X87: [turbofan] Add TruncationMode for TruncateFloat64ToInt32.

src/compiler/x87/code-generator-x87.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/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
 #include "src/scopes.h"
@@ skipping 404 matching lines @@
     case kArchRet:
       AssembleReturn();
       break;
     case kArchFramePointer:
       __ mov(i.OutputRegister(), ebp);
       break;
     case kArchStackPointer:
       __ mov(i.OutputRegister(), esp);
       break;
     case kArchTruncateDoubleToI: {
-      auto input = i.InputDoubleRegister(0);
-      USE(input);
-      DCHECK(input.code() == 0);
-      auto result_reg = i.OutputRegister();
-      __ TruncateX87TOSToI(result_reg);
+      if (!instr->InputAt(0)->IsDoubleRegister()) {
+        __ fld_d(i.InputOperand(0));
+      }
+      __ TruncateX87TOSToI(i.OutputRegister());
+      if (!instr->InputAt(0)->IsDoubleRegister()) {
+        __ fstp(0);
+      }
       break;
     }
     case kX87Add:
       if (HasImmediateInput(instr, 1)) {
         __ add(i.InputOperand(0), i.InputImmediate(1));
       } else {
         __ add(i.InputRegister(0), i.InputOperand(1));
       }
       break;
     case kX87And:
@@ skipping 1401 matching lines @@
       __ Nop(padding_size);
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8