Fix the hole loading optimization.

src/ia32/lithium-codegen-ia32.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 5058 matching lines @@
 
 
 void LCodeGen::EmitNumberUntagDNoSSE2(Register input_reg,
                                       Register temp_reg,
                                       bool deoptimize_on_undefined,
                                       bool deoptimize_on_minus_zero,
                                       LEnvironment* env,
                                       NumberUntagDMode mode) {
   Label load_smi, done;
 
-  if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED) {
+  STATIC_ASSERT(NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE >
+                NUMBER_CANDIDATE_IS_ANY_TAGGED);
+  if (mode >= NUMBER_CANDIDATE_IS_ANY_TAGGED) {
     // Smi check.
     __ JumpIfSmi(input_reg, &load_smi, Label::kNear);
 
     // Heap number map check.
     __ cmp(FieldOperand(input_reg, HeapObject::kMapOffset),
            factory()->heap_number_map());
     if (deoptimize_on_undefined) {
       DeoptimizeIf(not_equal, env);
     } else {
-      Label heap_number;
+      Label heap_number, convert;
       __ j(equal, &heap_number, Label::kNear);
 
+      // Convert undefined (or hole) to NaN.
       __ cmp(input_reg, factory()->undefined_value());
+      if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE) {
+        __ j(equal, &convert, Label::kNear);
+        __ cmp(input_reg, factory()->the_hole_value());
+      }
       DeoptimizeIf(not_equal, env);
 
-      // Convert undefined to NaN.
+      __ bind(&convert);
       ExternalReference nan =
           ExternalReference::address_of_canonical_non_hole_nan();
       __ fld_d(Operand::StaticVariable(nan));
       __ jmp(&done, Label::kNear);
+
       __ bind(&heap_number);
     }
     // Heap number to x87 conversion.
     __ fld_d(FieldOperand(input_reg, HeapNumber::kValueOffset));
     if (deoptimize_on_minus_zero) {
       __ fldz();
       __ FCmp();
       __ fld_d(FieldOperand(input_reg, HeapNumber::kValueOffset));
       __ j(not_zero, &done, Label::kNear);
 
       // Use general purpose registers to check if we have -0.0
       __ mov(temp_reg, FieldOperand(input_reg, HeapNumber::kExponentOffset));
       __ test(temp_reg, Immediate(HeapNumber::kSignMask));
       __ j(zero, &done, Label::kNear);
 
       // Pop FPU stack before deoptimizing.
       __ fstp(0);
       DeoptimizeIf(not_zero, env);
     }
     __ jmp(&done, Label::kNear);
-  } else if (mode == NUMBER_CANDIDATE_IS_SMI_OR_HOLE) {
-    __ test(input_reg, Immediate(kSmiTagMask));
-    DeoptimizeIf(not_equal, env);
-  } else if (mode == NUMBER_CANDIDATE_IS_SMI_CONVERT_HOLE) {
-    __ test(input_reg, Immediate(kSmiTagMask));
-    __ j(zero, &load_smi);
-    ExternalReference hole_nan_reference =
-        ExternalReference::address_of_the_hole_nan();
-    __ fld_d(Operand::StaticVariable(hole_nan_reference));
-    __ jmp(&done, Label::kNear);
   } else {
     ASSERT(mode == NUMBER_CANDIDATE_IS_SMI);
   }
 
   __ bind(&load_smi);
   __ SmiUntag(input_reg);  // Untag smi before converting to float.
   __ push(input_reg);
   __ fild_s(Operand(esp, 0));
   __ pop(input_reg);
   __ SmiTag(input_reg);  // Retag smi.
   __ bind(&done);
 }
 
 
 void LCodeGen::EmitNumberUntagD(Register input_reg,
                                 Register temp_reg,
                                 XMMRegister result_reg,
                                 bool deoptimize_on_undefined,
                                 bool deoptimize_on_minus_zero,
                                 LEnvironment* env,
                                 NumberUntagDMode mode) {
   Label load_smi, done;
 
-  if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED) {
+  STATIC_ASSERT(NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE >
+                NUMBER_CANDIDATE_IS_ANY_TAGGED);
+  if (mode >= NUMBER_CANDIDATE_IS_ANY_TAGGED) {
     // Smi check.
     __ JumpIfSmi(input_reg, &load_smi, Label::kNear);
 
     // Heap number map check.
     __ cmp(FieldOperand(input_reg, HeapObject::kMapOffset),
            factory()->heap_number_map());
     if (deoptimize_on_undefined) {
       DeoptimizeIf(not_equal, env);
     } else {
-      Label heap_number;
+      Label heap_number, convert;
       __ j(equal, &heap_number, Label::kNear);
 
+      // Convert undefined (and hole) to NaN.
       __ cmp(input_reg, factory()->undefined_value());
+      if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE) {
+        __ j(equal, &convert, Label::kNear);
+        __ cmp(input_reg, factory()->the_hole_value());
+      }
       DeoptimizeIf(not_equal, env);
 
-      // Convert undefined to NaN.
+      __ bind(&convert);
       ExternalReference nan =
           ExternalReference::address_of_canonical_non_hole_nan();
       __ movdbl(result_reg, Operand::StaticVariable(nan));
       __ jmp(&done, Label::kNear);
 
       __ bind(&heap_number);
     }
     // Heap number to XMM conversion.
     __ movdbl(result_reg, FieldOperand(input_reg, HeapNumber::kValueOffset));
     if (deoptimize_on_minus_zero) {
       XMMRegister xmm_scratch = xmm0;
       __ xorps(xmm_scratch, xmm_scratch);
       __ ucomisd(result_reg, xmm_scratch);
       __ j(not_zero, &done, Label::kNear);
       __ movmskpd(temp_reg, result_reg);
       __ test_b(temp_reg, 1);
       DeoptimizeIf(not_zero, env);
     }
     __ jmp(&done, Label::kNear);
-  } else if (mode == NUMBER_CANDIDATE_IS_SMI_OR_HOLE) {
-    __ test(input_reg, Immediate(kSmiTagMask));
-    DeoptimizeIf(not_equal, env);
-  } else if (mode == NUMBER_CANDIDATE_IS_SMI_CONVERT_HOLE) {
-    __ test(input_reg, Immediate(kSmiTagMask));
-    __ j(zero, &load_smi);
-    ExternalReference hole_nan_reference =
-        ExternalReference::address_of_the_hole_nan();
-    __ movdbl(result_reg, Operand::StaticVariable(hole_nan_reference));
-    __ jmp(&done, Label::kNear);
   } else {
     ASSERT(mode == NUMBER_CANDIDATE_IS_SMI);
   }
 
   // Smi to XMM conversion
   __ bind(&load_smi);
   __ SmiUntag(input_reg);  // Untag smi before converting to float.
   __ cvtsi2sd(result_reg, Operand(input_reg));
   __ SmiTag(input_reg);  // Retag smi.
   __ bind(&done);
@@ skipping 279 matching lines @@
   LOperand* result = instr->result();
   ASSERT(result->IsDoubleRegister());
 
   Register input_reg = ToRegister(input);
   bool deoptimize_on_minus_zero =
       instr->hydrogen()->deoptimize_on_minus_zero();
   Register temp_reg = deoptimize_on_minus_zero ? ToRegister(temp) : no_reg;
 
   NumberUntagDMode mode = NUMBER_CANDIDATE_IS_ANY_TAGGED;
   HValue* value = instr->hydrogen()->value();
-  if (value->type().IsSmi()) {
-    if (value->IsLoadKeyed()) {
-      HLoadKeyed* load = HLoadKeyed::cast(value);
-      if (load->UsesMustHandleHole()) {
-        if (load->hole_mode() == ALLOW_RETURN_HOLE) {
-          mode = NUMBER_CANDIDATE_IS_SMI_CONVERT_HOLE;
-        } else {
-          mode = NUMBER_CANDIDATE_IS_SMI_OR_HOLE;
-        }
-      } else {
-        mode = NUMBER_CANDIDATE_IS_SMI;
-      }
-    } else {
-      mode = NUMBER_CANDIDATE_IS_SMI;
+  if (value->representation().IsSmi()) {
+    mode = NUMBER_CANDIDATE_IS_SMI;
+  } else if (value->IsLoadKeyed()) {
+    HLoadKeyed* load = HLoadKeyed::cast(value);
+    if (load->UsesMustHandleHole()) {
+      mode = NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE;
     }
   }
 
   if (CpuFeatures::IsSupported(SSE2)) {
     CpuFeatureScope scope(masm(), SSE2);
     XMMRegister result_reg = ToDoubleRegister(result);
     EmitNumberUntagD(input_reg,
                      temp_reg,
                      result_reg,
                      instr->hydrogen()->deoptimize_on_undefined(),
@@ skipping 1054 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32