Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2017-08-21 Richard Biener <rguent...@suse.de>
PR tree-optimization/81900
* tree-ssa-pre.c (compute_antic_aux): Properly compute changed
for blocks with abnormal predecessors.
(compute_antic): Do not set visited flag prematurely.
* gcc.dg/torture/pr81900.c: New testcase.
Index: gcc/tree-ssa-pre.c
===================================================================
--- gcc/tree-ssa-pre.c (revision 251217)
+++ gcc/tree-ssa-pre.c (working copy)
@@ -2119,16 +2170,15 @@ static sbitmap has_abnormal_preds;
static bool
compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
{
- bool changed = false;
bitmap_set_t S, old, ANTIC_OUT;
bitmap_iterator bi;
unsigned int bii;
edge e;
edge_iterator ei;
- bool was_visited = BB_VISITED (block);
- old = ANTIC_OUT = S = NULL;
+ bool changed = ! BB_VISITED (block);
BB_VISITED (block) = 1;
+ old = ANTIC_OUT = S = NULL;
/* If any edges from predecessors are abnormal, antic_in is empty,
so do nothing. */
@@ -2217,7 +2267,7 @@ compute_antic_aux (basic_block block, bo
/* clean (ANTIC_IN (block)) is defered to after the iteration converged
because it can cause non-convergence, see for example PR81181. */
- if (!was_visited || !bitmap_set_equal (old, ANTIC_IN (block)))
+ if (!bitmap_set_equal (old, ANTIC_IN (block)))
changed = true;
maybe_dump_sets:
@@ -2396,9 +2446,6 @@ compute_antic (void)
if (e->flags & EDGE_ABNORMAL)
{
bitmap_set_bit (has_abnormal_preds, block->index);
-
- /* We also anticipate nothing. */
- BB_VISITED (block) = 1;
break;
}
Index: gcc/testsuite/gcc.dg/torture/pr81900.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr81900.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr81900.c (working copy)
@@ -0,0 +1,19 @@
+/* PR/81900 */
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-flto" } { "" } } */
+/* { dg-options "-fdump-tree-optimized" } */
+
+void Perl_croak() __attribute__((noreturn));
+char *Perl_sv_gets();
+void __attribute__((returns_twice)) __sigsetjmp ();
+void a() {
+ __sigsetjmp();
+ char *b;
+ if ((b = Perl_sv_gets()) == 0)
+ Perl_croak("No Perl script found in input\n");
+ if (*b == '#')
+ __asm__("" : : ""("badbad"));
+}
+
+/* Do not elide the test against zero. */
+/* { dg-final { scan-tree-dump " == 0B" "optimized" } } */
