ARM: Fast path for integer inputs to EmitVFPTruncate

src/arm/code-stubs-arm.cc

 // Copyright 2012 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 808 matching lines @@
     __ mov(dst1, Operand::Zero());
   }
   __ bind(&done);
 }
 
 
 void FloatingPointHelper::LoadNumberAsInt32Double(MacroAssembler* masm,
                                                   Register object,
                                                   Destination destination,
                                                   DwVfpRegister double_dst,
+                                                  DwVfpRegister double_scratch,
                                                   Register dst1,
                                                   Register dst2,
                                                   Register heap_number_map,
                                                   Register scratch1,
                                                   Register scratch2,
                                                   SwVfpRegister single_scratch,
                                                   Label* not_int32) {
   ASSERT(!scratch1.is(object) && !scratch2.is(object));
   ASSERT(!scratch1.is(scratch2));
   ASSERT(!heap_number_map.is(object) &&
@@ skipping 17 matching lines @@
   __ JumpIfNotHeapNumber(object, heap_number_map, scratch1, not_int32);
 
   // Load the number.
   if (CpuFeatures::IsSupported(VFP2)) {
     CpuFeatures::Scope scope(VFP2);
     // Load the double value.
     __ sub(scratch1, object, Operand(kHeapObjectTag));
     __ vldr(double_dst, scratch1, HeapNumber::kValueOffset);
 
     __ EmitVFPTruncate(kRoundToZero,
-                       single_scratch,
+                       scratch1,
                        double_dst,
-                       scratch1,
                        scratch2,
+                       double_scratch,
                        kCheckForInexactConversion);
 
     // Jump to not_int32 if the operation did not succeed.
     __ b(ne, not_int32);
 
     if (destination == kCoreRegisters) {
       __ vmov(dst1, dst2, double_dst);
     }
 
   } else {
@@ skipping 19 matching lines @@
 }
 
 
 void FloatingPointHelper::LoadNumberAsInt32(MacroAssembler* masm,
                                             Register object,
                                             Register dst,
                                             Register heap_number_map,
                                             Register scratch1,
                                             Register scratch2,
                                             Register scratch3,
-                                            DwVfpRegister double_scratch,
+                                            DwVfpRegister double_scratch0,
+                                            DwVfpRegister double_scratch1,
                                             Label* not_int32) {
   ASSERT(!dst.is(object));
   ASSERT(!scratch1.is(object) && !scratch2.is(object) && !scratch3.is(object));
   ASSERT(!scratch1.is(scratch2) &&
          !scratch1.is(scratch3) &&
          !scratch2.is(scratch3));
 
   Label done;
 
   __ UntagAndJumpIfSmi(dst, object, &done);
 
   if (FLAG_debug_code) {
     __ AbortIfNotRootValue(heap_number_map,
                            Heap::kHeapNumberMapRootIndex,
                            "HeapNumberMap register clobbered.");
   }
   __ JumpIfNotHeapNumber(object, heap_number_map, scratch1, not_int32);
 
   // Object is a heap number.
   // Convert the floating point value to a 32-bit integer.
   if (CpuFeatures::IsSupported(VFP2)) {
     CpuFeatures::Scope scope(VFP2);
-    SwVfpRegister single_scratch = double_scratch.low();
+
     // Load the double value.
     __ sub(scratch1, object, Operand(kHeapObjectTag));
-    __ vldr(double_scratch, scratch1, HeapNumber::kValueOffset);
+    __ vldr(double_scratch0, scratch1, HeapNumber::kValueOffset);
 
     __ EmitVFPTruncate(kRoundToZero,
-                       single_scratch,
-                       double_scratch,
+                       dst,
+                       double_scratch0,
                        scratch1,
-                       scratch2,
+                       double_scratch1,
                        kCheckForInexactConversion);
 
     // Jump to not_int32 if the operation did not succeed.
     __ b(ne, not_int32);
-    // Get the result in the destination register.
-    __ vmov(dst, single_scratch);
-
   } else {
     // Load the double value in the destination registers.
     __ ldr(scratch1, FieldMemOperand(object, HeapNumber::kExponentOffset));
     __ ldr(scratch2, FieldMemOperand(object, HeapNumber::kMantissaOffset));
 
     // Check for 0 and -0.
     __ bic(dst, scratch1, Operand(HeapNumber::kSignMask));
     __ orr(dst, scratch2, Operand(dst));
     __ cmp(dst, Operand::Zero());
     __ b(eq, &done);
@@ skipping 1884 matching lines @@
 
 
 void BinaryOpStub::GenerateInt32Stub(MacroAssembler* masm) {
   ASSERT(operands_type_ == BinaryOpIC::INT32);
 
   Register left = r1;
   Register right = r0;
   Register scratch1 = r7;
   Register scratch2 = r9;
   DwVfpRegister double_scratch = d0;
-  SwVfpRegister single_scratch = s3;
 
   Register heap_number_result = no_reg;
   Register heap_number_map = r6;
   __ LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
 
   Label call_runtime;
   // Labels for type transition, used for wrong input or output types.
   // Both label are currently actually bound to the same position. We use two
   // different label to differentiate the cause leading to type transition.
   Label transition;
@@ skipping 17 matching lines @@
       // and left) are preserved for the runtime call.
       FloatingPointHelper::Destination destination =
           (CpuFeatures::IsSupported(VFP2) && op_ != Token::MOD)
               ? FloatingPointHelper::kVFPRegisters
               : FloatingPointHelper::kCoreRegisters;
 
       FloatingPointHelper::LoadNumberAsInt32Double(masm,
                                                    right,
                                                    destination,
                                                    d7,
+                                                   d8,
                                                    r2,
                                                    r3,
                                                    heap_number_map,
                                                    scratch1,
                                                    scratch2,
                                                    s0,
                                                    &transition);
       FloatingPointHelper::LoadNumberAsInt32Double(masm,
                                                    left,
                                                    destination,
                                                    d6,
+                                                   d8,
                                                    r4,
                                                    r5,
                                                    heap_number_map,
                                                    scratch1,
                                                    scratch2,
                                                    s0,
                                                    &transition);
 
       if (destination == FloatingPointHelper::kVFPRegisters) {
         CpuFeatures::Scope scope(VFP2);
@@ skipping 15 matching lines @@
             UNREACHABLE();
         }
 
         if (op_ != Token::DIV) {
           // These operations produce an integer result.
           // Try to return a smi if we can.
           // Otherwise return a heap number if allowed, or jump to type
           // transition.
 
           __ EmitVFPTruncate(kRoundToZero,
-                             single_scratch,
+                             scratch1,
                              d5,
-                             scratch1,
-                             scratch2);
+                             scratch2,
+                             d8);
 
           if (result_type_ <= BinaryOpIC::INT32) {
             // If the ne condition is set, result does
             // not fit in a 32-bit integer.
             __ b(ne, &transition);
           }
 
           // Check if the result fits in a smi.
-          __ vmov(scratch1, single_scratch);
           __ add(scratch2, scratch1, Operand(0x40000000), SetCC);
           // If not try to return a heap number.
           __ b(mi, &return_heap_number);
           // Check for minus zero. Return heap number for minus zero.
           Label not_zero;
           __ cmp(scratch1, Operand::Zero());
           __ b(ne, &not_zero);
           __ vmov(scratch2, d5.high());
           __ tst(scratch2, Operand(HeapNumber::kSignMask));
           __ b(ne, &return_heap_number);
@@ skipping 74 matching lines @@
       // registers r0 and r1 (right and left) are preserved for the runtime
       // call.
       FloatingPointHelper::LoadNumberAsInt32(masm,
                                              left,
                                              r3,
                                              heap_number_map,
                                              scratch1,
                                              scratch2,
                                              scratch3,
                                              d0,
+                                             d1,
                                              &transition);
       FloatingPointHelper::LoadNumberAsInt32(masm,
                                              right,
                                              r2,
                                              heap_number_map,
                                              scratch1,
                                              scratch2,
                                              scratch3,
                                              d0,
+                                             d1,
                                              &transition);
 
       // The ECMA-262 standard specifies that, for shift operations, only the
       // 5 least significant bits of the shift value should be used.
       switch (op_) {
         case Token::BIT_OR:
           __ orr(r2, r3, Operand(r2));
           break;
         case Token::BIT_XOR:
           __ eor(r2, r3, Operand(r2));
@@ skipping 4568 matching lines @@
 
   __ Pop(lr, r5, r1);
   __ Ret();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM