Revision: 16671
Author: [email protected]
Date: Thu Sep 12 09:05:27 2013 UTC
Log: Fix phis for non-sse2 double values
Since hydrogen will try to merge phi-inputs using registers, even if
the values are spilled, we cannot mark LGoto as double clobbering
instruction.
BUG=
[email protected]
Review URL: https://codereview.chromium.org/23068038
http://code.google.com/p/v8/source/detail?r=16671
Modified:
/branches/bleeding_edge/src/ia32/lithium-codegen-ia32.cc
/branches/bleeding_edge/src/ia32/lithium-codegen-ia32.h
/branches/bleeding_edge/src/ia32/lithium-ia32.cc
/branches/bleeding_edge/src/ia32/lithium-ia32.h
=======================================
--- /branches/bleeding_edge/src/ia32/lithium-codegen-ia32.cc Tue Sep 10
12:37:30 2013 UTC
+++ /branches/bleeding_edge/src/ia32/lithium-codegen-ia32.cc Thu Sep 12
09:05:27 2013 UTC
@@ -382,9 +382,13 @@
instr->CompileToNative(this);
- if (!CpuFeatures::IsSupported(SSE2) &&
- FLAG_debug_code && FLAG_enable_slow_asserts) {
+ if (!CpuFeatures::IsSupported(SSE2)) {
+ if (instr->IsGoto()) {
+ x87_stack_.LeavingBlock(current_block_, LGoto::cast(instr));
+ } else if (FLAG_debug_code && FLAG_enable_slow_asserts &&
+ !instr->IsGap() && !instr->IsReturn()) {
__ VerifyX87StackDepth(x87_stack_.depth());
+ }
}
}
EnsureSpaceForLazyDeopt();
@@ -682,6 +686,21 @@
__ fstp(0);
stack_depth_--;
}
+ __ VerifyX87StackDepth(0);
+ }
+}
+
+
+void LCodeGen::X87Stack::LeavingBlock(int current_block_id, LGoto*
goto_instr) {
+ ASSERT(stack_depth_ <= 1);
+ // If ever used for new stubs producing two pairs of doubles joined into
two
+ // phis this assert hits. That situation is not handled, since the two
stacks
+ // might have st0 and st1 swapped.
+ if (current_block_id + 1 != goto_instr->block_id()) {
+ // If we have a value on the x87 stack on leaving a block, it must be a
+ // phi input. If the next block we compile is not the join block, we
have
+ // to discard the stack state.
+ stack_depth_ = 0;
}
}
@@ -2484,6 +2503,10 @@
__ jmp(chunk_->GetAssemblyLabel(LookupDestination(block)));
}
}
+
+
+void LCodeGen::DoClobberDoubles(LClobberDoubles* instr) {
+}
void LCodeGen::DoGoto(LGoto* instr) {
=======================================
--- /branches/bleeding_edge/src/ia32/lithium-codegen-ia32.h Tue Sep 10
12:37:30 2013 UTC
+++ /branches/bleeding_edge/src/ia32/lithium-codegen-ia32.h Thu Sep 12
09:05:27 2013 UTC
@@ -471,6 +471,7 @@
void PrepareToWrite(X87Register reg);
void CommitWrite(X87Register reg);
void FlushIfNecessary(LInstruction* instr, LCodeGen* cgen);
+ void LeavingBlock(int current_block_id, LGoto* goto_instr);
int depth() const { return stack_depth_; }
void pop() {
ASSERT(is_mutable_);
=======================================
--- /branches/bleeding_edge/src/ia32/lithium-ia32.cc Mon Sep 9 16:34:40
2013 UTC
+++ /branches/bleeding_edge/src/ia32/lithium-ia32.cc Thu Sep 12 09:05:27
2013 UTC
@@ -954,6 +954,16 @@
if (FLAG_stress_environments && !instr->HasEnvironment()) {
instr = AssignEnvironment(instr);
}
+ if (!CpuFeatures::IsSafeForSnapshot(SSE2) && instr->IsGoto() &&
+ LGoto::cast(instr)->jumps_to_join()) {
+ // TODO(olivf) Since phis of spilled values are joined as registers
+ // (not in the stack slot), we need to allow the goto gaps to keep
one
+ // x87 register alive. To ensure all other values are still spilled,
we
+ // insert a fpu register barrier right before.
+ LClobberDoubles* clobber = new(zone()) LClobberDoubles();
+ clobber->set_hydrogen_value(current);
+ chunk_->AddInstruction(clobber, current_block_);
+ }
instr->set_hydrogen_value(current);
chunk_->AddInstruction(instr, current_block_);
}
@@ -1046,7 +1056,7 @@
LInstruction* LChunkBuilder::DoGoto(HGoto* instr) {
- return new(zone()) LGoto(instr->FirstSuccessor()->block_id());
+ return new(zone()) LGoto(instr->FirstSuccessor());
}
@@ -1058,7 +1068,7 @@
HBasicBlock* successor = HConstant::cast(value)->BooleanValue()
? instr->FirstSuccessor()
: instr->SecondSuccessor();
- return new(zone()) LGoto(successor->block_id());
+ return new(zone()) LGoto(successor);
}
ToBooleanStub::Types expected = instr->expected_input_types();
=======================================
--- /branches/bleeding_edge/src/ia32/lithium-ia32.h Mon Sep 9 07:57:23
2013 UTC
+++ /branches/bleeding_edge/src/ia32/lithium-ia32.h Thu Sep 12 09:05:27
2013 UTC
@@ -73,6 +73,7 @@
V(ClampTToUint8) \
V(ClampTToUint8NoSSE2) \
V(ClassOfTestAndBranch) \
+ V(ClobberDoubles) \
V(CompareNumericAndBranch) \
V(CmpObjectEqAndBranch) \
V(CmpHoleAndBranch) \
@@ -406,19 +407,32 @@
};
+class LClobberDoubles V8_FINAL : public LTemplateInstruction<0, 0, 0> {
+ public:
+ LClobberDoubles() { ASSERT(!CpuFeatures::IsSafeForSnapshot(SSE2)); }
+
+ virtual bool ClobbersDoubleRegisters() const { return true; }
+
+ DECLARE_CONCRETE_INSTRUCTION(ClobberDoubles, "clobber-d")
+};
+
+
class LGoto V8_FINAL : public LTemplateInstruction<0, 0, 0> {
public:
- explicit LGoto(int block_id) : block_id_(block_id) { }
+ explicit LGoto(HBasicBlock* block) : block_(block) { }
virtual bool HasInterestingComment(LCodeGen* gen) const V8_OVERRIDE;
DECLARE_CONCRETE_INSTRUCTION(Goto, "goto")
virtual void PrintDataTo(StringStream* stream) V8_OVERRIDE;
virtual bool IsControl() const V8_OVERRIDE { return true; }
- int block_id() const { return block_id_; }
+ int block_id() const { return block_->block_id(); }
+ virtual bool ClobbersDoubleRegisters() const { return false; }
+
+ bool jumps_to_join() const { return block_->predecessors()->length() >
1; }
private:
- int block_id_;
+ HBasicBlock* block_;
};
--
--
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