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// Copyright 2014 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 "src/runtime/runtime-utils.h"
#include "src/arguments.h"
#include "src/assembler.h"
#include "src/base/utils/random-number-generator.h"
#include "src/bootstrapper.h"
#include "src/codegen.h"
#include "src/third_party/fdlibm/fdlibm.h"
namespace v8 {
namespace internal {
#define RUNTIME_UNARY_MATH(Name, name) \
RUNTIME_FUNCTION(Runtime_Math##Name) { \
HandleScope scope(isolate); \
DCHECK(args.length() == 1); \
isolate->counters()->math_##name##_runtime()->Increment(); \
CONVERT_DOUBLE_ARG_CHECKED(x, 0); \
return *isolate->factory()->NewHeapNumber(std::name(x)); \
}
RUNTIME_UNARY_MATH(LogRT, log)
#undef RUNTIME_UNARY_MATH
RUNTIME_FUNCTION(Runtime_DoubleHi) {
HandleScope scope(isolate);
DCHECK(args.length() == 1);
CONVERT_DOUBLE_ARG_CHECKED(x, 0);
uint64_t unsigned64 = double_to_uint64(x);
uint32_t unsigned32 = static_cast<uint32_t>(unsigned64 >> 32);
int32_t signed32 = bit_cast<int32_t, uint32_t>(unsigned32);
return *isolate->factory()->NewNumber(signed32);
}
RUNTIME_FUNCTION(Runtime_DoubleLo) {
HandleScope scope(isolate);
DCHECK(args.length() == 1);
CONVERT_DOUBLE_ARG_CHECKED(x, 0);
uint64_t unsigned64 = double_to_uint64(x);
uint32_t unsigned32 = static_cast<uint32_t>(unsigned64);
int32_t signed32 = bit_cast<int32_t, uint32_t>(unsigned32);
return *isolate->factory()->NewNumber(signed32);
}
RUNTIME_FUNCTION(Runtime_ConstructDouble) {
HandleScope scope(isolate);
DCHECK(args.length() == 2);
CONVERT_NUMBER_CHECKED(uint32_t, hi, Uint32, args[0]);
CONVERT_NUMBER_CHECKED(uint32_t, lo, Uint32, args[1]);
uint64_t result = (static_cast<uint64_t>(hi) << 32) | lo;
return *isolate->factory()->NewNumber(uint64_to_double(result));
}
RUNTIME_FUNCTION(Runtime_RemPiO2) {
SealHandleScope shs(isolate);
DisallowHeapAllocation no_gc;
DCHECK(args.length() == 2);
CONVERT_DOUBLE_ARG_CHECKED(x, 0);
CONVERT_ARG_CHECKED(JSTypedArray, result, 1);
RUNTIME_ASSERT(result->byte_length() == Smi::FromInt(2 * sizeof(double)));
FixedFloat64Array* array = FixedFloat64Array::cast(result->elements());
double* y = static_cast<double*>(array->DataPtr());
return Smi::FromInt(fdlibm::rempio2(x, y));
}
static const double kPiDividedBy4 = 0.78539816339744830962;
RUNTIME_FUNCTION(Runtime_MathAtan2) {
HandleScope scope(isolate);
DCHECK(args.length() == 2);
isolate->counters()->math_atan2_runtime()->Increment();
CONVERT_DOUBLE_ARG_CHECKED(x, 0);
CONVERT_DOUBLE_ARG_CHECKED(y, 1);
double result;
if (std::isinf(x) && std::isinf(y)) {
// Make sure that the result in case of two infinite arguments
// is a multiple of Pi / 4. The sign of the result is determined
// by the first argument (x) and the sign of the second argument
// determines the multiplier: one or three.
int multiplier = (x < 0) ? -1 : 1;
if (y < 0) multiplier *= 3;
result = multiplier * kPiDividedBy4;
} else {
result = std::atan2(x, y);
}
return *isolate->factory()->NewNumber(result);
}
RUNTIME_FUNCTION(Runtime_MathExpRT) {
HandleScope scope(isolate);
DCHECK(args.length() == 1);
isolate->counters()->math_exp_runtime()->Increment();
CONVERT_DOUBLE_ARG_CHECKED(x, 0);
lazily_initialize_fast_exp(isolate);
return *isolate->factory()->NewNumber(fast_exp(x, isolate));
}
// Slow version of Math.pow. We check for fast paths for special cases.
// Used if VFP3 is not available.
RUNTIME_FUNCTION(Runtime_MathPow) {
HandleScope scope(isolate);
DCHECK(args.length() == 2);
isolate->counters()->math_pow_runtime()->Increment();
CONVERT_DOUBLE_ARG_CHECKED(x, 0);
// If the second argument is a smi, it is much faster to call the
// custom powi() function than the generic pow().
if (args[1]->IsSmi()) {
int y = args.smi_at(1);
return *isolate->factory()->NewNumber(power_double_int(x, y));
}
CONVERT_DOUBLE_ARG_CHECKED(y, 1);
double result = power_helper(isolate, x, y);
if (std::isnan(result)) return isolate->heap()->nan_value();
return *isolate->factory()->NewNumber(result);
}
// Fast version of Math.pow if we know that y is not an integer and y is not
// -0.5 or 0.5. Used as slow case from full codegen.
RUNTIME_FUNCTION(Runtime_MathPowRT) {
HandleScope scope(isolate);
DCHECK(args.length() == 2);
isolate->counters()->math_pow_runtime()->Increment();
CONVERT_DOUBLE_ARG_CHECKED(x, 0);
CONVERT_DOUBLE_ARG_CHECKED(y, 1);
if (y == 0) {
return Smi::FromInt(1);
} else {
double result = power_double_double(x, y);
if (std::isnan(result)) return isolate->heap()->nan_value();
return *isolate->factory()->NewNumber(result);
}
}
RUNTIME_FUNCTION(Runtime_GenerateRandomNumbers) {
HandleScope scope(isolate);
DCHECK(args.length() == 1);
if (isolate->serializer_enabled()) {
// Random numbers in the snapshot are not really that random. And we cannot
// return a typed array as it cannot be serialized. To make calling
// Math.random possible when creating a custom startup snapshot, we simply
// return a normal array with a single random number.
Handle<HeapNumber> random_number = isolate->factory()->NewHeapNumber(
isolate->random_number_generator()->NextDouble());
Handle<FixedArray> array_backing = isolate->factory()->NewFixedArray(1);
array_backing->set(0, *random_number);
return *isolate->factory()->NewJSArrayWithElements(array_backing);
}
static const int kState0Offset = 0;
static const int kState1Offset = 1;
static const int kRandomBatchSize = 64;
CONVERT_ARG_HANDLE_CHECKED(Object, maybe_typed_array, 0);
Handle<JSTypedArray> typed_array;
// Allocate typed array if it does not yet exist.
if (maybe_typed_array->IsJSTypedArray()) {
typed_array = Handle<JSTypedArray>::cast(maybe_typed_array);
} else {
static const int kByteLength = kRandomBatchSize * kDoubleSize;
Handle<JSArrayBuffer> buffer =
isolate->factory()->NewJSArrayBuffer(SharedFlag::kNotShared, TENURED);
JSArrayBuffer::SetupAllocatingData(buffer, isolate, kByteLength, true,
SharedFlag::kNotShared);
typed_array = isolate->factory()->NewJSTypedArray(
kExternalFloat64Array, buffer, 0, kRandomBatchSize);
}
DisallowHeapAllocation no_gc;
double* array =
reinterpret_cast<double*>(typed_array->GetBuffer()->backing_store());
// Fetch existing state.
uint64_t state0 = double_to_uint64(array[kState0Offset]);
uint64_t state1 = double_to_uint64(array[kState1Offset]);
// Initialize state if not yet initialized.
while (state0 == 0 || state1 == 0) {
isolate->random_number_generator()->NextBytes(&state0, sizeof(state0));
isolate->random_number_generator()->NextBytes(&state1, sizeof(state1));
}
// Create random numbers.
for (int i = kState1Offset + 1; i < kRandomBatchSize; i++) {
// Generate random numbers using xorshift128+.
base::RandomNumberGenerator::XorShift128(&state0, &state1);
array[i] = base::RandomNumberGenerator::ToDouble(state0, state1);
}
// Persist current state.
array[kState0Offset] = uint64_to_double(state0);
array[kState1Offset] = uint64_to_double(state1);
return *typed_array;
}
} // namespace internal
} // namespace v8
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