[Bug tree-optimization/97623] [9/10/11 Regression] Extremely slow O2 compile (>>O(n^2))

[wsnyder at wsnyder dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97623

--- Comment #7 from Wilson Snyder <wsnyder at wsnyder dot org> ---
Thanks for the quick service.  I can't easily try GCC trunk, but:

-O2
  compile 98.61s
  runtime 25.76s

-O2 -fno-code-hoisting
  compile 40.13s
  runtime 26.40s (+2.5%)

-Os
  compile 4.25s
  runtime 23.42s (-10%)

That -Os runs faster is expected as this program is generally instruction-fetch
limited.  I'd have expected -fno-code-hoisting to help more, compile time wise.

Am I correct in understanding that the slowdown is roughly correlated to the
number of "if" or "?:" statements?