Viewing file:  tsan_vector_clock.cpp (3.6 KB) -rw-r--r--
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//===-- tsan_vector_clock.cpp ---------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of ThreadSanitizer (TSan), a race detector.
//
//===----------------------------------------------------------------------===//
#include "tsan_vector_clock.h"
#include "sanitizer_common/sanitizer_placement_new.h"
#include "tsan_mman.h"
namespace __tsan {
#if TSAN_VECTORIZE
const uptr kVectorClockSize = kThreadSlotCount * sizeof(Epoch) / sizeof(m128);
#endif
VectorClock::VectorClock() { Reset(); }
void VectorClock::Reset() {
#if !TSAN_VECTORIZE
for (uptr i = 0; i < kThreadSlotCount; i++)
clk_[i] = kEpochZero;
#else
m128 z = _mm_setzero_si128();
m128* vclk = reinterpret_cast<m128*>(clk_);
for (uptr i = 0; i < kVectorClockSize; i++) _mm_store_si128(&vclk[i], z);
#endif
}
void VectorClock::Acquire(const VectorClock* src) {
if (!src)
return;
#if !TSAN_VECTORIZE
for (uptr i = 0; i < kThreadSlotCount; i++)
clk_[i] = max(clk_[i], src->clk_[i]);
#else
m128* __restrict vdst = reinterpret_cast<m128*>(clk_);
m128 const* __restrict vsrc = reinterpret_cast<m128 const*>(src->clk_);
for (uptr i = 0; i < kVectorClockSize; i++) {
m128 s = _mm_load_si128(&vsrc[i]);
m128 d = _mm_load_si128(&vdst[i]);
m128 m = _mm_max_epu16(s, d);
_mm_store_si128(&vdst[i], m);
}
#endif
}
static VectorClock* AllocClock(VectorClock** dstp) {
if (UNLIKELY(!*dstp))
*dstp = New<VectorClock>();
return *dstp;
}
void VectorClock::Release(VectorClock** dstp) const {
VectorClock* dst = AllocClock(dstp);
dst->Acquire(this);
}
void VectorClock::ReleaseStore(VectorClock** dstp) const {
VectorClock* dst = AllocClock(dstp);
*dst = *this;
}
VectorClock& VectorClock::operator=(const VectorClock& other) {
#if !TSAN_VECTORIZE
for (uptr i = 0; i < kThreadSlotCount; i++)
clk_[i] = other.clk_[i];
#else
m128* __restrict vdst = reinterpret_cast<m128*>(clk_);
m128 const* __restrict vsrc = reinterpret_cast<m128 const*>(other.clk_);
for (uptr i = 0; i < kVectorClockSize; i++) {
m128 s = _mm_load_si128(&vsrc[i]);
_mm_store_si128(&vdst[i], s);
}
#endif
return *this;
}
void VectorClock::ReleaseStoreAcquire(VectorClock** dstp) {
VectorClock* dst = AllocClock(dstp);
#if !TSAN_VECTORIZE
for (uptr i = 0; i < kThreadSlotCount; i++) {
Epoch tmp = dst->clk_[i];
dst->clk_[i] = clk_[i];
clk_[i] = max(clk_[i], tmp);
}
#else
m128* __restrict vdst = reinterpret_cast<m128*>(dst->clk_);
m128* __restrict vclk = reinterpret_cast<m128*>(clk_);
for (uptr i = 0; i < kVectorClockSize; i++) {
m128 t = _mm_load_si128(&vdst[i]);
m128 c = _mm_load_si128(&vclk[i]);
m128 m = _mm_max_epu16(c, t);
_mm_store_si128(&vdst[i], c);
_mm_store_si128(&vclk[i], m);
}
#endif
}
void VectorClock::ReleaseAcquire(VectorClock** dstp) {
VectorClock* dst = AllocClock(dstp);
#if !TSAN_VECTORIZE
for (uptr i = 0; i < kThreadSlotCount; i++) {
dst->clk_[i] = max(dst->clk_[i], clk_[i]);
clk_[i] = dst->clk_[i];
}
#else
m128* __restrict vdst = reinterpret_cast<m128*>(dst->clk_);
m128* __restrict vclk = reinterpret_cast<m128*>(clk_);
for (uptr i = 0; i < kVectorClockSize; i++) {
m128 c = _mm_load_si128(&vclk[i]);
m128 d = _mm_load_si128(&vdst[i]);
m128 m = _mm_max_epu16(c, d);
_mm_store_si128(&vdst[i], m);
_mm_store_si128(&vclk[i], m);
}
#endif
}
} // namespace __tsan
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