https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112374
--- Comment #40 from Robin Dapp <rdapp at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #37)
[..]
> The above isn't complete, so one just has to guess what you mean outside of
> that, but the above doesn't seem to be correct. There are many internal
> calls, and most of them shouldn't have the above handling. Say if there is
> .MUL_OVERFLOW (op.ops[opi], op.ops[opi]) call, it should count as 2 uses,
> not one.
But we would count MUL_OVERFLOW as two uses because its else_pos = -1?
For clarity we could maybe move the else pos check into the if condition, yes.
One other thing, though. The else branch checks for is_gimple_debug and
flow_bb_inside_loop_p. We could handle this separately and continue.
Maybe something like this is clearer, replacing the whole loop (and moved the
else_idx check)?
FOR_EACH_IMM_USE_STMT (op_use_stmt, imm_iter, op.ops[opi])
{
if (is_gimple_debug (op_use_stmt)
|| (*code == ERROR_MARK
&& !flow_bb_inside_loop_p (loop,
gimple_bb (op_use_stmt))))
continue;
/* In case of a COND_OP (mask, op1, op2, op1) reduction we might have
op1 twice (once as definition, once as else) in the same
operation.
Allow this. */
gcall *call = dyn_cast<gcall *> (op_use_stmt);
internal_fn ifn;
if (call && gimple_call_internal_p (call)
&& (ifn = gimple_call_internal_fn (call))
&& internal_fn_else_index (ifn) > -1)
{
unsigned else_idx = internal_fn_else_index (ifn);
for (unsigned int j = 0; j < gimple_call_num_args (call); ++j)
{
if (j == else_idx)
continue;
if (gimple_call_arg (call, j) == op.ops[opi])
cnt++;
}
}
else
FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
cnt++;
}
