glibc/sysdeps/s390/s390-64/multiarch/ifunc-resolve.c

77 lines
2.7 KiB
C

/* IFUNC resolver function for CPU specific functions.
64 bit S/390 version.
Copyright (C) 2012-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <unistd.h>
#include <dl-procinfo.h>
#define STFLE_BITS_Z10 34 /* General instructions extension */
#define STFLE_BITS_Z196 45 /* Distinct operands, pop ... */
#ifndef NOT_IN_libc
#define IFUNC_RESOLVE(FUNC) \
asm (".globl " #FUNC "\n\t" \
".type " #FUNC ",@gnu_indirect_function\n\t" \
".set " #FUNC ",resolve_" #FUNC "\n\t" \
".globl __GI_" #FUNC "\n\t" \
".set __GI_" #FUNC "," #FUNC "\n"); \
\
/* Make the declarations of the optimized functions hidden in order
to prevent GOT slots being generated for them. */ \
extern __attribute__((visibility("hidden"))) void *FUNC##_z196; \
extern __attribute__((visibility("hidden"))) void *FUNC##_z10; \
extern __attribute__((visibility("hidden"))) void *FUNC##_z900; \
\
void *resolve_##FUNC (unsigned long int dl_hwcap) \
{ \
if (dl_hwcap & HWCAP_S390_STFLE) \
{ \
/* We want just 1 double word to be returned. */ \
register unsigned long reg0 asm("0") = 0; \
unsigned long stfle_bits; \
\
asm volatile(".machine push" "\n\t" \
".machine \"z9-109\"" "\n\t" \
"stfle %0" "\n\t" \
".machine pop" "\n" \
: "=QS" (stfle_bits), "+d" (reg0) \
: : "cc"); \
\
if ((stfle_bits & (1UL << (63 - STFLE_BITS_Z196))) != 0) \
return &FUNC##_z196; \
else if ((stfle_bits & (1UL << (63 - STFLE_BITS_Z10))) != 0) \
return &FUNC##_z10; \
else \
return &FUNC##_z900; \
} \
else \
return &FUNC##_z900; \
}
IFUNC_RESOLVE(memset)
IFUNC_RESOLVE(memcmp)
asm(".weak bcmp ; bcmp = memcmp");
/* In the static lib memcpy is needed before the reloc is resolved. */
#ifdef SHARED
IFUNC_RESOLVE(memcpy)
#endif
#endif