The following fixes a latent issue in fold_stmt uncovered by
PRE re-org. We muck with the gsi in inapprorpate ways.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2017-09-12 Richard Biener <rguent...@suse.de>
PR tree-optimization/82157
* tree-ssa-pre.c (remove_dead_inserted_code): Do not remove
stmts with side-effects.
* gcc.dg/torture/pr82157.c: New testcase.
Index: gcc/tree-ssa-pre.c
===================================================================
--- gcc/tree-ssa-pre.c (revision 252002)
+++ gcc/tree-ssa-pre.c (working copy)
@@ -4913,6 +4964,8 @@ remove_dead_inserted_code (void)
continue;
gimple *t = SSA_NAME_DEF_STMT (def);
+ if (gimple_has_side_effects (t))
+ continue;
/* Add uses to the worklist. */
ssa_op_iter iter;
Index: gcc/testsuite/gcc.dg/torture/pr82157.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr82157.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr82157.c (working copy)
@@ -0,0 +1,43 @@
+/* { dg-do compile } */
+
+int a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y,
z;
+
+int aa ()
+{
+ w = f < 0 || e >> f;
+ while (z)
+ h = i && (r && p) | ((l = p) == c % d);
+ k = v + 1 < a;
+ t = -(j < 1) * q;
+ return u;
+}
+
+int ab ()
+{
+ for (j = 0; 1; j = 5)
+ if (!s)
+ return d;
+}
+
+void ac ()
+{
+ char ad = aa ();
+ ab ();
+ if (x)
+ {
+ for (m = 0; m < 3; m = a)
+ {
+ y = a && b;
+ if (g)
+ break;
+ }
+ n = j;
+ }
+ o = j & ad;
+}
+
+int main ()
+{
+ ac ();
+ return 0;
+}
