Reimplement dynamic frame alignment for frames that are compiled via OSR or have more than 2 double…

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 2d469da6ed55867d5a32e0cdd6c22253888fc1da..03f98814e0c96887b458892ddfdcc422229df0da 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -79,6 +79,9 @@ bool LCodeGen::GenerateCode() {
   // the frame (that is done in GeneratePrologue).
   FrameScope frame_scope(masm_, StackFrame::MANUAL);
 
+  dynamic_frame_alignment_ = chunk()->num_double_slots() > 2 ||
+                             info()->osr_ast_id() != AstNode::kNoNumber;
+
   return GeneratePrologue() &&
       GenerateBody() &&
       GenerateDeferredCode() &&
@@ -153,6 +156,31 @@ bool LCodeGen::GeneratePrologue() {
     __ bind(&ok);
   }
 
+  __ mov(edx, Immediate(0));
+
+  if (dynamic_frame_alignment_) {
+     Label do_not_pad, align_loop;
+     STATIC_ASSERT(kDoubleSize == 2 * kPointerSize);
+     // Align esp to a multiple of 2 * kPointerSize.
+     __ test(esp, Immediate(kPointerSize));
+     __ j(zero, &do_not_pad, Label::kNear);
+     __ push(Immediate(0));
+     __ mov(ebx, esp);
+     __ mov(edx, Immediate(2));
+     // Copy arguments, receiver, and return address.
+     __ mov(ecx, Immediate(scope()->num_parameters() + 2));
+
+     __ bind(&align_loop);
+     __ mov(eax, Operand(ebx, 1 * kPointerSize));
+     __ mov(Operand(ebx, 0), eax);
+     __ add(Operand(ebx), Immediate(kPointerSize));
+     __ dec(ecx);
+     __ j(not_zero, &align_loop, Label::kNear);
+     __ mov(Operand(ebx, 0),
+            Immediate(Smi::FromInt(0x12345)));
+     __ bind(&do_not_pad);
+  }
+
   __ push(ebp);  // Caller's frame pointer.
   __ mov(ebp, esp);
   __ push(esi);  // Callee's context.
@@ -160,6 +188,7 @@ bool LCodeGen::GeneratePrologue() {
 
   // Reserve space for the stack slots needed by the code.
   int slots = GetStackSlotCount();
+  CHECK(slots >= 1);
   if (slots > 0) {
     if (FLAG_debug_code) {
       __ mov(Operand(eax), Immediate(slots));
@@ -183,6 +212,7 @@ bool LCodeGen::GeneratePrologue() {
 #endif
     }
   }
+  __ mov(Operand(ebp, JavaScriptFrameConstants::kLocal0Offset), edx);
 
   // Possibly allocate a local context.
   int heap_slots = scope()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
@@ -2098,8 +2128,21 @@ void LCodeGen::DoReturn(LReturn* instr) {
     __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
     __ CallRuntime(Runtime::kTraceExit, 1);
   }
+  if (dynamic_frame_alignment_) {
+    __ mov(edx, Operand(ebp, JavaScriptFrameConstants::kLocal0Offset));
+  }
   __ mov(esp, ebp);
   __ pop(ebp);
+  if (dynamic_frame_alignment_) {
+    Label aligned;
+    __ cmp(edx, Immediate(0));
+    __ j(equal, &aligned);
+    __ cmp(Operand(esp, (GetParameterCount() + 2) * kPointerSize),
+           Immediate(Smi::FromInt(0x12345)));
+    __ Assert(equal, "expected alignment marker");
+    __ Ret((GetParameterCount() + 2) * kPointerSize, ecx);
+    __ bind(&aligned);
+  }
   __ Ret((GetParameterCount() + 1) * kPointerSize, ecx);
 }