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[libc] deprecate LLVM_LIBC_MEMCPY_X86_USE_ONLY_REPMOVSB 

Differential Revision: https://reviews.llvm.org/D136693
This commit is contained in:
Guillaume Chatelet 2022-10-25 15:18:46 +00:00
parent 534f4bca58
commit fe8d211f1a
1 changed files with 6 additions and 5 deletions
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11
libc/src/string/memory_utils/memcpy_implementations.h
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@ -65,18 +65,19 @@ inline_memcpy_x86_maybe_interpose_repmovsb(Ptr __restrict dst,
CPtr __restrict src, size_t count) {
// Whether to use rep;movsb exclusively, not at all, or only above a certain
// threshold.
// TODO: Use only a single preprocessor definition to simplify the code.
#ifndef LLVM_LIBC_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE
#define LLVM_LIBC_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE -1
#endif
static constexpr bool kUseOnlyRepMovsb =
LLVM_LIBC_IS_DEFINED(LLVM_LIBC_MEMCPY_X86_USE_ONLY_REPMOVSB);
#ifdef LLVM_LIBC_MEMCPY_X86_USE_ONLY_REPMOVSB
#error LLVM_LIBC_MEMCPY_X86_USE_ONLY_REPMOVSB is deprecated use LLVM_LIBC_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE=0 instead.
#endif // LLVM_LIBC_MEMCPY_X86_USE_ONLY_REPMOVSB
static constexpr size_t kRepMovsbThreshold =
LLVM_LIBC_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE;
if constexpr (kUseOnlyRepMovsb)
if constexpr (kRepMovsbThreshold == 0)
return x86::Memcpy::repmovsb(dst, src, count);
else if constexpr (kRepMovsbThreshold >= 0) {
else if constexpr (kRepMovsbThreshold > 0) {
if (unlikely(count >= kRepMovsbThreshold))
return x86::Memcpy::repmovsb(dst, src, count);
else