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Diffstat (limited to 'vendor/portable-atomic/src/imp/x86.rs')
| -rw-r--r-- | vendor/portable-atomic/src/imp/x86.rs | 227 |
1 files changed, 0 insertions, 227 deletions
diff --git a/vendor/portable-atomic/src/imp/x86.rs b/vendor/portable-atomic/src/imp/x86.rs deleted file mode 100644 index 9ef4d74..0000000 --- a/vendor/portable-atomic/src/imp/x86.rs +++ /dev/null @@ -1,227 +0,0 @@ -// SPDX-License-Identifier: Apache-2.0 OR MIT - -// Atomic operations implementation on x86/x86_64. -// -// This module provides atomic operations not supported by LLVM or optimizes -// cases where LLVM code generation is not optimal. -// -// Note: On Miri and ThreadSanitizer which do not support inline assembly, we don't use -// this module and use CAS loop instead. -// -// Refs: -// - x86 and amd64 instruction reference https://www.felixcloutier.com/x86 -// -// Generated asm: -// - x86_64 https://godbolt.org/z/d17eTs5Ec - -use core::{arch::asm, sync::atomic::Ordering}; - -use super::core_atomic::{ - AtomicI16, AtomicI32, AtomicI64, AtomicI8, AtomicIsize, AtomicU16, AtomicU32, AtomicU64, - AtomicU8, AtomicUsize, -}; - -#[cfg(target_pointer_width = "32")] -macro_rules! ptr_modifier { - () => { - ":e" - }; -} -#[cfg(target_pointer_width = "64")] -macro_rules! ptr_modifier { - () => { - "" - }; -} - -macro_rules! atomic_int { - ($atomic_type:ident, $ptr_size:tt) => { - impl $atomic_type { - #[inline] - pub(crate) fn not(&self, _order: Ordering) { - let dst = self.as_ptr(); - // SAFETY: any data races are prevented by atomic intrinsics and the raw - // pointer passed in is valid because we got it from a reference. - // - // https://www.felixcloutier.com/x86/not - unsafe { - // atomic RMW is always SeqCst. - asm!( - concat!("lock not ", $ptr_size, " ptr [{dst", ptr_modifier!(), "}]"), - dst = in(reg) dst, - options(nostack, preserves_flags), - ); - } - } - #[inline] - pub(crate) fn neg(&self, _order: Ordering) { - let dst = self.as_ptr(); - // SAFETY: any data races are prevented by atomic intrinsics and the raw - // pointer passed in is valid because we got it from a reference. - // - // https://www.felixcloutier.com/x86/neg - unsafe { - // atomic RMW is always SeqCst. - asm!( - concat!("lock neg ", $ptr_size, " ptr [{dst", ptr_modifier!(), "}]"), - dst = in(reg) dst, - // Do not use `preserves_flags` because NEG modifies the CF, OF, SF, ZF, AF, and PF flag. - options(nostack), - ); - } - } - } - }; -} - -atomic_int!(AtomicI8, "byte"); -atomic_int!(AtomicU8, "byte"); -atomic_int!(AtomicI16, "word"); -atomic_int!(AtomicU16, "word"); -atomic_int!(AtomicI32, "dword"); -atomic_int!(AtomicU32, "dword"); -#[cfg(target_arch = "x86_64")] -atomic_int!(AtomicI64, "qword"); -#[cfg(target_arch = "x86_64")] -atomic_int!(AtomicU64, "qword"); -#[cfg(target_pointer_width = "32")] -atomic_int!(AtomicIsize, "dword"); -#[cfg(target_pointer_width = "32")] -atomic_int!(AtomicUsize, "dword"); -#[cfg(target_pointer_width = "64")] -atomic_int!(AtomicIsize, "qword"); -#[cfg(target_pointer_width = "64")] -atomic_int!(AtomicUsize, "qword"); - -#[cfg(target_arch = "x86")] -impl AtomicI64 { - #[inline] - pub(crate) fn not(&self, order: Ordering) { - self.fetch_not(order); - } - #[inline] - pub(crate) fn neg(&self, order: Ordering) { - self.fetch_neg(order); - } -} -#[cfg(target_arch = "x86")] -impl AtomicU64 { - #[inline] - pub(crate) fn not(&self, order: Ordering) { - self.fetch_not(order); - } - #[inline] - pub(crate) fn neg(&self, order: Ordering) { - self.fetch_neg(order); - } -} - -macro_rules! atomic_bit_opts { - ($atomic_type:ident, $int_type:ident, $val_modifier:tt, $ptr_size:tt) => { - // LLVM 14 and older don't support generating `lock bt{s,r,c}`. - // LLVM 15 only supports generating `lock bt{s,r,c}` for immediate bit offsets. - // LLVM 16+ can generate `lock bt{s,r,c}` for both immediate and register bit offsets. - // https://godbolt.org/z/TGhr5z4ds - // So, use fetch_* based implementations on LLVM 16+, otherwise use asm based implementations. - #[cfg(portable_atomic_llvm_16)] - impl_default_bit_opts!($atomic_type, $int_type); - #[cfg(not(portable_atomic_llvm_16))] - impl $atomic_type { - #[inline] - pub(crate) fn bit_set(&self, bit: u32, _order: Ordering) -> bool { - let dst = self.as_ptr(); - // SAFETY: any data races are prevented by atomic intrinsics and the raw - // pointer passed in is valid because we got it from a reference. - // the masking by the bit size of the type ensures that we do not shift - // out of bounds. - // - // https://www.felixcloutier.com/x86/bts - unsafe { - let r: u8; - // atomic RMW is always SeqCst. - asm!( - concat!("lock bts ", $ptr_size, " ptr [{dst", ptr_modifier!(), "}], {bit", $val_modifier, "}"), - "setb {r}", - dst = in(reg) dst, - bit = in(reg) (bit & ($int_type::BITS - 1)) as $int_type, - r = out(reg_byte) r, - // Do not use `preserves_flags` because BTS modifies the CF flag. - options(nostack), - ); - r != 0 - } - } - #[inline] - pub(crate) fn bit_clear(&self, bit: u32, _order: Ordering) -> bool { - let dst = self.as_ptr(); - // SAFETY: any data races are prevented by atomic intrinsics and the raw - // pointer passed in is valid because we got it from a reference. - // the masking by the bit size of the type ensures that we do not shift - // out of bounds. - // - // https://www.felixcloutier.com/x86/btr - unsafe { - let r: u8; - // atomic RMW is always SeqCst. - asm!( - concat!("lock btr ", $ptr_size, " ptr [{dst", ptr_modifier!(), "}], {bit", $val_modifier, "}"), - "setb {r}", - dst = in(reg) dst, - bit = in(reg) (bit & ($int_type::BITS - 1)) as $int_type, - r = out(reg_byte) r, - // Do not use `preserves_flags` because BTR modifies the CF flag. - options(nostack), - ); - r != 0 - } - } - #[inline] - pub(crate) fn bit_toggle(&self, bit: u32, _order: Ordering) -> bool { - let dst = self.as_ptr(); - // SAFETY: any data races are prevented by atomic intrinsics and the raw - // pointer passed in is valid because we got it from a reference. - // the masking by the bit size of the type ensures that we do not shift - // out of bounds. - // - // https://www.felixcloutier.com/x86/btc - unsafe { - let r: u8; - // atomic RMW is always SeqCst. - asm!( - concat!("lock btc ", $ptr_size, " ptr [{dst", ptr_modifier!(), "}], {bit", $val_modifier, "}"), - "setb {r}", - dst = in(reg) dst, - bit = in(reg) (bit & ($int_type::BITS - 1)) as $int_type, - r = out(reg_byte) r, - // Do not use `preserves_flags` because BTC modifies the CF flag. - options(nostack), - ); - r != 0 - } - } - } - }; -} - -impl_default_bit_opts!(AtomicI8, i8); -impl_default_bit_opts!(AtomicU8, u8); -atomic_bit_opts!(AtomicI16, i16, ":x", "word"); -atomic_bit_opts!(AtomicU16, u16, ":x", "word"); -atomic_bit_opts!(AtomicI32, i32, ":e", "dword"); -atomic_bit_opts!(AtomicU32, u32, ":e", "dword"); -#[cfg(target_arch = "x86_64")] -atomic_bit_opts!(AtomicI64, i64, "", "qword"); -#[cfg(target_arch = "x86_64")] -atomic_bit_opts!(AtomicU64, u64, "", "qword"); -#[cfg(target_arch = "x86")] -impl_default_bit_opts!(AtomicI64, i64); -#[cfg(target_arch = "x86")] -impl_default_bit_opts!(AtomicU64, u64); -#[cfg(target_pointer_width = "32")] -atomic_bit_opts!(AtomicIsize, isize, ":e", "dword"); -#[cfg(target_pointer_width = "32")] -atomic_bit_opts!(AtomicUsize, usize, ":e", "dword"); -#[cfg(target_pointer_width = "64")] -atomic_bit_opts!(AtomicIsize, isize, "", "qword"); -#[cfg(target_pointer_width = "64")] -atomic_bit_opts!(AtomicUsize, usize, "", "qword"); |