Reviewers: Michael Starzinger, danno, Paul Lind, kisg,
Description:
MIPS: Improve polymorphic loads on single slots.
Port r11132 (91bdad6108).
Original commit message:
If all property lookups for a polymorphic load actually result in the
same field index under all maps, we can actually emit a monomorphic load
that is guarded by a map check that verifies that the actual map is in
the set of handled maps. This also allows GVN to get rid of redundant
such map checks.
BUG=
TEST=
Please review this at http://codereview.chromium.org/9852007/
Affected files:
M src/mips/lithium-codegen-mips.cc
Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc
b/src/mips/lithium-codegen-mips.cc
index
1b36d5b5c25ff386d80e2a9ab7ec3a495cd48bce..e9023fa6eaff77ff664e5cf3cf87313018f11f67
100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -4242,9 +4242,16 @@ void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
LOperand* input = instr->InputAt(0);
ASSERT(input->IsRegister());
Register reg = ToRegister(input);
- Handle<Map> map = instr->hydrogen()->map();
- DoCheckMapCommon(reg, scratch, map, instr->hydrogen()->mode(),
- instr->environment());
+ Label success;
+ SmallMapList* map_set = instr->hydrogen()->map_set();
+ for (int i = 0; i < map_set->length() - 1; i++) {
+ Handle<Map> map = map_set->at(i);
+ __ CompareMapAndBranch(
+ reg, scratch, map, &success, eq, &success, REQUIRE_EXACT_MAP);
+ }
+ Handle<Map> map = map_set->last();
+ DoCheckMapCommon(reg, scratch, map, REQUIRE_EXACT_MAP,
instr->environment());
+ __ bind(&success);
}
--
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