The following fixes PR87280 (and PR87169 in a different way).
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2018-09-12 Richard Biener <rguent...@suse.de>
PR tree-optimization/87280
* tree-ssa-sccvn.c (process_bb): Handle the case of executable
edge but unreachable target.
(do_rpo_vn): For conservatively handling a PHI only mark
the backedge executable but not the block reachable.
* gcc.dg/torture/pr87280.c: New testcase.
Index: gcc/tree-ssa-sccvn.c
===================================================================
--- gcc/tree-ssa-sccvn.c (revision 264234)
+++ gcc/tree-ssa-sccvn.c (working copy)
@@ -5976,15 +5976,24 @@ process_bb (rpo_elim &avail, basic_block
{
FOR_EACH_EDGE (e, ei, bb->succs)
{
- if (e->flags & EDGE_EXECUTABLE)
- continue;
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file,
- "marking outgoing edge %d -> %d executable\n",
- e->src->index, e->dest->index);
- gcc_checking_assert (iterate || !(e->flags & EDGE_DFS_BACK));
- e->flags |= EDGE_EXECUTABLE;
- e->dest->flags |= BB_EXECUTABLE;
+ if (!(e->flags & EDGE_EXECUTABLE))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "marking outgoing edge %d -> %d executable\n",
+ e->src->index, e->dest->index);
+ gcc_checking_assert (iterate || !(e->flags & EDGE_DFS_BACK));
+ e->flags |= EDGE_EXECUTABLE;
+ e->dest->flags |= BB_EXECUTABLE;
+ }
+ else if (!(e->dest->flags & BB_EXECUTABLE))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "marking destination block %d reachable\n",
+ e->dest->index);
+ e->dest->flags |= BB_EXECUTABLE;
+ }
}
}
for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
@@ -6124,20 +6133,37 @@ process_bb (rpo_elim &avail, basic_block
e->flags |= EDGE_EXECUTABLE;
e->dest->flags |= BB_EXECUTABLE;
}
+ else if (!(e->dest->flags & BB_EXECUTABLE))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "marking destination block %d reachable\n",
+ e->dest->index);
+ e->dest->flags |= BB_EXECUTABLE;
+ }
}
else if (gsi_one_before_end_p (gsi))
{
FOR_EACH_EDGE (e, ei, bb->succs)
{
- if (e->flags & EDGE_EXECUTABLE)
- continue;
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file,
- "marking outgoing edge %d -> %d executable\n",
- e->src->index, e->dest->index);
- gcc_checking_assert (iterate || !(e->flags & EDGE_DFS_BACK));
- e->flags |= EDGE_EXECUTABLE;
- e->dest->flags |= BB_EXECUTABLE;
+ if (!(e->flags & EDGE_EXECUTABLE))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "marking outgoing edge %d -> %d executable\n",
+ e->src->index, e->dest->index);
+ gcc_checking_assert (iterate || !(e->flags & EDGE_DFS_BACK));
+ e->flags |= EDGE_EXECUTABLE;
+ e->dest->flags |= BB_EXECUTABLE;
+ }
+ else if (!(e->dest->flags & BB_EXECUTABLE))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "marking destination block %d reachable\n",
+ e->dest->index);
+ e->dest->flags |= BB_EXECUTABLE;
+ }
}
}
@@ -6399,7 +6425,6 @@ do_rpo_vn (function *fn, edge entry, bit
if (e->flags & EDGE_DFS_BACK)
{
e->flags |= EDGE_EXECUTABLE;
- e->dest->flags |= BB_EXECUTABLE;
/* There can be a non-latch backedge into the header
which is part of an outer irreducible region. We
cannot avoid iterating this block then. */
Index: gcc/testsuite/gcc.dg/torture/pr87280.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr87280.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr87280.c (working copy)
@@ -0,0 +1,61 @@
+/* { dg-do compile } */
+/* { dg-additional-options "--param rpo-vn-max-loop-depth=5" } */
+
+int uc;
+
+void
+j8 (int *xv, int f3)
+{
+ uc = 0;
+ while (uc < 1)
+ {
+ }
+
+ if (*xv == 0)
+ {
+ int *o8 = xv;
+
+ if (0)
+ {
+n3:
+ *o8 = 0;
+ while (*o8 < 1)
+ {
+h5:
+ *o8 = 0;
+ }
+ }
+
+ while (*xv < 1)
+ if (*xv == 0)
+ goto h5;
+
+g5:
+ ;
+ }
+
+ *xv = 0;
+ for (;;)
+ {
+ while (uc < 1)
+ {
+ }
+
+ while (f3 < 1)
+ {
+ if (*xv == 0)
+ goto n3;
+
+ while (f3 < 1)
+ while (*xv < 1)
+ while (*xv < 1)
+ while (*xv < 1)
+ while (*xv < 1)
+ {
+ }
+ }
+
+ if (*xv == 0)
+ goto g5;
+ }
+}
