mirror of
git://git.musl-libc.org/musl
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3b27725385
"Q" input constraint was used for the written object, instead of "=Q" output constraint. this should not cause problems because "memory" is on the clobber list, but "=Q" better documents the intent and more consistent with the actual asm code. this changes the generated code, because different registers are used, but other than the register names nothing should change.
77 lines
1.5 KiB
C
77 lines
1.5 KiB
C
__attribute__((__visibility__("hidden")))
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extern const void *__arm_atomics[3]; /* gettp, cas, barrier */
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#if ((__ARM_ARCH_6__ || __ARM_ARCH_6K__ || __ARM_ARCH_6ZK__) && !__thumb__) \
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|| __ARM_ARCH_7A__ || __ARM_ARCH_7R__ || __ARM_ARCH >= 7
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#define a_ll a_ll
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static inline int a_ll(volatile int *p)
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{
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int v;
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__asm__ __volatile__ ("ldrex %0, %1" : "=r"(v) : "Q"(*p));
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return v;
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}
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#define a_sc a_sc
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static inline int a_sc(volatile int *p, int v)
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{
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int r;
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__asm__ __volatile__ ("strex %0,%2,%1" : "=&r"(r), "=Q"(*p) : "r"(v) : "memory");
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return !r;
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}
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#if __ARM_ARCH_7A__ || __ARM_ARCH_7R__ || __ARM_ARCH >= 7
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#define a_barrier a_barrier
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static inline void a_barrier()
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{
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__asm__ __volatile__ ("dmb ish" : : : "memory");
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}
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#endif
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#define a_pre_llsc a_barrier
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#define a_post_llsc a_barrier
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#else
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#define a_cas a_cas
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static inline int a_cas(volatile int *p, int t, int s)
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{
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for (;;) {
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register int r0 __asm__("r0") = t;
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register int r1 __asm__("r1") = s;
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register volatile int *r2 __asm__("r2") = p;
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int old;
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__asm__ __volatile__ (
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"bl __a_cas"
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: "+r"(r0) : "r"(r1), "r"(r2)
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: "memory", "r3", "lr", "ip", "cc" );
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if (!r0) return t;
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if ((old=*p)!=t) return old;
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}
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}
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#endif
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#ifndef a_barrier
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#define a_barrier a_barrier
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static inline void a_barrier()
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{
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__asm__ __volatile__("bl __a_barrier"
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: : : "memory", "cc", "ip", "lr" );
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}
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#endif
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#define a_crash a_crash
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static inline void a_crash()
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{
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__asm__ __volatile__(
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#ifndef __thumb__
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".word 0xe7f000f0"
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#else
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".short 0xdeff"
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#endif
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: : : "memory");
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}
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