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authorNg, David <dng@quicinc.com>2009-08-18 16:08:59 -0700
committerNg, David <dng@quicinc.com>2009-08-18 16:08:59 -0700
commit6358065d732cf4c5eb49e52487f87b56ac607168 (patch)
tree3cf5f03e07fe246a077a04947b241e00e009209a
parent8e88603bdcf893086ec5e6b470d063a6be0fa0c5 (diff)
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bionic: Replace ARM SWP instruction with LDREX/STREX
Replace SWP instruction with ARMv6+ LDREX/STREX. Using hardcoded binary instructions as the current default Android compiler flag is set to compile for ARMv5 only.
-rw-r--r--libc/arch-arm/bionic/atomics_arm.S7
1 files changed, 6 insertions, 1 deletions
diff --git a/libc/arch-arm/bionic/atomics_arm.S b/libc/arch-arm/bionic/atomics_arm.S
index b2da09f..0fba152 100644
--- a/libc/arch-arm/bionic/atomics_arm.S
+++ b/libc/arch-arm/bionic/atomics_arm.S
@@ -130,7 +130,12 @@ __atomic_inc:
/* r0(new) r1(addr) -> r0(old) */
__atomic_swap:
- swp r0, r0, [r1]
+1:
+ .word 0xe1912f9f /* ldrex r2, [r1] */
+ .word 0xe1813f90 /* strex r3, r0, [r1] */
+ cmp r3, #0
+ bne 1b
+ mov r0, r2
bx lr
/* __futex_wait(*ftx, val, *timespec) */