* [PATCH] Fix PR71595
@ 2016-11-24 9:49 Richard Biener
0 siblings, 0 replies; only message in thread
From: Richard Biener @ 2016-11-24 9:49 UTC (permalink / raw)
To: gcc-patches
The following fixes PR71595, the failure to update loop-closed SSA
when unrolling. We fail to make remove_path note which blocks we
have to re-scan -- everything is in place, we just don't use it...
This also makes irred recompution more efficient from # removed path
times to a single time per function.
Bootstrap and regtest running on x86_64-unknown-linux-gnu.
Richard.
2016-11-24 Richard Biener <rguenther@suse.de>
PR tree-optimization/71595
* cfgloopmanip.h (remove_path): Add irred_invalidated and
loop_closed_ssa_invalidated parameters, defaulted to NULL.
* cfgloopmanip.c (remove_path): Likewise, pass them along to
called functions. Only fix irred flags if the caller didn't
request state.
* tree-ssa-loop-ivcanon.c (unloop_loops): Use add_bb_to_loop.
(unloop_loops): Pass irred_invalidated and loop_closed_ssa_invalidated
to remove_path.
* gcc.dg/torture/pr71595.c: New testcase.
diff --git a/gcc/cfgloopmanip.c b/gcc/cfgloopmanip.c
index eb86839..84b6b01 100644
--- a/gcc/cfgloopmanip.c
+++ b/gcc/cfgloopmanip.c
@@ -298,16 +298,20 @@ fix_bb_placements (basic_block from,
and update loop structures and dominators. Return true if we were able
to remove the path, false otherwise (and nothing is affected then). */
bool
-remove_path (edge e)
+remove_path (edge e, bool *irred_invalidated,
+ bitmap loop_closed_ssa_invalidated)
{
edge ae;
basic_block *rem_bbs, *bord_bbs, from, bb;
vec<basic_block> dom_bbs;
int i, nrem, n_bord_bbs;
- bool irred_invalidated = false;
+ bool local_irred_invalidated = false;
edge_iterator ei;
struct loop *l, *f;
+ if (! irred_invalidated)
+ irred_invalidated = &local_irred_invalidated;
+
if (!can_remove_branch_p (e))
return false;
@@ -317,7 +321,7 @@ remove_path (edge e)
that is inside an irreducible region is changed, or if such a loop is
removed. */
if (e->flags & EDGE_IRREDUCIBLE_LOOP)
- irred_invalidated = true;
+ *irred_invalidated = true;
/* We need to check whether basic blocks are dominated by the edge
e, but we only have basic block dominators. This is easy to
@@ -334,7 +338,7 @@ remove_path (edge e)
{
f = loop_outer (l);
if (dominated_by_p (CDI_DOMINATORS, l->latch, e->dest))
- unloop (l, &irred_invalidated, NULL);
+ unloop (l, irred_invalidated, loop_closed_ssa_invalidated);
}
/* Identify the path. */
@@ -348,13 +352,13 @@ remove_path (edge e)
/* Find "border" hexes -- i.e. those with predecessor in removed path. */
for (i = 0; i < nrem; i++)
bitmap_set_bit (seen, rem_bbs[i]->index);
- if (!irred_invalidated)
+ if (!*irred_invalidated)
FOR_EACH_EDGE (ae, ei, e->src->succs)
if (ae != e && ae->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)
&& !bitmap_bit_p (seen, ae->dest->index)
&& ae->flags & EDGE_IRREDUCIBLE_LOOP)
{
- irred_invalidated = true;
+ *irred_invalidated = true;
break;
}
@@ -369,7 +373,7 @@ remove_path (edge e)
bord_bbs[n_bord_bbs++] = ae->dest;
if (ae->flags & EDGE_IRREDUCIBLE_LOOP)
- irred_invalidated = true;
+ *irred_invalidated = true;
}
}
@@ -411,10 +415,10 @@ remove_path (edge e)
/* Fix placements of basic blocks inside loops and the placement of
loops in the loop tree. */
- fix_bb_placements (from, &irred_invalidated, NULL);
- fix_loop_placements (from->loop_father, &irred_invalidated);
+ fix_bb_placements (from, irred_invalidated, loop_closed_ssa_invalidated);
+ fix_loop_placements (from->loop_father, irred_invalidated);
- if (irred_invalidated
+ if (local_irred_invalidated
&& loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS))
mark_irreducible_loops ();
diff --git a/gcc/cfgloopmanip.h b/gcc/cfgloopmanip.h
index 0e7dc7a..5c4552c 100644
--- a/gcc/cfgloopmanip.h
+++ b/gcc/cfgloopmanip.h
@@ -34,7 +34,7 @@ enum
a complete peeling. */
extern edge mfb_kj_edge;
-extern bool remove_path (edge);
+extern bool remove_path (edge, bool * = NULL, bitmap = NULL);
extern void place_new_loop (struct function *, struct loop *);
extern void add_loop (struct loop *, struct loop *);
extern void scale_loop_frequencies (struct loop *, int, int);
diff --git a/gcc/testsuite/gcc.dg/torture/pr71595.c b/gcc/testsuite/gcc.dg/torture/pr71595.c
new file mode 100644
index 0000000..4202ad3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr71595.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+
+int a, d, e, f, g, h;
+static int b[][6] = { {0}, {0}, {1, 1}, {1} };
+
+void
+fn1 ()
+{
+ for (; f; f++)
+ if (g)
+ {
+ for (e = 0; e < 5; e++)
+ if (b[e + 2][1])
+ {
+ h = b[2][e] ? 0 : a;
+ d |= 4;
+ }
+ else
+ return;
+ }
+}
diff --git a/gcc/tree-ssa-loop-ivcanon.c b/gcc/tree-ssa-loop-ivcanon.c
index beb65b0..82e2237 100644
--- a/gcc/tree-ssa-loop-ivcanon.c
+++ b/gcc/tree-ssa-loop-ivcanon.c
@@ -647,7 +647,7 @@ unloop_loops (bitmap loop_closed_ssa_invalidated,
latch_edge->flags |= flags;
latch_edge->goto_locus = locus;
- latch_edge->dest->loop_father = current_loops->tree_root;
+ add_bb_to_loop (latch_edge->dest, current_loops->tree_root);
latch_edge->dest->count = 0;
latch_edge->dest->frequency = 0;
set_immediate_dominator (CDI_DOMINATORS, latch_edge->dest, latch_edge->src);
@@ -663,7 +663,7 @@ unloop_loops (bitmap loop_closed_ssa_invalidated,
edge e;
FOR_EACH_VEC_ELT (edges_to_remove, i, e)
{
- bool ok = remove_path (e);
+ bool ok = remove_path (e, irred_invalidated, loop_closed_ssa_invalidated);
gcc_assert (ok);
}
edges_to_remove.release ();
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