1 files changed, 36 insertions, 0 deletions
diff --git a/gcc/testsuite/gfortran.dg/single_char_string.f90 b/gcc/testsuite/gfortran.dg/single_char_string.f90
new file mode 100644
index 00000000000..479456cfea8
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/single_char_string.f90
@@ -0,0 +1,36 @@
+! { dg-do run }
+! { dg-options "-fdump-tree-original" }
+! PR12456 - Optimize string(k:k) as single character.
+
+Program pr12456
+character a
+character b
+character (len=5) :: c
+integer i
+
+b = 'a'
+a = b
+if (a .ne. 'a') call abort()
+if (a .ne. b) call abort()
+c (3:3) = 'a'
+if (c (3:3) .ne. b) call abort ()
+if (c (3:3) .ne. 'a') call abort ()
+if (LGT (a, c (3:3))) call abort ()
+if (LGT (a, 'a')) call abort ()
+
+i = 3
+c (i:i) = 'a'
+if (c (i:i) .ne. b) call abort ()
+if (c (i:i) .ne. 'a') call abort ()
+if (LGT (a, c (i:i))) call abort ()
+
+if (a .gt. char (255)) call abort ()
+end
+
+! There should not be _gfortran_compare_string and _gfortran_copy_string in
+! the dumped file.
+
+! { dg-final { scan-tree-dump-times "_gfortran_compare_string" 0 "original" } }
+! { dg-final { scan-tree-dump-times "_gfortran_copy_string" 0 "original" } }
+
+! { dg-final { cleanup-tree-dump "original" } }