This fixes PR64530 by fixing a mistake (oops) in the iteration
over all data-ref pairs in pg_add_dependence_edges.
Bootstrap and regtest pending on x86_64-unknown-linux-gnu.
Richard.
2015-01-12 Richard Biener <rguent...@suse.de>
PR tree-optimization/64530
* tree-loop-distribution.c (pg_add_dependence_edges): Shuffle
back dr1.
* gfortran.dg/pr64530.f90: New testcase.
Index: gcc/tree-loop-distribution.c
===================================================================
--- gcc/tree-loop-distribution.c (revision 219446)
+++ gcc/tree-loop-distribution.c (working copy)
@@ -1362,6 +1375,7 @@ pg_add_dependence_edges (struct graph *r
for (int ii = 0; drs1.iterate (ii, &dr1); ++ii)
for (int jj = 0; drs2.iterate (jj, &dr2); ++jj)
{
+ data_reference_p saved_dr1 = dr1;
int this_dir = 1;
ddr_p ddr;
/* Re-shuffle data-refs to be in dominator order. */
@@ -1407,6 +1421,8 @@ pg_add_dependence_edges (struct graph *r
dir = this_dir;
else if (dir != this_dir)
return 2;
+ /* Shuffle "back" dr1. */
+ dr1 = saved_dr1;
}
return dir;
}
Index: gcc/testsuite/gfortran.dg/pr64530.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr64530.f90 (revision 0)
+++ gcc/testsuite/gfortran.dg/pr64530.f90 (working copy)
@@ -0,0 +1,38 @@
+! { dg-do run }
+
+program bug
+ ! Bug triggered with at least three elements
+ integer, parameter :: asize = 3
+
+ double precision,save :: ave(asize)
+ double precision,save :: old(asize)
+ double precision,save :: tmp(asize)
+
+ ave(:) = 10.d0
+ old(:) = 3.d0
+ tmp(:) = 0.d0
+
+ call buggy(2.d0,asize,ave,old,tmp)
+ if (any (tmp(:) .ne. 3.5)) call abort
+end
+
+subroutine buggy(scale_factor, asize, ave, old, tmp)
+
+ implicit none
+ ! Args
+ double precision scale_factor
+ integer asize
+ double precision ave(asize)
+ double precision old(asize)
+ double precision tmp(asize)
+
+ ! Local
+ integer i
+
+ do i = 1, asize
+ tmp(i) = ave(i) - old(i)
+ old(i) = ave(i)
+ tmp(i) = tmp(i) / scale_factor
+ end do
+
+end subroutine buggy
