This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug middle-end/40106] [4.4/4.5 Regression] Weird interaction between optimize_insn_for_speed_p and -funsafe-math-optimizations
- From: "dominiq at lps dot ens dot fr" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 19 Mar 2010 15:40:20 -0000
- Subject: [Bug middle-end/40106] [4.4/4.5 Regression] Weird interaction between optimize_insn_for_speed_p and -funsafe-math-optimizations
- References: <bug-40106-12313@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #49 from dominiq at lps dot ens dot fr 2010-03-19 15:40 -------
A few remarks about comments #47 and #48
> Note that this PR isn't too serious as -fwhole-file isn't the default
> for Fortran so we do not run into this unfortunate interaction of
> profile estimation and inlining.
The test in comment #31 shows that you don't need -fwhole-file nor inlining to
trigger this PR.
> + || (n == 2
Isn't it n==3?
I have done some tests of replacing 1.5 in the test in comment #31 with some
other values (up to 15.5, but not in a systematic way). On
x86_64-apple-darwin10, the multiplications are always a win for size (based on
the size of a.out) over the call to pow. Is my metric flawed? If yes, what
should I use? If no could embedded system experts have a look at this kind of
optimization?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40106