Infrastructure classes for evaluating numeric relations between values.

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 672 matching lines @@
   PrintChangesTo(stream);
   PrintTypeTo(stream);
 }
 
 
 void HInstruction::PrintMnemonicTo(StringStream* stream) {
   stream->Add("%s ", Mnemonic());
 }
 
 
+HValue* HValue::AddNumericConstraint(HInstruction* insertion_point,

[Jakob Kummerow, 2013/02/12 15:10:42]

I don't think we need this. Let's just inline it everywhere.

[Massi, 2013/02/13 11:56:42]

Done.

+                                     HValue* related_value,
+                                     NumericRelation relation) {
+  return HNumericConstraint::New(
+      insertion_point, this, related_value, relation);
+}
+
+
 void HInstruction::Unlink() {
   ASSERT(IsLinked());
   ASSERT(!IsControlInstruction());  // Must never move control instructions.
   ASSERT(!IsBlockEntry());  // Doesn't make sense to delete these.
   ASSERT(previous_ != NULL);
   previous_->next_ = next_;
   if (next_ == NULL) {
     ASSERT(block()->last() == this);
     block()->set_last(previous_);
   } else {
@@ skipping 84 matching lines @@
   }
 
   // Verify that instructions that can be eliminated by GVN have overridden
   // HValue::DataEquals.  The default implementation is UNREACHABLE.  We
   // don't actually care whether DataEquals returns true or false here.
   if (CheckFlag(kUseGVN)) DataEquals(this);
 }
 #endif
 
 
+HNumericConstraint* HNumericConstraint::New(HInstruction* insertion_point,

[Jakob Kummerow, 2013/02/12 15:10:42]

This should probably be renamed (AddToGraph?). Also, please reorder the
arguments: constrained_value, relation, related_value, insertion_point.

[Massi, 2013/02/13 11:56:42]

Done.

+                                            HValue* constrained_value,
+                                            HValue* related_value,
+                                            NumericRelation relation) {
+  HNumericConstraint* result =
+      new(insertion_point->block()->zone()) HNumericConstraint(
+          constrained_value, related_value, relation);
+  result->InsertAfter(insertion_point);
+  return result;
+}
+
+
+void HNumericConstraint::PrintDataTo(StringStream* stream) {
+  stream->Add("(");
+  constrained_value()->PrintNameTo(stream);
+  stream->Add(" %s ", relation().Mnemonic());
+  related_value()->PrintNameTo(stream);
+  stream->Add(")");
+}
+
+
 void HDummyUse::PrintDataTo(StringStream* stream) {
   value()->PrintNameTo(stream);
 }
 
 
 void HUnaryCall::PrintDataTo(StringStream* stream) {
   value()->PrintNameTo(stream);
   stream->Add(" ");
   stream->Add("#%d", argument_count());
 }
 
 
 void HBinaryCall::PrintDataTo(StringStream* stream) {
   first()->PrintNameTo(stream);
   stream->Add(" ");
   second()->PrintNameTo(stream);
   stream->Add(" ");
   stream->Add("#%d", argument_count());
 }
 
 
+bool HBoundsCheck::CheckRelation(NumericRelation relation,
+                                         HValue* related_value) {

[Jakob Kummerow, 2013/02/12 15:10:42]

nit: indentation

[Massi, 2013/02/13 11:56:42]

Done.

+  if (related_value == length()) {
+    return NumericRelation::Lt().Implies(relation);

[Jakob Kummerow, 2013/02/12 15:10:42]

How about a comment:
// We know that a BoundsCheck is smaller than the length it compared against.

[Massi, 2013/02/13 11:56:42]

Done.

+  } else if (related_value == block()->graph()->GetConstant0()) {
+    return NumericRelation::Ge().Implies(relation);
+  } else {
+    return false;
+  }
+}
+
+
 void HBoundsCheck::PrintDataTo(StringStream* stream) {
   index()->PrintNameTo(stream);
   stream->Add(" ");
   length()->PrintNameTo(stream);
 }
 
 
 void HBoundsCheck::InferRepresentation(HInferRepresentation* h_infer) {
   ASSERT(CheckFlag(kFlexibleRepresentation));
   Representation r;
@@ skipping 2113 matching lines @@
 
 
 void HCheckFunction::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal