re PR tree-optimization/69980 (Supposedly wrong SLP code emitted)

2016-02-19  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/69980
	* tree-vect-slp.c (vect_attempt_slp_rearrange_stmts): Update
	permutation of those we need to keep.

	* gfortran.dg/vect/pr69980.f90: New testcase.

From-SVN: r233809

gcc/ChangeLog

+2016-02-19  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/69980
+	* tree-vect-slp.c (vect_attempt_slp_rearrange_stmts): Update
+	permutation of those we need to keep.
+
 2016-02-29  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR target/69706

gcc/testsuite/ChangeLog

+2016-02-19  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/69980
+	* gfortran.dg/vect/pr69980.f90: New testcase.
+
 2016-02-29  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gcc.target/sparc/20160229-1.c: New test.

gcc/testsuite/gfortran.dg/vect/pr69980.f90

+! { dg-do run }
+! { dg-additional-options "-Ofast -fno-inline" }
+
+subroutine check (a, b)
+   real *8, intent(in) :: a(4), b(4)
+
+   IF (abs(a(1)-b(1)) > 1) THEN
+      CALL ABORT
+   END IF
+end subroutine check
+
+program main
+  real *8 :: mu(4,26), mumax(4), mumax2(4)
+
+  integer :: i, k
+
+  do k=1,26
+     do i=1,4
+        mu(i, k) = 4*(i-1) + k
+     end do
+  end do
+
+  mumax = 0; 
+  do k=1,26
+     do i=1,3
+        mumax(i) = max(mumax(i), mu(i,k)+mu(i,k))
+     end do
+  end do
+
+  mumax2 = 0;
+  do i=1,3
+     do k=1,26
+        mumax2(i) = max(mumax2(i), mu(i,k)+mu(i,k))
+     end do
+  end do
+
+  CALL check (mumax, mumax2)
+
+  return
+end program

gcc/tree-vect-slp.c

@@ -1343,6 +1343,9 @@ vect_attempt_slp_rearrange_stmts (slp_instance slp_instn)
 	  || (group_size == GROUP_SIZE (vinfo_for_stmt (first_stmt))
 	      && GROUP_GAP (vinfo_for_stmt (first_stmt)) == 0))
 	SLP_TREE_LOAD_PERMUTATION (node).release ();
+      else
+	for (j = 0; j < SLP_TREE_LOAD_PERMUTATION (node).length (); ++j)
+	  SLP_TREE_LOAD_PERMUTATION (node)[j] = j;
     }
 
   return true;