tree-optimization/106995 - if-conversion and vanishing loops
Commit Message
When we version loops for vectorization during if-conversion it
can happen that either loop vanishes because we run some VN and
CFG cleanup. If the to-be vectorized part vanishes we already
redirect the versioning condition to the original loop. The following
does the same in case the original loop vanishes as happened
for the testcase in the bug in the past (but no longer).
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/106995
* tree-if-conv.cc (pass_if_conversion::execute): Also redirect the
versioning condition to the original loop if this very loop
vanished during CFG cleanup.
---
gcc/tree-if-conv.cc | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
@@ -3761,7 +3761,8 @@ pass_if_conversion::execute (function *fun)
if (!gimple_bb (g))
continue;
unsigned ifcvt_loop = tree_to_uhwi (gimple_call_arg (g, 0));
- if (!get_loop (fun, ifcvt_loop))
+ unsigned orig_loop = tree_to_uhwi (gimple_call_arg (g, 1));
+ if (!get_loop (fun, ifcvt_loop) || !get_loop (fun, orig_loop))
{
if (dump_file)
fprintf (dump_file, "If-converted loop vanished\n");