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From: "wsnyder at wsnyder dot org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug tree-optimization/97623] [9/10/11 Regression] Extremely slow O2
 compile (>>O(n^2))
Date: Fri, 30 Oct 2020 13:55:08 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D97623

--- 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-f=
etch
limited.  I'd have expected -fno-code-hoisting to help more, compile time w=
ise.

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