Revision: 16695
Author: [email protected]
Date: Thu Sep 12 21:17:43 2013 UTC
Log: MIPS: Improve code generation for the HRandom instruction.
Port r16684 (e0f70aa)
Original commit message:
Since the per-context random number generator is now
properly seeded upon context creation, we do not need
to check for lazy-initialization anymore, and so we
can implement the HRandom instruction w/o having to
call into the C function (which means we don't need
to MarkAsCall anymore).
TEST=cctest/test-random
BUG=
[email protected]
Review URL: https://codereview.chromium.org/23851028
Patch from Balazs Kilvady <[email protected]>.
http://code.google.com/p/v8/source/detail?r=16695
Modified:
/branches/bleeding_edge/src/mips/lithium-codegen-mips.cc
/branches/bleeding_edge/src/mips/lithium-codegen-mips.h
/branches/bleeding_edge/src/mips/lithium-mips.cc
/branches/bleeding_edge/src/mips/lithium-mips.h
=======================================
--- /branches/bleeding_edge/src/mips/lithium-codegen-mips.cc Mon Sep 9
16:34:40 2013 UTC
+++ /branches/bleeding_edge/src/mips/lithium-codegen-mips.cc Thu Sep 12
21:17:43 2013 UTC
@@ -3813,79 +3813,64 @@
void LCodeGen::DoRandom(LRandom* instr) {
- class DeferredDoRandom V8_FINAL : public LDeferredCode {
- public:
- DeferredDoRandom(LCodeGen* codegen, LRandom* instr)
- : LDeferredCode(codegen), instr_(instr) { }
- virtual void Generate() V8_OVERRIDE {
codegen()->DoDeferredRandom(instr_); }
- virtual LInstruction* instr() V8_OVERRIDE { return instr_; }
- private:
- LRandom* instr_;
- };
-
- DeferredDoRandom* deferred = new(zone()) DeferredDoRandom(this, instr);
- // Having marked this instruction as a call we can use any
- // registers.
- ASSERT(ToDoubleRegister(instr->result()).is(f0));
- ASSERT(ToRegister(instr->global_object()).is(a0));
-
+ // Assert that the register size is indeed the size of each seed.
static const int kSeedSize = sizeof(uint32_t);
STATIC_ASSERT(kPointerSize == kSeedSize);
- __ lw(a0, FieldMemOperand(a0, GlobalObject::kNativeContextOffset));
+ // Load native context.
+ Register global_object = ToRegister(instr->global_object());
+ Register native_context = global_object;
+ __ lw(native_context, FieldMemOperand(
+ global_object, GlobalObject::kNativeContextOffset));
+
+ // Load state (FixedArray of the native context's random seeds).
static const int kRandomSeedOffset =
FixedArray::kHeaderSize + Context::RANDOM_SEED_INDEX * kPointerSize;
- __ lw(a2, FieldMemOperand(a0, kRandomSeedOffset));
- // a2: FixedArray of the native context's random seeds
+ Register state = native_context;
+ __ lw(state, FieldMemOperand(native_context, kRandomSeedOffset));
// Load state[0].
- __ lw(a1, FieldMemOperand(a2, ByteArray::kHeaderSize));
- __ Branch(deferred->entry(), eq, a1, Operand(zero_reg));
+ Register state0 = ToRegister(instr->scratch());
+ __ lw(state0, FieldMemOperand(state, ByteArray::kHeaderSize));
// Load state[1].
- __ lw(a0, FieldMemOperand(a2, ByteArray::kHeaderSize + kSeedSize));
- // a1: state[0].
- // a0: state[1].
+ Register state1 = ToRegister(instr->scratch2());
+ __ lw(state1, FieldMemOperand(state, ByteArray::kHeaderSize +
kSeedSize));
// state[0] = 18273 * (state[0] & 0xFFFF) + (state[0] >> 16)
- __ And(a3, a1, Operand(0xFFFF));
- __ li(t0, Operand(18273));
- __ Mul(a3, a3, t0);
- __ srl(a1, a1, 16);
- __ Addu(a1, a3, a1);
+ Register scratch3 = ToRegister(instr->scratch3());
+ Register scratch4 = scratch0();
+ __ And(scratch3, state0, Operand(0xFFFF));
+ __ li(scratch4, Operand(18273));
+ __ Mul(scratch3, scratch3, scratch4);
+ __ srl(state0, state0, 16);
+ __ Addu(state0, scratch3, state0);
// Save state[0].
- __ sw(a1, FieldMemOperand(a2, ByteArray::kHeaderSize));
+ __ sw(state0, FieldMemOperand(state, ByteArray::kHeaderSize));
// state[1] = 36969 * (state[1] & 0xFFFF) + (state[1] >> 16)
- __ And(a3, a0, Operand(0xFFFF));
- __ li(t0, Operand(36969));
- __ Mul(a3, a3, t0);
- __ srl(a0, a0, 16),
- __ Addu(a0, a3, a0);
+ __ And(scratch3, state1, Operand(0xFFFF));
+ __ li(scratch4, Operand(36969));
+ __ Mul(scratch3, scratch3, scratch4);
+ __ srl(state1, state1, 16),
+ __ Addu(state1, scratch3, state1);
// Save state[1].
- __ sw(a0, FieldMemOperand(a2, ByteArray::kHeaderSize + kSeedSize));
+ __ sw(state1, FieldMemOperand(state, ByteArray::kHeaderSize +
kSeedSize));
// Random bit pattern = (state[0] << 14) + (state[1] & 0x3FFFF)
- __ And(a0, a0, Operand(0x3FFFF));
- __ sll(a1, a1, 14);
- __ Addu(v0, a0, a1);
-
- __ bind(deferred->exit());
+ Register random = scratch4;
+ __ And(random, state1, Operand(0x3FFFF));
+ __ sll(state0, state0, 14);
+ __ Addu(random, random, state0);
// 0x41300000 is the top half of 1.0 x 2^20 as a double.
- __ li(a2, Operand(0x41300000));
+ __ li(scratch3, Operand(0x41300000));
// Move 0x41300000xxxxxxxx (x = random bits in v0) to FPU.
- __ Move(f12, v0, a2);
+ DoubleRegister result = ToDoubleRegister(instr->result());
+ __ Move(result, random, scratch3);
// Move 0x4130000000000000 to FPU.
- __ Move(f14, zero_reg, a2);
- // Subtract to get the result.
- __ sub_d(f0, f12, f14);
-}
-
-
-void LCodeGen::DoDeferredRandom(LRandom* instr) {
- __ PrepareCallCFunction(1, scratch0());
- __ CallCFunction(ExternalReference::random_uint32_function(isolate()),
1);
- // Return value is in v0.
+ DoubleRegister scratch5 = double_scratch0();
+ __ Move(scratch5, zero_reg, scratch3);
+ __ sub_d(result, result, scratch5);
}
=======================================
--- /branches/bleeding_edge/src/mips/lithium-codegen-mips.h Mon Sep 9
16:34:40 2013 UTC
+++ /branches/bleeding_edge/src/mips/lithium-codegen-mips.h Thu Sep 12
21:17:43 2013 UTC
@@ -147,7 +147,6 @@
void DoDeferredTaggedToI(LTaggedToI* instr);
void DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr);
void DoDeferredStackCheck(LStackCheck* instr);
- void DoDeferredRandom(LRandom* instr);
void DoDeferredStringCharCodeAt(LStringCharCodeAt* instr);
void DoDeferredStringCharFromCode(LStringCharFromCode* instr);
void DoDeferredAllocate(LAllocate* instr);
=======================================
--- /branches/bleeding_edge/src/mips/lithium-mips.cc Mon Sep 9 16:34:40
2013 UTC
+++ /branches/bleeding_edge/src/mips/lithium-mips.cc Thu Sep 12 21:17:43
2013 UTC
@@ -1624,9 +1624,13 @@
LInstruction* LChunkBuilder::DoRandom(HRandom* instr) {
ASSERT(instr->representation().IsDouble());
ASSERT(instr->global_object()->representation().IsTagged());
- LOperand* global_object = UseFixed(instr->global_object(), a0);
- LRandom* result = new(zone()) LRandom(global_object);
- return MarkAsCall(DefineFixedDouble(result, f0), instr);
+ LOperand* global_object = UseTempRegister(instr->global_object());
+ LOperand* scratch = TempRegister();
+ LOperand* scratch2 = TempRegister();
+ LOperand* scratch3 = TempRegister();
+ LRandom* result = new(zone()) LRandom(
+ global_object, scratch, scratch2, scratch3);
+ return DefineFixedDouble(result, f0);
}
=======================================
--- /branches/bleeding_edge/src/mips/lithium-mips.h Mon Sep 9 15:02:41
2013 UTC
+++ /branches/bleeding_edge/src/mips/lithium-mips.h Thu Sep 12 21:17:43
2013 UTC
@@ -1444,13 +1444,22 @@
};
-class LRandom V8_FINAL : public LTemplateInstruction<1, 1, 0> {
+class LRandom V8_FINAL : public LTemplateInstruction<1, 1, 3> {
public:
- explicit LRandom(LOperand* global_object) {
+ LRandom(LOperand* global_object,
+ LOperand* scratch,
+ LOperand* scratch2,
+ LOperand* scratch3) {
inputs_[0] = global_object;
+ temps_[0] = scratch;
+ temps_[1] = scratch2;
+ temps_[2] = scratch3;
}
- LOperand* global_object() { return inputs_[0]; }
+ LOperand* global_object() const { return inputs_[0]; }
+ LOperand* scratch() const { return temps_[0]; }
+ LOperand* scratch2() const { return temps_[1]; }
+ LOperand* scratch3() const { return temps_[2]; }
DECLARE_CONCRETE_INSTRUCTION(Random, "random")
DECLARE_HYDROGEN_ACCESSOR(Random)
--
--
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