[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 Alexander Monakov changed: What|Removed |Added Status|WAITING |RESOLVED Resolution|---

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 --- Comment #13 from Alexander Monakov --- This is most likely a variant of https://bugzilla.redhat.com/show_bug.cgi?id=1421121 so hitting this bug requires a specific CPU model. It looks as if SSE-AVX transition penalties appear when

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 --- Comment #12 from Martin Reinecke --- Created attachment 43961 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43961=edit perf annotate output with -march=native

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 --- Comment #11 from Martin Reinecke --- Created attachment 43960 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43960=edit perf annotate output without -march=native

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 --- Comment #10 from Martin Liška --- And please rebuild the binaries with -g and attach perf annotate output. Thanks.

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 --- Comment #9 from Martin Reinecke --- Sure! martin@martin-Latitude-E7450 ~/tmp $ gcc -O3 testcase2.c -lm martin@martin-Latitude-E7450 ~/tmp $ perf stat ./a.out Performance counter stats for './a.out':

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 Alexander Monakov changed: What|Removed |Added CC||amonakov at gcc dot gnu.org ---

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 --- Comment #7 from Martin Reinecke --- Here is the output of --verbose: martin@martin-Latitude-E7450 ~/tmp $ gcc -O3 testcase2.c --verbose -lm -S Using built-in specs. COLLECT_GCC=gcc Target: x86_64-pc-linux-gnu

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 --- Comment #6 from Martin Reinecke --- Created attachment 43958 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43958=edit assembler output with -march=native

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 --- Comment #5 from Martin Reinecke --- Created attachment 43957 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43957=edit assembler output without -march=native

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 --- Comment #4 from Martin Reinecke --- Created attachment 43956 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43956=edit reduced test case

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 --- Comment #3 from Martin Liška --- And please output of adding --verbose option.

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 Martin Liška changed: What|Removed |Added Status|UNCONFIRMED |WAITING Last reconfirmed|

[Bug tree-optimization/85416] Massive performance regression when switching on "-march=native"

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85416 --- Comment #1 from Martin Reinecke --- Just re-tested on an Intel Core i5-4570; on this CPU, there is no performance degradation.