[Bug rtl-optimization/19210] [4.0 Regression] not using do-loop for some loops
dje at gcc dot gnu dot org
gcc-bugzilla@gcc.gnu.org
Fri Dec 31 23:55:00 GMT 2004
------- Additional Comments From dje at gcc dot gnu dot org 2004-12-31 23:55 -------
XLC includes the option
strict_induction
Turns off induction variable optimizations
that have the potential to alter the semantics of a
user's program. The default is "nostrict_induction" at
-O2 or higher and "strict_induction" otherwise.
"nostrict_induction" is recomended if your program does
not have overflows or wrap arounds of loop induction
variables.
We probably need something similar in GCC. Note that XLC enables it when
optimizing.
Most programmers do not expect to be limited by the undefined wrapping behavior.
They are not using the extremes.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19210
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