mirror of
git://git.musl-libc.org/musl
synced 2025-01-07 23:20:05 +00:00
9b95fd0944
this cleans up what had become widespread direct inline use of "GNU C"
style attributes directly in the source, and lowers the barrier to
increased use of hidden visibility, which will be useful to recovering
some of the efficiency lost when the protected visibility hack was
dropped in commit dc2f368e56, especially
on archs where the PLT ABI is costly.
108 lines
2.1 KiB
C
108 lines
2.1 KiB
C
#include "libc.h"
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#if __ARM_ARCH_4__ || __ARM_ARCH_4T__ || __ARM_ARCH == 4
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#define BLX "mov lr,pc\n\tbx"
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#else
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#define BLX "blx"
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#endif
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extern hidden uintptr_t __a_cas_ptr, __a_barrier_ptr;
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#if ((__ARM_ARCH_6__ || __ARM_ARCH_6K__ || __ARM_ARCH_6KZ__ || __ARM_ARCH_6ZK__) && !__thumb__) \
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|| __ARM_ARCH_6T2__ || __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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register uintptr_t r3 __asm__("r3") = __a_cas_ptr;
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int old;
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__asm__ __volatile__ (
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BLX " r3"
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: "+r"(r0), "+r"(r3) : "r"(r1), "r"(r2)
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: "memory", "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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register uintptr_t ip __asm__("ip") = __a_barrier_ptr;
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__asm__ __volatile__( BLX " ip" : "+r"(ip) : : "memory", "cc", "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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#if __ARM_ARCH >= 5
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#define a_clz_32 a_clz_32
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static inline int a_clz_32(uint32_t x)
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{
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__asm__ ("clz %0, %1" : "=r"(x) : "r"(x));
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return x;
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}
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#if __ARM_ARCH_6T2__ || __ARM_ARCH_7A__ || __ARM_ARCH_7R__ || __ARM_ARCH >= 7
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#define a_ctz_32 a_ctz_32
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static inline int a_ctz_32(uint32_t x)
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{
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uint32_t xr;
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__asm__ ("rbit %0, %1" : "=r"(xr) : "r"(x));
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return a_clz_32(xr);
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}
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#endif
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#endif
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