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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
// ----------------------------------------------------------------------------
// Negate modulo p_521, z := (-x) mod p_521, assuming x reduced
// Input x[9]; output z[9]
//
// extern void bignum_neg_p521(uint64_t z[static 9], const uint64_t x[static 9]);
//
// Standard x86-64 ABI: RDI = z, RSI = x
// Microsoft x64 ABI: RCX = z, RDX = x
// ----------------------------------------------------------------------------
macro_rules! z {
() => {
"rdi"
};
}
macro_rules! x {
() => {
"rsi"
};
}
macro_rules! p {
() => {
"rax"
};
}
macro_rules! d0 {
() => {
"rcx"
};
}
macro_rules! d1 {
() => {
"rdx"
};
}
macro_rules! d2 {
() => {
"r8"
};
}
macro_rules! d3 {
() => {
"r9"
};
}
macro_rules! d4 {
() => {
"r10"
};
}
macro_rules! d5 {
() => {
"r11"
};
}
/// Negate modulo p_521, z := (-x) mod p_521, assuming x reduced
///
/// Input x[9]; output z[9]
pub(crate) fn bignum_neg_p521(z: &mut [u64; 9], x: &[u64; 9]) {
// SAFETY: inline assembly. see [crate::low::inline_assembly_safety] for safety info.
unsafe {
core::arch::asm!(
Q!(" endbr64 " ),
// Load most inputs (into the limited registers) and OR all of them to get p
Q!(" mov " d0!() ", [" x!() "]"),
Q!(" mov " p!() ", " d0!()),
Q!(" mov " d1!() ", [" x!() "+ 8]"),
Q!(" or " p!() ", " d1!()),
Q!(" mov " d2!() ", [" x!() "+ 16]"),
Q!(" or " p!() ", " d2!()),
Q!(" mov " d3!() ", [" x!() "+ 24]"),
Q!(" or " p!() ", " d3!()),
Q!(" mov " d4!() ", [" x!() "+ 32]"),
Q!(" or " p!() ", " d4!()),
Q!(" mov " d5!() ", [" x!() "+ 40]"),
Q!(" or " p!() ", " d5!()),
Q!(" or " p!() ", [" x!() "+ 48]"),
Q!(" or " p!() ", [" x!() "+ 56]"),
Q!(" or " p!() ", [" x!() "+ 64]"),
// Turn p into a bitmask for "input is nonzero", so that we avoid doing
// -0 = p_521 and hence maintain strict modular reduction
Q!(" neg " p!()),
Q!(" sbb " p!() ", " p!()),
// Since p_521 is all 1s, the subtraction is just an exclusive-or with p
// to give an optional inversion, with a slight fiddle for the top digit.
Q!(" xor " d0!() ", " p!()),
Q!(" mov " "[" z!() "], " d0!()),
Q!(" xor " d1!() ", " p!()),
Q!(" mov " "[" z!() "+ 8], " d1!()),
Q!(" xor " d2!() ", " p!()),
Q!(" mov " "[" z!() "+ 16], " d2!()),
Q!(" xor " d3!() ", " p!()),
Q!(" mov " "[" z!() "+ 24], " d3!()),
Q!(" xor " d4!() ", " p!()),
Q!(" mov " "[" z!() "+ 32], " d4!()),
Q!(" xor " d5!() ", " p!()),
Q!(" mov " "[" z!() "+ 40], " d5!()),
Q!(" mov " d0!() ", [" x!() "+ 48]"),
Q!(" xor " d0!() ", " p!()),
Q!(" mov " "[" z!() "+ 48], " d0!()),
Q!(" mov " d1!() ", [" x!() "+ 56]"),
Q!(" xor " d1!() ", " p!()),
Q!(" mov " "[" z!() "+ 56], " d1!()),
Q!(" mov " d2!() ", [" x!() "+ 64]"),
Q!(" and " p!() ", 0x1FF"),
Q!(" xor " d2!() ", " p!()),
Q!(" mov " "[" z!() "+ 64], " d2!()),
// Return
inout("rdi") z.as_mut_ptr() => _,
inout("rsi") x.as_ptr() => _,
// clobbers
out("r10") _,
out("r11") _,
out("r8") _,
out("r9") _,
out("rax") _,
out("rcx") _,
out("rdx") _,
)
};
}