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// generated source. do not edit.
#![allow(non_upper_case_globals, unused_macros, unused_imports)]
use crate::low::macros::*;
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0 OR ISC OR MIT-0
// ----------------------------------------------------------------------------
// Given table: uint64_t[height*width], copy table[idx*width...(idx+1)*width-1]
// into z[0..width-1]. width must be a multiple of 8.
// This function is constant-time with respect to the value of `idx`. This is
// achieved by reading the whole table and using the bit-masking to get the
// `idx`-th row.
//
// extern void bignum_copy_row_from_table_8n
// (uint64_t *z, const uint64_t *table, uint64_t height, uint64_t width, uint64_t idx);
//
// Standard ARM ABI: X0 = z, X1 = table, X2 = height, X3 = width, X4 = idx
// ----------------------------------------------------------------------------
macro_rules! z {
() => {
"x0"
};
}
macro_rules! table {
() => {
"x1"
};
}
macro_rules! height {
() => {
"x2"
};
}
macro_rules! width {
() => {
"x3"
};
}
macro_rules! idx {
() => {
"x4"
};
}
macro_rules! i {
() => {
"x5"
};
}
macro_rules! mask {
() => {
"x6"
};
}
macro_rules! j {
() => {
"x7"
};
}
macro_rules! vmask {
() => {
"v16"
};
}
/// Given table: uint64_t[height*width], copy table[idx*width...(idx+1)*width-1]
///
/// into z[0..width-1]. width must be a multiple of 8.
/// This function is constant-time with respect to the value of `idx`. This is
/// achieved by reading the whole table and using the bit-masking to get the
/// `idx`-th row.
pub(crate) fn bignum_copy_row_from_table_8n(
z: &mut [u64],
table: &[u64],
height: u64,
width: u64,
index: u64,
) {
debug_assert!(z.len() as u64 == width);
debug_assert!(width.is_multiple_of(8));
// SAFETY: inline assembly. see [crate::low::inline_assembly_safety] for safety info.
unsafe {
core::arch::asm!(
Q!(" cbz " height!() ", " Label!("bignum_copy_row_from_table_8n_end", 2, After)),
Q!(" cbz " width!() ", " Label!("bignum_copy_row_from_table_8n_end", 2, After)),
Q!(" mov " i!() ", " width!()),
Q!(" mov " "x6, " z!()),
Q!(" dup " "v16.2d, xzr"),
Q!(Label!("bignum_copy_row_from_table_8n_initzero", 3) ":"),
Q!(" str " "q16, [x6]"),
Q!(" str " "q16, [x6, #16]"),
Q!(" str " "q16, [x6, #32]"),
Q!(" str " "q16, [x6, #48]"),
Q!(" add " "x6, x6, #64"),
Q!(" subs " i!() ", " i!() ", #8"),
Q!(" bne " Label!("bignum_copy_row_from_table_8n_initzero", 3, Before)),
Q!(" mov " i!() ", xzr"),
Q!(" mov " "x8, " table!()),
Q!(Label!("bignum_copy_row_from_table_8n_outerloop", 4) ":"),
Q!(" cmp " i!() ", " idx!()),
Q!(" csetm " mask!() ", eq"),
Q!(" dup " vmask!() ".2d, " mask!()),
Q!(" mov " j!() ", " width!()),
Q!(" mov " "x9, " z!()),
Q!(Label!("bignum_copy_row_from_table_8n_innerloop", 5) ":"),
Q!(" ldr " "q17, [x8]"),
Q!(" ldr " "q18, [x9]"),
Q!(" bit " "v18.16b, v17.16b, " vmask!() ".16b"),
Q!(" str " "q18, [x9]"),
Q!(" ldr " "q17, [x8, #16]"),
Q!(" ldr " "q18, [x9, #16]"),
Q!(" bit " "v18.16b, v17.16b, " vmask!() ".16b"),
Q!(" str " "q18, [x9, #16]"),
Q!(" ldr " "q17, [x8, #32]"),
Q!(" ldr " "q18, [x9, #32]"),
Q!(" bit " "v18.16b, v17.16b, " vmask!() ".16b"),
Q!(" str " "q18, [x9, #32]"),
Q!(" ldr " "q17, [x8, #48]"),
Q!(" ldr " "q18, [x9, #48]"),
Q!(" bit " "v18.16b, v17.16b, " vmask!() ".16b"),
Q!(" str " "q18, [x9, #48]"),
Q!(" add " "x8, x8, #64"),
Q!(" add " "x9, x9, #64"),
Q!(" subs " j!() ", " j!() ", #8"),
Q!(" bne " Label!("bignum_copy_row_from_table_8n_innerloop", 5, Before)),
Q!(Label!("bignum_copy_row_from_table_8n_innerloop_done", 6) ":"),
Q!(" add " i!() ", " i!() ", #1"),
Q!(" cmp " i!() ", " height!()),
Q!(" bne " Label!("bignum_copy_row_from_table_8n_outerloop", 4, Before)),
Q!(Label!("bignum_copy_row_from_table_8n_end", 2) ":"),
inout("x0") z.as_mut_ptr() => _,
inout("x1") table.as_ptr() => _,
inout("x2") height => _,
inout("x3") width => _,
inout("x4") index => _,
// clobbers
out("v16") _,
out("v17") _,
out("v18") _,
out("x5") _,
out("x6") _,
out("x7") _,
out("x8") _,
out("x9") _,
)
};
}