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Use SSE3 instructions - if available - for faster To(U)Int32

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conversion in bit operation stubs. Disable serialization
support by default to allow us to use SSE3 instructions and
faster write barrier code when running without snapshot.
Review URL: http://codereview.chromium.org/27046

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1364 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
kasperl@chromium.org 2009-02-25 14:57:46 +00:00
parent 539a29cbd3
commit 1e42e70021
12 changed files with 121 additions and 61 deletions
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1
src/api.cc
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@ -2175,7 +2175,6 @@ bool v8::V8::Initialize() {
if (i::V8::HasBeenSetup()) return true;
HandleScope scope;
if (i::Snapshot::Initialize()) {
i::Serializer::disable();
return true;
} else {
return i::V8::Initialize(NULL);

61
src/assembler-ia32.cc
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@ -69,27 +69,27 @@ XMMRegister xmm7 = { 7 };
// Implementation of CpuFeatures
// Safe default is no features.
uint32_t CpuFeatures::supported_ = 0;
uint32_t CpuFeatures::enabled_ = 0;
uint64_t CpuFeatures::supported_ = 0;
uint64_t CpuFeatures::enabled_ = 0;
typedef int (*F0)();
// The Probe method needs executable memory, so it uses Heap::CreateCode.
// Allocation failure is silent and leads to safe default.
void CpuFeatures::Probe() {
supported_ = 0;
ASSERT(Heap::HasBeenSetup());
ASSERT(supported_ == 0);
if (Serializer::enabled()) return; // No features if we might serialize.
Assembler assm(NULL, 0);
Label done;
Label cpuid, done;
#define __ assm.
// Save old esp, since we are going to modify the stack.
__ push(ebp);
__ pushfd();
__ push(ecx);
__ push(edx);
__ push(ebx);
__ mov(ebp, Operand(esp));
// If we can modify bit 21 of the EFLAGS register, then CPUID is supported.
__ pushfd();
__ pop(eax);
@ -100,34 +100,48 @@ void CpuFeatures::Probe() {
__ pushfd();
__ pop(eax);
__ xor_(eax, Operand(edx)); // Different if CPUID is supported.
__ j(zero, &done);
// Invoke CPUID with 1 in eax to get feature information in edx.
__ j(not_zero, &cpuid);
// CPUID not supported. Clear the supported features in edx:eax.
__ xor_(eax, Operand(eax));
__ xor_(edx, Operand(edx));
__ jmp(&done);
// Invoke CPUID with 1 in eax to get feature information in
// ecx:edx. Temporarily enable CPUID support because we know it's
// safe here.
__ bind(&cpuid);
__ mov(eax, 1);
// Temporarily force CPUID support, since we know it is safe here.
supported_ = (1 << CPUID);
{ Scope fscope(CPUID);
__ cpuid();
}
supported_ = 0;
// Return result in eax.
// Move the result from ecx:edx to edx:eax and make sure to mark the
// CPUID feature as supported.
__ mov(eax, Operand(edx));
__ or_(eax, 1 << CPUID);
__ mov(edx, Operand(ecx));
// Done.
__ bind(&done);
__ mov(esp, Operand(ebp));
__ pop(ebx);
__ pop(edx);
__ pop(ecx);
__ popfd();
__ pop(ebp);
__ ret(0);
#undef __
CodeDesc desc;
assm.GetCode(&desc);
Object* code =
Heap::CreateCode(desc, NULL, Code::ComputeFlags(Code::STUB), NULL);
if (!code->IsCode()) return;
F0 f = FUNCTION_CAST<F0>(Code::cast(code)->entry());
uint32_t res = f();
supported_ = (res | (1 << CPUID));
typedef uint64_t (*F0)();
F0 probe = FUNCTION_CAST<F0>(Code::cast(code)->entry());
supported_ = probe();
}
@ -1614,6 +1628,15 @@ void Assembler::fistp_s(const Operand& adr) {
}
void Assembler::fisttp_s(const Operand& adr) {
ASSERT(CpuFeatures::IsEnabled(CpuFeatures::SSE3));
EnsureSpace ensure_space(this);
last_pc_ = pc_;
EMIT(0xDB);
emit_operand(ecx, adr);
}
void Assembler::fist_s(const Operand& adr) {
EnsureSpace ensure_space(this);
last_pc_ = pc_;
@ -1809,6 +1832,14 @@ void Assembler::frndint() {
}
void Assembler::fnclex() {
EnsureSpace ensure_space(this);
last_pc_ = pc_;
EMIT(0xDB);
EMIT(0xE2);
}
void Assembler::sahf() {
EnsureSpace ensure_space(this);
last_pc_ = pc_;

21
src/assembler-ia32.h
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@ -347,14 +347,18 @@ class CpuFeatures : public AllStatic {
// Feature flags bit positions. They are mostly based on the CPUID spec.
// (We assign CPUID itself to one of the currently reserved bits --
// feel free to change this if needed.)
enum Feature { SSE2 = 26, CMOV = 15, RDTSC = 4, CPUID = 10 };
enum Feature { SSE3 = 32, SSE2 = 26, CMOV = 15, RDTSC = 4, CPUID = 10 };
// Detect features of the target CPU. Set safe defaults if the serializer
// is enabled (snapshots must be portable).
static void Probe();
// Check whether a feature is supported by the target CPU.
static bool IsSupported(Feature f) { return supported_ & (1 << f); }
static bool IsSupported(Feature f) {
return (supported_ & (static_cast<uint64_t>(1) << f)) != 0;
}
// Check whether a feature is currently enabled.
static bool IsEnabled(Feature f) { return enabled_ & (1 << f); }
static bool IsEnabled(Feature f) {
return (enabled_ & (static_cast<uint64_t>(1) << f)) != 0;
}
// Enable a specified feature within a scope.
class Scope BASE_EMBEDDED {
#ifdef DEBUG
@ -362,19 +366,19 @@ class CpuFeatures : public AllStatic {
explicit Scope(Feature f) {
ASSERT(CpuFeatures::IsSupported(f));
old_enabled_ = CpuFeatures::enabled_;
CpuFeatures::enabled_ |= (1 << f);
CpuFeatures::enabled_ |= (static_cast<uint64_t>(1) << f);
}
~Scope() { CpuFeatures::enabled_ = old_enabled_; }
private:
uint32_t old_enabled_;
uint64_t old_enabled_;
#else
public:
explicit Scope(Feature f) {}
#endif
};
private:
static uint32_t supported_;
static uint32_t enabled_;
static uint64_t supported_;
static uint64_t enabled_;
};
@ -635,6 +639,8 @@ class Assembler : public Malloced {
void fistp_s(const Operand& adr);
void fistp_d(const Operand& adr);
void fisttp_s(const Operand& adr);
void fabs();
void fchs();
@ -663,6 +669,7 @@ class Assembler : public Malloced {
void fcompp();
void fnstsw_ax();
void fwait();
void fnclex();
void frndint();

67
src/codegen-ia32.cc
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@ -4507,31 +4507,44 @@ void GenericBinaryOpStub::Generate(MacroAssembler* masm) {
FloatingPointHelper::CheckFloatOperands(masm, &call_runtime, ebx);
FloatingPointHelper::LoadFloatOperands(masm, ecx);
Label non_int32_operands, non_smi_result, skip_allocation;
Label skip_allocation, non_smi_result, operand_conversion_failure;
// Reserve space for converted numbers.
__ sub(Operand(esp), Immediate(2 * kPointerSize));
// Check if right operand is int32.
__ fist_s(Operand(esp, 1 * kPointerSize));
__ fild_s(Operand(esp, 1 * kPointerSize));
__ fucompp();
__ fnstsw_ax();
__ sahf();
__ j(not_zero, &non_int32_operands);
__ j(parity_even, &non_int32_operands);
bool use_sse3 = CpuFeatures::IsSupported(CpuFeatures::SSE3);
if (use_sse3) {
// Truncate the operands to 32-bit integers and check for
// exceptions in doing so.
CpuFeatures::Scope scope(CpuFeatures::SSE3);
__ fisttp_s(Operand(esp, 0 * kPointerSize));
__ fisttp_s(Operand(esp, 1 * kPointerSize));
__ fnstsw_ax();
__ test(eax, Immediate(1));
__ j(not_zero, &operand_conversion_failure);
} else {
// Check if right operand is int32.
__ fist_s(Operand(esp, 0 * kPointerSize));
__ fild_s(Operand(esp, 0 * kPointerSize));
__ fucompp();
__ fnstsw_ax();
__ sahf();
__ j(not_zero, &operand_conversion_failure);
__ j(parity_even, &operand_conversion_failure);
// Check if left operand is int32.
__ fist_s(Operand(esp, 0 * kPointerSize));
__ fild_s(Operand(esp, 0 * kPointerSize));
__ fucompp();
__ fnstsw_ax();
__ sahf();
__ j(not_zero, &non_int32_operands);
__ j(parity_even, &non_int32_operands);
// Check if left operand is int32.
__ fist_s(Operand(esp, 1 * kPointerSize));
__ fild_s(Operand(esp, 1 * kPointerSize));
__ fucompp();
__ fnstsw_ax();
__ sahf();
__ j(not_zero, &operand_conversion_failure);
__ j(parity_even, &operand_conversion_failure);
}
// Get int32 operands and perform bitop.
__ pop(eax);
__ pop(ecx);
__ pop(eax);
switch (op_) {
case Token::BIT_OR: __ or_(eax, Operand(ecx)); break;
case Token::BIT_AND: __ and_(eax, Operand(ecx)); break;
@ -4579,10 +4592,22 @@ void GenericBinaryOpStub::Generate(MacroAssembler* masm) {
__ fstp_d(FieldOperand(eax, HeapNumber::kValueOffset));
__ ret(2 * kPointerSize);
}
__ bind(&non_int32_operands);
// Restore stacks and operands before calling runtime.
__ ffree(0);
// Clear the FPU exception flag and reset the stack before calling
// the runtime system.
__ bind(&operand_conversion_failure);
__ add(Operand(esp), Immediate(2 * kPointerSize));
if (use_sse3) {
// If we've used the SSE3 instructions for truncating the
// floating point values to integers and it failed, we have a
// pending #IA exception. Clear it.
__ fnclex();
} else {
// The non-SSE3 variant does early bailout if the right
// operand isn't a 32-bit integer, so we may have a single
// value on the FPU stack we need to get rid of.
__ ffree(0);
}
// SHR should return uint32 - go to runtime for non-smi/negative result.
if (op_ == Token::SHR) __ bind(&non_smi_result);

3
src/cpu-ia32.cc
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@ -30,11 +30,12 @@
#include "v8.h"
#include "cpu.h"
#include "macro-assembler.h"
namespace v8 { namespace internal {
void CPU::Setup() {
// Nothing to do.
CpuFeatures::Probe();
}

2
src/mksnapshot.cc
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@ -162,6 +162,8 @@ int main(int argc, char** argv) {
const int kExtensionCount = 1;
const char* extension_list[kExtensionCount] = { "v8/gc" };
v8::ExtensionConfiguration extensions(kExtensionCount, extension_list);
i::Serializer::Enable();
v8::Context::New(&extensions);
// Make sure all builtin scripts are cached.

4
src/serialize.cc
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@ -930,7 +930,7 @@ Serializer::~Serializer() {
}
bool Serializer::serialization_enabled_ = true;
bool Serializer::serialization_enabled_ = false;
#ifdef DEBUG
@ -993,7 +993,7 @@ void Serializer::Serialize() {
Heap::IterateRoots(this);
PutLog();
PutContextStack();
disable();
Disable();
}

3
src/serialize.h
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@ -147,7 +147,8 @@ class Serializer: public ObjectVisitor {
static bool enabled() { return serialization_enabled_; }
static void disable() { serialization_enabled_ = false; }
static void Enable() { serialization_enabled_ = true; }
static void Disable() { serialization_enabled_ = false; }
private:
friend class ReferenceUpdater;

8
src/v8.cc
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@ -51,9 +51,6 @@ bool V8::Initialize(Deserializer *des) {
Logger::Setup();
if (des) des->GetLog();
// Setup the CPU support.
CPU::Setup();
// Setup the platform OS support.
OS::Setup();
@ -83,6 +80,11 @@ bool V8::Initialize(Deserializer *des) {
StubCache::Clear();
}
// Setup the CPU support. Must be done after heap setup and after
// any deserialization because we have to have the initial heap
// objects in place for creating the code object used for probing.
CPU::Setup();
return true;
}

8
test/cctest/test-assembler-ia32.cc
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@ -164,8 +164,6 @@ TEST(AssemblerIa323) {
v8::internal::byte buffer[256];
Assembler assm(buffer, sizeof buffer);
Serializer::disable(); // Needed for Probe when running without snapshot.
CpuFeatures::Probe();
CHECK(CpuFeatures::IsSupported(CpuFeatures::SSE2));
{ CpuFeatures::Scope fscope(CpuFeatures::SSE2);
__ cvttss2si(eax, Operand(esp, 4));
@ -197,8 +195,6 @@ TEST(AssemblerIa324) {
v8::internal::byte buffer[256];
Assembler assm(buffer, sizeof buffer);
Serializer::disable(); // Needed for Probe when running without snapshot.
CpuFeatures::Probe();
CHECK(CpuFeatures::IsSupported(CpuFeatures::SSE2));
CpuFeatures::Scope fscope(CpuFeatures::SSE2);
__ cvttsd2si(eax, Operand(esp, 4));
@ -246,8 +242,6 @@ typedef double (*F5)(double x, double y);
TEST(AssemblerIa326) {
InitializeVM();
v8::HandleScope scope;
Serializer::disable(); // Needed for Probe when running without snapshot.
CpuFeatures::Probe();
CHECK(CpuFeatures::IsSupported(CpuFeatures::SSE2));
CpuFeatures::Scope fscope(CpuFeatures::SSE2);
v8::internal::byte buffer[256];
@ -290,8 +284,6 @@ typedef double (*F6)(int x);
TEST(AssemblerIa328) {
InitializeVM();
v8::HandleScope scope;
Serializer::disable(); // Needed for Probe when running without snapshot.
CpuFeatures::Probe();
CHECK(CpuFeatures::IsSupported(CpuFeatures::SSE2));
CpuFeatures::Scope fscope(CpuFeatures::SSE2);
v8::internal::byte buffer[256];

2
test/cctest/test-disasm-ia32.cc
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@ -56,8 +56,6 @@ static void DummyStaticFunction(Object* result) {
TEST(DisasmIa320) {
InitializeVM();
Serializer::disable(); // Needed for Probe when running without snapshot.
CpuFeatures::Probe();
v8::HandleScope scope;
v8::internal::byte buffer[1024];
Assembler assm(buffer, sizeof buffer);

2
test/cctest/test-serialize.cc
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@ -157,6 +157,7 @@ static void Serialize() {
const int kExtensionCount = 1;
const char* extension_list[kExtensionCount] = { "v8/gc" };
v8::ExtensionConfiguration extensions(kExtensionCount, extension_list);
Serializer::Enable();
v8::Persistent<v8::Context> env = v8::Context::New(&extensions);
env->Enter();
@ -187,6 +188,7 @@ TEST(SerializeNondestructive) {
if (Snapshot::IsEnabled()) return;
StatsTable::SetCounterFunction(counter_function);
v8::HandleScope scope;
Serializer::Enable();
v8::Persistent<v8::Context> env = v8::Context::New();
v8::Context::Scope context_scope(env);
Serializer().Serialize();