Push safepoint registers in deferred number-to-i/u only on-demand.

src/ia32/lithium-codegen-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4879 matching lines @@
 
 
 void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
   class DeferredNumberTagI V8_FINAL : public LDeferredCode {
    public:
     DeferredNumberTagI(LCodeGen* codegen,
                        LNumberTagI* instr,
                        const X87Stack& x87_stack)
         : LDeferredCode(codegen, x87_stack), instr_(instr) { }
     virtual void Generate() V8_OVERRIDE {
-      codegen()->DoDeferredNumberTagI(instr_, instr_->value(), SIGNED_INT32);
+      codegen()->DoDeferredNumberTagIU(instr_, instr_->value(), instr_->temp(),
+                                       NULL, SIGNED_INT32);
     }
     virtual LInstruction* instr() V8_OVERRIDE { return instr_; }
    private:
     LNumberTagI* instr_;
   };
 
   LOperand* input = instr->value();
   ASSERT(input->IsRegister() && input->Equals(instr->result()));
   Register reg = ToRegister(input);
 
   DeferredNumberTagI* deferred =
       new(zone()) DeferredNumberTagI(this, instr, x87_stack_);
   __ SmiTag(reg);
   __ j(overflow, deferred->entry());
   __ bind(deferred->exit());
 }
 
 
 void LCodeGen::DoNumberTagU(LNumberTagU* instr) {
   class DeferredNumberTagU V8_FINAL : public LDeferredCode {
    public:
     DeferredNumberTagU(LCodeGen* codegen,
                        LNumberTagU* instr,
                        const X87Stack& x87_stack)
         : LDeferredCode(codegen, x87_stack), instr_(instr) { }
     virtual void Generate() V8_OVERRIDE {
-      codegen()->DoDeferredNumberTagI(instr_, instr_->value(), UNSIGNED_INT32);
+      codegen()->DoDeferredNumberTagIU(instr_, instr_->value(), instr_->temp1(),
+                                       instr_->temp2(), UNSIGNED_INT32);
     }
     virtual LInstruction* instr() V8_OVERRIDE { return instr_; }
    private:
     LNumberTagU* instr_;
   };
 
   LOperand* input = instr->value();
   ASSERT(input->IsRegister() && input->Equals(instr->result()));
   Register reg = ToRegister(input);
 
   DeferredNumberTagU* deferred =
       new(zone()) DeferredNumberTagU(this, instr, x87_stack_);
   __ cmp(reg, Immediate(Smi::kMaxValue));
   __ j(above, deferred->entry());
   __ SmiTag(reg);
   __ bind(deferred->exit());
 }
 
 
-void LCodeGen::DoDeferredNumberTagI(LInstruction* instr,
-                                    LOperand* value,
-                                    IntegerSignedness signedness) {
-  Label slow;
+void LCodeGen::DoDeferredNumberTagIU(LInstruction* instr,
+                                     LOperand* value,
+                                     LOperand* temp1,
+                                     LOperand* temp2,
+                                     IntegerSignedness signedness) {
+  Label done, slow;
   Register reg = ToRegister(value);
-  Register tmp = reg.is(eax) ? ecx : eax;
+  Register tmp = ToRegister(temp1);
   XMMRegister xmm_scratch = double_scratch0();
 
-  // Preserve the value of all registers.
-  PushSafepointRegistersScope scope(this);
-
-  Label done;
-
   if (signedness == SIGNED_INT32) {
     // There was overflow, so bits 30 and 31 of the original integer
     // disagree. Try to allocate a heap number in new space and store
     // the value in there. If that fails, call the runtime system.
     __ SmiUntag(reg);
     __ xor_(reg, 0x80000000);
     if (CpuFeatures::IsSupported(SSE2)) {
       CpuFeatureScope feature_scope(masm(), SSE2);
       __ Cvtsi2sd(xmm_scratch, Operand(reg));
     } else {
       __ push(reg);
       __ fild_s(Operand(esp, 0));
       __ pop(reg);
     }
   } else {
     if (CpuFeatures::IsSupported(SSE2)) {
       CpuFeatureScope feature_scope(masm(), SSE2);
-      __ LoadUint32(xmm_scratch, reg,
-                    ToDoubleRegister(LNumberTagU::cast(instr)->temp()));
+      __ LoadUint32(xmm_scratch, reg, ToDoubleRegister(temp2));
     } else {
       // There's no fild variant for unsigned values, so zero-extend to a 64-bit
       // int manually.
       __ push(Immediate(0));
       __ push(reg);
       __ fild_d(Operand(esp, 0));
       __ pop(reg);
       __ pop(reg);
     }
   }
 
   if (FLAG_inline_new) {
     __ AllocateHeapNumber(reg, tmp, no_reg, &slow);
     __ jmp(&done, Label::kNear);
   }
 
   // Slow case: Call the runtime system to do the number allocation.
   __ bind(&slow);
+  {
+    // TODO(3095996): Put a valid pointer value in the stack slot where the
+    // result register is stored, as this register is in the pointer map, but
+    // contains an integer value.
+    __ Set(reg, Immediate(0));
 
-  // TODO(3095996): Put a valid pointer value in the stack slot where the result
-  // register is stored, as this register is in the pointer map, but contains an
-  // integer value.
-  __ StoreToSafepointRegisterSlot(reg, Immediate(0));
-  // NumberTagI and NumberTagD use the context from the frame, rather than
-  // the environment's HContext or HInlinedContext value.
-  // They only call Runtime::kAllocateHeapNumber.
-  // The corresponding HChange instructions are added in a phase that does
-  // not have easy access to the local context.
-  __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
-  __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
-  RecordSafepointWithRegisters(
-      instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
-  if (!reg.is(eax)) __ mov(reg, eax);
+    // Preserve the value of all registers.
+    PushSafepointRegistersScope scope(this);
+
+    // NumberTagI and NumberTagD use the context from the frame, rather than
+    // the environment's HContext or HInlinedContext value.
+    // They only call Runtime::kAllocateHeapNumber.
+    // The corresponding HChange instructions are added in a phase that does
+    // not have easy access to the local context.
+    __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
+    __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
+    RecordSafepointWithRegisters(
+        instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
+    __ StoreToSafepointRegisterSlot(reg, eax);
+  }
 
   // Done. Put the value in xmm_scratch into the value of the allocated heap
   // number.
   __ bind(&done);
   if (CpuFeatures::IsSupported(SSE2)) {
     CpuFeatureScope feature_scope(masm(), SSE2);
     __ movsd(FieldOperand(reg, HeapNumber::kValueOffset), xmm_scratch);
   } else {
     __ fstp_d(FieldOperand(reg, HeapNumber::kValueOffset));
   }
-  __ StoreToSafepointRegisterSlot(reg, reg);
 }
 
 
 void LCodeGen::DoNumberTagD(LNumberTagD* instr) {
   class DeferredNumberTagD V8_FINAL : public LDeferredCode {
    public:
     DeferredNumberTagD(LCodeGen* codegen,
                        LNumberTagD* instr,
                        const X87Stack& x87_stack)
         : LDeferredCode(codegen, x87_stack), instr_(instr) { }
@@ skipping 1237 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32