The following fixes PR57122 where splitting an edge from the
loop latch is wrongly detected as latch-edge split (happens
in case an irreducible region is inside the loop).
Bootstrap and regtest pending on x86_64-unknown-linux-gnu.
Richard.
2013-04-30 Richard Biener <rguent...@suse.de>
PR middle-end/57122
* cfghooks.c (split_edge): Properly check for the loop
latch edge.
* gcc.dg/torture/pr57122.c: New testcase.
Index: gcc/cfghooks.c
===================================================================
--- gcc/cfghooks.c (revision 198441)
+++ gcc/cfghooks.c (working copy)
@@ -662,7 +662,9 @@ split_edge (edge e)
loop = find_common_loop (src->loop_father, dest->loop_father);
add_bb_to_loop (ret, loop);
- if (loop->latch == src)
+ /* If we split the latch edge of loop adjust the latch block. */
+ if (loop->latch == src
+ && loop->header == dest)
loop->latch = ret;
}
Index: gcc/testsuite/gcc.dg/torture/pr57122.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr57122.c (revision 0)
+++ gcc/testsuite/gcc.dg/torture/pr57122.c (working copy)
@@ -0,0 +1,27 @@
+/* { dg-do compile } */
+
+unsigned a;
+int b, c;
+
+void f(void)
+{
+ if(a)
+ {
+ for(a = 0; a < 2; a++)
+ a /= 7;
+
+ for(;; a++)
+ {
+ if(a)
+ lbl1:
+ b++;
+
+ if(c)
+ goto lbl1;
+lbl2:
+ ;
+ }
+ }
+
+ goto lbl2;
+}
