Reviewers: Toon Verwaest,
Description:
Reland "Fix phis for non-sse2 double values"
Remove VerifyX87StackDepth from non-debug code.
BUG=
[email protected]
Please review this at https://codereview.chromium.org/23621038/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files (+57, -7 lines):
M src/ia32/lithium-codegen-ia32.h
M src/ia32/lithium-codegen-ia32.cc
M src/ia32/lithium-ia32.h
M src/ia32/lithium-ia32.cc
M src/ia32/macro-assembler-ia32.cc
Index: src/ia32/lithium-codegen-ia32.cc
diff --git a/src/ia32/lithium-codegen-ia32.cc
b/src/ia32/lithium-codegen-ia32.cc
index
860646c2fd60417e2fdfe5640eabe15cb61c0211..632ad9783fe95ed300365096a36e34fd4909cf1d
100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -382,9 +382,13 @@ bool LCodeGen::GenerateBody() {
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 @@ void
LCodeGen::X87Stack::FlushIfNecessary(LInstruction* instr, LCodeGen* cgen) {
__ fstp(0);
stack_depth_--;
}
+ if (FLAG_debug_code && FLAG_enable_slow_asserts) __
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;
}
}
@@ -2486,6 +2505,10 @@ void LCodeGen::EmitGoto(int block) {
}
+void LCodeGen::DoClobberDoubles(LClobberDoubles* instr) {
+}
+
+
void LCodeGen::DoGoto(LGoto* instr) {
EmitGoto(instr->block_id());
}
Index: src/ia32/lithium-codegen-ia32.h
diff --git a/src/ia32/lithium-codegen-ia32.h
b/src/ia32/lithium-codegen-ia32.h
index
cc1747d07bef74e9299cdcd0ffac43218a214836..b097694f179c0972dd2501f61523d50c3b0d7119
100644
--- a/src/ia32/lithium-codegen-ia32.h
+++ b/src/ia32/lithium-codegen-ia32.h
@@ -471,6 +471,7 @@ class LCodeGen V8_FINAL BASE_EMBEDDED {
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_);
Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index
07dbf13d19a3d4b20ccfb8d99cdc1ab0ddb1885b..e2eee19c841bf223e2b1f45898cfcbd6e2a2ddce
100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -954,6 +954,16 @@ void LChunkBuilder::VisitInstruction(HInstruction*
current) {
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 @@ LEnvironment* LChunkBuilder::CreateEnvironment(
LInstruction* LChunkBuilder::DoGoto(HGoto* instr) {
- return new(zone()) LGoto(instr->FirstSuccessor()->block_id());
+ return new(zone()) LGoto(instr->FirstSuccessor());
}
@@ -1058,7 +1068,7 @@ LInstruction* LChunkBuilder::DoBranch(HBranch* instr)
{
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();
Index: src/ia32/lithium-ia32.h
diff --git a/src/ia32/lithium-ia32.h b/src/ia32/lithium-ia32.h
index
ab964af65f30529824bbed2efd108273821b92cc..d96764f3b5edbe465a97a9f57cae60a25a36457c
100644
--- a/src/ia32/lithium-ia32.h
+++ b/src/ia32/lithium-ia32.h
@@ -73,6 +73,7 @@ class LCodeGen;
V(ClampTToUint8) \
V(ClampTToUint8NoSSE2) \
V(ClassOfTestAndBranch) \
+ V(ClobberDoubles) \
V(CompareNumericAndBranch) \
V(CmpObjectEqAndBranch) \
V(CmpHoleAndBranch) \
@@ -406,19 +407,32 @@ class LInstructionGap V8_FINAL : public LGap {
};
+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_;
};
Index: src/ia32/macro-assembler-ia32.cc
diff --git a/src/ia32/macro-assembler-ia32.cc
b/src/ia32/macro-assembler-ia32.cc
index
fbfe9ddb8c86d6c46b9693ce3ac6dbfd6faddd9f..79248042b83073f71cef4de9d1cd293bc21eba2a
100644
--- a/src/ia32/macro-assembler-ia32.cc
+++ b/src/ia32/macro-assembler-ia32.cc
@@ -2798,6 +2798,8 @@ void MacroAssembler::Ret(int bytes_dropped, Register
scratch) {
void MacroAssembler::VerifyX87StackDepth(uint32_t depth) {
// Make sure the floating point stack is either empty or has depth items.
ASSERT(depth <= 7);
+ // This is a very expensive.
+ ASSERT(FLAG_debug_code && FLAG_enable_slow_asserts);
// The top-of-stack (tos) is 7 if there is one item pushed.
int tos = (8 - depth) % 8;
--
--
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