I have a reduced test case for LAPACK CLS Drivers testsuite failures with
gfortran. See PR 5900 for background. The following assumes some knowledge
of the LAPACK testsuite
Step 1 was to reduce the ctest.in input file for the xlintstc test routine
(below).
I then identified a point where the g77-3.4 and gfortran results diverged.
The problem is in routine CLAIC1, which is called by CGELSX and CGELSY, and
occurs at line 285 of claic1.f, which is
TMP = SQRT( SINE*CONJG( SINE )+COSINE*CONJG( COSINE ) )
The reduced testcase below:
o passes with g77-3.4 on cygwin and irix
o fails with gfortran-20050120 on cygwin
################ test case ##########
program claic1_bug
real x, correct
parameter(correct=2.30457878)
call claic1(x)
if ( abs(x-correct) .gt. 1.0e-4 ) then
write(6,*) 'x = ', x,' expected ',correct
call abort
end if
end
subroutine claic1( tmp )
implicit none
real tmp
complex cosine, sine
sine = cmplx(0.2331063,-0.488660812)
cosine = cmplx(2.2400794,0.)
tmp = sqrt( sine*conjg( sine )+cosine*conjg( cosine ) )
end
############## reduced input file for xlintstc ###################
Data file for testing COMPLEX LAPACK linear equation routines
1 Number of values of M
3 Values of M (row dimension)
1 Number of values of N
3 Values of N (column dimension)
1 Number of values of NRHS
1 Values of NRHS (number of right hand sides)
1 Number of values of NB
1 Values of NB (the blocksize)
1 Values of NX (crossover point)
30.0 Threshold value of test ratio
T Put T to test the LAPACK routines
T Put T to test the driver routines
F Put T to test the error exits
CLS 1 List types on next line if 0 < NTYPES < 6
1
CEQ
--
Summary: LAPACK routine claic1.f bug
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: billingd at gcc dot gnu dot org
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: i686-pc-cygwin
GCC host triplet: i686-pc-cygwin
GCC target triplet: i686-pc-cygwin
OtherBugsDependingO 5900
nThis:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19551
