------- Comment #2 from changpeng dot fang at amd dot com 2010-02-26 00:28
-------
Subject: RE: gcc could not vectorize floating point
reduction statements
Thanks for pointing this out. Actually I am working on a fortran program and
found the
the reduction statement. The fortran code can not be vectorized even with
-ffast-math.
Do you think this is the problem of fortran frontend? Thanks, -- Changpeng
c%3.1
subroutine s311 (ntimes,ld,n,ctime,dtime,a,b,c,d,e,aa,bb,cc)
c
c reductions
c sum reduction
c
integer ntimes, ld, n, i, nl
double precision a(n), b(n), c(n), d(n), e(n), aa(ld,n),
+ bb(ld,n), cc(ld,n)
double precision chksum, sum
real t1, t2, second, ctime, dtime
call init(ld,n,a,b,c,d,e,aa,bb,cc,'s311 ')
t1 = second()
do 1 nl = 1,ntimes
sum = 0.d0
do 10 i = 1,n
sum = sum + a(i)
10 continue
call dummy(ld,n,a,b,c,d,e,aa,bb,cc,sum)
1 continue
t2 = second() - t1 - ctime - ( dtime * float(ntimes) )
chksum = sum
call check (chksum,ntimes*n,n,t2,'s311 ')
return
end
________________________________________
From: pinskia at gcc dot gnu dot org [gcc-bugzi...@gcc.gnu.org]
Sent: Thursday, February 25, 2010 5:57 PM
To: Fang, Changpeng
Subject: [Bug middle-end/43184] gcc could not vectorize floating point
reduction statements
------- Comment #1 from pinskia at gcc dot gnu dot org 2010-02-25 23:57
-------
>gcc 4.5 could not vectorize floating point reductions.
Yes it can; add -ffast-math. floating point reductions need -ffast-math as it
can change the results in some cases (negative zero and I think clamping cases
too).
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43184
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43184
