aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/sparc/cpu_relax.c
diff options
context:
space:
mode:
authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2019-11-12 19:11:10 +0000
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2019-11-27 10:31:13 -0300
commit3b5ebe85aabfa44583a18a7ef51bc4d387e362c1 (patch)
tree8853a1bcbe48f93c1e696ae89e503922845c6e8c /sysdeps/sparc/cpu_relax.c
parent5d9b7b9fa734c5381e0295c85c0e40520d9f6063 (diff)
downloadglibc-3b5ebe85aabfa44583a18a7ef51bc4d387e362c1.tar
glibc-3b5ebe85aabfa44583a18a7ef51bc4d387e362c1.tar.gz
glibc-3b5ebe85aabfa44583a18a7ef51bc4d387e362c1.tar.bz2
glibc-3b5ebe85aabfa44583a18a7ef51bc4d387e362c1.zip
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>
Diffstat (limited to 'sysdeps/sparc/cpu_relax.c')
-rw-r--r--sysdeps/sparc/cpu_relax.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/sysdeps/sparc/cpu_relax.c b/sysdeps/sparc/cpu_relax.c
new file mode 100644
index 0000000000..973dfb5935
--- /dev/null
+++ b/sysdeps/sparc/cpu_relax.c
@@ -0,0 +1,40 @@
+/* CPU strand yielding for busy loops. Linux/sparc 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>
+
+#ifdef __sparc_v9__
+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)
+#endif