MIPS: [turbofan] Fix addition for deoptimization.

src/compiler/mips64/code-generator-mips64.cc

 // Copyright 2014 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/ast/scopes.h"
 #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/compiler/osr.h"
@@ skipping 1776 matching lines @@
   // instructions that do the actual comparison. Essential that the input
   // registers to compare pseudo-op are not modified before this branch op, as
   // they are tested here.
 
   if (instr->arch_opcode() == kMips64Tst) {
     cc = FlagsConditionToConditionTst(branch->condition);
     __ And(at, i.InputRegister(0), i.InputOperand(1));
     __ Branch(tlabel, cc, at, Operand(zero_reg));
   } else if (instr->arch_opcode() == kMips64Dadd ||
              instr->arch_opcode() == kMips64Dsub) {
+    Label done;
     cc = FlagsConditionToConditionOvf(branch->condition);
     __ dsra32(kScratchReg, i.OutputRegister(), 0);
     __ sra(at, i.OutputRegister(), 31);
-    __ Branch(tlabel, cc, at, Operand(kScratchReg));
+    __ Branch(&done, NegateCondition(cc), at, Operand(kScratchReg));
+    // If we deoptimize, check if output register is the same as input
+    // registers, if yes input values are overwritten so fix them first.
+    if (instr->InputAt(1)->IsRegister()) {
+      if (i.InputRegister(0).is(i.OutputRegister()) &&
+          i.InputRegister(1).is(i.OutputRegister())) {
+        __ dsra(i.OutputRegister(), i.OutputRegister(), 1);
+      }
+    }
+    __ Branch(tlabel);
+    __ bind(&done);
   } else if (instr->arch_opcode() == kMips64DaddOvf) {
     switch (branch->condition) {
       case kOverflow:
         __ DaddBranchOvf(i.OutputRegister(), i.InputRegister(0),
                          i.InputOperand(1), tlabel, flabel);
         break;
       case kNotOverflow:
         __ DaddBranchOvf(i.OutputRegister(), i.InputRegister(0),
                          i.InputOperand(1), flabel, tlabel);
         break;
@@ skipping 561 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8