Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(445)

Unified Diff: src/hydrogen-instructions.h

Issue 11783055: Make the array bounds check elimination phase optional (and set the foundation for introducing SSI … (Closed) Base URL: https://v8.googlecode.com/svn/branches/bleeding_edge
Patch Set: Addressed review comments. Created 7 years, 11 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 23390dc1115a48df3305bad9bc237afb6c3e45ad..6f77add81f164944e685a1d9ee3a42081b3d9f36 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -348,6 +348,10 @@ class Representation {
}
const char* Mnemonic() const;
+ Representation KeyedAccessIndexRequirement() {
Jakob Kummerow 2013/01/10 16:06:47 nit: I'm a bit unhappy about adding instruction-sp
+ return IsInteger32() ? Integer32() : Tagged();
+ }
+
private:
explicit Representation(Kind k) : kind_(k) { }
@@ -672,6 +676,14 @@ class HValue: public ZoneObject {
return NULL;
}
+ // There are HInstructions that do not really change a value, they
+ // only add pieces of information to it (like bounds checks, map checks
+ // or SSI definitions after conditional branches).
+ // This method must always return the original HValue SSA definition (the
+ // register allocator relies on this to avoid allocating multiple registers
+ // for the same value).
+ virtual HValue* ActualValue() { return this; }
+
bool IsDefinedAfter(HBasicBlock* other) const;
// Operands.
@@ -2955,44 +2967,40 @@ enum BoundsCheckKeyMode {
class HBoundsCheck: public HTemplateInstruction<2> {
public:
HBoundsCheck(HValue* index, HValue* length,
- BoundsCheckKeyMode key_mode = DONT_ALLOW_SMI_KEY)
+ BoundsCheckKeyMode key_mode = DONT_ALLOW_SMI_KEY,
+ Representation r = Representation::None())
: key_mode_(key_mode) {
SetOperandAt(0, index);
SetOperandAt(1, length);
- set_representation(Representation::Integer32());
+ if (r.IsNone()) {
+ // In the normal compilation pipeline the representation is flexible
+ // (see comment to RequiredInputRepresentation).
+ SetFlag(kFlexibleRepresentation);
+ } else {
+ // When compiling stubs we want to set the representation explicitly
+ // so the compilation pipeline can skip the HInferRepresentation phase.
+ set_representation(r);
+ }
SetFlag(kUseGVN);
}
virtual Representation RequiredInputRepresentation(int arg_index) {
- if (key_mode_ == DONT_ALLOW_SMI_KEY ||
- !length()->representation().IsTagged()) {
- return Representation::Integer32();
- }
- // If the index is tagged and isn't constant, then allow the length
- // to be tagged, since it is usually already tagged from loading it out of
- // the length field of a JSArray. This allows for direct comparison without
- // untagging.
- if (index()->representation().IsTagged() && !index()->IsConstant()) {
- return Representation::Tagged();
- }
- // Also allow the length to be tagged if the index is constant, because
- // it can be tagged to allow direct comparison.
- if (index()->IsConstant() &&
- index()->representation().IsInteger32() &&
- arg_index == 1) {
- return Representation::Tagged();
- }
- return Representation::Integer32();
+ return representation();
}
virtual Representation observed_input_representation(int index) {
return Representation::Integer32();
}
virtual void PrintDataTo(StringStream* stream);
+ virtual void InferRepresentation(HInferRepresentation* h_infer);
HValue* index() { return OperandAt(0); }
HValue* length() { return OperandAt(1); }
+ virtual HValue* ActualValue() {
+ return index();
+ }
+
DECLARE_CONCRETE_INSTRUCTION(BoundsCheck)
protected:
@@ -4446,7 +4454,9 @@ class HLoadKeyed
return is_external() ? Representation::External()
: Representation::Tagged();
}
- if (index == 1) return Representation::Integer32();
+ if (index == 1) {
+ return OperandAt(1)->representation().KeyedAccessIndexRequirement();
+ }
return Representation::None();
}
@@ -4661,7 +4671,7 @@ class HStoreKeyed
return is_external() ? Representation::External()
: Representation::Tagged();
} else if (index == 1) {
- return Representation::Integer32();
+ return OperandAt(1)->representation().KeyedAccessIndexRequirement();
}
ASSERT_EQ(index, 2);
« src/hydrogen.cc ('K') | « src/hydrogen.cc ('k') | src/hydrogen-instructions.cc » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698