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* [Bug fortran/22572] New: Double occurrence of matmul intrinsic not optimised
@ 2005-07-20 17:50 schnetter at aei dot mpg dot de
2005-07-20 17:54 ` [Bug fortran/22572] " schnetter at aei dot mpg dot de
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: schnetter at aei dot mpg dot de @ 2005-07-20 17:50 UTC (permalink / raw)
To: gcc-bugs
GNU Fortran 95 (GCC 4.1.0 20050715 (experimental)), when run with the options
-Wall -O3 -march=pentium4 -S, optimises one of the two calls to the sin
intrinsic away in the following function:
function optsin (x)
implicit none
double precision :: optsin
double precision, intent(in) :: x
optsin = sin(x) / (1 + sin(x))
end function optsin
In the "equivalent" function
function optmatmul (a, b, ni, nj)
implicit none
integer, intent(in) :: ni, nj
double precision :: optmatmul(ni, nj)
double precision, intent(in) :: a(ni, nj), b(ni, nj)
optmatmul = matmul(a, b) / (1 + matmul(a, b))
end function optmatmul
the two calls to matmul both remain present in the assembler output, although
they are known to return the same result.
--
Summary: Double occurrence of matmul intrinsic not optimised
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: schnetter at aei dot mpg dot de
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: i686-pc-linux-gnu
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22572
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug fortran/22572] Double occurrence of matmul intrinsic not optimised
2005-07-20 17:50 [Bug fortran/22572] New: Double occurrence of matmul intrinsic not optimised schnetter at aei dot mpg dot de
@ 2005-07-20 17:54 ` schnetter at aei dot mpg dot de
2005-07-20 18:02 ` pinskia at gcc dot gnu dot org
2005-07-21 5:12 ` pinskia at gcc dot gnu dot org
2 siblings, 0 replies; 4+ messages in thread
From: schnetter at aei dot mpg dot de @ 2005-07-20 17:54 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |enhancement
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22572
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug fortran/22572] Double occurrence of matmul intrinsic not optimised
2005-07-20 17:50 [Bug fortran/22572] New: Double occurrence of matmul intrinsic not optimised schnetter at aei dot mpg dot de
2005-07-20 17:54 ` [Bug fortran/22572] " schnetter at aei dot mpg dot de
@ 2005-07-20 18:02 ` pinskia at gcc dot gnu dot org
2005-07-21 5:12 ` pinskia at gcc dot gnu dot org
2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-07-20 18:02 UTC (permalink / raw)
To: gcc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22572
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug fortran/22572] Double occurrence of matmul intrinsic not optimised
2005-07-20 17:50 [Bug fortran/22572] New: Double occurrence of matmul intrinsic not optimised schnetter at aei dot mpg dot de
2005-07-20 17:54 ` [Bug fortran/22572] " schnetter at aei dot mpg dot de
2005-07-20 18:02 ` pinskia at gcc dot gnu dot org
@ 2005-07-21 5:12 ` pinskia at gcc dot gnu dot org
2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-07-21 5:12 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-07-21 05:08 -------
Confirmed.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2005-07-21 05:08:29
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22572
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2005-07-21 5:08 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2005-07-20 17:50 [Bug fortran/22572] New: Double occurrence of matmul intrinsic not optimised schnetter at aei dot mpg dot de
2005-07-20 17:54 ` [Bug fortran/22572] " schnetter at aei dot mpg dot de
2005-07-20 18:02 ` pinskia at gcc dot gnu dot org
2005-07-21 5:12 ` pinskia at gcc dot gnu dot org
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