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Improved code for megamorphic stub on ia32.

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Review URL: http://codereview.chromium.org/150225

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2342 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
bak@chromium.org 2009-07-03 06:34:59 +00:00
parent c15df35204
commit 6bc979e879
3 changed files with 62 additions and 30 deletions
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8
src/ia32/ic-ia32.cc
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@ -437,7 +437,7 @@ void CallIC::GenerateMegamorphic(MacroAssembler* masm, int argc) {
// Probe the stub cache.
Code::Flags flags =
Code::ComputeFlags(Code::CALL_IC, NOT_IN_LOOP, MONOMORPHIC, NORMAL, argc);
StubCache::GenerateProbe(masm, flags, edx, ecx, ebx);
StubCache::GenerateProbe(masm, flags, edx, ecx, ebx, eax);
// If the stub cache probing failed, the receiver might be a value.
// For value objects, we use the map of the prototype objects for
@ -474,7 +474,7 @@ void CallIC::GenerateMegamorphic(MacroAssembler* masm, int argc) {
// Probe the stub cache for the value object.
__ bind(&probe);
StubCache::GenerateProbe(masm, flags, edx, ecx, ebx);
StubCache::GenerateProbe(masm, flags, edx, ecx, ebx, no_reg);
// Cache miss: Jump to runtime.
__ bind(&miss);
@ -648,7 +648,7 @@ void LoadIC::GenerateMegamorphic(MacroAssembler* masm) {
Code::Flags flags = Code::ComputeFlags(Code::LOAD_IC,
NOT_IN_LOOP,
MONOMORPHIC);
StubCache::GenerateProbe(masm, flags, eax, ecx, ebx);
StubCache::GenerateProbe(masm, flags, eax, ecx, ebx, edx);
// Cache miss: Jump to runtime.
Generate(masm, ExternalReference(IC_Utility(kLoadIC_Miss)));
@ -878,7 +878,7 @@ void StoreIC::GenerateMegamorphic(MacroAssembler* masm) {
Code::Flags flags = Code::ComputeFlags(Code::STORE_IC,
NOT_IN_LOOP,
MONOMORPHIC);
StubCache::GenerateProbe(masm, flags, edx, ecx, ebx);
StubCache::GenerateProbe(masm, flags, edx, ecx, ebx, no_reg);
// Cache miss: Jump to runtime.
Generate(masm, ExternalReference(IC_Utility(kStoreIC_Miss)));

80
src/ia32/stub-cache-ia32.cc
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@ -41,39 +41,61 @@ static void ProbeTable(MacroAssembler* masm,
Code::Flags flags,
StubCache::Table table,
Register name,
Register offset) {
Register offset,
Register extra) {
ExternalReference key_offset(SCTableReference::keyReference(table));
ExternalReference value_offset(SCTableReference::valueReference(table));
Label miss;
// Save the offset on the stack.
__ push(offset);
if (extra.is_valid()) {
// Get the code entry from the cache.
__ mov(extra, Operand::StaticArray(offset, times_2, value_offset));
// Check that the key in the entry matches the name.
__ cmp(name, Operand::StaticArray(offset, times_2, key_offset));
__ j(not_equal, &miss, not_taken);
// Check that the key in the entry matches the name.
__ cmp(name, Operand::StaticArray(offset, times_2, key_offset));
__ j(not_equal, &miss, not_taken);
// Get the code entry from the cache.
__ mov(offset, Operand::StaticArray(offset, times_2, value_offset));
// Check that the flags match what we're looking for.
__ mov(offset, FieldOperand(extra, Code::kFlagsOffset));
__ and_(offset, ~Code::kFlagsNotUsedInLookup);
__ cmp(offset, flags);
__ j(not_equal, &miss);
// Check that the flags match what we're looking for.
__ mov(offset, FieldOperand(offset, Code::kFlagsOffset));
__ and_(offset, ~Code::kFlagsNotUsedInLookup);
__ cmp(offset, flags);
__ j(not_equal, &miss);
// Jump to the first instruction in the code stub.
__ add(Operand(extra), Immediate(Code::kHeaderSize - kHeapObjectTag));
__ jmp(Operand(extra));
// Restore offset and re-load code entry from cache.
__ pop(offset);
__ mov(offset, Operand::StaticArray(offset, times_2, value_offset));
__ bind(&miss);
} else {
// Save the offset on the stack.
__ push(offset);
// Jump to the first instruction in the code stub.
__ add(Operand(offset), Immediate(Code::kHeaderSize - kHeapObjectTag));
__ jmp(Operand(offset));
// Check that the key in the entry matches the name.
__ cmp(name, Operand::StaticArray(offset, times_2, key_offset));
__ j(not_equal, &miss, not_taken);
// Miss: Restore offset and fall through.
__ bind(&miss);
__ pop(offset);
// Get the code entry from the cache.
__ mov(offset, Operand::StaticArray(offset, times_2, value_offset));
// Check that the flags match what we're looking for.
__ mov(offset, FieldOperand(offset, Code::kFlagsOffset));
__ and_(offset, ~Code::kFlagsNotUsedInLookup);
__ cmp(offset, flags);
__ j(not_equal, &miss);
// Restore offset and re-load code entry from cache.
__ pop(offset);
__ mov(offset, Operand::StaticArray(offset, times_2, value_offset));
// Jump to the first instruction in the code stub.
__ add(Operand(offset), Immediate(Code::kHeaderSize - kHeapObjectTag));
__ jmp(Operand(offset));
// Pop at miss.
__ bind(&miss);
__ pop(offset);
}
}
@ -81,7 +103,8 @@ void StubCache::GenerateProbe(MacroAssembler* masm,
Code::Flags flags,
Register receiver,
Register name,
Register scratch) {
Register scratch,
Register extra) {
Label miss;
// Make sure that code is valid. The shifting code relies on the
@ -94,6 +117,9 @@ void StubCache::GenerateProbe(MacroAssembler* masm,
// Make sure that there are no register conflicts.
ASSERT(!scratch.is(receiver));
ASSERT(!scratch.is(name));
ASSERT(!extra.is(receiver));
ASSERT(!extra.is(name));
ASSERT(!extra.is(scratch));
// Check that the receiver isn't a smi.
__ test(receiver, Immediate(kSmiTagMask));
@ -106,15 +132,19 @@ void StubCache::GenerateProbe(MacroAssembler* masm,
__ and_(scratch, (kPrimaryTableSize - 1) << kHeapObjectTagSize);
// Probe the primary table.
ProbeTable(masm, flags, kPrimary, name, scratch);
ProbeTable(masm, flags, kPrimary, name, scratch, extra);
// Primary miss: Compute hash for secondary probe.
__ mov(scratch, FieldOperand(name, String::kLengthOffset));
__ add(scratch, FieldOperand(receiver, HeapObject::kMapOffset));
__ xor_(scratch, flags);
__ and_(scratch, (kPrimaryTableSize - 1) << kHeapObjectTagSize);
__ sub(scratch, Operand(name));
__ add(Operand(scratch), Immediate(flags));
__ and_(scratch, (kSecondaryTableSize - 1) << kHeapObjectTagSize);
// Probe the secondary table.
ProbeTable(masm, flags, kSecondary, name, scratch);
ProbeTable(masm, flags, kSecondary, name, scratch, extra);
// Cache miss: Fall-through and let caller handle the miss by
// entering the runtime system.

4
src/stub-cache.h
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@ -197,11 +197,13 @@ class StubCache : public AllStatic {
static void GenerateMiss(MacroAssembler* masm);
// Generate code for probing the stub cache table.
// If extra != no_reg it might be used as am extra scratch register.
static void GenerateProbe(MacroAssembler* masm,
Code::Flags flags,
Register receiver,
Register name,
Register scratch);
Register scratch,
Register extra);
enum Table {
kPrimary,