Reviewers: danno, Paul Lind, kisg,
Description:
MIPS: DoNumberTagD performance improvement
Port r12711 (a8d45ac2)
Original commit message:
Allocate heap entry untagged and tag at end to avoid having to subtract off
the tag offset before storing the value.
BUG=
TEST=
Please review this at https://chromiumcodereview.appspot.com/11280106/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files:
M src/mips/lithium-codegen-mips.cc
M src/mips/macro-assembler-mips.h
M src/mips/macro-assembler-mips.cc
M src/mips/stub-cache-mips.cc
Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc
b/src/mips/lithium-codegen-mips.cc
index
e19caf34c2a901be98b7a9eb414fcb59c9e10c35..1bf928a95b9b670c577790b501fe76c90f13217a
100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -4251,7 +4251,7 @@ void LCodeGen::DoDeferredNumberTagI(LInstruction*
instr,
if (FLAG_inline_new) {
__ LoadRoot(t2, Heap::kHeapNumberMapRootIndex);
- __ AllocateHeapNumber(t1, a3, t0, t2, &slow);
+ __ AllocateHeapNumber(t1, a3, t0, t2, &slow, DONT_TAG_RESULT);
__ Move(dst, t1);
__ Branch(&done);
}
@@ -4265,11 +4265,13 @@ void LCodeGen::DoDeferredNumberTagI(LInstruction*
instr,
__ StoreToSafepointRegisterSlot(zero_reg, dst);
CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr);
__ Move(dst, v0);
+ __ Subu(dst, dst, kHeapObjectTag);
// Done. Put the value in dbl_scratch into the value of the allocated
heap
// number.
__ bind(&done);
- __ sdc1(dbl_scratch, FieldMemOperand(dst, HeapNumber::kValueOffset));
+ __ sdc1(dbl_scratch, MemOperand(dst, HeapNumber::kValueOffset));
+ __ Addu(dst, dst, kHeapObjectTag);
__ StoreToSafepointRegisterSlot(dst, dst);
}
@@ -4294,12 +4296,16 @@ void LCodeGen::DoNumberTagD(LNumberTagD* instr) {
DeferredNumberTagD* deferred = new(zone()) DeferredNumberTagD(this,
instr);
if (FLAG_inline_new) {
__ LoadRoot(scratch, Heap::kHeapNumberMapRootIndex);
- __ AllocateHeapNumber(reg, temp1, temp2, scratch, deferred->entry());
+ // We want the untagged address first for performance
+ __ AllocateHeapNumber(reg, temp1, temp2, scratch, deferred->entry(),
+ DONT_TAG_RESULT);
} else {
__ Branch(deferred->entry());
}
__ bind(deferred->exit());
- __ sdc1(input_reg, FieldMemOperand(reg, HeapNumber::kValueOffset));
+ __ sdc1(input_reg, MemOperand(reg, HeapNumber::kValueOffset));
+ // Now that we have finished with the object's real address tag it
+ __ Addu(reg, reg, kHeapObjectTag);
}
@@ -4312,6 +4318,7 @@ void LCodeGen::DoDeferredNumberTagD(LNumberTagD*
instr) {
PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr);
+ __ Subu(v0, v0, kHeapObjectTag);
__ StoreToSafepointRegisterSlot(v0, reg);
}
Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc
b/src/mips/macro-assembler-mips.cc
index
11c641d93afcdcc9b0651bb2d39422f44b6b7659..afdc273717c310a8975648e9fb35d8d0878da6cf
100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -3215,7 +3215,8 @@ void MacroAssembler::AllocateHeapNumber(Register
result,
Register scratch1,
Register scratch2,
Register heap_number_map,
- Label* need_gc) {
+ Label* need_gc,
+ TaggingMode tagging_mode) {
// Allocate an object in the heap for the heap number and tag it as a
heap
// object.
AllocateInNewSpace(HeapNumber::kSize,
@@ -3223,11 +3224,16 @@ void MacroAssembler::AllocateHeapNumber(Register
result,
scratch1,
scratch2,
need_gc,
- TAG_OBJECT);
+ tagging_mode == TAG_RESULT ? TAG_OBJECT :
+ NO_ALLOCATION_FLAGS);
// Store heap number map in the allocated object.
AssertRegisterIsRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
- sw(heap_number_map, FieldMemOperand(result, HeapObject::kMapOffset));
+ if (tagging_mode == TAG_RESULT) {
+ sw(heap_number_map, FieldMemOperand(result, HeapObject::kMapOffset));
+ } else {
+ sw(heap_number_map, MemOperand(result, HeapObject::kMapOffset));
+ }
}
Index: src/mips/macro-assembler-mips.h
diff --git a/src/mips/macro-assembler-mips.h
b/src/mips/macro-assembler-mips.h
index
b57e51486c510b9391814a60ac460acb48522eaa..f5d695d7533579edc2f3b8dbc8f22ee6b9ae7e94
100644
--- a/src/mips/macro-assembler-mips.h
+++ b/src/mips/macro-assembler-mips.h
@@ -65,6 +65,14 @@ enum AllocationFlags {
SIZE_IN_WORDS = 1 << 2
};
+// Flags used for AllocateHeapNumber
+enum TaggingMode {
+ // Tag the result.
+ TAG_RESULT,
+ // Don't tag
+ DONT_TAG_RESULT
+};
+
// Flags used for the ObjectToDoubleFPURegister function.
enum ObjectToDoubleFlags {
// No special flags.
@@ -536,7 +544,8 @@ class MacroAssembler: public Assembler {
Register scratch1,
Register scratch2,
Register heap_number_map,
- Label* gc_required);
+ Label* gc_required,
+ TaggingMode tagging_mode = TAG_RESULT);
void AllocateHeapNumberWithValue(Register result,
FPURegister value,
Register scratch1,
Index: src/mips/stub-cache-mips.cc
diff --git a/src/mips/stub-cache-mips.cc b/src/mips/stub-cache-mips.cc
index
563e302f5d9d2a5da53e087a488b0f4ca67b7571..5f7ad525b006ff863aa09625cb00122b8d4616c0
100644
--- a/src/mips/stub-cache-mips.cc
+++ b/src/mips/stub-cache-mips.cc
@@ -3810,20 +3810,27 @@ void
KeyedLoadStubCompiler::GenerateLoadExternalArray(
__ Ret();
__ bind(&box_int);
- // Allocate a HeapNumber for the result and perform int-to-double
- // conversion.
- // The arm version uses a temporary here to save r0, but we don't need
to
- // (a0 is not modified).
- __ LoadRoot(t1, Heap::kHeapNumberMapRootIndex);
- __ AllocateHeapNumber(v0, a3, t0, t1, &slow);
if (CpuFeatures::IsSupported(FPU)) {
CpuFeatures::Scope scope(FPU);
+ // Allocate a HeapNumber for the result and perform int-to-double
+ // conversion.
+ // The arm version uses a temporary here to save r0, but we don't
need to
+ // (a0 is not modified).
+ __ LoadRoot(t1, Heap::kHeapNumberMapRootIndex);
+ __ AllocateHeapNumber(v0, a3, t0, t1, &slow, DONT_TAG_RESULT);
__ mtc1(value, f0);
__ cvt_d_w(f0, f0);
- __ sdc1(f0, FieldMemOperand(v0, HeapNumber::kValueOffset));
+ __ sdc1(f0, MemOperand(v0, HeapNumber::kValueOffset));
+ __ Addu(v0, v0, kHeapObjectTag);
__ Ret();
} else {
+ // Allocate a HeapNumber for the result and perform int-to-double
+ // conversion.
+ // The arm version uses a temporary here to save r0, but we don't
need to
+ // (a0 is not modified).
+ __ LoadRoot(t1, Heap::kHeapNumberMapRootIndex);
+ __ AllocateHeapNumber(v0, a3, t0, t1, &slow, TAG_RESULT);
Register dst1 = t2;
Register dst2 = t3;
FloatingPointHelper::Destination dest =
@@ -3860,7 +3867,7 @@ void KeyedLoadStubCompiler::GenerateLoadExternalArray(
// conversion. Don't use a0 and a1 as AllocateHeapNumber clobbers all
// registers - also when jumping due to exhausted young space.
__ LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
- __ AllocateHeapNumber(v0, t2, t3, t6, &slow);
+ __ AllocateHeapNumber(v0, t2, t3, t6, &slow, DONT_TAG_RESULT);
// This is replaced by a macro:
// __ mtc1(value, f0); // LS 32-bits.
@@ -3869,8 +3876,9 @@ void KeyedLoadStubCompiler::GenerateLoadExternalArray(
__ Cvt_d_uw(f0, value, f22);
- __ sdc1(f0, FieldMemOperand(v0, HeapNumber::kValueOffset));
+ __ sdc1(f0, MemOperand(v0, HeapNumber::kValueOffset));
+ __ Addu(v0, v0, kHeapObjectTag);
__ Ret();
} else {
// Check whether unsigned integer fits into smi.
@@ -3903,7 +3911,7 @@ void KeyedLoadStubCompiler::GenerateLoadExternalArray(
// clobbers all registers - also when jumping due to exhausted young
// space.
__ LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
- __ AllocateHeapNumber(t2, t3, t5, t6, &slow);
+ __ AllocateHeapNumber(t2, t3, t5, t6, &slow, TAG_RESULT);
__ sw(hiword, FieldMemOperand(t2, HeapNumber::kExponentOffset));
__ sw(loword, FieldMemOperand(t2, HeapNumber::kMantissaOffset));
@@ -3920,17 +3928,19 @@ void
KeyedLoadStubCompiler::GenerateLoadExternalArray(
// AllocateHeapNumber clobbers all registers - also when jumping due
to
// exhausted young space.
__ LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
- __ AllocateHeapNumber(v0, t3, t5, t6, &slow);
+ __ AllocateHeapNumber(v0, t3, t5, t6, &slow, DONT_TAG_RESULT);
// The float (single) value is already in fpu reg f0 (if we use
float).
__ cvt_d_s(f0, f0);
- __ sdc1(f0, FieldMemOperand(v0, HeapNumber::kValueOffset));
+ __ sdc1(f0, MemOperand(v0, HeapNumber::kValueOffset));
+
+ __ Addu(v0, v0, kHeapObjectTag);
__ Ret();
} else {
// Allocate a HeapNumber for the result. Don't use a0 and a1 as
// AllocateHeapNumber clobbers all registers - also when jumping due
to
// exhausted young space.
__ LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
- __ AllocateHeapNumber(v0, t3, t5, t6, &slow);
+ __ AllocateHeapNumber(v0, t3, t5, t6, &slow, TAG_RESULT);
// FPU is not available, do manual single to double conversion.
// a2: floating point value (binary32).
@@ -3985,16 +3995,18 @@ void
KeyedLoadStubCompiler::GenerateLoadExternalArray(
// AllocateHeapNumber clobbers all registers - also when jumping due
to
// exhausted young space.
__ LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
- __ AllocateHeapNumber(v0, t3, t5, t6, &slow);
+ __ AllocateHeapNumber(v0, t3, t5, t6, &slow, DONT_TAG_RESULT);
// The double value is already in f0
- __ sdc1(f0, FieldMemOperand(v0, HeapNumber::kValueOffset));
+ __ sdc1(f0, MemOperand(v0, HeapNumber::kValueOffset));
+
+ __ Addu(v0, v0, kHeapObjectTag);
__ Ret();
} else {
// Allocate a HeapNumber for the result. Don't use a0 and a1 as
// AllocateHeapNumber clobbers all registers - also when jumping due
to
// exhausted young space.
__ LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
- __ AllocateHeapNumber(v0, t3, t5, t6, &slow);
+ __ AllocateHeapNumber(v0, t3, t5, t6, &slow, TAG_RESULT);
__ sw(a2, FieldMemOperand(v0, HeapNumber::kMantissaOffset));
__ sw(a3, FieldMemOperand(v0, HeapNumber::kExponentOffset));
@@ -4512,7 +4524,7 @@ void
KeyedLoadStubCompiler::GenerateLoadFastDoubleElement(
// Non-NaN. Allocate a new heap number and copy the double value into it.
__ LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
__ AllocateHeapNumber(heap_number_reg, scratch2, scratch3,
- heap_number_map, &slow_allocate_heapnumber);
+ heap_number_map, &slow_allocate_heapnumber,
TAG_RESULT);
// Don't need to reload the upper 32 bits of the double, it's already in
// scratch.
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
