Hello,
This issues is about the correct order in which we need to call the
routines that fix up the control flow for us.
Best,
Andrey
2018-04-03 Andrey Belevantsev <a...@ispras.ru>
PR rtl-optimization/83962
* sel-sched-ir.c (tidy_control_flow): Correct the order in which we call
tidy_fallthru_edge
and tidy_control_flow.
* gcc.dg/pr83962.c: New test.
diff --git a/gcc/sel-sched-ir.c b/gcc/sel-sched-ir.c
index a965d2ec42f..f6de96a7f3d 100644
--- a/gcc/sel-sched-ir.c
+++ b/gcc/sel-sched-ir.c
@@ -3839,9 +3839,13 @@ tidy_control_flow (basic_block xbb, bool full_tidying)
&& INSN_SCHED_TIMES (BB_END (xbb)) == 0
&& !IN_CURRENT_FENCE_P (BB_END (xbb)))
{
- if (sel_remove_insn (BB_END (xbb), false, false))
- return true;
+ /* We used to call sel_remove_insn here that can trigger
tidy_control_flow
+ before we fix up the fallthru edge. Correct that ordering by
+ explicitly doing the latter before the former. */
+ clear_expr (INSN_EXPR (BB_END (xbb)));
tidy_fallthru_edge (EDGE_SUCC (xbb, 0));
+ if (tidy_control_flow (xbb, false))
+ return true;
}
first = sel_bb_head (xbb);
diff --git a/gcc/testsuite/gcc.dg/pr83962.c b/gcc/testsuite/gcc.dg/pr83962.c
new file mode 100644
index 00000000000..0547e218715
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr83962.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target powerpc*-*-* ia64-*-* i?86-*-* x86_64-*-* } } */
+/* { dg-options "-std=gnu99 -O1 -fselective-scheduling2 -fschedule-insns2
-fcse-follow-jumps -fno-ssa-phiopt -fno-guess-branch-probability" } */
+unsigned int ca;
+
+void
+v6 (long long unsigned int as, int p9)
+{
+ while (p9 < 1)
+ as = (as != ca) || (as > 1);
+}
