Fix stack alignment issue with the new fast Math.random() code

src/ia32/codegen-ia32.cc

 // Copyright 2006-2009 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 4919 matching lines @@
   ASSERT(ebp_as_smi.is_valid());
   __ mov(ebp_as_smi.reg(), Operand(ebp));
   __ shr(ebp_as_smi.reg(), kSmiTagSize);
   frame_->Push(&ebp_as_smi);
 }
 
 
 void CodeGenerator::GenerateRandomPositiveSmi(ZoneList<Expression*>* args) {
   ASSERT(args->length() == 0);
   frame_->SpillAll();
+
+  // Make sure the frame is aligned like the OS expects.
+  static const int kFrameAlignment = OS::ActivationFrameAlignment();
+  if (kFrameAlignment > 0) {
+    ASSERT(IsPowerOf2(kFrameAlignment));
+    __ mov(edi, Operand(esp));  // Save in callee-saved register.
+    __ and_(esp, -kFrameAlignment);
+  }
+
+  // Call V8::RandomPositiveSmi().
   __ call(FUNCTION_ADDR(V8::RandomPositiveSmi), RelocInfo::RUNTIME_ENTRY);
+
+  // Restore stack pointer from callee-saved register edi.
+  if (kFrameAlignment > 0) {
+    __ mov(esp, Operand(edi));
+  }
+
   Result result = allocator_->Allocate(eax);
   frame_->Push(&result);
 }
 
 
 void CodeGenerator::VisitCallRuntime(CallRuntime* node) {
   if (CheckForInlineRuntimeCall(node)) {
     return;
   }
 
@@ skipping 2550 matching lines @@
 
   // Slow-case: Go through the JavaScript implementation.
   __ bind(&slow);
   __ InvokeBuiltin(Builtins::INSTANCE_OF, JUMP_FUNCTION);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal