Implement flooring division by a constant via truncating division by a constant.

src/x64/lithium-x64.h

 // 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 741 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(FlooringDivByPowerOf2I,
                                "flooring-div-by-power-of-2-i")
   DECLARE_HYDROGEN_ACCESSOR(MathFloorOfDiv)
 
  private:
   int32_t divisor_;
 };
 
 
-class LFlooringDivByConstI V8_FINAL : public LTemplateInstruction<1, 1, 2> {
+class LFlooringDivByConstI V8_FINAL : public LTemplateInstruction<1, 1, 3> {
  public:
   LFlooringDivByConstI(LOperand* dividend,
                        int32_t divisor,
                        LOperand* temp1,
-                       LOperand* temp2) {
+                       LOperand* temp2,
+                       LOperand* temp3) {
     inputs_[0] = dividend;
     divisor_ = divisor;
     temps_[0] = temp1;
     temps_[1] = temp2;
+    temps_[2] = temp3;
   }
 
   LOperand* dividend() { return inputs_[0]; }
   int32_t divisor() const { return divisor_; }
   LOperand* temp1() { return temps_[0]; }
-  LOperand* temp2() { return temps_[0]; }
+  LOperand* temp2() { return temps_[1]; }
+  LOperand* temp3() { return temps_[2]; }
 
   DECLARE_CONCRETE_INSTRUCTION(FlooringDivByConstI, "flooring-div-by-const-i")
   DECLARE_HYDROGEN_ACCESSOR(MathFloorOfDiv)
 
  private:
   int32_t divisor_;
 };
 
 
 class LMulI V8_FINAL : public LTemplateInstruction<1, 2, 0> {
@@ skipping 2001 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::int
 
 #endif  // V8_X64_LITHIUM_X64_H_