MIPS: Fix hole handling, and ensure smi representation is handled properly

src/mips/lithium-codegen-mips.cc

 // 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 3626 matching lines @@
   Representation exponent_type = instr->hydrogen()->right()->representation();
   // Having marked this as a call, we can use any registers.
   // Just make sure that the input/output registers are the expected ones.
   ASSERT(!instr->right()->IsDoubleRegister() ||
          ToDoubleRegister(instr->right()).is(f4));
   ASSERT(!instr->right()->IsRegister() ||
          ToRegister(instr->right()).is(a2));
   ASSERT(ToDoubleRegister(instr->left()).is(f2));
   ASSERT(ToDoubleRegister(instr->result()).is(f0));
 
-  if (exponent_type.IsTagged()) {
+  if (exponent_type.IsSmi()) {
+    MathPowStub stub(MathPowStub::TAGGED);
+    __ CallStub(&stub);
+  } else if (exponent_type.IsTagged()) {
     Label no_deopt;
     __ JumpIfSmi(a2, &no_deopt);
     __ lw(t3, FieldMemOperand(a2, HeapObject::kMapOffset));
     DeoptimizeIf(ne, instr->environment(), t3, Operand(at));
     __ bind(&no_deopt);
     MathPowStub stub(MathPowStub::TAGGED);
     __ CallStub(&stub);
   } else if (exponent_type.IsInteger32()) {
     MathPowStub stub(MathPowStub::INTEGER);
     __ CallStub(&stub);
@@ skipping 983 matching lines @@
 void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
   Register scratch = scratch0();
   Register input = ToRegister(instr->value());
   Register result = ToRegister(instr->result());
   if (instr->needs_check()) {
     STATIC_ASSERT(kHeapObjectTag == 1);
     // If the input is a HeapObject, value of scratch won't be zero.
     __ And(scratch, input, Operand(kHeapObjectTag));
     __ SmiUntag(result, input);
     DeoptimizeIf(ne, instr->environment(), scratch, Operand(zero_reg));
-  } else if (instr->hydrogen()->value()->IsLoadKeyed()) {
-    HLoadKeyed* load = HLoadKeyed::cast(instr->hydrogen()->value());
-    if (load->UsesMustHandleHole()) {
-      __ And(scratch, input, Operand(kHeapObjectTag));
-      __ SmiUntag(result, input);
-      if (load->hole_mode() == ALLOW_RETURN_HOLE) {
-        Label done;
-        __ Branch(&done, eq, scratch, Operand(zero_reg));
-        __ li(result, Operand(Smi::FromInt(0)));
-        __ bind(&done);
-      } else {
-        DeoptimizeIf(ne, instr->environment(), scratch, Operand(zero_reg));
-      }
-    } else {
-      __ SmiUntag(result, input);
-    }
   } else {
     __ SmiUntag(result, input);
   }
 }
 
 
 void LCodeGen::EmitNumberUntagD(Register input_reg,
                                 DoubleRegister result_reg,
                                 bool deoptimize_on_undefined,
                                 bool deoptimize_on_minus_zero,
@@ skipping 1088 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal