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musl/arch/mipsn32/pthread_arch.h

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add mips n32 port (ILP32 ABI for mips64) based on patch submitted by Jaydeep Patil, with minor changes.
2016-04-18 05:19:13 +00:00
static inline struct pthread *__pthread_self()
{
#if __mips_isa_rev < 2
register char *tp __asm__("$3");
make thread-pointer-loading asm non-volatile this will allow the compiler to cache and reuse the result, meaning we no longer have to take care not to load it more than once for the sake of archs where the load may be expensive. depends on commit 1c84c99913bf1cd47b866ed31e665848a0da84a2 for correctness, since otherwise the compiler could hoist loads during stage 3 of dynamic linking before the initial thread-pointer setup.
2018-10-16 18:08:01 +00:00
__asm__ (".word 0x7c03e83b" : "=r" (tp) );
add mips n32 port (ILP32 ABI for mips64) based on patch submitted by Jaydeep Patil, with minor changes.
2016-04-18 05:19:13 +00:00
#else
char *tp;
make thread-pointer-loading asm non-volatile this will allow the compiler to cache and reuse the result, meaning we no longer have to take care not to load it more than once for the sake of archs where the load may be expensive. depends on commit 1c84c99913bf1cd47b866ed31e665848a0da84a2 for correctness, since otherwise the compiler could hoist loads during stage 3 of dynamic linking before the initial thread-pointer setup.
2018-10-16 18:08:01 +00:00
__asm__ ("rdhwr %0, $29" : "=r" (tp) );
add mips n32 port (ILP32 ABI for mips64) based on patch submitted by Jaydeep Patil, with minor changes.
2016-04-18 05:19:13 +00:00
#endif
return (pthread_t)(tp - 0x7000 - sizeof(struct pthread));
}
#define TLS_ABOVE_TP
fix TLS layout of TLS variant I when there is a gap above TP In TLS variant I the TLS is above TP (or above a fixed offset from TP) but on some targets there is a reserved gap above TP before TLS starts. This matters for the local-exec tls access model when the offsets of TLS variables from the TP are hard coded by the linker into the executable, so the libc must compute these offsets the same way as the linker. The tls offset of the main module has to be alignup(GAP_ABOVE_TP, main_tls_align). If there is no TLS in the main module then the gap can be ignored since musl does not use it and the tls access models of shared libraries are not affected. The previous setup only worked if (tls_align & -GAP_ABOVE_TP) == 0 (i.e. TLS did not require large alignment) because the gap was treated as a fixed offset from TP. Now the TP points at the end of the pthread struct (which is aligned) and there is a gap above it (which may also need alignment). The fix required changing TP_ADJ and __pthread_self on affected targets (aarch64, arm and sh) and in the tlsdesc asm the offset to access the dtv changed too.
2018-06-01 23:52:01 +00:00
#define GAP_ABOVE_TP 0
add mips n32 port (ILP32 ABI for mips64) based on patch submitted by Jaydeep Patil, with minor changes.
2016-04-18 05:19:13 +00:00
#define TP_ADJ(p) ((char *)(p) + sizeof(struct pthread) + 0x7000)
#define DTP_OFFSET 0x8000
#define MC_PC pc