Un-revert the reversion.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2017-10-30 Richard Biener <rguent...@suse.de>
PR tree-optimization/82762
Revert
2017-10-23 Richard Biener <rguent...@suse.de>
PR tree-optimization/82129
Revert
2017-08-01 Richard Biener <rguent...@suse.de>
PR tree-optimization/81181
* tree-ssa-pre.c (compute_antic_aux): Defer clean() to ...
(compute_antic): ... end of iteration here.
Index: gcc/tree-ssa-pre.c
===================================================================
--- gcc/tree-ssa-pre.c (revision 254211)
+++ gcc/tree-ssa-pre.c (working copy)
@@ -2029,7 +2039,8 @@ static sbitmap has_abnormal_preds;
ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
-*/
+
+ Note that clean() is deferred until after the iteration. */
static bool
compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
@@ -2165,7 +2176,8 @@ compute_antic_aux (basic_block block, bo
bitmap_value_insert_into_set (ANTIC_IN (block),
expression_for_id (bii));
- clean (ANTIC_IN (block));
+ /* clean (ANTIC_IN (block)) is defered to after the iteration converged
+ because it can cause non-convergence, see for example PR81181. */
if (!bitmap_set_equal (old, ANTIC_IN (block)))
changed = true;
@@ -2397,6 +2409,12 @@ compute_antic (void)
gcc_checking_assert (num_iterations < 500);
}
+ /* We have to clean after the dataflow problem converged as cleaning
+ can cause non-convergence because it is based on expressions
+ rather than values. */
+ FOR_EACH_BB_FN (block, cfun)
+ clean (ANTIC_IN (block));
+
statistics_histogram_event (cfun, "compute_antic iterations",
num_iterations);
Index: gcc/testsuite/gcc.dg/torture/pr82762.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr82762.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr82762.c (working copy)
@@ -0,0 +1,46 @@
+/* { dg-do compile } */
+
+int printf (const char *, ...);
+
+int b, c, d, e, f, g, j, k;
+char h, i;
+volatile int l;
+
+int m (int n, int o)
+{
+ return o < 0 || o > 1 ? n : o;
+}
+
+int p (int n, unsigned o)
+{
+ return n - o;
+}
+
+int q ()
+{
+ char r;
+ int a, s, t, u, v, w;
+L:
+ if (t)
+ printf ("%d", d);
+ u = v;
+ while (j)
+ {
+ while (e)
+ for (w = 0; w != 54; w += 6)
+ {
+ l;
+ s = p (u < 1, i || c);
+ r = s < 0 || s > 1 ? 0 : 1 >> s;
+ v = r;
+ g = h;
+ }
+ if (h)
+ return f;
+ if (u)
+ for (a = 0; a != 54; a += 6)
+ f = m (2, -(k || b));
+ }
+ d = t;
+ goto L;
+}
