When turning a jump to a return into a return, we need to clear
EDGE_CROSSING of the fallthru edge to prevent a checking failure.
I considered not applying the transformation when the edge has
EDGE_CROSSING set, but it still seems like we ought to eliminate the
unnecessary jump in that case.
Bootstrapped and regression tested on x86_64. Also did a profiled
bootstrap and regression test on x86_64.
Installing on the trunk.
Jeff
commit db24bdc743cf23ea12d2dcf8254d86ab366bb46d
Author: Jeff Law <jeffreya...@gmail.com>
Date: Tue Oct 11 00:44:26 2022 -0400
[PR rtl-optimization/107182] Clear EDGE_CROSSING for jump->ret optimization
When turning a jump to a return into a return, we need to clear
EDGE_CROSSING
of the fallthru edge to prevent a checking failure.
I considered not applying the transformation when the edge has EDGE_CROSSING
set, but it still seems like we ought to eliminate the unnecessary jump in
that case.
gcc/
PR rtl-optimization/107182
* cfgrtl.cc (fixup_reorder_chain): When optimizing a jump to a
return, clear EDGE_CROSSING on the appropriate edge.
diff --git a/gcc/cfgrtl.cc b/gcc/cfgrtl.cc
index 281a432f6a6..f31941a61f9 100644
--- a/gcc/cfgrtl.cc
+++ b/gcc/cfgrtl.cc
@@ -4055,6 +4055,7 @@ fixup_reorder_chain (void)
ret_label = PATTERN (ret);
dest = EXIT_BLOCK_PTR_FOR_FN (cfun);
+ e_fall->flags &= ~EDGE_CROSSING;
/* E_FALL->dest might become unreachable as a result of
replacing the jump with a return. So arrange to remove
unreachable blocks. */
