Revision: 10795
Author: jkumme...@chromium.org
Date: Wed Feb 22 07:18:29 2012
Log: Profiler experiments: interrupt check at function exit
Review URL: https://chromiumcodereview.appspot.com/9432026
http://code.google.com/p/v8/source/detail?r=10795
Modified:
/branches/bleeding_edge/src/flag-definitions.h
/branches/bleeding_edge/src/ia32/full-codegen-ia32.cc
=======================================
--- /branches/bleeding_edge/src/flag-definitions.h Mon Feb 20 06:02:59 2012
+++ /branches/bleeding_edge/src/flag-definitions.h Wed Feb 22 07:18:29 2012
@@ -177,6 +177,8 @@
"primitive functions trigger their own optimization")
DEFINE_bool(count_based_interrupts, false,
"trigger profiler ticks based on counting instead of timing")
+DEFINE_bool(interrupt_at_exit, false,
+ "insert an interrupt check at function exit")
DEFINE_bool(weighted_back_edges, false,
"weight back edges by jump distance for interrupt triggering")
DEFINE_int(interrupt_budget, 10000,
@@ -187,6 +189,7 @@
DEFINE_implication(experimental_profiler, watch_ic_patching)
DEFINE_implication(experimental_profiler, self_optimization)
DEFINE_implication(experimental_profiler, count_based_interrupts)
+DEFINE_implication(experimental_profiler, interrupt_at_exit)
DEFINE_implication(experimental_profiler, weighted_back_edges)
DEFINE_bool(trace_opt_verbose, false, "extra verbose compilation tracing")
=======================================
--- /branches/bleeding_edge/src/ia32/full-codegen-ia32.cc Wed Feb 22
04:47:42 2012
+++ /branches/bleeding_edge/src/ia32/full-codegen-ia32.cc Wed Feb 22
07:18:29 2012
@@ -332,7 +332,7 @@
int weight = 1;
if (FLAG_weighted_back_edges) {
ASSERT(back_edge_target->is_bound());
- int distance = masm_->pc_offset() - back_edge_target->pos();
+ int distance = masm_->SizeOfCodeGeneratedSince(back_edge_target);
weight = Min(127, Max(1, distance / 100));
}
__ sub(Operand::Cell(profiling_counter_),
Immediate(Smi::FromInt(weight)));
@@ -389,6 +389,26 @@
__ push(eax);
__ CallRuntime(Runtime::kTraceExit, 1);
}
+ if (FLAG_interrupt_at_exit) {
+ // Pretend that the exit is a backwards jump to the entry.
+ int weight = 1;
+ if (FLAG_weighted_back_edges) {
+ int distance = masm_->pc_offset();
+ weight = Min(127, Max(1, distance / 100));
+ }
+ __ sub(Operand::Cell(profiling_counter_),
+ Immediate(Smi::FromInt(weight)));
+ Label ok;
+ __ j(positive, &ok, Label::kNear);
+ __ push(eax);
+ InterruptStub stub;
+ __ CallStub(&stub);
+ __ pop(eax);
+ // Reset the countdown.
+ __ mov(Operand::Cell(profiling_counter_),
+ Immediate(Smi::FromInt(FLAG_interrupt_budget)));
+ __ bind(&ok);
+ }
#ifdef DEBUG
// Add a label for checking the size of the code used for returning.
Label check_exit_codesize;
--
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