[PATCH] D15564: [ELF] - Optimize .eh_frame section: remove CIE if all FDEs referencing it were removed.

[Rafael Espíndola via llvm-commits]

On 5 January 2016 at 12:03, Rui Ueyama <ruiu at google.com> wrote:
> This patch does not particularly seem that it has a negative impact on
> performance. It is reasonable to see only noises when comparing performances
> before and after this patch. I believe Rafael left the note for "just in
> case".

Correct. It allocates a bit more memory, so I just wanted a benchmark
for sanity check.

The way I run benchmarks is:

* Test on tmpfs. I.E., do a clang build on tmpfs.
* Disable address space randomization
  echo 0 > /proc/sys/kernel/randomize_va_space
* Build a static binary
* Disable cpu frequency scaling
   for i in    /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
   do
     echo performance > /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
   done
* Use SCHED_FIFO, lock to a single cpu and use a high priority:
   schedtool -F -p 99 -a 0x4 -e perf stat -r 10 ld.lld ....


Cheers,
Rafael