The following fixes LOOP_VECTORIZED IFNs made useless by CFG cleanup
after if-conversion by re-verifying the mentioned loops still exist.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2019-02-08 Richard Biener <rguent...@suse.de>
PR tree-optimization/89247
* tree-if-conv.c: Include tree-cfgcleanup.h.
(version_loop_for_if_conversion): Record LOOP_VECTORIZED call.
(tree_if_conversion): Pass through predicate vector.
(pass_if_conversion::execute): Do CFG cleanup and SSA update
inline, see if any if-converted loops we refrece in
LOOP_VECTORIZED calls vanished and fixup.
* tree-if-conv.h (tree_if_conversion): Adjust prototype.
* gcc.dg/torture/pr89247.c: New testcase.
Index: gcc/tree-if-conv.c
===================================================================
--- gcc/tree-if-conv.c (revision 268668)
+++ gcc/tree-if-conv.c (working copy)
@@ -119,6 +119,7 @@ along with GCC; see the file COPYING3.
#include "internal-fn.h"
#include "fold-const.h"
#include "tree-ssa-sccvn.h"
+#include "tree-cfgcleanup.h"
/* Only handle PHIs with no more arguments unless we are asked to by
simd pragma. */
@@ -2719,7 +2720,7 @@ combine_blocks (struct loop *loop)
consistent after the condition is folded in the vectorizer. */
static struct loop *
-version_loop_for_if_conversion (struct loop *loop)
+version_loop_for_if_conversion (struct loop *loop, vec<gimple *> *preds)
{
basic_block cond_bb;
tree cond = make_ssa_name (boolean_type_node);
@@ -2759,6 +2760,7 @@ version_loop_for_if_conversion (struct l
new_loop->force_vectorize = false;
gsi = gsi_last_bb (cond_bb);
gimple_call_set_arg (g, 1, build_int_cst (integer_type_node, new_loop->num));
+ preds->safe_push (g);
gsi_insert_before (&gsi, g, GSI_SAME_STMT);
update_ssa (TODO_update_ssa);
return new_loop;
@@ -2979,7 +2981,7 @@ ifcvt_local_dce (basic_block bb)
changed. */
unsigned int
-tree_if_conversion (struct loop *loop)
+tree_if_conversion (struct loop *loop, vec<gimple *> *preds)
{
unsigned int todo = 0;
bool aggressive_if_conv;
@@ -3027,7 +3029,7 @@ tree_if_conversion (struct loop *loop)
struct loop *vloop
= (versionable_outer_loop_p (loop_outer (loop))
? loop_outer (loop) : loop);
- struct loop *nloop = version_loop_for_if_conversion (vloop);
+ struct loop *nloop = version_loop_for_if_conversion (vloop, preds);
if (nloop == NULL)
goto cleanup;
if (vloop != loop)
@@ -3139,11 +3141,12 @@ pass_if_conversion::execute (function *f
if (number_of_loops (fun) <= 1)
return 0;
+ auto_vec<gimple *> preds;
FOR_EACH_LOOP (loop, 0)
if (flag_tree_loop_if_convert == 1
|| ((flag_tree_loop_vectorize || loop->force_vectorize)
&& !loop->dont_vectorize))
- todo |= tree_if_conversion (loop);
+ todo |= tree_if_conversion (loop, &preds);
if (todo)
{
@@ -3158,7 +3161,30 @@ pass_if_conversion::execute (function *f
gcc_assert (!bb->aux);
}
- return todo;
+ /* Perform IL update now, it might elide some loops. */
+ if (todo & TODO_cleanup_cfg)
+ {
+ cleanup_tree_cfg ();
+ if (need_ssa_update_p (fun))
+ todo |= TODO_update_ssa;
+ }
+ if (todo & TODO_update_ssa_any)
+ update_ssa (todo & TODO_update_ssa_any);
+
+ /* If if-conversion elided the loop fall back to the original one. */
+ for (unsigned i = 0; i < preds.length (); ++i)
+ {
+ gimple *g = preds[i];
+ unsigned ifcvt_loop = tree_to_uhwi (gimple_call_arg (g, 0));
+ if (!get_loop (fun, ifcvt_loop))
+ {
+ if (dump_file)
+ fprintf (dump_file, "If-converted loop vanished\n");
+ fold_loop_internal_call (g, boolean_false_node);
+ }
+ }
+
+ return 0;
}
} // anon namespace
Index: gcc/tree-if-conv.h
===================================================================
--- gcc/tree-if-conv.h (revision 268668)
+++ gcc/tree-if-conv.h (working copy)
@@ -19,6 +19,6 @@ along with GCC; see the file COPYING3.
#ifndef GCC_TREE_IF_CONV_H
#define GCC_TREE_IF_CONV_H
-unsigned int tree_if_conversion (struct loop *);
+unsigned int tree_if_conversion (struct loop *, vec<gimple *> * = NULL);
#endif /* GCC_TREE_IF_CONV_H */
Index: gcc/testsuite/gcc.dg/torture/pr89247.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr89247.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr89247.c (working copy)
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+
+int *a;
+void b()
+{
+ void *c = &&d;
+ for (;;)
+ d:
+ if (*a)
+ ;
+ else
+ *a = ({ 0 < b; });
+}
