aaron.ballman added a comment. In D112059#3094464 <https://reviews.llvm.org/D112059#3094464>, @nickdesaulniers wrote:
> Here's a [hastily and poorly written] script to measure the average cycle > counts for 30 invocations using linux `perf`: > https://gist.github.com/nickdesaulniers/4a20ba10c26ac2ad02cb0425b8b0f826 > > For Diff 382671 (latest; storing redecl state), builds of the linux kernel > x86_64 defconfig+CONFIG_FORTIFY_SOURCE=y: > > $ /tmp/measure_30.sh 'make LLVM=1 -j72' 'make LLVM=1 -j72 clean' > ... > Average of 30 runs: 10780685107280.83 cycles > > For Diff 382344 (earlier; walking redecl chain), builds of the linux kernel > x86_64 defconfig+CONFIG_FORTIFY_SOURCE=y: > > $ /tmp/measure_30.sh 'make LLVM=1 -j72' 'make LLVM=1 -j72 clean' > ... > Average of 30 runs: 10745227016663.00 cycles > > Damn, so what I proposed was slower, at least for the major case that I care > about. I suspect that perhaps there's more forward declarations than actual > functions we end up generating IR for, perhaps...either way, I'm sorry for > suggesting the "storing redecl state" approach. If we want to go back to the > earlier version in Diff 382344, at this point, I'd be happy to accept that > revision. Sorry for causing whiplash on this. Thank you for measuring this as well! And no worries on the whiplash (easy for me to say as a reviewer, hah) -- I think it was a reasonable thought to explore and measure the performance of. FWIW, I'd be happy accepting the earlier revision as well. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D112059/new/ https://reviews.llvm.org/D112059 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
