Hi!
The following testcase ICEs since r10-3199.
There is a switch with default label, where the controlling expression has
range just 0..7 and there are case labels for all those 8 values, but
nothing has yet optimized away the default.
Since r10-3199, set_switch_stmt_execution_predicate sets the switch to
default label's edge's predicate to a false predicate and then
compute_bb_predicates propagates the predicates through the cfg, but false
predicates aren't really added. The caller of compute_bb_predicates
in one place handles NULL bb->aux as false predicate:
if (fbi.info)
{
if (bb->aux)
bb_predicate = *(predicate *) bb->aux;
else
bb_predicate = false;
}
else
bb_predicate = true;
but then in two further spots that the patch below is changing
it assumes bb->aux must be non-NULL. Those two spots are guarded by a
condition that is only true if fbi.info is non-NULL, so I think the right
fix is to treat NULL aux as false predicate in those spots too.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/10.2?
2020-07-10 Jakub Jelinek <ja...@redhat.com>
PR ipa/96130
* ipa-fnsummary.c (analyze_function_body): Treat NULL bb->aux
as false predicate.
* gcc.dg/torture/pr96130.c: New test.
--- gcc/ipa-fnsummary.c.jj 2020-04-05 00:27:26.000000000 +0200
+++ gcc/ipa-fnsummary.c 2020-07-10 16:12:59.155168850 +0200
@@ -2766,7 +2766,10 @@ analyze_function_body (struct cgraph_nod
edge ex;
unsigned int j;
class tree_niter_desc niter_desc;
- bb_predicate = *(predicate *) loop->header->aux;
+ if (loop->header->aux)
+ bb_predicate = *(predicate *) loop->header->aux;
+ else
+ bb_predicate = false;
exits = get_loop_exit_edges (loop);
FOR_EACH_VEC_ELT (exits, j, ex)
@@ -2799,7 +2802,10 @@ analyze_function_body (struct cgraph_nod
for (unsigned i = 0; i < loop->num_nodes; i++)
{
gimple_stmt_iterator gsi;
- bb_predicate = *(predicate *) body[i]->aux;
+ if (body[i]->aux)
+ bb_predicate = *(predicate *) body[i]->aux;
+ else
+ bb_predicate = false;
for (gsi = gsi_start_bb (body[i]); !gsi_end_p (gsi);
gsi_next (&gsi))
{
--- gcc/testsuite/gcc.dg/torture/pr96130.c.jj 2020-07-10 16:15:28.794082127
+0200
+++ gcc/testsuite/gcc.dg/torture/pr96130.c 2020-07-10 16:14:49.273633241
+0200
@@ -0,0 +1,26 @@
+/* PR ipa/96130 */
+/* { dg-do compile } */
+
+struct S { unsigned j : 3; };
+int k, l, m;
+
+void
+foo (struct S x)
+{
+ while (l != 5)
+ switch (x.j)
+ {
+ case 1:
+ case 3:
+ case 4:
+ case 6:
+ case 2:
+ case 5:
+ l = m;
+ case 7:
+ case 0:
+ k = 0;
+ default:
+ break;
+ }
+}
Jakub
