MIPS: Never hchange nan-hole to hole or hole to nan-hole. Only allow changing hole to nan if all us…

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 744 matching lines @@
     int deoptimization_index = deoptimizations_.length();
     int pc_offset = masm()->pc_offset();
     environment->Register(deoptimization_index,
                           translation.index(),
                           (mode == Safepoint::kLazyDeopt) ? pc_offset : -1);
     deoptimizations_.Add(environment, zone());
   }
 }
 
 
-void LCodeGen::DeoptimizeIf(Condition cc,
+void LCodeGen::DeoptimizeIf(Condition condition,
                             LEnvironment* environment,
                             Deoptimizer::BailoutType bailout_type,
                             Register src1,
                             const Operand& src2) {
   RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
   ASSERT(environment->HasBeenRegistered());
   int id = environment->deoptimization_index();
   ASSERT(info()->IsOptimizing() || info()->IsStub());
   Address entry =
       Deoptimizer::GetDeoptimizationEntry(isolate(), id, bailout_type);
   if (entry == NULL) {
     Abort(kBailoutWasNotPrepared);
     return;
   }
 
   ASSERT(FLAG_deopt_every_n_times < 2);  // Other values not supported on MIPS.
   if (FLAG_deopt_every_n_times == 1 &&
       !info()->IsStub() &&
       info()->opt_count() == id) {
     ASSERT(frame_is_built_);
     __ Call(entry, RelocInfo::RUNTIME_ENTRY);
     return;
   }
 
   if (info()->ShouldTrapOnDeopt()) {
     Label skip;
-    if (cc != al) {
-      __ Branch(&skip, NegateCondition(cc), src1, src2);
+    if (condition != al) {
+      __ Branch(&skip, NegateCondition(condition), src1, src2);
     }
     __ stop("trap_on_deopt");
     __ bind(&skip);
   }
 
   ASSERT(info()->IsStub() || frame_is_built_);
-  if (cc == al && frame_is_built_) {
-    __ Call(entry, RelocInfo::RUNTIME_ENTRY, cc, src1, src2);
+  if (condition == al && frame_is_built_) {
+    __ Call(entry, RelocInfo::RUNTIME_ENTRY, condition, src1, src2);
   } else {
     // We often have several deopts to the same entry, reuse the last
     // jump entry if this is the case.
     if (deopt_jump_table_.is_empty() ||
         (deopt_jump_table_.last().address != entry) ||
         (deopt_jump_table_.last().bailout_type != bailout_type) ||
         (deopt_jump_table_.last().needs_frame != !frame_is_built_)) {
       Deoptimizer::JumpTableEntry table_entry(entry,
                                               bailout_type,
                                               !frame_is_built_);
       deopt_jump_table_.Add(table_entry, zone());
     }
-    __ Branch(&deopt_jump_table_.last().label, cc, src1, src2);
+    __ Branch(&deopt_jump_table_.last().label, condition, src1, src2);
   }
 }
 
 
-void LCodeGen::DeoptimizeIf(Condition cc,
+void LCodeGen::DeoptimizeIf(Condition condition,
                             LEnvironment* environment,
                             Register src1,
                             const Operand& src2) {
   Deoptimizer::BailoutType bailout_type = info()->IsStub()
       ? Deoptimizer::LAZY
       : Deoptimizer::EAGER;
-  DeoptimizeIf(cc, environment, bailout_type, src1, src2);
+  DeoptimizeIf(condition, environment, bailout_type, src1, src2);
 }
 
 
 void LCodeGen::RegisterDependentCodeForEmbeddedMaps(Handle<Code> code) {
   ZoneList<Handle<Map> > maps(1, zone());
   int mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
   for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
     RelocInfo::Mode mode = it.rinfo()->rmode();
     if (mode == RelocInfo::EMBEDDED_OBJECT &&
         it.rinfo()->target_object()->IsMap()) {
@@ skipping 1149 matching lines @@
 
 int LCodeGen::GetNextEmittedBlock() const {
   for (int i = current_block_ + 1; i < graph()->blocks()->length(); ++i) {
     if (!chunk_->GetLabel(i)->HasReplacement()) return i;
   }
   return -1;
 }
 
 template<class InstrType>
 void LCodeGen::EmitBranch(InstrType instr,
-                          Condition cc, Register src1, const Operand& src2) {
+                          Condition condition,
+                          Register src1,
+                          const Operand& src2) {
   int left_block = instr->TrueDestination(chunk_);
   int right_block = instr->FalseDestination(chunk_);
 
   int next_block = GetNextEmittedBlock();
-  if (right_block == left_block || cc == al) {
+  if (right_block == left_block || condition == al) {
     EmitGoto(left_block);
   } else if (left_block == next_block) {
     __ Branch(chunk_->GetAssemblyLabel(right_block),
-              NegateCondition(cc), src1, src2);
+              NegateCondition(condition), src1, src2);
   } else if (right_block == next_block) {
-    __ Branch(chunk_->GetAssemblyLabel(left_block), cc, src1, src2);
+    __ Branch(chunk_->GetAssemblyLabel(left_block), condition, src1, src2);
   } else {
-    __ Branch(chunk_->GetAssemblyLabel(left_block), cc, src1, src2);
+    __ Branch(chunk_->GetAssemblyLabel(left_block), condition, src1, src2);
     __ Branch(chunk_->GetAssemblyLabel(right_block));
   }
 }
 
 
 template<class InstrType>
 void LCodeGen::EmitBranchF(InstrType instr,
-                           Condition cc, FPURegister src1, FPURegister src2) {
+                           Condition condition,
+                           FPURegister src1,
+                           FPURegister src2) {
   int right_block = instr->FalseDestination(chunk_);
   int left_block = instr->TrueDestination(chunk_);
 
   int next_block = GetNextEmittedBlock();
   if (right_block == left_block) {
     EmitGoto(left_block);
   } else if (left_block == next_block) {
     __ BranchF(chunk_->GetAssemblyLabel(right_block), NULL,
-               NegateCondition(cc), src1, src2);
+               NegateCondition(condition), src1, src2);
   } else if (right_block == next_block) {
-    __ BranchF(chunk_->GetAssemblyLabel(left_block), NULL, cc, src1, src2);
+    __ BranchF(chunk_->GetAssemblyLabel(left_block), NULL,
+               condition, src1, src2);
   } else {
-    __ BranchF(chunk_->GetAssemblyLabel(left_block), NULL, cc, src1, src2);
+    __ BranchF(chunk_->GetAssemblyLabel(left_block), NULL,
+               condition, src1, src2);
     __ Branch(chunk_->GetAssemblyLabel(right_block));
   }
 }
 
 
+template<class InstrType>
+void LCodeGen::EmitFalseBranchF(InstrType instr,
+                                Condition condition,
+                                FPURegister src1,
+                                FPURegister src2) {
+  int false_block = instr->FalseDestination(chunk_);
+  __ BranchF(chunk_->GetAssemblyLabel(false_block), NULL,
+             condition, src1, src2);
+}
+
+
 void LCodeGen::DoDebugBreak(LDebugBreak* instr) {
   __ stop("LDebugBreak");
 }
 
 
 void LCodeGen::DoIsNumberAndBranch(LIsNumberAndBranch* instr) {
   Representation r = instr->hydrogen()->value()->representation();
   if (r.IsSmiOrInteger32() || r.IsDouble()) {
     EmitBranch(instr, al, zero_reg, Operand(zero_reg));
   } else {
@@ skipping 240 matching lines @@
 
 
 void LCodeGen::DoCmpObjectEqAndBranch(LCmpObjectEqAndBranch* instr) {
   Register left = ToRegister(instr->left());
   Register right = ToRegister(instr->right());
 
   EmitBranch(instr, eq, left, Operand(right));
 }
 
 
+void LCodeGen::DoCmpHoleAndBranch(LCmpHoleAndBranch* instr) {
+  if (instr->hydrogen()->representation().IsTagged()) {
+    Register input_reg = ToRegister(instr->object());
+    __ li(at, Operand(factory()->the_hole_value()));
+    EmitBranch(instr, eq, input_reg, Operand(at));
+    return;
+  }
+
+  DoubleRegister input_reg = ToDoubleRegister(instr->object());
+  EmitFalseBranchF(instr, eq, input_reg, input_reg);
+
+  Register scratch = scratch0();
+  __ FmoveHigh(scratch, input_reg);
+  EmitBranch(instr, eq, scratch, Operand(kHoleNanUpper32));
+}
+
+
 Condition LCodeGen::EmitIsObject(Register input,
                                  Register temp1,
                                  Register temp2,
                                  Label* is_not_object,
                                  Label* is_object) {
   __ JumpIfSmi(input, is_not_object);
 
   __ LoadRoot(temp2, Heap::kNullValueRootIndex);
   __ Branch(is_object, eq, input, Operand(temp2));
 
@@ skipping 1836 matching lines @@
 
   // Name is always in a2.
   __ li(a2, Operand(instr->name()));
   Handle<Code> ic = (instr->strict_mode_flag() == kStrictMode)
       ? isolate()->builtins()->StoreIC_Initialize_Strict()
       : isolate()->builtins()->StoreIC_Initialize();
   CallCode(ic, RelocInfo::CODE_TARGET, instr);
 }
 
 
-void LCodeGen::ApplyCheckIf(Condition cc,
+void LCodeGen::ApplyCheckIf(Condition condition,
                             LBoundsCheck* check,
                             Register src1,
                             const Operand& src2) {
   if (FLAG_debug_code && check->hydrogen()->skip_check()) {
     Label done;
-    __ Branch(&done, NegateCondition(cc), src1, src2);
+    __ Branch(&done, NegateCondition(condition), src1, src2);
     __ stop("eliminated bounds check failed");
     __ bind(&done);
   } else {
-    DeoptimizeIf(cc, check->environment(), src1, src2);
+    DeoptimizeIf(condition, check->environment(), src1, src2);
   }
 }
 
 
 void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
   if (instr->hydrogen()->skip_check()) return;
 
   Condition condition = instr->hydrogen()->allow_equality() ? hi : hs;
   if (instr->index()->IsConstantOperand()) {
     int constant_index =
@@ skipping 522 matching lines @@
    private:
     LNumberTagD* instr_;
   };
 
   DoubleRegister input_reg = ToDoubleRegister(instr->value());
   Register scratch = scratch0();
   Register reg = ToRegister(instr->result());
   Register temp1 = ToRegister(instr->temp());
   Register temp2 = ToRegister(instr->temp2());
 
-  bool convert_hole = false;
-  HValue* change_input = instr->hydrogen()->value();
-  if (change_input->IsLoadKeyed()) {
-    HLoadKeyed* load = HLoadKeyed::cast(change_input);
-    convert_hole = load->UsesMustHandleHole();
-  }
-
-  Label no_special_nan_handling;
-  Label done;
-  if (convert_hole) {
-    DoubleRegister input_reg = ToDoubleRegister(instr->value());
-    __ BranchF(&no_special_nan_handling, NULL, eq, input_reg, input_reg);
-    __ Move(reg, scratch0(), input_reg);
-    Label canonicalize;
-    __ Branch(&canonicalize, ne, scratch0(), Operand(kHoleNanUpper32));
-    __ li(reg, factory()->undefined_value());
-    __ Branch(&done);
-    __ bind(&canonicalize);
-    __ Move(input_reg,
-            FixedDoubleArray::canonical_not_the_hole_nan_as_double());
-  }
-
-  __ bind(&no_special_nan_handling);
   DeferredNumberTagD* deferred = new(zone()) DeferredNumberTagD(this, instr);
   if (FLAG_inline_new) {
     __ LoadRoot(scratch, Heap::kHeapNumberMapRootIndex);
     // We want the untagged address first for performance
     __ AllocateHeapNumber(reg, temp1, temp2, scratch, deferred->entry(),
                           DONT_TAG_RESULT);
   } else {
     __ Branch(deferred->entry());
   }
   __ bind(deferred->exit());
   __ sdc1(input_reg, MemOperand(reg, HeapNumber::kValueOffset));
   // Now that we have finished with the object's real address tag it
   __ Addu(reg, reg, kHeapObjectTag);
-  __ bind(&done);
 }
 
 
 void LCodeGen::DoDeferredNumberTagD(LNumberTagD* instr) {
   // TODO(3095996): Get rid of this. For now, we need to make the
   // result register contain a valid pointer because it is already
   // contained in the register pointer map.
   Register reg = ToRegister(instr->result());
   __ mov(reg, zero_reg);
 
@@ skipping 21 matching lines @@
     __ SmiUntag(result, input);
     DeoptimizeIf(ne, instr->environment(), scratch, Operand(zero_reg));
   } else {
     __ SmiUntag(result, input);
   }
 }
 
 
 void LCodeGen::EmitNumberUntagD(Register input_reg,
                                 DoubleRegister result_reg,
-                                bool allow_undefined_as_nan,
+                                bool can_convert_undefined_to_nan,
                                 bool deoptimize_on_minus_zero,
                                 LEnvironment* env,
                                 NumberUntagDMode mode) {
   Register scratch = scratch0();
 
   Label load_smi, heap_number, done;
 
-  STATIC_ASSERT(NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE >
-                NUMBER_CANDIDATE_IS_ANY_TAGGED);
-  if (mode >= NUMBER_CANDIDATE_IS_ANY_TAGGED) {
+  if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED) {
     // Smi check.
     __ UntagAndJumpIfSmi(scratch, input_reg, &load_smi);
 
     // Heap number map check.
     __ lw(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
     __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
-    if (!allow_undefined_as_nan) {
+    if (!can_convert_undefined_to_nan) {
       DeoptimizeIf(ne, env, scratch, Operand(at));
     } else {
       Label heap_number, convert;
       __ Branch(&heap_number, eq, scratch, Operand(at));
 
       // Convert undefined (and hole) to NaN.
       __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
-      if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE) {
-        __ Branch(&convert, eq, input_reg, Operand(at));
-        __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
-      }
       DeoptimizeIf(ne, env, input_reg, Operand(at));
 
       __ bind(&convert);
       __ LoadRoot(at, Heap::kNanValueRootIndex);
       __ ldc1(result_reg, FieldMemOperand(at, HeapNumber::kValueOffset));
       __ Branch(&done);
 
       __ bind(&heap_number);
     }
     // Heap number to double register conversion.
@@ skipping 127 matching lines @@
 
 void LCodeGen::DoNumberUntagD(LNumberUntagD* instr) {
   LOperand* input = instr->value();
   ASSERT(input->IsRegister());
   LOperand* result = instr->result();
   ASSERT(result->IsDoubleRegister());
 
   Register input_reg = ToRegister(input);
   DoubleRegister result_reg = ToDoubleRegister(result);
 
-  NumberUntagDMode mode = NUMBER_CANDIDATE_IS_ANY_TAGGED;
   HValue* value = instr->hydrogen()->value();
-  if (value->type().IsSmi()) {
-    mode = NUMBER_CANDIDATE_IS_SMI;
-  } else if (value->IsLoadKeyed()) {
-    HLoadKeyed* load = HLoadKeyed::cast(value);
-    if (load->UsesMustHandleHole()) {
-      if (load->hole_mode() == ALLOW_RETURN_HOLE) {
-        mode = NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE;
-      }
-    }
-  }
+  NumberUntagDMode mode = value->representation().IsSmi()
+      ? NUMBER_CANDIDATE_IS_SMI : NUMBER_CANDIDATE_IS_ANY_TAGGED;
 
   EmitNumberUntagD(input_reg, result_reg,
-                   instr->hydrogen()->allow_undefined_as_nan(),
+                   instr->hydrogen()->can_convert_undefined_to_nan(),
                    instr->hydrogen()->deoptimize_on_minus_zero(),
                    instr->environment(),
                    mode);
 }
 
 
 void LCodeGen::DoDoubleToI(LDoubleToI* instr) {
   Register result_reg = ToRegister(instr->result());
   Register scratch1 = scratch0();
   Register scratch2 = ToRegister(instr->temp());
@@ skipping 814 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal