1 files changed, 53 insertions, 0 deletions
diff --git a/gcc/testsuite/gfortran.dg/matmul_1.f90 b/gcc/testsuite/gfortran.dg/matmul_1.f90
new file mode 100644
index 000000000..6496f88a2
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/matmul_1.f90
@@ -0,0 +1,53 @@
+!{ dg-do run }
+! Test MATMUL for various arguments and results
+! (test values checked with GNU octave).
+! PR18857 was due to an incorrect assertion that component base==0
+! for both input arguments and the result.
+! provided by Paul Thomas - pault@gcc.gnu.org
+
+Program matmul_1
+  integer, parameter                                :: N = 5
+  integer, parameter                                :: T = 4
+  integer                                           :: i
+  real(kind=T), dimension(:,:), allocatable         :: a, b, c
+  real(kind=T), dimension(N,N)                      :: x, y, z
+
+  allocate (a(2*N, N), b(N, N), c(2*N, N))
+
+  do i = 1, 2*N
+    a(i, :) = real (i)
+  end do
+  b = 4.0_T
+
+  do i = 1, N
+    x(i, :) = real (i)
+  end do
+  y = 2.0_T
+
+!                           whole array
+
+  z = 0.0_T
+  z = matmul (x, y)
+  if (sum (z) /= 750.0_T) call abort ()
+
+!                           array sections
+
+  c = 0.0_T
+  c(1:3,1:2) = matmul (a(7:9,3:N), b(3:N,3:4))
+  if (sum (c) /= 576.0_T) call abort ()
+
+!                           uses a temp
+
+  c = 0.0_T
+  c = matmul (a, b + x)
+  if (sum (c) /= 9625.0_T) call abort ()
+
+!                           returns to a temp
+
+  c = 0.0_T
+  c = a + matmul (a, b)
+  if (sum (c) /= 5775.0_T) call abort ()
+
+  deallocate (a, b, c)
+
+end program matmul_1