Optimize fast element conversion in arm using batch store/loads.

src/arm/code-stubs-arm.cc

 // Copyright 2011 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 6914 matching lines @@
   // Used in KeyedStoreStubCompiler::CompileStoreField via GenerateStoreField.
   { r2, r1, r3, EMIT_REMEMBERED_SET },
   { r3, r1, r2, EMIT_REMEMBERED_SET },
   // KeyedStoreStubCompiler::GenerateStoreFastElement.
   { r4, r2, r3, EMIT_REMEMBERED_SET },
   // FastElementsConversionStub::GenerateSmiOnlyToObject
   // and FastElementsConversionStub::GenerateSmiOnlyToDouble
   // and FastElementsConversionStub::GenerateDoubleToObject
   { r2, r3, r9, EMIT_REMEMBERED_SET },
   // FastElementsConversionStub::GenerateDoubleToObject
-  { r6, r0, r2, EMIT_REMEMBERED_SET },
+  { r6, r2, r0, EMIT_REMEMBERED_SET },
   { r2, r6, r9, EMIT_REMEMBERED_SET },
   // Null termination.
   { no_reg, no_reg, no_reg, EMIT_REMEMBERED_SET}
 };
 
 
 bool RecordWriteStub::IsPregenerated() {
   for (AheadOfTimeWriteBarrierStubList* entry = kAheadOfTime;
        !entry->object.is(no_reg);
        entry++) {
@@ skipping 293 matching lines @@
                       r3,
                       r9,
                       kLRHasBeenSaved,
                       kDontSaveFPRegs,
                       EMIT_REMEMBERED_SET,
                       OMIT_SMI_CHECK);
   __ pop(lr);
 
   // Prepare for conversion loop.
   __ add(r3, r4, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
-  __ add(r6, r6, Operand(FixedDoubleArray::kHeaderSize));
-  __ add(r4, r6, Operand(r5, LSL, 2));
-  __ mov(r5, Operand(kHoleNanLower32));
-  __ mov(r7, Operand(kHoleNanUpper32));
+  __ add(r7, r6, Operand(FixedDoubleArray::kHeaderSize));
+  __ add(r6, r7, Operand(r5, LSL, 2));
+  __ mov(r4, Operand(kHoleNanLower32));
+  __ mov(r5, Operand(kHoleNanUpper32));
   // r3: begin of source FixedArray element fields, not tagged
-  // r4: end of destination FixedDoubleArray, not tagged
-  // r6: begin of FixedDoubleArray element fields, not tagged
-  // r5: kHoleNanLower32
-  // r7: kHoleNanUpper32
-  if (vfp3_supported) __ Push(r0, r1);
+  // r4: kHoleNanLower32
+  // r5: kHoleNanUpper32
+  // r6: end of destination FixedDoubleArray, not tagged
+  // r7: begin of FixedDoubleArray element fields, not tagged
+  if (vfp3_supported) __ Push(r1, r0);
 
   __ b(&entry);
 
   // Call into runtime if GC is required.
   __ bind(&gc_required);
   KeyedStoreIC::GenerateRuntimeSetProperty(masm, strict_mode);
 
   // Convert and copy elements.
   __ bind(&loop);
   __ ldr(r9, MemOperand(r3, 4, PostIndex));
   // r9: current element
   __ JumpIfNotSmi(r9, &convert_hole);
 
   // Normal smi, convert to double and store.
   __ SmiUntag(r9);
   if (vfp3_supported) {
     CpuFeatures::Scope scope(VFP3);
     __ vmov(s0, r9);
     __ vcvt_f64_s32(d0, s0);
-    __ vstr(d0, r6, 0);
-    __ add(r6, r6, Operand(8));
+    __ vstr(d0, r7, 0);
+    __ add(r7, r7, Operand(8));
   } else {
     FloatingPointHelper::ConvertIntToDouble(masm,
                                             r9,
                                             FloatingPointHelper::kCoreRegisters,
                                             d0,
                                             r0,
                                             r1,
                                             ip,
                                             s0);
-    __ str(r0, MemOperand(r6, 4, PostIndex));  // mantissa
-    __ str(r1, MemOperand(r6, 4, PostIndex));  // exponent
+    __ Strd(r0, r1, MemOperand(r7, 8, PostIndex));
   }
   __ b(&entry);
 
   // Hole found, store the-hole NaN.
   __ bind(&convert_hole);
-  __ str(r5, MemOperand(r6, 4, PostIndex));  // mantissa
-  __ str(r7, MemOperand(r6, 4, PostIndex));  // exponent
+  __ Strd(r4, r5, MemOperand(r7, 8, PostIndex));
 
   __ bind(&entry);
-  __ cmp(r6, r4);
+  __ cmp(r7, r6);
   __ b(lt, &loop);
 
-  if (vfp3_supported) __ Pop(r0, r1);
+  if (vfp3_supported) __ Pop(r1, r0);
 }
 
 
 void FastElementsConversionStub::GenerateDoubleToObject(
     MacroAssembler* masm, StrictModeFlag strict_mode) {
   // ----------- S t a t e -------------
   //  -- r0    : value
   //  -- r1    : key
   //  -- r2    : receiver
   //  -- lr    : return address
   //  -- r3    : target map, scratch for subsequent call
   //  -- r4    : scratch (elements)
   // -----------------------------------
   Label entry, loop, convert_hole, gc_required;
 
   __ push(lr);
-  __ Push(r0, r1, r2, r3);
+  __ Push(r3, r2, r1, r0);
 
   __ ldr(r4, FieldMemOperand(r2, JSObject::kElementsOffset));
   __ ldr(r5, FieldMemOperand(r4, FixedArray::kLengthOffset));
   // r4: source FixedDoubleArray
   // r5: number of elements (smi-tagged)
 
   // Allocate new FixedArray.
   __ mov(r0, Operand(FixedDoubleArray::kHeaderSize));
   __ add(r0, r0, Operand(r5, LSL, 1));
   __ AllocateInNewSpace(r0, r6, r7, r9, &gc_required, NO_ALLOCATION_FLAGS);
@@ skipping 14 matching lines @@
   // r3: begin of destination FixedArray element fields, not tagged
   // r4: begin of source FixedDoubleArray element fields, not tagged, +4
   // r5: end of destination FixedArray, not tagged
   // r6: destination FixedArray
   // r7: the-hole pointer
   // r9: heap number map
   __ b(&entry);
 
   // Call into runtime if GC is required.
   __ bind(&gc_required);
-  __ Pop(r2, r3);
-  __ Pop(r0, r1);
+  __ Pop(r3, r2, r1, r0);
   __ pop(lr);
   KeyedStoreIC::GenerateRuntimeSetProperty(masm, strict_mode);
 
   __ bind(&loop);
-  __ ldr(lr, MemOperand(r4, 8, PostIndex));
+  __ ldr(r1, MemOperand(r4, 8, PostIndex));
   // lr: current element's upper 32 bit
   // r4: address of next element's upper 32 bit
-  __ cmp(lr, Operand(kHoleNanUpper32));
+  __ cmp(r1, Operand(kHoleNanUpper32));
   __ b(eq, &convert_hole);
 
   // Non-hole double, copy value into a heap number.
-  __ AllocateHeapNumber(r0, r1, r2, r9, &gc_required);
-  __ str(lr, FieldMemOperand(r0, HeapNumber::kExponentOffset));
-  __ ldr(lr, MemOperand(r4, 12, NegOffset));
-  __ str(lr, FieldMemOperand(r0, HeapNumber::kMantissaOffset));
-  __ mov(r2, r3);
-  __ str(r0, MemOperand(r3, 4, PostIndex));
+  __ AllocateHeapNumber(r2, r0, lr, r9, &gc_required);
+  // r2: new heap number
+  __ ldr(r0, MemOperand(r4, 12, NegOffset));
+  __ Strd(r0, r1, FieldMemOperand(r2, HeapNumber::kValueOffset));
+  __ mov(r0, r3);
+  __ str(r2, MemOperand(r3, 4, PostIndex));
   __ RecordWrite(r6,
+                 r0,
                  r2,
-                 r0,
                  kLRHasBeenSaved,
                  kDontSaveFPRegs,
                  EMIT_REMEMBERED_SET,
                  OMIT_SMI_CHECK);
   __ b(&entry);
 
   // Replace the-hole NaN with the-hole pointer.
   __ bind(&convert_hole);
   __ str(r7, MemOperand(r3, 4, PostIndex));
 
   __ bind(&entry);
   __ cmp(r3, r5);
   __ b(lt, &loop);
 
-  __ Pop(r2, r3);
-  __ Pop(r0, r1);
+  __ Pop(r3, r2, r1, r0);
   // Update receiver's map.
   __ str(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
   __ RecordWriteField(r2,
                       HeapObject::kMapOffset,
                       r3,
                       r9,
                       kLRHasBeenSaved,
                       kDontSaveFPRegs,
                       EMIT_REMEMBERED_SET,
                       OMIT_SMI_CHECK);
   // Replace receiver's backing store with newly created and filled FixedArray.
   __ str(r6, FieldMemOperand(r2, JSObject::kElementsOffset));
   __ RecordWriteField(r2,
                       JSObject::kElementsOffset,
                       r6,
                       r9,
                       kLRHasBeenSaved,
                       kDontSaveFPRegs,
                       EMIT_REMEMBERED_SET,
                       OMIT_SMI_CHECK);
   __ pop(lr);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM