re PR tree-optimization/82157 (ICE on valid code at -O2 and -O3: cannot update SSA form)

2017-09-12  Richard Biener  <rguenther@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.

From-SVN: r252020

gcc/ChangeLog

+2017-09-12  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/82157
+	* tree-ssa-pre.c (remove_dead_inserted_code): Do not remove
+	stmts with side-effects.
+
 2017-09-12  Richard Sandiford  <richard.sandiford@linaro.org>
 	    Alan Hayward  <alan.hayward@arm.com>
 	    David Sherwood <david.sherwood@arm.com>

gcc/testsuite/ChangeLog

+2017-09-12  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/82157
+	* gcc.dg/torture/pr82157.c: New testcase.
+
 2017-09-12  Simon Atanasyan  <simon.atanasyan@imgtec.com>
 
 	* gcc.target/mips/near-far-1.c: Add check for 'short_call'

gcc/testsuite/gcc.dg/torture/pr82157.c

+/* { 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;
+}

gcc/tree-ssa-pre.c

@@ -4913,6 +4913,8 @@ 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;