ARM: Load the heap number map into a register and keep it

there throughout the binary op stub (used for checking and
creating heap numbers).
Review URL: http://codereview.chromium.org/2843010

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4897 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/codegen-arm.h

@@ -669,7 +669,9 @@ class GenericBinaryOpStub : public CodeStub {
   }
 
   void Generate(MacroAssembler* masm);
-  void HandleNonSmiBitwiseOp(MacroAssembler* masm, Register lhs, Register rhs);
+  void HandleNonSmiBitwiseOp(MacroAssembler* masm,
+                             Register lhs,
+                             Register rhs);
   void HandleBinaryOpSlowCases(MacroAssembler* masm,
                                Label* not_smi,
                                Register lhs,

src/arm/full-codegen-arm.cc

@@ -2156,7 +2156,8 @@ void FullCodeGenerator::EmitRandomHeapNumber(ZoneList<Expression*>* args) {
   Label slow_allocate_heapnumber;
   Label heapnumber_allocated;
 
-  __ AllocateHeapNumber(r4, r1, r2, &slow_allocate_heapnumber);
+  __ LoadRoot(r6, Heap::kHeapNumberMapRootIndex);
+  __ AllocateHeapNumber(r4, r1, r2, r6, &slow_allocate_heapnumber);
   __ jmp(&heapnumber_allocated);
 
   __ bind(&slow_allocate_heapnumber);

src/arm/ic-arm.cc

@@ -1339,7 +1339,8 @@ void KeyedLoadIC::GenerateExternalArray(MacroAssembler* masm,
     __ bind(&box_int);
     // Allocate a HeapNumber for the result and perform int-to-double
     // conversion. Use r0 for result as key is not needed any more.
-    __ AllocateHeapNumber(r0, r3, r4, &slow);
+    __ LoadRoot(r6, Heap::kHeapNumberMapRootIndex);
+    __ AllocateHeapNumber(r0, r3, r4, r6, &slow);
 
     if (CpuFeatures::IsSupported(VFP3)) {
       CpuFeatures::Scope scope(VFP3);
@@ -1370,7 +1371,8 @@ void KeyedLoadIC::GenerateExternalArray(MacroAssembler* masm,
       // Allocate a HeapNumber for the result and perform int-to-double
       // conversion. Don't use r0 and r1 as AllocateHeapNumber clobbers all
       // registers - also when jumping due to exhausted young space.
-      __ AllocateHeapNumber(r2, r3, r4, &slow);
+      __ LoadRoot(r6, Heap::kHeapNumberMapRootIndex);
+      __ AllocateHeapNumber(r2, r3, r4, r6, &slow);
 
       __ vcvt_f64_u32(d0, s0);
       __ sub(r1, r2, Operand(kHeapObjectTag));
@@ -1407,7 +1409,8 @@ void KeyedLoadIC::GenerateExternalArray(MacroAssembler* masm,
       // Wrap it into a HeapNumber. Don't use r0 and r1 as AllocateHeapNumber
       // clobbers all registers - also when jumping due to exhausted young
       // space.
-      __ AllocateHeapNumber(r4, r5, r6, &slow);
+      __ LoadRoot(r6, Heap::kHeapNumberMapRootIndex);
+      __ AllocateHeapNumber(r4, r5, r7, r6, &slow);
 
       __ str(hiword, FieldMemOperand(r4, HeapNumber::kExponentOffset));
       __ str(loword, FieldMemOperand(r4, HeapNumber::kMantissaOffset));
@@ -1423,7 +1426,8 @@ void KeyedLoadIC::GenerateExternalArray(MacroAssembler* masm,
       // Allocate a HeapNumber for the result. Don't use r0 and r1 as
       // AllocateHeapNumber clobbers all registers - also when jumping due to
       // exhausted young space.
-      __ AllocateHeapNumber(r2, r3, r4, &slow);
+      __ LoadRoot(r6, Heap::kHeapNumberMapRootIndex);
+      __ AllocateHeapNumber(r2, r3, r4, r6, &slow);
       __ vcvt_f64_f32(d0, s0);
       __ sub(r1, r2, Operand(kHeapObjectTag));
       __ vstr(d0, r1, HeapNumber::kValueOffset);
@@ -1434,7 +1438,8 @@ void KeyedLoadIC::GenerateExternalArray(MacroAssembler* masm,
       // Allocate a HeapNumber for the result. Don't use r0 and r1 as
       // AllocateHeapNumber clobbers all registers - also when jumping due to
       // exhausted young space.
-      __ AllocateHeapNumber(r3, r4, r5, &slow);
+      __ LoadRoot(r6, Heap::kHeapNumberMapRootIndex);
+      __ AllocateHeapNumber(r3, r4, r5, r6, &slow);
       // VFP is not available, do manual single to double conversion.
 
       // r2: floating point value (binary32)

src/arm/macro-assembler-arm.cc

@@ -1528,6 +1528,16 @@ void MacroAssembler::Assert(Condition cc, const char* msg) {
 }
 
 
+void MacroAssembler::AssertRegisterIsRoot(Register reg,
+                                          Heap::RootListIndex index) {
+  if (FLAG_debug_code) {
+    LoadRoot(ip, index);
+    cmp(reg, ip);
+    Check(eq, "Register did not match expected root");
+  }
+}
+
+
 void MacroAssembler::Check(Condition cc, const char* msg) {
   Label L;
   b(cc, &L);
@@ -1646,6 +1656,7 @@ void MacroAssembler::JumpIfNotBothSequentialAsciiStrings(Register first,
 void MacroAssembler::AllocateHeapNumber(Register result,
                                         Register scratch1,
                                         Register scratch2,
+                                        Register heap_number_map,
                                         Label* gc_required) {
   // Allocate an object in the heap for the heap number and tag it as a heap
   // object.
@@ -1656,9 +1667,9 @@ void MacroAssembler::AllocateHeapNumber(Register result,
                      gc_required,
                      TAG_OBJECT);
 
-  // Get heap number map and store it in the allocated object.
-  LoadRoot(scratch1, Heap::kHeapNumberMapRootIndex);
-  str(scratch1, FieldMemOperand(result, HeapObject::kMapOffset));
+  // Store heap number map in the allocated object.
+  AssertRegisterIsRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
+  str(heap_number_map, FieldMemOperand(result, HeapObject::kMapOffset));
 }
 
 

src/arm/macro-assembler-arm.h

@@ -379,6 +379,7 @@ class MacroAssembler: public Assembler {
   void AllocateHeapNumber(Register result,
                           Register scratch1,
                           Register scratch2,
+                          Register heap_number_map,
                           Label* gc_required);
 
   // ---------------------------------------------------------------------------
@@ -558,6 +559,7 @@ class MacroAssembler: public Assembler {
   // Calls Abort(msg) if the condition cc is not satisfied.
   // Use --debug_code to enable.
   void Assert(Condition cc, const char* msg);
+  void AssertRegisterIsRoot(Register reg, Heap::RootListIndex index);
 
   // Like Assert(), but always enabled.
   void Check(Condition cc, const char* msg);