[libcxx-commits] [PATCH] D84055: [libcxx][lit] Cache the value of the feature lambda

Sat Oct 10 05:50:02 PDT 2020

arichardson abandoned this revision.
arichardson added a comment.

The startup improvement is very similar but slightly higher than D89110 <https://reviews.llvm.org/D89110>: 5,048,426,054 cycles instead of 5,421,406,209 baseline. D89110 <https://reviews.llvm.org/D89110> reports 5,135,758,720. Not sure if this is worth it since this seems more fragile.

  Performance counter stats for './bin/llvm-lit -v --no-execute projects/libcxx/test/libcxx/selftest/dsl/' (10 runs):

        2842.501038      task-clock (msec)         #    0.968 CPUs utilized            ( +-  0.47% )
                503      context-switches          #    0.177 K/sec                    ( +-  0.31% )
                 38      cpu-migrations            #    0.013 K/sec                    ( +-  6.02% )
            204,788      page-faults               #    0.072 M/sec                    ( +-  0.01% )
      5,048,426,054      cycles                    #    1.776 GHz                      ( +-  0.25% )
      5,494,868,028      instructions              #    1.09  insn per cycle           ( +-  0.01% )
      1,099,097,312      branches                  #  386.666 M/sec                    ( +-  0.01% )
         29,349,374      branch-misses             #    2.67% of all branches          ( +-  0.02% )

        2.935697590 seconds time elapsed                                          ( +-  0.45% )

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D84055/new/

https://reviews.llvm.org/D84055