INT_MAX+1 during the original conversion.
;; We simply have to create a mask and make sure we are adding together only the lanes that need
;; to be accounted for. Digesting it all the steps then are:
;;
;; Step 1 - Account for NaN and negative floats by setting these src values to zero.
;; Step 2 - Make a copy (tmp1) of the src value since we need to convert twice for
;; reasons described above.
;; Step 3 - Convert the original src values. This will convert properly all floats up to INT_MAX
;; Step 4 - Subtract INT_MAX from the copy set (tmp1). Note, all zero and negative values are those
;; values that were originally in the range (0..INT_MAX). This will come in handy during
;; step 7 when we zero negative lanes.
;; Step 5 - Create a bit mask for tmp1 that will correspond to all lanes originally less than
;; UINT_MAX that are now less than INT_MAX thanks to the subtraction.
;; Step 6 - Convert the second set of values (tmp1)
;; Step 7 - Prep the converted second set by zeroing out negative lanes (these have already been
;; converted correctly with the first set) and by setting overflow lanes to 0x7FFFFFFF
;; as this will allow us to properly saturate overflow lanes when adding to 0x80000000
;; Step 8 - Add the orginal converted src and the converted tmp1 where float values originally less
;; than and equal to INT_MAX will be unchanged, float values originally between INT_MAX+1 and
;; UINT_MAX will add together (INT_MAX) + (SRC - INT_MAX), and float values originally
;; greater than UINT_MAX will be saturated to UINT_MAX (0xFFFFFFFF) after adding (0x8000000 + 0x7FFFFFFF).
;;
;;
;; The table below illustrates the result after each step where it matters for the converted set.
;; Note the original value range (original src set) is the final dst in Step 8:
;;
;; Original src set:
;; | Original Value Range | Step 1 | Step 3 | Step 8 |
;; | -FLT_MIN..FLT_MAX | 0.0..FLT_MAX | 0..INT_MAX(w/overflow) | 0..UINT_MAX(w/saturation) |
;;
;; Copied src set (tmp1):
;; | Step 2 | Step 4 |
;; | 0.0..FLT_MAX | (0.0-(INT_MAX+1))..(FLT_MAX-(INT_MAX+1)) |
;;
;; | Step 6 | Step 7 |
;; | (0-(INT_MAX+1))..(UINT_MAX-(INT_MAX+1))(w/overflow) | ((INT_MAX+1)-(INT_MAX+1))..(INT_MAX+1) |
(rule 1 (lower (has_type $I32X4 (fcvt_to_uint_sat val @ (value_type $F32X4))))
(let ((src Xmm val)
;; Converting to unsigned int so if float src is negative or NaN
;; will first set to zero.
(tmp2 Xmm (x64_pxor src src)) ;; make a zero
(dst Xmm (x64_maxps src tmp2))
;; Set tmp2 to INT_MAX+1. It is important to note here that after it looks
;; like we are only converting INT_MAX (0x7FFFFFFF) but in fact because
;; single precision IEEE-754 floats can only accurately represent contingous
;; integers up to 2^23 and outside of this range it rounds to the closest
;; integer that it can represent. In the case of INT_MAX, this value gets
;; represented as 0x4f000000 which is the integer value (INT_MAX+1).
(tmp2 Xmm (x64_pcmpeqd tmp2 tmp2))
(tmp2 Xmm (x64_psrld tmp2 (RegMemImm.Imm 1)))
(tmp2 Xmm (x64_cvtdq2ps tmp2))
;; Make a copy of these lanes and then do the first conversion.
;; Overflow lanes greater than the maximum allowed signed value will
;; set to 0x80000000. Negative and NaN lanes will be 0x0
(tmp1 Xmm dst)
(dst Xmm (x64_cvttps2dq $F32X4 dst))
;; Set lanes to src - max_signed_int
(tmp1 Xmm (x64_subps tmp1 tmp2))
;; Create mask for all positive lanes to saturate (i.e. greater than
;; or equal to the maxmimum allowable unsigned int).
(tmp2 Xmm (x64_cmpps tmp2 tmp1 (FcmpImm.LessThanOrEqual)))
;; Convert those set of lanes that have the max_signed_int factored out.
(tmp1 Xmm (x64_cvttps2dq $F32X4 tmp1))
;; Prepare converted lanes by zeroing negative lanes and prepping lanes
;; that have positive overflow (based on the mask) by setting these lanes
;; to 0x7FFFFFFF
(tmp1 Xmm (x64_pxor tmp1 tmp2))
(tmp2 Xmm (x64_pxor tmp2 tmp2)) ;; make another zero
(tmp1 Xmm (x64_pmaxsd tmp1 tmp2)))
;; Add this second set of converted lanes to the original to properly handle
;; values greater than max signed int.
(x64_paddd tmp1 dst)))
;; Rules for `iadd_pairwise` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower
(has_type $I16X8 (iadd_pairwise
(swiden_low val @ (value_type $I8X16))
(swiden_high val))))
(let ((mul_const Xmm (x64_xmm_load_const $I8X16 (iadd_pairwise_mul_const_16))))
(x64_pmaddubsw mul_const val)))
(rule (lower
(has_type $I32X4 (iadd_pairwise
(swiden_low val @ (value_type $I16X8))
(swiden_high val))))
(let ((mul_const Xmm (x64_xmm_load_const $I16X8 (iadd_pairwise_mul_const_32))))
(x64_pmaddwd val mul_const)))
(rule (lower
(has_type $I16X8 (iadd_pairwise
(uwiden_low val @ (value_type $I8X16))
(uwiden_high val))))
(let ((mul_const Xmm (x64_xmm_load_const $I8X16 (iadd_pairwise_mul_const_16))))
(x64_pmaddubsw val mul_const)))
(rule (lower
(has_type $I32X4 (iadd_pairwise
(uwiden_low val @ (value_type $I16X8))
(uwiden_high val))))
(let ((xor_const Xmm (x64_xmm_load_const $I16X8 (iadd_pairwise_xor_const_32)))
(dst Xmm (x64_pxor val xor_const))
(madd_const Xmm (x64_xmm_load_const $I16X8 (iadd_pairwise_mul_const_32)))
(dst Xmm (x64_pmaddwd dst madd_const))
(addd_const Xmm (x64_xmm_load_const $I16X8 (iadd_pairwise_addd_const_32))))
(x64_paddd dst addd_const)))
;; Rules for `swiden_low` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I16X8 (swiden_low val @ (value_type $I8X16))))
(x64_pmovsxbw val))
(rule (lower (has_type $I32X4 (swiden_low val @ (value_type $I16X8))))
(x64_pmovsxwd val))
(rule (lower (has_type $I64X2 (swiden_low val @ (value_type $I32X4))))
(x64_pmovsxdq val))
;; Rules for `swiden_high` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I16X8 (swiden_high val @ (value_type $I8X16))))
(let ((x Xmm val))
(x64_pmovsxbw (x64_palignr x x 8 (OperandSize.Size32)))))
(rule (lower (has_type $I32X4 (swiden_high val @ (value_type $I16X8))))
(let ((x Xmm val))
(x64_pmovsxwd (x64_palignr x x 8 (OperandSize.Size32)))))
(rule (lower (has_type $I64X2 (swiden_high val @ (value_type $I32X4))))
(x64_pmovsxdq (x64_pshufd val 0xEE (OperandSize.Size32))))
;; Rules for `uwiden_low` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I16X8 (uwiden_low val @ (value_type $I8X16))))
(x64_pmovzxbw val))
(rule (lower (has_type $I32X4 (uwiden_low val @ (value_type $I16X8))))
(x64_pmovzxwd val))
(rule (lower (has_type $I64X2 (uwiden_low val @ (value_type $I32X4))))
(x64_pmovzxdq val))
;; Rules for `uwiden_high` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I16X8 (uwiden_high val @ (value_type $I8X16))))
(let ((x Xmm val))
(x64_pmovzxbw (x64_palignr x x 8 (OperandSize.Size32)))))
(rule (lower (has_type $I32X4 (uwiden_high val @ (value_type $I16X8))))
(let ((x Xmm val))
(x64_pmovzxwd (x64_palignr x x 8 (OperandSize.Size32)))))
(rule (lower (has_type $I64X2 (uwiden_high val @ (value_type $I32X4))))
(x64_pmovzxdq (x64_pshufd val 0xEE (OperandSize.Size32))))
;; Rules for `snarrow` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I8X16 (snarrow a @ (value_type $I16X8) b)))
(x64_packsswb a b))
(rule (lower (has_type $I16X8 (snarrow a @ (value_type $I32X4) b)))
(x64_packssdw a b))
;; We're missing a `snarrow` case for $I64X2
;; https://github.com/bytecodealliance/wasmtime/issues/4734
;; This rule is a special case for handling the translation of the wasm op
;; `i32x4.trunc_sat_f64x2_s_zero`. It can be removed once we have an
;; implementation of `snarrow` for `I64X2`.
(rule (lower (has_type $I32X4 (snarrow (has_type $I64X2 (fcvt_to_sint_sat val))
(vconst (u128_from_constant 0)))))
(let ((a Xmm val)
;; y = i32x4.trunc_sat_f64x2_s_zero(x) is lowered to:
;; MOVE xmm_tmp, xmm_x
;; CMPEQPD xmm_tmp, xmm_x
;; MOVE xmm_y, xmm_x
;; ANDPS xmm_tmp, [wasm_f64x2_splat(2147483647.0)]
;; MINPD xmm_y, xmm_tmp
;; CVTTPD2DQ xmm_y, xmm_y
(tmp1 Xmm (x64_cmppd a a (FcmpImm.Equal)))
(umax_mask Xmm (x64_xmm_load_const $F64X2 (snarrow_umax_mask)))
;; ANDPD xmm_y, [wasm_f64x2_splat(2147483647.0)]
(tmp1 Xmm (x64_andps tmp1 umax_mask))
(dst Xmm (x64_minpd a tmp1)))
(x64_cvttpd2dq dst)))
;; Rules for `unarrow` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I8X16 (unarrow a @ (value_type $I16X8) b)))
(x64_packuswb a b))
(rule (lower (has_type $I16X8 (unarrow a @ (value_type $I32X4) b)))
(x64_packusdw a b))
;; We're missing a `unarrow` case for $I64X2
;; https://github.com/bytecodealliance/wasmtime/issues/4734
;; Rules for `bitcast` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I32 (bitcast src @ (value_type $F32))))
(bitcast_xmm_to_gpr $F32 src))
(rule (lower (has_type $F32 (bitcast src @ (value_type $I32))))
(bitcast_gpr_to_xmm $I32 src))
(rule (lower (has_type $I64 (bitcast src @ (value_type $F64))))
(bitcast_xmm_to_gpr $F64 src))
(rule (lower (has_type $F64 (bitcast src @ (value_type $I64))))
(bitcast_gpr_to_xmm $I64 src))
;; Rules for `fcopysign` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fcopysign a @ (value_type $F32) b)))
(let ((sign_bit Xmm (imm $F32 0x80000000)))
(x64_orps
(x64_andnps sign_bit a)
(x64_andps sign_bit b))))
(rule (lower (has_type $F64 (fcopysign a @ (value_type $F64) b)))
(let ((sign_bit Xmm (imm $F64 0x8000000000000000)))
(x64_orpd
(x64_andnpd sign_bit a)
(x64_andpd sign_bit b))))
;; Rules for `ceil` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (use_sse41 $true) (ceil a @ (value_type $F32))))
(x64_roundss a (RoundImm.RoundUp)))
(rule (lower (has_type (use_sse41 $false) (ceil a @ (value_type $F32))))
(libcall_1 (LibCall.CeilF32) a))
(rule (lower (has_type (use_sse41 $true) (ceil a @ (value_type $F64))))
(x64_roundsd a (RoundImm.RoundUp)))
(rule (lower (has_type (use_sse41 $false) (ceil a @ (value_type $F64))))
(libcall_1 (LibCall.CeilF64) a))
(rule (lower (has_type (use_sse41 $true) (ceil a @ (value_type $F32X4))))
(x64_roundps a (RoundImm.RoundUp)))
(rule (lower (has_type (use_sse41 $true) (ceil a @ (value_type $F64X2))))
(x64_roundpd a (RoundImm.RoundUp)))
;; Rules for `floor` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (use_sse41 $true) (floor a @ (value_type $F32))))
(x64_roundss a (RoundImm.RoundDown)))
(rule (lower (has_type (use_sse41 $false) (floor a @ (value_type $F32))))
(libcall_1 (LibCall.FloorF32) a))
(rule (lower (has_type (use_sse41 $true) (floor a @ (value_type $F64))))
(x64_roundsd a (RoundImm.RoundDown)))
(rule (lower (has_type (use_sse41 $false) (floor a @ (value_type $F64))))
(libcall_1 (LibCall.FloorF64) a))
(rule (lower (has_type (use_sse41 $true) (floor a @ (value_type $F32X4))))
(x64_roundps a (RoundImm.RoundDown)))
(rule (lower (has_type (use_sse41 $true) (floor a @ (value_type $F64X2))))
(x64_roundpd a (RoundImm.RoundDown)))
;; Rules for `nearest` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (use_sse41 $true) (nearest a @ (value_type $F32))))
(x64_roundss a (RoundImm.RoundNearest)))
(rule (lower (has_type (use_sse41 $false) (nearest a @ (value_type $F32))))
(libcall_1 (LibCall.NearestF32) a))
(rule (lower (has_type (use_sse41 $true) (nearest a @ (value_type $F64))))
(x64_roundsd a (RoundImm.RoundNearest)))
(rule (lower (has_type (use_sse41 $false) (nearest a @ (value_type $F64))))
(libcall_1 (LibCall.NearestF64) a))
(rule (lower (has_type (use_sse41 $true) (nearest a @ (value_type $F32X4))))
(x64_roundps a (RoundImm.RoundNearest)))
(rule (lower (has_type (use_sse41 $true) (nearest a @ (value_type $F64X2))))
(x64_roundpd a (RoundImm.RoundNearest)))
;; Rules for `trunc` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (use_sse41 $true) (trunc a @ (value_type $F32))))
(x64_roundss a (RoundImm.RoundZero)))
(rule (lower (has_type (use_sse41 $false) (trunc a @ (value_type $F32))))
(libcall_1 (LibCall.TruncF32) a))
(rule (lower (has_type (use_sse41 $true) (trunc a @ (value_type $F64))))
(x64_roundsd a (RoundImm.RoundZero)))
(rule (lower (has_type (use_sse41 $false) (trunc a @ (value_type $F64))))
(libcall_1 (LibCall.TruncF64) a))
(rule (lower (has_type (use_sse41 $true) (trunc a @ (value_type $F32X4))))
(x64_roundps a (RoundImm.RoundZero)))
(rule (lower (has_type (use_sse41 $true) (trunc a @ (value_type $F64X2))))
(x64_roundpd a (RoundImm.RoundZero)))
;; Rules for `stack_addr` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (stack_addr stack_slot offset))
(stack_addr_impl stack_slot offset))
;; Rules for `udiv` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (udiv a @ (value_type ty) b))
(div_or_rem (DivOrRemKind.UnsignedDiv) a b))
;; Rules for `sdiv` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (sdiv a @ (value_type ty) b))
(div_or_rem (DivOrRemKind.SignedDiv) a b))
;; Rules for `urem` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (urem a @ (value_type ty) b))
(div_or_rem (DivOrRemKind.UnsignedRem) a b))
;; Rules for `srem` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (srem a @ (value_type ty) b))
(div_or_rem (DivOrRemKind.SignedRem) a b))
;; Rules for `umulhi` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (umulhi a @ (value_type $I16) b))
(let ((res ValueRegs (mul_hi $I16 $false a b))
(hi Gpr (value_regs_get_gpr res 1)))
hi))
(rule (lower (umulhi a @ (value_type $I32) b))
(let ((res ValueRegs (mul_hi $I32 $false a b))
(hi Gpr (value_regs_get_gpr res 1)))
hi))
(rule (lower (umulhi a @ (value_type $I64) b))
(let ((res ValueRegs (mul_hi $I64 $false a b))
(hi Gpr (value_regs_get_gpr res 1)))
hi))
;; Rules for `smulhi` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (smulhi a @ (value_type $I16) b))
(let ((res ValueRegs (mul_hi $I16 $true a b))
(hi Gpr (value_regs_get_gpr res 1)))
hi))
(rule (lower (smulhi a @ (value_type $I32) b))
(let ((res ValueRegs (mul_hi $I32 $true a b))
(hi Gpr (value_regs_get_gpr res 1)))
hi))
(rule (lower (smulhi a @ (value_type $I64) b))
(let ((res ValueRegs (mul_hi $I64 $true a b))
(hi Gpr (value_regs_get_gpr res 1)))
hi))
;; Rules for `get_pinned_reg` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (get_pinned_reg))
(read_pinned_gpr))
;; Rules for `set_pinned_reg` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (set_pinned_reg a @ (value_type ty)))
(side_effect (write_pinned_gpr a)))
;; Rules for `vconst` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type ty (vconst const)))
;; TODO use Inst::gen_constant() instead.
(x64_xmm_load_const ty (const_to_vconst const)))
;; Rules for `raw_bitcast` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; A raw_bitcast is just a mechanism for correcting the type of V128 values (see
;; https://github.com/bytecodealliance/wasmtime/issues/1147). As such, this IR
;; instruction should emit no machine code but a move is necessary to give the
;; register allocator a definition for the output virtual register.
(rule (lower (raw_bitcast val))
(put_in_regs val))
;; Rules for `shuffle` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; If `lhs` and `rhs` are the same we can use a single PSHUFB to shuffle the XMM
;; register. We statically build `constructed_mask` to zero out any unknown lane
;; indices (may not be completely necessary: verification could fail incorrect
;; mask values) and fix the indexes to all point to the `dst` vector.
(rule 3 (lower (shuffle a a (vec_mask_from_immediate mask)))
(x64_pshufb a (x64_xmm_load_const $I8X16 (shuffle_0_31_mask mask))))
;; For the case where the shuffle mask contains out-of-bounds values (values
;; greater than 31) we must mask off those resulting values in the result of
;; `vpermi2b`.
(rule 2 (lower (has_type (and (avx512vl_enabled $true) (avx512vbmi_enabled $true))
(shuffle a b (vec_mask_from_immediate
(perm_from_mask_with_zeros mask zeros)))))
(x64_andps
(x64_xmm_load_const $I8X16 zeros)
(x64_vpermi2b b a (x64_xmm_load_const $I8X16 mask))))
;; However, if the shuffle mask contains no out-of-bounds values, we can use
;; `vpermi2b` without any masking.
(rule 1 (lower (has_type (and (avx512vl_enabled $true) (avx512vbmi_enabled $true))
(shuffle a b (vec_mask_from_immediate mask))))
(x64_vpermi2b b a (x64_xmm_load_const $I8X16 (perm_from_mask mask))))
;; If `lhs` and `rhs` are different, we must shuffle each separately and then OR
;; them together. This is necessary due to PSHUFB semantics. As in the case
;; above, we build the `constructed_mask` for each case statically.
(rule (lower (shuffle a b (vec_mask_from_immediate mask)))
(x64_por
(x64_pshufb a (x64_xmm_load_const $I8X16 (shuffle_0_15_mask mask)))
(x64_pshufb b (x64_xmm_load_const $I8X16 (shuffle_16_31_mask mask)))))
;; Rules for `swizzle` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; SIMD swizzle; the following inefficient implementation is due to the Wasm
;; SIMD spec requiring mask indexes greater than 15 to have the same semantics
;; as a 0 index. For the spec discussion, see
;; https://github.com/WebAssembly/simd/issues/93. The CLIF semantics match the
;; Wasm SIMD semantics for this instruction. The instruction format maps to
;; variables like: %dst = swizzle %src, %mask
(rule (lower (swizzle src mask))
(let ((mask Xmm (x64_paddusb
mask
(x64_xmm_load_const $I8X16 (swizzle_zero_mask)))))
(x64_pshufb src mask)))
;; Rules for `extractlane` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Remove the extractlane instruction, leaving the float where it is. The upper
;; bits will remain unchanged; for correctness, this relies on Cranelift type
;; checking to avoid using those bits.
(rule 2 (lower (has_type (ty_scalar_float _) (extractlane val (u8_from_uimm8 0))))
val)
;; Cases 2-4 for an F32X4
(rule 1 (lower (has_type $F32 (extractlane val @ (value_type (ty_vec128 ty))
(u8_from_uimm8 lane))))
(x64_pshufd val lane (OperandSize.Size32)))
;; This is the only remaining case for F64X2
(rule 1 (lower (has_type $F64 (extractlane val @ (value_type (ty_vec128 ty))
(u8_from_uimm8 1))))
;; 0xee == 0b11_10_11_10
(x64_pshufd val 0xee (OperandSize.Size32)))
(rule 0 (lower (extractlane val @ (value_type ty @ (multi_lane 8 16)) (u8_from_uimm8 lane)))
(x64_pextrb ty val lane))
(rule 0 (lower (extractlane val @ (value_type ty @ (multi_lane 16 8)) (u8_from_uimm8 lane)))
(x64_pextrw ty val lane))
(rule 0 (lower (extractlane val @ (value_type ty @ (multi_lane 32 4)) (u8_from_uimm8 lane)))
(x64_pextrd ty val lane))
(rule 0 (lower (extractlane val @ (value_type ty @ (multi_lane 64 2)) (u8_from_uimm8 lane)))
(x64_pextrd ty val lane))
;; Rules for `scalar_to_vector` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Case 1: when moving a scalar float, we simply move from one XMM register
;; to another, expecting the register allocator to elide this. Here we
;; assume that the upper bits of a scalar float have not been munged with
;; (the same assumption the old backend makes).
(rule 1 (lower (scalar_to_vector src @ (value_type (ty_scalar_float _))))
src)
;; Case 2: when moving a scalar value of any other type, use MOVD to zero
;; the upper lanes.
(rule (lower (scalar_to_vector src @ (value_type ty)))
(bitcast_gpr_to_xmm ty src))
;; Case 3: when presented with `load + scalar_to_vector`, coalesce into a single
;; MOVSS/MOVSD instruction.
(rule 2 (lower (scalar_to_vector (and (sinkable_load src) (value_type (ty_32 _)))))
(x64_movss_load (sink_load_to_xmm_mem src)))
(rule 3 (lower (scalar_to_vector (and (sinkable_load src) (value_type (ty_64 _)))))
(x64_movsd_load (sink_load_to_xmm_mem src)))
;; Rules for `splat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (multi_lane 8 16) (splat src)))
(let ((vec Xmm (vec_insert_lane $I8X16 (xmm_uninit_value) src 0))
(zeros Xmm (x64_pxor vec vec)))
;; Shuffle the lowest byte lane to all other lanes.
(x64_pshufb vec zeros)))
(rule (lower (has_type (multi_lane 16 8) (splat src)))
(let (;; Force the input into a register so that we don't create a
;; VCodeConstant.
(src RegMem (RegMem.Reg src))
(vec Xmm (vec_insert_lane $I16X8 (xmm_uninit_value) src 0))
(vec Xmm (vec_insert_lane $I16X8 vec src 1)))
;; Shuffle the lowest two lanes to all other lanes.
(x64_pshufd vec 0 (OperandSize.Size32))))
(rule 1 (lower (has_type (multi_lane 32 4) (splat src @ (value_type (ty_scalar_float _)))))
(lower_splat_32x4 $F32X4 src))
(rule (lower (has_type (multi_lane 32 4) (splat src)))
(lower_splat_32x4 $I32X4 src))
(decl lower_splat_32x4 (Type Value) Xmm)
(rule (lower_splat_32x4 ty src)
(let ((src RegMem src)
(vec Xmm (vec_insert_lane ty (xmm_uninit_value) src 0)))
;; Shuffle the lowest lane to all other lanes.
(x64_pshufd vec 0 (OperandSize.Size32))))
(rule 1 (lower (has_type (multi_lane 64 2) (splat src @ (value_type (ty_scalar_float _)))))
(lower_splat_64x2 $F64X2 src))
(rule (lower (has_type (multi_lane 64 2) (splat src)))
(lower_splat_64x2 $I64X2 src))
(decl lower_splat_64x2 (Type Value) Xmm)
(rule (lower_splat_64x2 ty src)
(let (;; Force the input into a register so that we don't create a
;; VCodeConstant.
(src RegMem (RegMem.Reg src))
(vec Xmm (vec_insert_lane ty (xmm_uninit_value) src 0)))
(vec_insert_lane ty vec src 1)))
;; Rules for `vany_true` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (vany_true val))
(let ((val Xmm val))
(with_flags (x64_ptest val val) (x64_setcc (CC.NZ)))))
;; Rules for `vall_true` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (vall_true val @ (value_type ty)))
(let ((src Xmm val)
(zeros Xmm (x64_pxor src src))
(cmp Xmm (x64_pcmpeq (vec_int_type ty) src zeros)))
(with_flags (x64_ptest cmp cmp) (x64_setcc (CC.Z)))))
;; Rules for `vhigh_bits` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; The Intel specification allows using both 32-bit and 64-bit GPRs as
;; destination for the "move mask" instructions. This is controlled by the REX.R
;; bit: "In 64-bit mode, the instruction can access additional registers when
;; used with a REX.R prefix. The default operand size is 64-bit in 64-bit mode"
;; (PMOVMSKB in IA Software Development Manual, vol. 2). This being the case, we
;; will always clear REX.W since its use is unnecessary (`OperandSize` is used
;; for setting/clearing REX.W) as we need at most 16 bits of output for
;; `vhigh_bits`.
(rule (lower (vhigh_bits val @ (value_type (multi_lane 8 16))))
(x64_pmovmskb (OperandSize.Size32) val))
(rule (lower (vhigh_bits val @ (value_type (multi_lane 32 4))))
(x64_movmskps (OperandSize.Size32) val))
(rule (lower (vhigh_bits val @ (value_type (multi_lane 64 2))))
(x64_movmskpd (OperandSize.Size32) val))
;; There is no x86 instruction for extracting the high bit of 16-bit lanes so
;; here we:
;; - duplicate the 16-bit lanes of `src` into 8-bit lanes:
;; PACKSSWB([x1, x2, ...], [x1, x2, ...]) = [x1', x2', ..., x1', x2', ...]
;; - use PMOVMSKB to gather the high bits; now we have duplicates, though
;; - shift away the bottom 8 high bits to remove the duplicates.
(rule (lower (vhigh_bits val @ (value_type (multi_lane 16 8))))
(let ((src Xmm val)
(tmp Xmm (x64_packsswb src src))
(tmp Gpr (x64_pmovmskb (OperandSize.Size32) tmp)))
(x64_shr $I64 tmp (Imm8Reg.Imm8 8))))
;; Rules for `iconcat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (iconcat lo @ (value_type $I64) hi))
(value_regs lo hi))
;; Rules for `isplit` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (isplit val @ (value_type $I128)))
(let ((regs ValueRegs val)
(lo Reg (value_regs_get regs 0))
(hi Reg (value_regs_get regs 1)))
(output_pair lo hi)))
;; Rules for `tls_value` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (tls_model (TlsModel.ElfGd)) (tls_value (symbol_value_data name _ _))))
(elf_tls_get_addr name))
(rule (lower (has_type (tls_model (TlsModel.Macho)) (tls_value (symbol_value_data name _ _))))
(macho_tls_get_addr name))
(rule (lower (has_type (tls_model (TlsModel.Coff)) (tls_value (symbol_value_data name _ _))))
(coff_tls_get_addr name))
;; Rules for `sqmul_round_sat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (sqmul_round_sat qx @ (value_type $I16X8) qy))
(let ((src1 Xmm qx)
(src2 Xmm qy)
(mask Xmm (x64_xmm_load_const $I16X8 (sqmul_round_sat_mask)))
(dst Xmm (x64_pmulhrsw src1 src2))
(cmp Xmm (x64_pcmpeqw mask dst)))
(x64_pxor dst cmp)))
;; Rules for `sqmul_round_sat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; TODO: currently we only lower a special case of `uunarrow` needed to support
;; the translation of wasm's i32x4.trunc_sat_f64x2_u_zero operation.
;; https://github.com/bytecodealliance/wasmtime/issues/4791
;;
;; y = i32x4.trunc_sat_f64x2_u_zero(x) is lowered to:
;; MOVAPD xmm_y, xmm_x
;; XORPD xmm_tmp, xmm_tmp
;; MAXPD xmm_y, xmm_tmp
;; MINPD xmm_y, [wasm_f64x2_splat(4294967295.0)]
;; ROUNDPD xmm_y, xmm_y, 0x0B
;; ADDPD xmm_y, [wasm_f64x2_splat(0x1.0p+52)]
;; SHUFPS xmm_y, xmm_xmp, 0x88
(rule (lower (uunarrow (fcvt_to_uint_sat src @ (value_type $F64X2))
(vconst (u128_from_constant 0))))
(let ((src Xmm src)
;; MOVAPD xmm_y, xmm_x
;; XORPD xmm_tmp, xmm_tmp
(zeros Xmm (x64_xorpd src src))
(dst Xmm (x64_maxpd src zeros))
(umax_mask Xmm (x64_xmm_load_const $F64X2 (uunarrow_umax_mask)))
;; MINPD xmm_y, [wasm_f64x2_splat(4294967295.0)]
(dst Xmm (x64_minpd dst umax_mask))
;; ROUNDPD xmm_y, xmm_y, 0x0B
(dst Xmm (x64_roundpd dst (RoundImm.RoundZero)))
;; ADDPD xmm_y, [wasm_f64x2_splat(0x1.0p+52)]
(uint_mask Xmm (x64_xmm_load_const $F64X2 (uunarrow_uint_mask)))
(dst Xmm (x64_addpd dst uint_mask)))
;; SHUFPS xmm_y, xmm_xmp, 0x88
(x64_shufps dst zeros 0x88)))
;; Rules for `nop` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (nop))
(invalid_reg))