Revision: 21500
Author: [email protected]
Date: Mon May 26 14:40:55 2014 UTC
Log: MIPS: Skip write barriers in the fast case when setting up local
context.
Port r21481 (5973b48)
Original commit message:
The FastNewContextStub always allocates in new space, so we don't
need to update the write barrier when copying the parameters to
the newly allocated context.
BUG=
[email protected]
Review URL: https://codereview.chromium.org/302633002
Patch from Balazs Kilvady <[email protected]>.
http://code.google.com/p/v8/source/detail?r=21500
Modified:
/branches/bleeding_edge/src/mips/full-codegen-mips.cc
/branches/bleeding_edge/src/mips/lithium-codegen-mips.cc
=======================================
--- /branches/bleeding_edge/src/mips/full-codegen-mips.cc Fri May 16
15:18:24 2014 UTC
+++ /branches/bleeding_edge/src/mips/full-codegen-mips.cc Mon May 26
14:40:55 2014 UTC
@@ -219,6 +219,7 @@
if (heap_slots > 0) {
Comment cmnt(masm_, "[ Allocate context");
// Argument to NewContext is the function, which is still in a1.
+ bool need_write_barrier = true;
if (FLAG_harmony_scoping && info->scope()->is_global_scope()) {
__ push(a1);
__ Push(info->scope()->GetScopeInfo());
@@ -226,6 +227,8 @@
} else if (heap_slots <= FastNewContextStub::kMaximumSlots) {
FastNewContextStub stub(isolate(), heap_slots);
__ CallStub(&stub);
+ // Result of FastNewContextStub is always in new space.
+ need_write_barrier = false;
} else {
__ push(a1);
__ CallRuntime(Runtime::kHiddenNewFunctionContext, 1);
@@ -249,8 +252,15 @@
__ sw(a0, target);
// Update the write barrier.
- __ RecordWriteContextSlot(
- cp, target.offset(), a0, a3, kRAHasBeenSaved, kDontSaveFPRegs);
+ if (need_write_barrier) {
+ __ RecordWriteContextSlot(
+ cp, target.offset(), a0, a3, kRAHasBeenSaved,
kDontSaveFPRegs);
+ } else if (FLAG_debug_code) {
+ Label done;
+ __ JumpIfInNewSpace(cp, a0, &done);
+ __ Abort(kExpectedNewSpaceObject);
+ __ bind(&done);
+ }
}
}
}
=======================================
--- /branches/bleeding_edge/src/mips/lithium-codegen-mips.cc Thu May 22
17:00:50 2014 UTC
+++ /branches/bleeding_edge/src/mips/lithium-codegen-mips.cc Mon May 26
14:40:55 2014 UTC
@@ -198,10 +198,13 @@
int heap_slots = info()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
if (heap_slots > 0) {
Comment(";;; Allocate local context");
+ bool need_write_barrier = true;
// Argument to NewContext is the function, which is in a1.
if (heap_slots <= FastNewContextStub::kMaximumSlots) {
FastNewContextStub stub(isolate(), heap_slots);
__ CallStub(&stub);
+ // Result of FastNewContextStub is always in new space.
+ need_write_barrier = false;
} else {
__ push(a1);
__ CallRuntime(Runtime::kHiddenNewFunctionContext, 1);
@@ -224,8 +227,15 @@
MemOperand target = ContextOperand(cp, var->index());
__ sw(a0, target);
// Update the write barrier. This clobbers a3 and a0.
- __ RecordWriteContextSlot(
- cp, target.offset(), a0, a3, GetRAState(), kSaveFPRegs);
+ if (need_write_barrier) {
+ __ RecordWriteContextSlot(
+ cp, target.offset(), a0, a3, GetRAState(), kSaveFPRegs);
+ } else if (FLAG_debug_code) {
+ Label done;
+ __ JumpIfInNewSpace(cp, a0, &done);
+ __ Abort(kExpectedNewSpaceObject);
+ __ bind(&done);
+ }
}
}
Comment(";;; End allocate local context");
--
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
---
You received this message because you are subscribed to the Google Groups "v8-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
