perf tools: Cache register accesses for unwind processing

Caching registers value into an array. Got about 4% speed up
of perf_reg_value function for report command processing
dwarf unwind stacks.

Output from report over 1.5 GB data with DWARF unwind stacks:
(TODO fix perf diff)

  current code:
   5.84%     perf  perf                       [.] perf_reg_value
  change:
   1.94%     perf  perf                       [.] perf_reg_value

And little bit of overall speed up:
(perf stat -r 5 -e '{cycles,instructions}:u' ...)

  current code:
   310,298,611,754      cycles                     ( +-  0.33% )
   439,669,689,341      instructions               ( +-  0.03% )

     188.656753166 seconds time elapsed            ( +-  0.82% )

  change:
   291,315,329,878      cycles                     ( +-  0.22% )
   391,763,485,304      instructions               ( +-  0.03%  )

     180.742249687 seconds time elapsed            ( +-  0.64% )

Acked-by: Namhyung Kim <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Corey Ashford <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jean Pihet <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Jiri Olsa <[email protected]>

0 files changed, 0 insertions, 0 deletions