Hi!
The find_cond_trap code isn't really prepared to turn conditional return
into unconditional when converting non-conditional trap into conditional,
without RTL checking it generates (label_ref (return)), the edges updates
are also wrong.
This patch just disables that transformation, IMHO trading conditional
return + unconditional trap with conditional trap + unconditional return
isn't worth it.
Martin Sebor has kindly bootstrapped/regtested this on powerpc64le-linux,
ok for trunk?
2015-12-23 Jakub Jelinek <ja...@redhat.com>
PR target/69015
* ifcvt.c (find_cond_trap): Give up if returnjump_p (jump).
* gcc.dg/pr69015.c: New test.
--- gcc/ifcvt.c.jj 2015-12-10 17:01:06.000000000 +0100
+++ gcc/ifcvt.c 2015-12-22 19:43:07.404639873 +0100
@@ -4526,8 +4526,11 @@ find_cond_trap (basic_block test_bb, edg
return FALSE;
/* If the conditional jump is more than just a conditional jump, then
- we can not do if-conversion on this block. */
- if (! onlyjump_p (jump))
+ we can not do if-conversion on this block. Give up for returnjump_p,
+ changing a conditional return followed by unconditional trap for
+ conditional trap followed by unconditional return is likely not
+ beneficial and harder to handle. */
+ if (! onlyjump_p (jump) || returnjump_p (jump))
return FALSE;
/* We must be comparing objects whose modes imply the size. */
--- gcc/testsuite/gcc.dg/pr69015.c.jj 2015-12-22 19:52:32.457756578 +0100
+++ gcc/testsuite/gcc.dg/pr69015.c 2015-12-22 19:53:39.544820625 +0100
@@ -0,0 +1,10 @@
+/* PR target/69015 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-if-conversion" } */
+
+void
+foo (int c)
+{
+ if (c)
+ __builtin_trap ();
+}
Jakub
