[Bug c/99953] New: In AVX, SIMD support environment, strlen performance without optimization is 3 times faster than optimized strlen function.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99953 Bug ID: 99953 Summary: In AVX, SIMD support environment, strlen performance without optimization is 3 times faster than optimized strlen function. Product: gcc Ve

[Bug c/99953] In AVX, SIMD support environment, strlen performance without optimization is 3 times faster than optimized strlen function.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99953 --- Comment #1 from Hyun Sik Park --- Created attachment 50520 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50520&action=edit simple test source

[Bug c/99953] In AVX, SIMD support environment, strlen performance without optimization is 3 times faster than optimized strlen function.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99953 --- Comment #2 from Hyun Sik Park --- Test environment: gcc version 9.3.0 (Ubuntu 9.3.0–17ubuntu1~20.04)/Acer Aspire V3–372/Intel(R) Core(TM) i5–6200U CPU @ 2.30GHz 4 Core

[Bug target/99953] In AVX, SIMD support environment, strlen performance without optimization is 3 times faster than optimized strlen function.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99953 --- Comment #5 from Hyun Sik Park --- $ gcc -march=native strlen.c $ ./a.out no optimize => 0.07860 o1 optimize => 0.62609 o2 optimize => 0.24775 o3 optimize => 0.22288 Same result.

[Bug target/99953] In AVX, SIMD support environment, strlen performance without optimization is 3 times faster than optimized strlen function.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99953 --- Comment #7 from Hyun Sik Park --- Thank you. I was tested and the result is below. $ ./a.out no optimize => 0.09640 o1 optimize => 0.09126 o2 optimize => 0.09422 o3 optimize => 0.09081 experiment_optimize_3 17d5: 48 01