Similar to if-combine if-conversion invalidates range info on stmts
that are executed unconditionally only after the transform. Thus
we have to invalidate it.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2015-08-05 Richard Biener <rguent...@suse.de>
PR tree-optimization/67121
* tree-if-conv.c (combine_blocks): Clear range-info produced
by stmts no longer executed conditionally.
* gcc.dg/torture/pr67121.c: New testcase.
Index: gcc/tree-if-conv.c
===================================================================
--- gcc/tree-if-conv.c (revision 226612)
+++ gcc/tree-if-conv.c (working copy)
@@ -2199,9 +2199,11 @@ combine_blocks (struct loop *loop, bool
/* Merge basic blocks: first remove all the edges in the loop,
except for those from the exit block. */
exit_bb = NULL;
+ bool *predicated = XNEWVEC (bool, orig_loop_num_nodes);
for (i = 0; i < orig_loop_num_nodes; i++)
{
bb = ifc_bbs[i];
+ predicated[i] = !is_true_predicate (bb_predicate (bb));
free_bb_predicate (bb);
if (bb_with_exit_edge_p (loop, bb))
{
@@ -2259,9 +2261,21 @@ combine_blocks (struct loop *loop, bool
if (bb == exit_bb || bb == loop->latch)
continue;
- /* Make stmts member of loop->header. */
+ /* Make stmts member of loop->header and clear range info from all stmts
+ in BB which is now no longer executed conditional on a predicate we
+ could have derived it from. */
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
- gimple_set_bb (gsi_stmt (gsi), merge_target_bb);
+ {
+ gimple stmt = gsi_stmt (gsi);
+ gimple_set_bb (stmt, merge_target_bb);
+ if (predicated[i])
+ {
+ ssa_op_iter i;
+ tree op;
+ FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_DEF)
+ reset_flow_sensitive_info (op);
+ }
+ }
/* Update stmt list. */
last = gsi_last_bb (merge_target_bb);
@@ -2281,6 +2295,7 @@ combine_blocks (struct loop *loop, bool
free (ifc_bbs);
ifc_bbs = NULL;
+ free (predicated);
}
/* Version LOOP before if-converting it; the original loop
Index: gcc/testsuite/gcc.dg/torture/pr67121.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr67121.c (revision 0)
+++ gcc/testsuite/gcc.dg/torture/pr67121.c (working copy)
@@ -0,0 +1,31 @@
+/* { dg-do run } */
+
+int a[6], b, c = 226, d, e, f;
+signed char g;
+
+void
+fn1 (int p1)
+{
+ b = a[p1];
+}
+
+int
+main ()
+{
+ a[0] = 1;
+ for (f = 0; f < 9; f++)
+ {
+ signed char h = c;
+ int i = 1;
+ g = h < 0 ? h : h >> i;
+ e = g;
+ for (d = 1; d; d = 0)
+ ;
+ }
+ fn1 (g >> 8 & 1);
+
+ if (b != 0)
+ __builtin_abort ();
+
+ return 0;
+}
