[turbofan] Add the RoundInt32ToFloat32 operator to turbofan.

src/compiler/ia32/code-generator-ia32.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/code-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 731 matching lines @@
     case kSSEFloat64ToInt32:
       __ cvttsd2si(i.OutputRegister(), i.InputOperand(0));
       break;
     case kSSEFloat64ToUint32: {
       __ Move(kScratchDoubleReg, -2147483648.0);
       __ addsd(kScratchDoubleReg, i.InputOperand(0));
       __ cvttsd2si(i.OutputRegister(), kScratchDoubleReg);
       __ add(i.OutputRegister(), Immediate(0x80000000));
       break;
     }
+    case kSSEInt32ToFloat32:
+      __ cvtsi2ss(i.OutputDoubleRegister(), i.InputOperand(0));
+      break;
     case kSSEInt32ToFloat64:
       __ cvtsi2sd(i.OutputDoubleRegister(), i.InputOperand(0));
       break;
     case kSSEUint32ToFloat64:
       __ LoadUint32(i.OutputDoubleRegister(), i.InputOperand(0));
       break;
     case kSSEFloat64ExtractLowWord32:
       if (instr->InputAt(0)->IsDoubleStackSlot()) {
         __ mov(i.OutputRegister(), i.InputOperand(0));
       } else {
@@ skipping 935 matching lines @@
     int padding_size = last_lazy_deopt_pc_ + space_needed - current_pc;
     __ Nop(padding_size);
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8