Analyzers
Community support for Analyzers (Intel VTune™ Profiler, Intel Advisor, Intel Inspector)
4892 Discussions

Calculating Branch Mispredicts on IPF

Intel_C_Intel
Employee
‎07-21-2003 09:31 PM
376 Views
Can someone please tell me the simplest way (if one exists) to calculate branch mispredicts on the Itanium 2 platform. Since there is no recipe for this ratio already in the tool, you are forced to go to the Events dialog and select from what appear to be many many branch event counters. I opted to grab "Branch Events" and "BE_BR_MISPRED_DETAIL-ANY".

I'm having trouble believing the output. Please help.
0 Kudos

Link Copied

1 Reply
bnshah
Beginner
‎07-22-2003 07:44 PM
376 Views
There is no easy way due to the complexity of the Itanium 2 branch prediction logic. Here is a forumula you can use. It will you the branch misprediction ratio. .

((BR_MISPRED_DETAIL.ALL.ALL_PRED - BR_MISPRED_DETAIL2.ALL.ALL_UNKNOWN_PRED) -
(BR_MISPRED_DETAIL.ALL.CORRECT_PRED - BR_MISPRED_DETAIL2.ALL.ALL_UNKNOWN_PATH_CORRECT_PRED) ) /
(BR_MISPRED_DETAIL.ALL.ALL_PRED - BR_MISPRED_DETAIL2.ALL.ALL_UNKNOWN_PRED)

0 Kudos
Copy link
Reply

Community support is provided during standard business hours (Monday to Friday 7AM - 5PM PST). Other contact methods are available here.

Intel does not verify all solutions, including but not limited to any file transfers that may appear in this community. Accordingly, Intel disclaims all express and implied warranties, including without limitation, the implied warranties of merchantability, fitness for a particular purpose, and non-infringement, as well as any warranty arising from course of performance, course of dealing, or usage in trade.

For more complete information about compiler optimizations, see our Optimization Notice.