Add branch-misprediction profiling to Cachegrind. When the (new) flag
--branch-sim=yes is specified, Cachegrind simulates a simple indirect
branch predictor and a conditional branch predictor. The latter
considers both the branch instruction's address and the behaviour of
the last few conditional branches. Return stack prediction is not
modelled.
The new counted events are: conditional branches (Bc), mispredicted
conditional branches (Bcm), indirect branches (Bi) and mispredicted
indirect branches (Bim). Postprocessing tools (cg_annotate, cg_merge)
handle the new events as you would expect. Note that branch
simulation is not enabled by default as it gives a 20%-25% slowdown,
so you need to ask for it explicitly using --branch-sim=yes.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@6733 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/NEWS b/NEWS
index b77531a..622247e 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,11 @@
Other user-visible changes:
+- Cachegrind has been extended to do branch-misprediction profiling.
+ Both conditional and indirect branches are profiled. The default
+ behaviour of Cachegrind is unchanged. To use the new functionality,
+ give the option --branch-sim=yes.
+
- A new suppression kind has been introduced: "Jump". This is for
suppressing jump-to-invalid-address errors. Previously you had to use an
"Addr1" suppression, which didn't make much sense.