Re: [PATCH] expr.cc: avoid unexpected side effects in expand_expr_divmod optimization

[Jakub Jelinek <jakub@redhat.com>]

On Thu, Dec 08, 2022 at 02:02:36PM +0100, Jose E. Marchesi wrote:
> So, I guess the right fix would be to call assemble_external_libcall
> during final?  The `.global FOO' directive would be generated
> immediately before the call sequence, but I guess that would be ok.

During final only if all the targets can deal with the effects of
assemble_external_libcall being done in the middle of emitting assembly
for the function.

Otherwise, it could be e.g. done in the first loop of shorten_branches.

Note, in calls.cc it is done only for emit_library_call_value_1
and not for emit_call_1, so if we do it late, we need to be able to find
out what call is to a libcall and what is to a normal call.  If there is
no way to differentiate it right now, perhaps we need some flag somewhere,
say on a SYMBOL_REF.  And then assemble_external_libcall either only
if such a SYMBOL_REF appears in CALL_INSN or sibcall JUMP_INSN, or
perhaps anywhere in the function and its constant pool.

	Jakub