https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #17 from Richard Biener ---
(In reply to Uroš Bizjak from comment #14)
> Created attachment 52428 [details]
> Proposed patch
>
> The attached patch implements:
>
> fmod (a, p) = a - trunc (a/p) * p
> drem (a, p) = a - roundeven (a/
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #16 from rguenther at suse dot de ---
On Fri, 11 Feb 2022, ubizjak at gmail dot com wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
>
> --- Comment #13 from Uroš Bizjak ---
> (In reply to Richard Biener from comment #
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #15 from Dave.Love at manchester dot ac.uk ---
"ubizjak at gmail dot com" writes:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
>
> --- Comment #14 from Uroš Bizjak ---
> Created attachment 52428
> --> https://gcc.gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #14 from Uroš Bizjak ---
Created attachment 52428
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52428&action=edit
Proposed patch
The attached patch implements:
fmod (a, p) = a - trunc (a/p) * p
drem (a, p) = a - roundeven (a
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #13 from Uroš Bizjak ---
(In reply to Richard Biener from comment #12)
> Just as data-point on znver2 Uros testcase shows
>
> rguenther@ryzen:/tmp> gcc-11 t.c -Ofast -lm -march=znver2
> rguenther@ryzen:/tmp> numactl --physcpubind=3
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #12 from Richard Biener ---
Just as data-point on znver2 Uros testcase shows
rguenther@ryzen:/tmp> gcc-11 t.c -Ofast -lm -march=znver2
rguenther@ryzen:/tmp> numactl --physcpubind=3 /usr/bin/time ./a.out
19.18user 0.00system 0:19.18
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #11 from joseph at codesourcery dot com ---
An implementation using division like that definitely isn't valid without
-funsafe-math-optimizations (it gives nonsense results when the exponent
difference between the arguments is too
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #10 from Uroš Bizjak ---
FYI, the following testcase:
--cut here--
#include
float
__attribute__((noinline))
_fmodf (float x, float y)
{
return x - truncf (x/y) * y;
}
int
main ()
{
float a, b;
volatile float z;
for (a =
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
Richard Biener changed:
What|Removed |Added
CC||jsm28 at gcc dot gnu.org
--- Comment #
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
Richard Biener changed:
What|Removed |Added
CC||rguenth at gcc dot gnu.org
--- Comment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #7 from Uroš Bizjak ---
IMO, inlined fmod (and drem) should eventually be expanded in a generic way in
the middle-end as:
fmod (a, p) = a - trunc (a/p) * p
drem (a, p) = a - roundeven (a/p) * p
so division can be later simplified t
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
Uroš Bizjak changed:
What|Removed |Added
Status|UNCONFIRMED |NEW
Last reconfirmed|
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #5 from anlauf at gcc dot gnu.org ---
There's a mixture of single and double precision in the testcase variants.
I haven't checked thoroughly enough if both variants are really equivalent.
Do you see the issue if you have only single
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #4 from Dave Love ---
On further consideration, perhaps this is just a Fortran issue. I thought
-ffast-math should turn off all the relevant checks to allow reducing mod to
the arithmetic expression, but it probably doesn't. Also,
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #3 from Dave Love ---
Created attachment 51709
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51709&action=edit
gglx.s extract
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #2 from Dave Love ---
Created attachment 51708
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51708&action=edit
ggl.s extract
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103008
--- Comment #1 from Dave Love ---
Created attachment 51707
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51707&action=edit
gglx.f90
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