Remove the first_right_arg hack for HMod.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 995 matching lines @@
       __ negl(left_reg);
       if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
         DeoptimizeIf(zero, instr->environment());
       }
       __ jmp(&done, Label::kNear);
     }
 
     __ bind(&left_is_not_negative);
     __ andl(left_reg, Immediate(divisor - 1));
     __ bind(&done);
-
-  } else if (hmod->fixed_right_arg().has_value) {
-    Register left_reg = ToRegister(instr->left());
-    ASSERT(left_reg.is(ToRegister(instr->result())));
-    Register right_reg = ToRegister(instr->right());
-
-    int32_t divisor = hmod->fixed_right_arg().value;
-    ASSERT(IsPowerOf2(divisor));
-
-    // Check if our assumption of a fixed right operand still holds.
-    __ cmpl(right_reg, Immediate(divisor));
-    DeoptimizeIf(not_equal, instr->environment());
-
-    Label left_is_not_negative, done;
-    if (left->CanBeNegative()) {
-      __ testl(left_reg, left_reg);
-      __ j(not_sign, &left_is_not_negative, Label::kNear);
-      __ negl(left_reg);
-      __ andl(left_reg, Immediate(divisor - 1));
-      __ negl(left_reg);
-      if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
-        DeoptimizeIf(zero, instr->environment());
-      }
-      __ jmp(&done, Label::kNear);
-    }
-
-    __ bind(&left_is_not_negative);
-    __ andl(left_reg, Immediate(divisor - 1));
-    __ bind(&done);
-
   } else {
     Register left_reg = ToRegister(instr->left());
     ASSERT(left_reg.is(rax));
     Register right_reg = ToRegister(instr->right());
     ASSERT(!right_reg.is(rax));
     ASSERT(!right_reg.is(rdx));
     Register result_reg = ToRegister(instr->result());
     ASSERT(result_reg.is(rdx));
 
     Label done;
@@ skipping 4638 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64