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2016-09-22 John David Anglin <dave.anglin@bell.net>
* sysdeps/unix/sysv/linux/hppa/atomic-machine.h: Don't include
abort-instr.h.
(EFAULT): Remove conditional define.
(ENOSYS): Likewise.
(atomic_compare_and_exchange_val_acq): Use instruction nullification
instead of conditional branch instructions.
--- a/sysdeps/unix/sysv/linux/hppa/atomic-machine.h
+++ b/sysdeps/unix/sysv/linux/hppa/atomic-machine.h
@@ -17,13 +17,6 @@
<http://www.gnu.org/licenses/>. */
#include <stdint.h> /* Required for type definitions e.g. uint8_t. */
-#include <abort-instr.h> /* Required for ABORT_INSTRUCTIUON. */
-
-/* We need EFAULT, ENONSYS */
-#if !defined EFAULT && !defined ENOSYS
-#define EFAULT 14
-#define ENOSYS 251
-#endif
#ifndef _ATOMIC_MACHINE_H
#define _ATOMIC_MACHINE_H 1
@@ -62,7 +55,7 @@ typedef uintmax_t uatomic_max_t;
#define _ASM_EDEADLOCK "-45"
/* The only basic operation needed is compare and exchange. The mem
- pointer must be word aligned. */
+ pointer must be word aligned. We no longer loop on deadlock. */
#define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
({ \
register long lws_errno asm("r21"); \
@@ -74,20 +67,15 @@ typedef uintmax_t uatomic_max_t;
"0: \n\t" \
"ble " _LWS "(%%sr2, %%r0) \n\t" \
"ldi " _LWS_CAS ", %%r20 \n\t" \
- "ldi " _ASM_EAGAIN ", %%r20 \n\t" \
- "cmpb,=,n %%r20, %%r21, 0b \n\t" \
- "nop \n\t" \
- "ldi " _ASM_EDEADLOCK ", %%r20 \n\t" \
- "cmpb,=,n %%r20, %%r21, 0b \n\t" \
- "nop \n\t" \
+ "cmpiclr,<> " _ASM_EAGAIN ", %%r21, %%r0\n\t" \
+ "b,n 0b \n\t" \
+ "cmpclr,= %%r0, %%r21, %%r0 \n\t" \
+ "iitlbp %%r0,(%%sr0, %%r0) \n\t" \
: "=r" (lws_ret), "=r" (lws_errno) \
: "r" (lws_mem), "r" (lws_old), "r" (lws_new) \
: _LWS_CLOBBER \
); \
\
- if (lws_errno == -EFAULT || lws_errno == -ENOSYS) \
- ABORT_INSTRUCTION; \
- \
(__typeof (oldval)) lws_ret; \
})
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