1 files changed, 36 insertions, 0 deletions
diff --git a/gcc/testsuite/gfortran.dg/matmul_3.f90 b/gcc/testsuite/gfortran.dg/matmul_3.f90
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+++ b/gcc/testsuite/gfortran.dg/matmul_3.f90
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+! { dg-do run }
+! Check the fix for PR28005, in which the mechanism for dealing
+! with matmul (transpose (a), b) would cause wrong results for
+! matmul (a(i, 1:n), b(1:n, 1:n)).
+!
+! Based on the original testcase contributed by
+! Tobias Burnus  <tobias.burnus@physik.fu-berlin.de>
+!   
+   implicit none
+   integer, parameter         ::  nmax = 3
+   integer                    ::  i, n = 2
+   integer, dimension(nmax,nmax) ::  iB=0 , iC=1
+   integer, dimension(nmax,nmax) ::  iX1=99, iX2=99, iChk
+   iChk = reshape((/30,66,102,36,81,126,42,96,150/),(/3,3/))
+
+! This would give 3, 3, 99
+   iB = reshape((/1 ,3 ,0 ,2 ,5 ,0 ,0 ,0 ,0 /),(/3,3/))
+   iX1(1:n,1) = matmul( iB(2,1:n),iC(1:n,1:n) )
+
+! This would give 4, 4, 99
+   ib(3,1) = 1
+   iX2(1:n,1) = matmul( iB(2,1:n),iC(1:n,1:n) )
+
+! Whereas, we should have 8, 8, 99
+   if (any (iX1(1:n,1) .ne. (/8, 8, 99/))) call abort ()
+   if (any (iX1 .ne. iX2)) call abort ()
+
+! Make sure that the fix does not break transpose temporaries.
+   iB = reshape((/(i, i = 1, 9)/),(/3,3/))
+   ic = transpose (iB)
+   iX1 = transpose (iB)
+   iX1 = matmul (iX1, iC)
+   iX2 = matmul (transpose (iB), iC)
+   if (any (iX1 .ne. iX2)) call abort ()
+   if (any (iX1 .ne. iChk)) call abort ()
+end