Support double allocations when folding allocation.

src/ia32/lithium-codegen-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 38d2011d0b736badcf452b9254febc7ef6d1fa38..8315d8209a451496bbd69179564b37448ce07e1e 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -4334,7 +4334,16 @@ void LCodeGen::DoCallRuntime(LCallRuntime* instr) {
 void LCodeGen::DoInnerAllocatedObject(LInnerAllocatedObject* instr) {
   Register result = ToRegister(instr->result());
   Register base = ToRegister(instr->base_object());
-  __ lea(result, Operand(base, instr->offset()));
+  int offset = instr->offset();
+  if (instr->hydrogen()->MustAllocateDoubleAligned()) {
+    ASSERT(kPointerAlignment * 2 == kDoubleAlignment);
+    Label aligned;
+    __ test(base, Immediate(kDoubleAlignmentMask));
+    __ j(zero, &aligned, Label::kNear);

[Michael Starzinger, 2013/07/22 19:46:56]

This is a NOP. The jump at runtime does not affect the modification of offset at
compile time. Also a test+jump seems like overkill.

+    offset += (kDoubleSize / 2);
+    __ bind(&aligned);
+  }
+  __ lea(result, Operand(base, offset));
 }