Faster to number conversion

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 16f502ddaf7b11f3d9600ecd40b025dc899e38d1..8cc251c39f69a30d5c33730c7fe2ea57caaeefad 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -2310,7 +2310,7 @@ HConstant* HConstant::CopyToRepresentation(Representation r, Zone* zone) const {
 }
 
 
-HConstant* HConstant::CopyToTruncatedInt32(Zone* zone) const {
+HConstant* HConstant::CopyToTruncatedInt32(Zone* zone) {
   if (has_int32_value_) {
     return new(zone) HConstant(int32_value_,
                                Representation::Integer32(),
@@ -2323,6 +2323,20 @@ HConstant* HConstant::CopyToTruncatedInt32(Zone* zone) const {
                                is_not_in_new_space_,
                                handle_);
   }
+  HConstant* number = CopyToTruncatedNumber(zone);
+  return (number != NULL) ? number->CopyToTruncatedInt32(zone) : NULL;
+}
+
+
+HConstant* HConstant::CopyToTruncatedNumber(Zone* zone) {

[Toon Verwaest, 2013/07/22 08:31:44]

Shouldn't we also return "this" for values that are already numbers?

[oliv, 2013/07/22 13:56:43]

there is no point to copying the constant if we are already a number (since
unlike the int32 case we do not change representation).

returning 'this' is afaik not a good idea, since then the client does not know,
if the instruction was already added or not...

+  if (handle()->IsBoolean()) {
+    return handle()->BooleanValue() ?
+      new(zone) HConstant(1) : new(zone) HConstant(0);
+  } else if (handle()->IsUndefined()) {
+    return new(zone) HConstant(OS::nan_value());
+  } else if (handle()->IsNull()) {
+    return new(zone) HConstant(0);
+  }
   return NULL;
 }