> On 13 Sep 2017, at 1:15 PM, Michael Clark <michaeljcl...@mac.com> wrote: > > - https://rv8.io/bench#optimisation > - https://rv8.io/bench#executable-file-sizes > > -O2 is 98% perf of -O3 on x86-64 > -Os is 81% perf of -O3 on x86-64 > > -O2 saves 5% space on -O3 on x86-64 > -Os saves 8% space on -Os on x86-64 > > 17% drop in performance for 3% saving in space is not a good trade for a > “general” size optimisation. It’s more like executable compression.
Sorry fixed typo: -O2 is 98% perf of -O3 on x86-64 -Os is 81% perf of -O3 on x86-64 -O2 saves 5% space on -O3 on x86-64 -Os saves 8% space on -O3 on x86-64 The extra ~3% space saving for ~17% drop in performance doesn’t seem like a good general option for size based on the cost in performance. Again. I really like GCC’s -O2 and hope that its binaries don’t grow in size nor slow down.