Re: slowdown with -std=gnu18 with respect to -std=c99

[Stéphane Glondu via Gcc-help <gcc-help@xxxxxxxxxxx>]

As additional data points, the performance with several versions of gcc
(as packaged in Debian testing/unstable):

             | gcc-9 | gcc-10 | gcc-11 | gcc-12 |
 ------------|-------|--------|--------|--------|
  -std=c99   | 24    | 23.5   | 23     | 23     |
  -std=gnu18 | 43    | 16.8   | 38     | 38     |

One can see that the performance stays relatively constant with
-std=c99, but varies significantly with -std=gnu18.

-- 
Stéphane