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// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <math.h>
#include <stdint.h>
#include <stdlib.h>
#include <limits>
#include "include/v8config.h"
#include "src/base/bits.h"
#include "src/base/ieee754.h"
#include "src/utils/memcopy.h"
#if defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER) || \
defined(THREAD_SANITIZER) || defined(LEAK_SANITIZER) || \
defined(UNDEFINED_SANITIZER)
#define V8_WITH_SANITIZER
#endif
#if defined(V8_OS_WIN) && defined(V8_WITH_SANITIZER)
// With ASAN on Windows we have to reset the thread-in-wasm flag. Exceptions
// caused by ASAN let the thread-in-wasm flag get out of sync. Even marking
// functions with DISABLE_ASAN is not sufficient when the compiler produces
// calls to memset. Therefore we add test-specific code for ASAN on
// Windows.
#define RESET_THREAD_IN_WASM_FLAG_FOR_ASAN_ON_WINDOWS
#include "src/trap-handler/trap-handler.h"
#endif
#include "src/common/v8memory.h"
#include "src/utils/utils.h"
#include "src/wasm/wasm-external-refs.h"
namespace v8 {
namespace internal {
namespace wasm {
void f32_trunc_wrapper(Address data) {
WriteUnalignedValue<float>(data, truncf(ReadUnalignedValue<float>(data)));
}
void f32_floor_wrapper(Address data) {
WriteUnalignedValue<float>(data, floorf(ReadUnalignedValue<float>(data)));
}
void f32_ceil_wrapper(Address data) {
WriteUnalignedValue<float>(data, ceilf(ReadUnalignedValue<float>(data)));
}
void f32_nearest_int_wrapper(Address data) {
WriteUnalignedValue<float>(data, nearbyintf(ReadUnalignedValue<float>(data)));
}
void f64_trunc_wrapper(Address data) {
WriteUnalignedValue<double>(data, trunc(ReadUnalignedValue<double>(data)));
}
void f64_floor_wrapper(Address data) {
WriteUnalignedValue<double>(data, floor(ReadUnalignedValue<double>(data)));
}
void f64_ceil_wrapper(Address data) {
WriteUnalignedValue<double>(data, ceil(ReadUnalignedValue<double>(data)));
}
void f64_nearest_int_wrapper(Address data) {
WriteUnalignedValue<double>(data,
nearbyint(ReadUnalignedValue<double>(data)));
}
void int64_to_float32_wrapper(Address data) {
int64_t input = ReadUnalignedValue<int64_t>(data);
WriteUnalignedValue<float>(data, static_cast<float>(input));
}
void uint64_to_float32_wrapper(Address data) {
uint64_t input = ReadUnalignedValue<uint64_t>(data);
float result = static_cast<float>(input);
#if V8_CC_MSVC
// With MSVC we use static_cast<float>(uint32_t) instead of
// static_cast<float>(uint64_t) to achieve round-to-nearest-ties-even
// semantics. The idea is to calculate
// static_cast<float>(high_word) * 2^32 + static_cast<float>(low_word). To
// achieve proper rounding in all cases we have to adjust the high_word
// with a "rounding bit" sometimes. The rounding bit is stored in the LSB of
// the high_word if the low_word may affect the rounding of the high_word.
uint32_t low_word = static_cast<uint32_t>(input & 0xFFFFFFFF);
uint32_t high_word = static_cast<uint32_t>(input >> 32);
float shift = static_cast<float>(1ull << 32);
// If the MSB of the high_word is set, then we make space for a rounding bit.
if (high_word < 0x80000000) {
high_word <<= 1;
shift = static_cast<float>(1ull << 31);
}
if ((high_word & 0xFE000000) && low_word) {
// Set the rounding bit.
high_word |= 1;
}
result = static_cast<float>(high_word);
result *= shift;
result += static_cast<float>(low_word);
#endif
WriteUnalignedValue<float>(data, result);
}
void int64_to_float64_wrapper(Address data) {
int64_t input = ReadUnalignedValue<int64_t>(data);
WriteUnalignedValue<double>(data, static_cast<double>(input));
}
void uint64_to_float64_wrapper(Address data) {
uint64_t input = ReadUnalignedValue<uint64_t>(data);
double result = static_cast<double>(input);
#if V8_CC_MSVC
// With MSVC we use static_cast<double>(uint32_t) instead of
// static_cast<double>(uint64_t) to achieve round-to-nearest-ties-even
// semantics. The idea is to calculate
// static_cast<double>(high_word) * 2^32 + static_cast<double>(low_word).
uint32_t low_word = static_cast<uint32_t>(input & 0xFFFFFFFF);
uint32_t high_word = static_cast<uint32_t>(input >> 32);
double shift = static_cast<double>(1ull << 32);
result = static_cast<double>(high_word);
result *= shift;
result += static_cast<double>(low_word);
#endif
WriteUnalignedValue<double>(data, result);
}
int32_t float32_to_int64_wrapper(Address data) {
// We use "<" here to check the upper bound because of rounding problems: With
// "<=" some inputs would be considered within int64 range which are actually
// not within int64 range.
float input = ReadUnalignedValue<float>(data);
if (input >= static_cast<float>(std::numeric_limits<int64_t>::min()) &&
input < static_cast<float>(std::numeric_limits<int64_t>::max())) {
WriteUnalignedValue<int64_t>(data, static_cast<int64_t>(input));
return 1;
}
return 0;
}
int32_t float32_to_uint64_wrapper(Address data) {
float input = ReadUnalignedValue<float>(data);
// We use "<" here to check the upper bound because of rounding problems: With
// "<=" some inputs would be considered within uint64 range which are actually
// not within uint64 range.
if (input > -1.0 &&
input < static_cast<float>(std::numeric_limits<uint64_t>::max())) {
WriteUnalignedValue<uint64_t>(data, static_cast<uint64_t>(input));
return 1;
}
return 0;
}
int32_t float64_to_int64_wrapper(Address data) {
// We use "<" here to check the upper bound because of rounding problems: With
// "<=" some inputs would be considered within int64 range which are actually
// not within int64 range.
double input = ReadUnalignedValue<double>(data);
if (input >= static_cast<double>(std::numeric_limits<int64_t>::min()) &&
input < static_cast<double>(std::numeric_limits<int64_t>::max())) {
WriteUnalignedValue<int64_t>(data, static_cast<int64_t>(input));
return 1;
}
return 0;
}
int32_t float64_to_uint64_wrapper(Address data) {
// We use "<" here to check the upper bound because of rounding problems: With
// "<=" some inputs would be considered within uint64 range which are actually
// not within uint64 range.
double input = ReadUnalignedValue<double>(data);
if (input > -1.0 &&
input < static_cast<double>(std::numeric_limits<uint64_t>::max())) {
WriteUnalignedValue<uint64_t>(data, static_cast<uint64_t>(input));
return 1;
}
return 0;
}
int32_t int64_div_wrapper(Address data) {
int64_t dividend = ReadUnalignedValue<int64_t>(data);
int64_t divisor = ReadUnalignedValue<int64_t>(data + sizeof(dividend));
if (divisor == 0) {
return 0;
}
if (divisor == -1 && dividend == std::numeric_limits<int64_t>::min()) {
return -1;
}
WriteUnalignedValue<int64_t>(data, dividend / divisor);
return 1;
}
int32_t int64_mod_wrapper(Address data) {
int64_t dividend = ReadUnalignedValue<int64_t>(data);
int64_t divisor = ReadUnalignedValue<int64_t>(data + sizeof(dividend));
if (divisor == 0) {
return 0;
}
WriteUnalignedValue<int64_t>(data, dividend % divisor);
return 1;
}
int32_t uint64_div_wrapper(Address data) {
uint64_t dividend = ReadUnalignedValue<uint64_t>(data);
uint64_t divisor = ReadUnalignedValue<uint64_t>(data + sizeof(dividend));
if (divisor == 0) {
return 0;
}
WriteUnalignedValue<uint64_t>(data, dividend / divisor);
return 1;
}
int32_t uint64_mod_wrapper(Address data) {
uint64_t dividend = ReadUnalignedValue<uint64_t>(data);
uint64_t divisor = ReadUnalignedValue<uint64_t>(data + sizeof(dividend));
if (divisor == 0) {
return 0;
}
WriteUnalignedValue<uint64_t>(data, dividend % divisor);
return 1;
}
uint32_t word32_ctz_wrapper(Address data) {
return base::bits::CountTrailingZeros(ReadUnalignedValue<uint32_t>(data));
}
uint32_t word64_ctz_wrapper(Address data) {
return base::bits::CountTrailingZeros(ReadUnalignedValue<uint64_t>(data));
}
uint32_t word32_popcnt_wrapper(Address data) {
return base::bits::CountPopulation(ReadUnalignedValue<uint32_t>(data));
}
uint32_t word64_popcnt_wrapper(Address data) {
return base::bits::CountPopulation(ReadUnalignedValue<uint64_t>(data));
}
uint32_t word32_rol_wrapper(Address data) {
uint32_t input = ReadUnalignedValue<uint32_t>(data);
uint32_t shift = ReadUnalignedValue<uint32_t>(data + sizeof(input)) & 31;
return (input << shift) | (input >> ((32 - shift) & 31));
}
uint32_t word32_ror_wrapper(Address data) {
uint32_t input = ReadUnalignedValue<uint32_t>(data);
uint32_t shift = ReadUnalignedValue<uint32_t>(data + sizeof(input)) & 31;
return (input >> shift) | (input << ((32 - shift) & 31));
}
void float64_pow_wrapper(Address data) {
double x = ReadUnalignedValue<double>(data);
double y = ReadUnalignedValue<double>(data + sizeof(x));
WriteUnalignedValue<double>(data, base::ieee754::pow(x, y));
}
// Asan on Windows triggers exceptions in this function to allocate
// shadow memory lazily. When this function is called from WebAssembly,
// these exceptions would be handled by the trap handler before they get
// handled by Asan, and thereby confuse the thread-in-wasm flag.
// Therefore we disable ASAN for this function. Alternatively we could
// reset the thread-in-wasm flag before calling this function. However,
// as this is only a problem with Asan on Windows, we did not consider
// it worth the overhead.
DISABLE_ASAN void memory_copy_wrapper(Address dst, Address src, uint32_t size) {
// Use explicit forward and backward copy to match the required semantics for
// the memory.copy instruction. It is assumed that the caller of this
// function has already performed bounds checks, so {src + size} and
// {dst + size} should not overflow.
DCHECK(src + size >= src && dst + size >= dst);
uint8_t* dst8 = reinterpret_cast<uint8_t*>(dst);
uint8_t* src8 = reinterpret_cast<uint8_t*>(src);
if (src < dst && src + size > dst && dst + size > src) {
dst8 += size - 1;
src8 += size - 1;
for (; size > 0; size--) {
*dst8-- = *src8--;
}
} else {
for (; size > 0; size--) {
*dst8++ = *src8++;
}
}
}
// Asan on Windows triggers exceptions in this function that confuse the
// WebAssembly trap handler, so Asan is disabled. See the comment on
// memory_copy_wrapper above for more info.
void memory_fill_wrapper(Address dst, uint32_t value, uint32_t size) {
#if defined(RESET_THREAD_IN_WASM_FLAG_FOR_ASAN_ON_WINDOWS)
bool thread_was_in_wasm = trap_handler::IsThreadInWasm();
if (thread_was_in_wasm) {
trap_handler::ClearThreadInWasm();
}
#endif
// Use an explicit forward copy to match the required semantics for the
// memory.fill instruction. It is assumed that the caller of this function
// has already performed bounds checks, so {dst + size} should not overflow.
DCHECK(dst + size >= dst);
uint8_t* dst8 = reinterpret_cast<uint8_t*>(dst);
uint8_t value8 = static_cast<uint8_t>(value);
for (; size > 0; size--) {
*dst8++ = value8;
}
#if defined(RESET_THREAD_IN_WASM_FLAG_FOR_ASAN_ON_WINDOWS)
if (thread_was_in_wasm) {
trap_handler::SetThreadInWasm();
}
#endif
}
static WasmTrapCallbackForTesting wasm_trap_callback_for_testing = nullptr;
void set_trap_callback_for_testing(WasmTrapCallbackForTesting callback) {
wasm_trap_callback_for_testing = callback;
}
void call_trap_callback_for_testing() {
if (wasm_trap_callback_for_testing) {
wasm_trap_callback_for_testing();
}
}
} // namespace wasm
} // namespace internal
} // namespace v8
#undef V8_WITH_SANITIZER
#undef RESET_THREAD_IN_WASM_FLAG_FOR_ASAN_ON_WINDOWS