ARM: Fast path for integer inputs to EmitVFPTruncate

src/arm/lithium-codegen-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 3481 matching lines @@
     // If smi, handle it directly.
     EmitIntegerMathAbs(instr);
     __ bind(deferred->exit());
   }
 }
 
 
 void LCodeGen::DoMathFloor(LUnaryMathOperation* instr) {
   DoubleRegister input = ToDoubleRegister(instr->value());
   Register result = ToRegister(instr->result());
-  SwVfpRegister single_scratch = double_scratch0().low();
-  Register scratch1 = scratch0();
-  Register scratch2 = ToRegister(instr->temp());
+  Register scratch = scratch0();
 
   __ EmitVFPTruncate(kRoundToMinusInf,
-                     single_scratch,
+                     result,
                      input,
-                     scratch1,
-                     scratch2);
+                     scratch,
+                     double_scratch0());
   DeoptimizeIf(ne, instr->environment());
 
-  // Move the result back to general purpose register r0.
-  __ vmov(result, single_scratch);
-
   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
     // Test for -0.
     Label done;
     __ cmp(result, Operand(0));
     __ b(ne, &done);
-    __ vmov(scratch1, input.high());
-    __ tst(scratch1, Operand(HeapNumber::kSignMask));
+    __ vmov(scratch, input.high());
+    __ tst(scratch, Operand(HeapNumber::kSignMask));
     DeoptimizeIf(ne, instr->environment());
     __ bind(&done);
   }
 }
 
 
 void LCodeGen::DoMathRound(LUnaryMathOperation* instr) {
   DoubleRegister input = ToDoubleRegister(instr->value());
   Register result = ToRegister(instr->result());
+  DwVfpRegister double_scratch1 = ToDoubleRegister(instr->temp());
   Register scratch = scratch0();
   Label done, check_sign_on_zero;
 
   // Extract exponent bits.
   __ vmov(result, input.high());
   __ ubfx(scratch,
           result,
           HeapNumber::kExponentShift,
           HeapNumber::kExponentBits);
 
@@ skipping 22 matching lines @@
   __ vmov(result, double_scratch0().high());
   __ eor(result, result, Operand(scratch), SetCC);
   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
     DeoptimizeIf(mi, instr->environment());
   } else {
     __ mov(result, Operand(0), LeaveCC, mi);
     __ b(mi, &done);
   }
 
   __ EmitVFPTruncate(kRoundToMinusInf,
-                     double_scratch0().low(),
+                     result,
                      double_scratch0(),
-                     result,
-                     scratch);
+                     scratch,
+                     double_scratch1);
   DeoptimizeIf(ne, instr->environment());
-  __ vmov(result, double_scratch0().low());
 
   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
     // Test for -0.
     __ cmp(result, Operand(0));
     __ b(ne, &done);
     __ bind(&check_sign_on_zero);
     __ vmov(scratch, input.high());
     __ tst(scratch, Operand(HeapNumber::kSignMask));
     DeoptimizeIf(ne, instr->environment());
   }
@@ skipping 1005 matching lines @@
   __ vcvt_f64_s32(result_reg, flt_scratch);
   __ bind(&done);
 }
 
 
 void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr) {
   Register input_reg = ToRegister(instr->value());
   Register scratch1 = scratch0();
   Register scratch2 = ToRegister(instr->temp());
   DwVfpRegister double_scratch = double_scratch0();
-  SwVfpRegister single_scratch = double_scratch.low();
+  DwVfpRegister double_scratch2 = ToDoubleRegister(instr->temp3());
 
   ASSERT(!scratch1.is(input_reg) && !scratch1.is(scratch2));
   ASSERT(!scratch2.is(input_reg) && !scratch2.is(scratch1));
 
   Label done;
 
   // The input was optimistically untagged; revert it.
   // The carry flag is set when we reach this deferred code as we just executed
   // SmiUntag(heap_object, SetCC)
   STATIC_ASSERT(kHeapObjectTag == 1);
   __ adc(input_reg, input_reg, Operand(input_reg));
 
   // Heap number map check.
   __ ldr(scratch1, FieldMemOperand(input_reg, HeapObject::kMapOffset));
   __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
   __ cmp(scratch1, Operand(ip));
 
   if (instr->truncating()) {
     Register scratch3 = ToRegister(instr->temp2());
-    DwVfpRegister double_scratch2 = ToDoubleRegister(instr->temp3());
+    SwVfpRegister single_scratch = double_scratch.low();
     ASSERT(!scratch3.is(input_reg) &&
            !scratch3.is(scratch1) &&
            !scratch3.is(scratch2));
     // Performs a truncating conversion of a floating point number as used by
     // the JS bitwise operations.
     Label heap_number;
     __ b(eq, &heap_number);
     // Check for undefined. Undefined is converted to zero for truncating
     // conversions.
     __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
@@ skipping 14 matching lines @@
                         scratch3);
 
   } else {
     CpuFeatures::Scope scope(VFP3);
     // Deoptimize if we don't have a heap number.
     DeoptimizeIf(ne, instr->environment());
 
     __ sub(ip, input_reg, Operand(kHeapObjectTag));
     __ vldr(double_scratch, ip, HeapNumber::kValueOffset);
     __ EmitVFPTruncate(kRoundToZero,
-                       single_scratch,
+                       input_reg,
                        double_scratch,
                        scratch1,
-                       scratch2,
+                       double_scratch2,
                        kCheckForInexactConversion);
     DeoptimizeIf(ne, instr->environment());
-    // Load the result.
-    __ vmov(input_reg, single_scratch);
 
     if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
       __ cmp(input_reg, Operand(0));
       __ b(ne, &done);
       __ vmov(scratch1, double_scratch.high());
       __ tst(scratch1, Operand(HeapNumber::kSignMask));
       DeoptimizeIf(ne, instr->environment());
     }
   }
   __ bind(&done);
@@ skipping 43 matching lines @@
                    instr->hydrogen()->deoptimize_on_minus_zero(),
                    instr->environment());
 }
 
 
 void LCodeGen::DoDoubleToI(LDoubleToI* instr) {
   Register result_reg = ToRegister(instr->result());
   Register scratch1 = scratch0();
   Register scratch2 = ToRegister(instr->temp());
   DwVfpRegister double_input = ToDoubleRegister(instr->value());
-  SwVfpRegister single_scratch = double_scratch0().low();
 
   Label done;
 
   if (instr->truncating()) {
     Register scratch3 = ToRegister(instr->temp2());
+    SwVfpRegister single_scratch = double_scratch0().low();
     __ EmitECMATruncate(result_reg,
                         double_input,
                         single_scratch,
                         scratch1,
                         scratch2,
                         scratch3);
   } else {
-    VFPRoundingMode rounding_mode = kRoundToMinusInf;
-    __ EmitVFPTruncate(rounding_mode,
-                       single_scratch,
+    DwVfpRegister double_scratch = double_scratch0();
+    __ EmitVFPTruncate(kRoundToMinusInf,
+                       result_reg,
                        double_input,
                        scratch1,
-                       scratch2,
+                       double_scratch,
                        kCheckForInexactConversion);
+
     // Deoptimize if we had a vfp invalid exception,
     // including inexact operation.
     DeoptimizeIf(ne, instr->environment());
-    // Retrieve the result.
-    __ vmov(result_reg, single_scratch);
   }
     __ bind(&done);
 }
 
 
 void LCodeGen::DoCheckSmi(LCheckSmi* instr) {
   LOperand* input = instr->value();
   __ tst(ToRegister(input), Operand(kSmiTagMask));
   DeoptimizeIf(ne, instr->environment());
 }
@@ skipping 917 matching lines @@
   __ sub(scratch, result, Operand(index, LSL, kPointerSizeLog2 - kSmiTagSize));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal