Hello,
Coverity flagged a real issue in this patch:
On Mon, 16 Jan 2023, Jan Hubicka via Gcc-patches wrote:
> --- a/gcc/ipa-utils.cc
> +++ b/gcc/ipa-utils.cc
[...]
> +bitmap
> +find_always_executed_bbs (function *fun, bool assume_return_or_eh)
> +{
> + auto_vec<basic_block, 20> stack;
> + auto_vec<basic_block, 20> terminating_bbs;
> + hash_set<basic_block> visited;
> + edge e;
> + edge_iterator ei;
> +
> + /* First walk all BBs reachable from entry stopping on statements that may
> + terminate execution. Everything past this statement is not going to be
> executed
> + each invocation. */
> + stack.safe_push (ENTRY_BLOCK_PTR_FOR_FN (fun));
> + while (!stack.is_empty ())
> + {
> + basic_block bb = stack.pop ();
> + bool found = false, found_exit = false;
> + if (!assume_return_or_eh
> + && (EDGE_COUNT (bb->succs) == 0 || (bb->flags & BB_IRREDUCIBLE_LOOP)))
> + found = true;
> + FOR_EACH_EDGE (e, ei, bb->succs)
> + {
> + if (e->dest == EXIT_BLOCK_PTR_FOR_FN (fun))
> + {
> + found_exit = true;
> + break;
> + }
> + /* Watch for infinite loops. */
> + if (!found && (assume_return_or_eh & EDGE_DFS_BACK)
^^^^^^^^^^^^^^^
This bitwise 'and' always evaluates to zero, making the entire clause
always-false.
Alexander
