cranelift_codegen/isa/aarch64/
mod.rs

1//! ARM 64-bit Instruction Set Architecture.
2
3use crate::dominator_tree::DominatorTree;
4use crate::ir::{self, Function, Type};
5use crate::isa::aarch64::settings as aarch64_settings;
6#[cfg(feature = "unwind")]
7use crate::isa::unwind::systemv;
8use crate::isa::{Builder as IsaBuilder, FunctionAlignment, IsaFlagsHashKey, TargetIsa};
9#[cfg(feature = "unwind")]
10use crate::machinst::CompiledCode;
11use crate::machinst::{
12    CompiledCodeStencil, MachInst, MachTextSectionBuilder, Reg, SigSet, TextSectionBuilder, VCode,
13    compile,
14};
15use crate::result::CodegenResult;
16use crate::settings as shared_settings;
17use alloc::string::String;
18use alloc::{boxed::Box, vec::Vec};
19use core::fmt;
20use cranelift_control::ControlPlane;
21#[cfg(feature = "unwind")]
22use target_lexicon::OperatingSystem;
23use target_lexicon::{Aarch64Architecture, Architecture, Triple};
24
25// New backend:
26mod abi;
27pub mod inst;
28mod lower;
29pub mod settings;
30
31use self::inst::EmitInfo;
32
33/// An AArch64 backend.
34pub struct AArch64Backend {
35    triple: Triple,
36    flags: shared_settings::Flags,
37    isa_flags: aarch64_settings::Flags,
38}
39
40impl AArch64Backend {
41    /// Create a new AArch64 backend with the given (shared) flags.
42    pub fn new_with_flags(
43        triple: Triple,
44        flags: shared_settings::Flags,
45        isa_flags: aarch64_settings::Flags,
46    ) -> AArch64Backend {
47        AArch64Backend {
48            triple,
49            flags,
50            isa_flags,
51        }
52    }
53
54    /// This performs lowering to VCode, register-allocates the code, computes block layout and
55    /// finalizes branches. The result is ready for binary emission.
56    fn compile_vcode(
57        &self,
58        func: &Function,
59        domtree: &DominatorTree,
60        ctrl_plane: &mut ControlPlane,
61    ) -> CodegenResult<(VCode<inst::Inst>, regalloc2::Output)> {
62        let emit_info = EmitInfo::new(self.flags.clone(), self.isa_flags.clone());
63        let sigs = SigSet::new::<abi::AArch64MachineDeps>(func, &self.flags)?;
64        let abi = abi::AArch64Callee::new(func, self, &self.isa_flags, &sigs)?;
65        compile::compile::<AArch64Backend>(func, domtree, self, abi, emit_info, sigs, ctrl_plane)
66    }
67}
68
69impl TargetIsa for AArch64Backend {
70    fn compile_function(
71        &self,
72        func: &Function,
73        domtree: &DominatorTree,
74        want_disasm: bool,
75        ctrl_plane: &mut ControlPlane,
76    ) -> CodegenResult<CompiledCodeStencil> {
77        let (vcode, regalloc_result) = self.compile_vcode(func, domtree, ctrl_plane)?;
78
79        let emit_result = vcode.emit(&regalloc_result, want_disasm, &self.flags, ctrl_plane);
80        let value_labels_ranges = emit_result.value_labels_ranges;
81        let buffer = emit_result.buffer;
82
83        if let Some(disasm) = emit_result.disasm.as_ref() {
84            log::debug!("disassembly:\n{disasm}");
85        }
86
87        Ok(CompiledCodeStencil {
88            buffer,
89            vcode: emit_result.disasm,
90            value_labels_ranges,
91            bb_starts: emit_result.bb_offsets,
92            bb_edges: emit_result.bb_edges,
93        })
94    }
95
96    fn name(&self) -> &'static str {
97        "aarch64"
98    }
99
100    fn triple(&self) -> &Triple {
101        &self.triple
102    }
103
104    fn flags(&self) -> &shared_settings::Flags {
105        &self.flags
106    }
107
108    fn isa_flags(&self) -> Vec<shared_settings::Value> {
109        self.isa_flags.iter().collect()
110    }
111
112    fn isa_flags_hash_key(&self) -> IsaFlagsHashKey<'_> {
113        IsaFlagsHashKey(self.isa_flags.hash_key())
114    }
115
116    fn is_branch_protection_enabled(&self) -> bool {
117        self.isa_flags.use_bti()
118    }
119
120    fn dynamic_vector_bytes(&self, _dyn_ty: Type) -> u32 {
121        16
122    }
123
124    #[cfg(feature = "unwind")]
125    fn emit_unwind_info(
126        &self,
127        result: &CompiledCode,
128        kind: crate::isa::unwind::UnwindInfoKind,
129    ) -> CodegenResult<Option<crate::isa::unwind::UnwindInfo>> {
130        use crate::isa::unwind::UnwindInfo;
131        use crate::isa::unwind::UnwindInfoKind;
132        Ok(match kind {
133            UnwindInfoKind::SystemV => {
134                let mapper = self::inst::unwind::systemv::RegisterMapper;
135                Some(UnwindInfo::SystemV(
136                    crate::isa::unwind::systemv::create_unwind_info_from_insts(
137                        &result.buffer.unwind_info[..],
138                        result.buffer.data().len(),
139                        &mapper,
140                    )?,
141                ))
142            }
143            UnwindInfoKind::Windows => Some(UnwindInfo::WindowsArm64(
144                crate::isa::unwind::winarm64::create_unwind_info_from_insts(
145                    &result.buffer.unwind_info[..],
146                )?,
147            )),
148            _ => None,
149        })
150    }
151
152    #[cfg(feature = "unwind")]
153    fn create_systemv_cie(&self) -> Option<gimli::write::CommonInformationEntry> {
154        let is_apple_os = match self.triple.operating_system {
155            OperatingSystem::Darwin(_)
156            | OperatingSystem::IOS(_)
157            | OperatingSystem::MacOSX { .. }
158            | OperatingSystem::TvOS(_) => true,
159            _ => false,
160        };
161
162        if self.isa_flags.sign_return_address()
163            && self.isa_flags.sign_return_address_with_bkey()
164            && !is_apple_os
165        {
166            unimplemented!(
167                "Specifying that the B key is used with pointer authentication instructions in the CIE is not implemented."
168            );
169        }
170
171        Some(inst::unwind::systemv::create_cie())
172    }
173
174    fn text_section_builder(&self, num_funcs: usize) -> Box<dyn TextSectionBuilder> {
175        Box::new(MachTextSectionBuilder::<inst::Inst>::new(num_funcs))
176    }
177
178    #[cfg(feature = "unwind")]
179    fn map_regalloc_reg_to_dwarf(&self, reg: Reg) -> Result<u16, systemv::RegisterMappingError> {
180        inst::unwind::systemv::map_reg(reg).map(|reg| reg.0)
181    }
182
183    fn function_alignment(&self) -> FunctionAlignment {
184        inst::Inst::function_alignment()
185    }
186
187    fn page_size_align_log2(&self) -> u8 {
188        use target_lexicon::*;
189        match self.triple().operating_system {
190            OperatingSystem::MacOSX { .. }
191            | OperatingSystem::Darwin(_)
192            | OperatingSystem::IOS(_)
193            | OperatingSystem::TvOS(_) => {
194                debug_assert_eq!(1 << 14, 0x4000);
195                14
196            }
197            _ => {
198                debug_assert_eq!(1 << 16, 0x10000);
199                16
200            }
201        }
202    }
203
204    #[cfg(feature = "disas")]
205    fn to_capstone(&self) -> Result<capstone::Capstone, capstone::Error> {
206        use capstone::prelude::*;
207        let mut cs = Capstone::new()
208            .arm64()
209            .mode(arch::arm64::ArchMode::Arm)
210            .detail(true)
211            .build()?;
212        // AArch64 uses inline constants rather than a separate constant pool right now.
213        // Without this option, Capstone will stop disassembling as soon as it sees
214        // an inline constant that is not also a valid instruction. With this option,
215        // Capstone will print a `.byte` directive with the bytes of the inline constant
216        // and continue to the next instruction.
217        cs.set_skipdata(true)?;
218        Ok(cs)
219    }
220
221    fn pretty_print_reg(&self, reg: Reg, _size: u8) -> String {
222        inst::regs::pretty_print_reg(reg)
223    }
224
225    fn has_native_fma(&self) -> bool {
226        true
227    }
228
229    fn has_round(&self) -> bool {
230        true
231    }
232
233    fn has_blendv_lowering(&self, _: Type) -> bool {
234        false
235    }
236
237    fn has_x86_pshufb_lowering(&self) -> bool {
238        false
239    }
240
241    fn has_x86_pmulhrsw_lowering(&self) -> bool {
242        false
243    }
244
245    fn has_x86_pmaddubsw_lowering(&self) -> bool {
246        false
247    }
248
249    fn default_argument_extension(&self) -> ir::ArgumentExtension {
250        // This is copied/carried over from a historical piece of code in
251        // Wasmtime:
252        //
253        // https://github.com/bytecodealliance/wasmtime/blob/a018a5a9addb77d5998021a0150192aa955c71bf/crates/cranelift/src/lib.rs#L366-L374
254        //
255        // Whether or not it is still applicable here is unsure, but it's left
256        // the same as-is for now to reduce the likelihood of problems arising.
257        ir::ArgumentExtension::Uext
258    }
259}
260
261impl fmt::Display for AArch64Backend {
262    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
263        f.debug_struct("MachBackend")
264            .field("name", &self.name())
265            .field("triple", &self.triple())
266            .field("flags", &format!("{}", self.flags()))
267            .finish()
268    }
269}
270
271/// Create a new `isa::Builder`.
272pub fn isa_builder(triple: Triple) -> IsaBuilder {
273    assert!(triple.architecture == Architecture::Aarch64(Aarch64Architecture::Aarch64));
274    IsaBuilder {
275        triple,
276        setup: aarch64_settings::builder(),
277        constructor: |triple, shared_flags, builder| {
278            let isa_flags = aarch64_settings::Flags::new(&shared_flags, builder);
279            let backend = AArch64Backend::new_with_flags(triple, shared_flags, isa_flags);
280            Ok(backend.wrapped())
281        },
282    }
283}
cranelift_codegen/isa/aarch64/mod.rs

cranelift_codegen/isa/aarch64/
mod.rs
