https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79534
James Greenhalgh <jgreenhalgh at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2017-03-29 Ever confirmed|0 |1 --- Comment #5 from James Greenhalgh <jgreenhalgh at gcc dot gnu.org> --- It is always helpful to provide the full command line and configuration used, along with rough details of the platform you are using. Compiling with: gcc -O3 -mcpu=cortex-a57 I can see the performance difference reported here when running on Cortex-A57, Cortex-A72 and Cortex-A53 based systems, while with: gcc -O3 (i.e. using the generic tuning structures) I see no meaningful performance differences across multiple microarchitectures. So, confirmed. Though this is more likely to be a deficiency in the heuristics in the back-end ifcvt cost model than a regression directly introduced by Honza's patch.