Change GenerateLoadStringLength to have two scratch registers on all...

Change GenerateLoadStringLength to have two scratch registers on all platforms.  This is needed so that the LoadIC can pass the receiver in a register, and not have it overwritten, and also simplifies the code.
Review URL: http://codereview.chromium.org/596011

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3820 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/ic-arm.cc

@@ -190,7 +190,7 @@ void LoadIC::GenerateStringLength(MacroAssembler* masm) {
 
   __ ldr(r0, MemOperand(sp, 0));
 
-  StubCompiler::GenerateLoadStringLength2(masm, r0, r1, r3, &miss);
+  StubCompiler::GenerateLoadStringLength(masm, r0, r1, r3, &miss);
   // Cache miss: Jump to runtime.
   __ bind(&miss);
   StubCompiler::GenerateLoadMiss(masm, Code::LOAD_IC);

src/arm/stub-cache-arm.cc

@@ -215,7 +215,7 @@ static void GenerateStringCheck(MacroAssembler* masm,
 // If the receiver object is not a string or a wrapped string object the
 // execution continues at the miss label. The register containing the
 // receiver is potentially clobbered.
-void StubCompiler::GenerateLoadStringLength2(MacroAssembler* masm,
+void StubCompiler::GenerateLoadStringLength(MacroAssembler* masm,
                                             Register receiver,
                                             Register scratch1,
                                             Register scratch2,
@@ -1672,7 +1672,7 @@ Object* KeyedLoadStubCompiler::CompileLoadStringLength(String* name) {
   __ cmp(r2, Operand(Handle<String>(name)));
   __ b(ne, &miss);
 
-  GenerateLoadStringLength2(masm(), r0, r1, r3, &miss);
+  GenerateLoadStringLength(masm(), r0, r1, r3, &miss);
   __ bind(&miss);
   __ DecrementCounter(&Counters::keyed_load_string_length, 1, r1, r3);
 

src/ia32/ic-ia32.cc

@@ -200,7 +200,7 @@ void LoadIC::GenerateStringLength(MacroAssembler* masm) {
 
   __ mov(eax, Operand(esp, kPointerSize));
 
-  StubCompiler::GenerateLoadStringLength(masm, eax, edx, &miss);
+  StubCompiler::GenerateLoadStringLength(masm, eax, edx, ebx, &miss);
   __ bind(&miss);
   StubCompiler::GenerateLoadMiss(masm, Code::LOAD_IC);
 }

src/ia32/stub-cache-ia32.cc

@@ -226,13 +226,14 @@ static void GenerateStringCheck(MacroAssembler* masm,
 
 void StubCompiler::GenerateLoadStringLength(MacroAssembler* masm,
                                             Register receiver,
-                                            Register scratch,
+                                            Register scratch1,
+                                            Register scratch2,
                                             Label* miss) {
   Label load_length, check_wrapper;
 
   // Check if the object is a string leaving the instance type in the
   // scratch register.
-  GenerateStringCheck(masm, receiver, scratch, miss, &check_wrapper);
+  GenerateStringCheck(masm, receiver, scratch1, miss, &check_wrapper);
 
   // Load length from the string and convert to a smi.
   __ bind(&load_length);
@@ -242,13 +243,13 @@ void StubCompiler::GenerateLoadStringLength(MacroAssembler* masm,
 
   // Check if the object is a JSValue wrapper.
   __ bind(&check_wrapper);
-  __ cmp(scratch, JS_VALUE_TYPE);
+  __ cmp(scratch1, JS_VALUE_TYPE);
   __ j(not_equal, miss, not_taken);
 
   // Check if the wrapped value is a string and load the length
   // directly if it is.
-  __ mov(receiver, FieldOperand(receiver, JSValue::kValueOffset));
-  GenerateStringCheck(masm, receiver, scratch, miss, miss);
+  __ mov(scratch2, FieldOperand(receiver, JSValue::kValueOffset));
+  GenerateStringCheck(masm, scratch2, scratch1, miss, miss);
   __ jmp(&load_length);
 }
 
@@ -1773,7 +1774,7 @@ Object* KeyedLoadStubCompiler::CompileLoadStringLength(String* name) {
   __ cmp(Operand(eax), Immediate(Handle<String>(name)));
   __ j(not_equal, &miss, not_taken);
 
-  GenerateLoadStringLength(masm(), ecx, edx, &miss);
+  GenerateLoadStringLength(masm(), ecx, edx, ebx, &miss);
   __ bind(&miss);
   __ DecrementCounter(&Counters::keyed_load_string_length, 1);
   GenerateLoadMiss(masm(), Code::KEYED_LOAD_IC);

src/stub-cache.h

@@ -355,10 +355,6 @@ class StubCompiler BASE_EMBEDDED {
                                       Register scratch,
                                       Label* miss_label);
   static void GenerateLoadStringLength(MacroAssembler* masm,
-                                       Register receiver,
-                                       Register scratch,
-                                       Label* miss_label);
-  static void GenerateLoadStringLength2(MacroAssembler* masm,
                                         Register receiver,
                                         Register scratch1,
                                         Register scratch2,

src/x64/ic-x64.cc

@@ -1302,7 +1302,7 @@ void LoadIC::GenerateStringLength(MacroAssembler* masm) {
 
   __ movq(rax, Operand(rsp, kPointerSize));
 
-  StubCompiler::GenerateLoadStringLength(masm, rax, rdx, &miss);
+  StubCompiler::GenerateLoadStringLength(masm, rax, rdx, rbx, &miss);
   __ bind(&miss);
   StubCompiler::GenerateLoadMiss(masm, Code::LOAD_IC);
 }

src/x64/stub-cache-x64.cc

@@ -314,13 +314,14 @@ static void GenerateStringCheck(MacroAssembler* masm,
 
 void StubCompiler::GenerateLoadStringLength(MacroAssembler* masm,
                                             Register receiver,
-                                            Register scratch,
+                                            Register scratch1,
+                                            Register scratch2,
                                             Label* miss) {
   Label load_length, check_wrapper;
 
   // Check if the object is a string leaving the instance type in the
   // scratch register.
-  GenerateStringCheck(masm, receiver, scratch, miss, &check_wrapper);
+  GenerateStringCheck(masm, receiver, scratch1, miss, &check_wrapper);
 
   // Load length directly from the string.
   __ bind(&load_length);
@@ -330,13 +331,14 @@ void StubCompiler::GenerateLoadStringLength(MacroAssembler* masm,
 
   // Check if the object is a JSValue wrapper.
   __ bind(&check_wrapper);
-  __ cmpl(scratch, Immediate(JS_VALUE_TYPE));
+  __ cmpl(scratch1, Immediate(JS_VALUE_TYPE));
   __ j(not_equal, miss);
 
   // Check if the wrapped value is a string and load the length
   // directly if it is.
-  __ movq(receiver, FieldOperand(receiver, JSValue::kValueOffset));
-  GenerateStringCheck(masm, receiver, scratch, miss, miss);
+  __ movq(scratch2, FieldOperand(receiver, JSValue::kValueOffset));
+  GenerateStringCheck(masm, scratch2, scratch1, miss, miss);
+  __ movq(receiver, scratch2);
   __ jmp(&load_length);
 }
 
@@ -1325,7 +1327,7 @@ Object* KeyedLoadStubCompiler::CompileLoadStringLength(String* name) {
   __ Cmp(rax, Handle<String>(name));
   __ j(not_equal, &miss);
 
-  GenerateLoadStringLength(masm(), rcx, rdx, &miss);
+  GenerateLoadStringLength(masm(), rcx, rdx, rbx, &miss);
   __ bind(&miss);
   __ DecrementCounter(&Counters::keyed_load_string_length, 1);
   GenerateLoadMiss(masm(), Code::KEYED_LOAD_IC);