sparc: Use atomic compiler builtins on sparc

This patch removes the arch-specific atomic instruction, relying on
compiler builtins.  The __sparc32_atomic_locks support is removed
and a configure check is added to check if compiler uses libatomic
to implement CAS.

It also removes the sparc specific sem_* and pthread_barrier_*
implementations.  It in turn allows buidling against a LEON3/LEON4
sparcv8 target, although it will still be incompatible with generic
sparcv9.

Checked on sparcv9-linux-gnu and sparc64-linux-gnu.  I also checked
with build against sparcv8-linux-gnu with -mcpu=leon3.

Tested-by: Andreas Larsson <andreas@gaisler.com>

1 files changed, 0 insertions, 38 deletions

diff --git a/sysdeps/sparc/sparc64/cpu_relax.c b/sysdeps/sparc/sparc64/cpu_relax.c
deleted file mode 100644
index b86afdec2c..0000000000
--- a/sysdeps/sparc/sparc64/cpu_relax.c
+++ /dev/null
@@ -1,38 +0,0 @@
-/* CPU strand yielding for busy loops.  Linux/sparc64 version.
-   Copyright (C) 2017-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <sparc-ifunc.h>
-
-static void
-__cpu_relax_generic (void)
-{
-  asm volatile ("rd %ccr, %g0;"
-		"rd %ccr, %g0;"
-		"rd %ccr, %g0");
-}
-
-static void
-__cpu_relax_pause (void)
-{
-  asm volatile ("wr %g0, 128, %asr27");
-}
-
-sparc_libc_ifunc (__cpu_relax,
-		  hwcap & HWCAP_SPARC_PAUSE
-		  ? __cpu_relax_pause
-		  : __cpu_relax_generic)