Remove push(holder_reg) in CheckAccessGlobalProxy.

R=jkummerow@chromium.org
BUG=v8:119

Review URL: https://chromiumcodereview.appspot.com/13177002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14150 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/macro-assembler-arm.cc

@@ -1402,7 +1402,6 @@ void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
 
   // Check the context is a native context.
   if (emit_debug_code()) {
-    // TODO(119): avoid push(holder_reg)/pop(holder_reg)
     // Cannot use ip as a temporary in this verification code. Due to the fact
     // that ip is clobbered as part of cmp with an object Operand.
     push(holder_reg);  // Temporarily save holder on the stack.
@@ -1421,7 +1420,6 @@ void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
 
   // Check the context is a native context.
   if (emit_debug_code()) {
-    // TODO(119): avoid push(holder_reg)/pop(holder_reg)
     // Cannot use ip as a temporary in this verification code. Due to the fact
     // that ip is clobbered as part of cmp with an object Operand.
     push(holder_reg);  // Temporarily save holder on the stack.

src/ia32/macro-assembler-ia32.cc

@@ -1024,69 +1024,65 @@ void MacroAssembler::ThrowUncatchable(Register value) {
 
 
 void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
-                                            Register scratch,
+                                            Register scratch1,
+                                            Register scratch2,
                                             Label* miss) {
   Label same_contexts;
 
-  ASSERT(!holder_reg.is(scratch));
+  ASSERT(!holder_reg.is(scratch1));
+  ASSERT(!holder_reg.is(scratch2));
+  ASSERT(!scratch1.is(scratch2));
 
   // Load current lexical context from the stack frame.
-  mov(scratch, Operand(ebp, StandardFrameConstants::kContextOffset));
+  mov(scratch1, Operand(ebp, StandardFrameConstants::kContextOffset));
 
   // When generating debug code, make sure the lexical context is set.
   if (emit_debug_code()) {
-    cmp(scratch, Immediate(0));
+    cmp(scratch1, Immediate(0));
     Check(not_equal, "we should not have an empty lexical context");
   }
   // Load the native context of the current context.
   int offset =
       Context::kHeaderSize + Context::GLOBAL_OBJECT_INDEX * kPointerSize;
-  mov(scratch, FieldOperand(scratch, offset));
-  mov(scratch, FieldOperand(scratch, GlobalObject::kNativeContextOffset));
+  mov(scratch1, FieldOperand(scratch1, offset));
+  mov(scratch1, FieldOperand(scratch1, GlobalObject::kNativeContextOffset));
 
   // Check the context is a native context.
   if (emit_debug_code()) {
-    push(scratch);
     // Read the first word and compare to native_context_map.
-    mov(scratch, FieldOperand(scratch, HeapObject::kMapOffset));
-    cmp(scratch, isolate()->factory()->native_context_map());
+    cmp(FieldOperand(scratch1, HeapObject::kMapOffset),
+        isolate()->factory()->native_context_map());
     Check(equal, "JSGlobalObject::native_context should be a native context.");
-    pop(scratch);
   }
 
   // Check if both contexts are the same.
-  cmp(scratch, FieldOperand(holder_reg, JSGlobalProxy::kNativeContextOffset));
+  cmp(scratch1, FieldOperand(holder_reg, JSGlobalProxy::kNativeContextOffset));
   j(equal, &same_contexts);
 
   // Compare security tokens, save holder_reg on the stack so we can use it
   // as a temporary register.
   //
-  // TODO(119): avoid push(holder_reg)/pop(holder_reg)
-  push(holder_reg);
   // Check that the security token in the calling global object is
   // compatible with the security token in the receiving global
   // object.
-  mov(holder_reg,
+  mov(scratch2,
       FieldOperand(holder_reg, JSGlobalProxy::kNativeContextOffset));
 
   // Check the context is a native context.
   if (emit_debug_code()) {
-    cmp(holder_reg, isolate()->factory()->null_value());
+    cmp(scratch2, isolate()->factory()->null_value());
     Check(not_equal, "JSGlobalProxy::context() should not be null.");
 
-    push(holder_reg);
     // Read the first word and compare to native_context_map(),
-    mov(holder_reg, FieldOperand(holder_reg, HeapObject::kMapOffset));
-    cmp(holder_reg, isolate()->factory()->native_context_map());
+    cmp(FieldOperand(scratch2, HeapObject::kMapOffset),
+        isolate()->factory()->native_context_map());
     Check(equal, "JSGlobalObject::native_context should be a native context.");
-    pop(holder_reg);
   }
 
   int token_offset = Context::kHeaderSize +
                      Context::SECURITY_TOKEN_INDEX * kPointerSize;
-  mov(scratch, FieldOperand(scratch, token_offset));
-  cmp(scratch, FieldOperand(holder_reg, token_offset));
-  pop(holder_reg);
+  mov(scratch1, FieldOperand(scratch1, token_offset));
+  cmp(scratch1, FieldOperand(scratch2, token_offset));
   j(not_equal, miss);
 
   bind(&same_contexts);

src/ia32/macro-assembler-ia32.h

@@ -548,7 +548,8 @@ class MacroAssembler: public Assembler {
   // on access to global objects across environments. The holder register
   // is left untouched, but the scratch register is clobbered.
   void CheckAccessGlobalProxy(Register holder_reg,
-                              Register scratch,
+                              Register scratch1,
+                              Register scratch2,
                               Label* miss);
 
   void GetNumberHash(Register r0, Register scratch);

src/ia32/stub-cache-ia32.cc

@@ -748,7 +748,7 @@ void StubCompiler::GenerateStoreField(MacroAssembler* masm,
 
   // Perform global security token check if needed.
   if (object->IsJSGlobalProxy()) {
-    __ CheckAccessGlobalProxy(receiver_reg, scratch1, miss_label);
+    __ CheckAccessGlobalProxy(receiver_reg, scratch1, scratch2, miss_label);
   }
 
   // Check that we are allowed to write this.
@@ -972,10 +972,6 @@ Register StubCompiler::CheckPrototypes(Handle<JSObject> object,
     } else {
       bool in_new_space = heap()->InNewSpace(*prototype);
       Handle<Map> current_map(current->map());
-      if (in_new_space) {
-        // Save the map in scratch1 for later.
-        __ mov(scratch1, FieldOperand(reg, HeapObject::kMapOffset));
-      }
       if (!current.is_identical_to(first) || check == CHECK_ALL_MAPS) {
         __ CheckMap(reg, current_map, miss, DONT_DO_SMI_CHECK,
                     ALLOW_ELEMENT_TRANSITION_MAPS);
@@ -985,8 +981,14 @@ Register StubCompiler::CheckPrototypes(Handle<JSObject> object,
       // the map check so that we know that the object is actually a global
       // object.
       if (current->IsJSGlobalProxy()) {
-        __ CheckAccessGlobalProxy(reg, scratch2, miss);
+        __ CheckAccessGlobalProxy(reg, scratch1, scratch2, miss);
+      }
+
+      if (in_new_space) {
+        // Save the map in scratch1 for later.
+        __ mov(scratch1, FieldOperand(reg, HeapObject::kMapOffset));
       }
+
       reg = holder_reg;  // From now on the object will be in holder_reg.
 
       if (in_new_space) {
@@ -1020,7 +1022,7 @@ Register StubCompiler::CheckPrototypes(Handle<JSObject> object,
   // Perform security check for access to the global object.
   ASSERT(holder->IsJSGlobalProxy() || !holder->IsAccessCheckNeeded());
   if (holder->IsJSGlobalProxy()) {
-    __ CheckAccessGlobalProxy(reg, scratch1, miss);
+    __ CheckAccessGlobalProxy(reg, scratch1, scratch2, miss);
   }
 
   // If we've skipped any global objects, it's not enough to verify that
@@ -2657,7 +2659,7 @@ Handle<Code> StoreStubCompiler::CompileStoreInterceptor(
 
   // Perform global security token check if needed.
   if (object->IsJSGlobalProxy()) {
-    __ CheckAccessGlobalProxy(edx, ebx, &miss);
+    __ CheckAccessGlobalProxy(receiver(), scratch1(), scratch2(), &miss);
   }
 
   // Stub never generated for non-global objects that require access

src/mips/macro-assembler-mips.cc

@@ -369,7 +369,6 @@ void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
 
   // Check the context is a native context.
   if (emit_debug_code()) {
-    // TODO(119): Avoid push(holder_reg)/pop(holder_reg).
     push(holder_reg);  // Temporarily save holder on the stack.
     // Read the first word and compare to the native_context_map.
     lw(holder_reg, FieldMemOperand(scratch, HeapObject::kMapOffset));
@@ -385,7 +384,6 @@ void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
 
   // Check the context is a native context.
   if (emit_debug_code()) {
-    // TODO(119): Avoid push(holder_reg)/pop(holder_reg).
     push(holder_reg);  // Temporarily save holder on the stack.
     mov(holder_reg, at);  // Move at to its holding place.
     LoadRoot(at, Heap::kNullValueRootIndex);