public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug target/110132] New: aarch64: Bogus -Wbuiltin-declaration-mismatch with ls64 builtins
@ 2023-06-05 21:32 acoplan at gcc dot gnu.org
  2023-06-05 21:43 ` [Bug target/110132] " acoplan at gcc dot gnu.org
                   ` (6 more replies)
  0 siblings, 7 replies; 8+ messages in thread
From: acoplan at gcc dot gnu.org @ 2023-06-05 21:32 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110132

            Bug ID: 110132
           Summary: aarch64: Bogus -Wbuiltin-declaration-mismatch with
                    ls64 builtins
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: acoplan at gcc dot gnu.org
  Target Milestone: ---

If one subverts arm_acle.h and tries to create a minimal preprocessed test case
using ls64 builtins:

$ cat ls64.i
#pragma GCC aarch64 "arm_acle.h"
typedef __arm_data512_t data512_t;
void f(void *p, data512_t d) {
  __builtin_aarch64_st64b(p, d);
}
./xgcc -B . -c ls64.i -S -o /dev/null -march=armv8.7-a
ls64.i: In function ‘f’:
ls64.i:4:3: warning: implicit declaration of function ‘__builtin_aarch64_st64b’
[-Wimplicit-function-declaration]
    4 |   __builtin_aarch64_st64b(p, d);
      |   ^~~~~~~~~~~~~~~~~~~~~~~
ls64.i:4:3: warning: incompatible implicit declaration of built-in function
‘__builtin_aarch64_st64b’ [-Wbuiltin-declaration-mismatch]

we get these bogus warnings. The normal flow for e.g. Advanced SIMD builtins
is:
 - Backend calls add_builtin_function.
 - c_builtin_function adds the builtin to the list of visible_builtins.
 - push_file_scope gets called and builtins in visible_builtins are made
visible.

The problem here is that aarch64_init_ls64_builtins is called when processing
the pragma for arm_acle.h, which is *after* push_file_scope gets called, so the
builtins never get made visible by the C FE.

I think it might be easiest to make the ls64 handling more SVE-like and use the
simulate_builtin_function_decl langhook (which doesn't have this deferred
visibility situation), dropping the wrapper functions from arm_acle.h
altogether.

^ permalink raw reply	[flat|nested] 8+ messages in thread
end of thread, other threads:[~2023-06-22 10:21 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-06-05 21:32 [Bug target/110132] New: aarch64: Bogus -Wbuiltin-declaration-mismatch with ls64 builtins acoplan at gcc dot gnu.org
2023-06-05 21:43 ` [Bug target/110132] " acoplan at gcc dot gnu.org
2023-06-06 13:56 ` acoplan at gcc dot gnu.org
2023-06-07 16:46 ` cvs-commit at gcc dot gnu.org
2023-06-07 16:50 ` acoplan at gcc dot gnu.org
2023-06-20 21:22 ` cvs-commit at gcc dot gnu.org
2023-06-22 10:19 ` cvs-commit at gcc dot gnu.org
2023-06-22 10:21 ` acoplan at gcc dot gnu.org

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).