Merge bleeding_edge r17376:17693.

src/hydrogen-instructions.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 1237 matching lines @@
 }
 
 
 static bool IsIdentityOperation(HValue* arg1, HValue* arg2, int32_t identity) {
   return arg1->representation().IsSpecialization() &&
     arg2->EqualsInteger32Constant(identity);
 }
 
 
 HValue* HAdd::Canonicalize() {
-  if (IsIdentityOperation(left(), right(), 0)) return left();
-  if (IsIdentityOperation(right(), left(), 0)) return right();
+  // Adding 0 is an identity operation except in case of -0: -0 + 0 = +0
+  if (IsIdentityOperation(left(), right(), 0) &&
+      !left()->representation().IsDouble()) {  // Left could be -0.
+    return left();
+  }
+  if (IsIdentityOperation(right(), left(), 0) &&
+      !left()->representation().IsDouble()) {  // Right could be -0.
+    return right();
+  }
   return this;
 }
 
 
 HValue* HSub::Canonicalize() {
   if (IsIdentityOperation(left(), right(), 0)) return left();
   return this;
 }
 
 
@@ skipping 1572 matching lines @@
           : new(zone) Range();
       result->Shl(c->Integer32Value());
       return result;
     }
   }
   return HValue::InferRange(zone);
 }
 
 
 Range* HLoadNamedField::InferRange(Zone* zone) {
-  if (access().representation().IsByte()) {
-    return new(zone) Range(0, 255);
+  if (access().representation().IsInteger8()) {
+    return new(zone) Range(kMinInt8, kMaxInt8);
+  }
+  if (access().representation().IsUInteger8()) {
+    return new(zone) Range(kMinUInt8, kMaxUInt8);
+  }
+  if (access().representation().IsInteger16()) {
+    return new(zone) Range(kMinInt16, kMaxInt16);
+  }
+  if (access().representation().IsUInteger16()) {
+    return new(zone) Range(kMinUInt16, kMaxUInt16);
   }
   if (access().IsStringLength()) {
     return new(zone) Range(0, String::kMaxLength);
   }
   return HValue::InferRange(zone);
 }
 
 
 Range* HLoadKeyed::InferRange(Zone* zone) {
   switch (elements_kind()) {
+    case EXTERNAL_BYTE_ELEMENTS:
+      return new(zone) Range(kMinInt8, kMaxInt8);
+    case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
     case EXTERNAL_PIXEL_ELEMENTS:
-      return new(zone) Range(0, 255);
-    case EXTERNAL_BYTE_ELEMENTS:
-      return new(zone) Range(-128, 127);
-    case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
-      return new(zone) Range(0, 255);
+      return new(zone) Range(kMinUInt8, kMaxUInt8);
     case EXTERNAL_SHORT_ELEMENTS:
-      return new(zone) Range(-32768, 32767);
+      return new(zone) Range(kMinInt16, kMaxInt16);
     case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
-      return new(zone) Range(0, 65535);
+      return new(zone) Range(kMinUInt16, kMaxUInt16);
     default:
       return HValue::InferRange(zone);
   }
 }
 
 
 void HCompareGeneric::PrintDataTo(StringStream* stream) {
   stream->Add(Token::Name(token()));
   stream->Add(" ");
   HBinaryOperation::PrintDataTo(stream);
@@ skipping 38 matching lines @@
   return false;
 }
 
 
 void HCompareHoleAndBranch::InferRepresentation(
     HInferRepresentationPhase* h_infer) {
   ChangeRepresentation(value()->representation());
 }
 
 
+bool HCompareMinusZeroAndBranch::KnownSuccessorBlock(HBasicBlock** block) {
+  if (value()->representation().IsSmiOrInteger32()) {
+    // A Smi or Integer32 cannot contain minus zero.
+    *block = SecondSuccessor();
+    return true;
+  }
+  *block = NULL;
+  return false;
+}
+
+
+void HCompareMinusZeroAndBranch::InferRepresentation(
+    HInferRepresentationPhase* h_infer) {
+  ChangeRepresentation(value()->representation());
+}
+
+
+
 void HGoto::PrintDataTo(StringStream* stream) {
   stream->Add("B%d", SuccessorAt(0)->block_id());
 }
 
 
 void HCompareNumericAndBranch::InferRepresentation(
     HInferRepresentationPhase* h_infer) {
   Representation left_rep = left()->representation();
   Representation right_rep = right()->representation();
   Representation observed_left = observed_input_representation(0);
@@ skipping 1035 matching lines @@
       if ((right_val == 0) && (left_val < 0)) {
         return H_CONSTANT_DOUBLE(static_cast<uint32_t>(left_val));
       }
       return H_CONSTANT_INT(static_cast<uint32_t>(left_val) >> right_val);
     }
   }
   return new(zone) HShr(context, left, right);
 }
 
 
+HInstruction* HSeqStringGetChar::New(Zone* zone,
+                                     HValue* context,
+                                     String::Encoding encoding,
+                                     HValue* string,
+                                     HValue* index) {
+  if (FLAG_fold_constants && string->IsConstant() && index->IsConstant()) {
+    HConstant* c_string = HConstant::cast(string);
+    HConstant* c_index = HConstant::cast(index);
+    if (c_string->HasStringValue() && c_index->HasInteger32Value()) {
+      Handle<String> s = c_string->StringValue();
+      int32_t i = c_index->Integer32Value();
+      ASSERT_LE(0, i);
+      ASSERT_LT(i, s->length());
+      return H_CONSTANT_INT(s->Get(i));
+    }
+  }
+  return new(zone) HSeqStringGetChar(encoding, string, index);
+}
+
+
 #undef H_CONSTANT_INT
 #undef H_CONSTANT_DOUBLE
 
 
 void HBitwise::PrintDataTo(StringStream* stream) {
   stream->Add(Token::Name(op_));
   stream->Add(" ");
   HBitwiseBinaryOperation::PrintDataTo(stream);
 }
 
@@ skipping 294 matching lines @@
       break;
     case kExternalMemory:
       stream->Add("[external-memory]");
       break;
   }
 
   stream->Add("@%d", offset());
 }
 
 } }  // namespace v8::internal