When an unconditional jump with side effects targets an immediately
following label, rtl_tidy_fallthru_edge is called. Since it has side
effects, it doesn't remove the jump, but the label is still marked
as fallthru. This later causes a verification error. Do nothing in this
case instead.
gcc/ChangeLog:
* cfgrtl.c (rtl_tidy_fallthru_edge): Bail for unconditional jumps
with side effects.
---
gcc/ChangeLog | 5 +++++
gcc/cfgrtl.c | 2 ++
2 files changed, 7 insertions(+)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 56e31f6..4c7046f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,10 @@
2016-01-02 Marcin Kościelnicki <[email protected]>
+ * cfgrtl.c (rtl_tidy_fallthru_edge): Bail for unconditional jumps
+ with side effects.
+
+2016-01-02 Marcin Kościelnicki <[email protected]>
+
* function.c (reposition_prologue_and_epilogue_notes): Avoid
verification error if the last insn of prologue is an unconditional
jump.
diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c
index fbfc7cd..dc4c2b1 100644
--- a/gcc/cfgrtl.c
+++ b/gcc/cfgrtl.c
@@ -1762,6 +1762,8 @@ rtl_tidy_fallthru_edge (edge e)
If block B consisted only of this single jump, turn it into a deleted
note. */
q = BB_END (b);
+ if (JUMP_P (q) && !onlyjump_p (q))
+ return;
if (JUMP_P (q)
&& onlyjump_p (q)
&& (any_uncondjump_p (q)
--
2.6.4
