libc/private/__get_tls.h

/*
 * Copyright (C) 2008 The Android Open Source Project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef __BIONIC_PRIVATE_GET_TLS_H_
#define __BIONIC_PRIVATE_GET_TLS_H_

#if defined(__arm__)
# define __get_tls() \
    ({ void** __val; \
       __asm__("mrc p15, 0, %0, c13, c0, 3" : "=r"(__val)); \
       __val; })
#elif defined(__mips__)
# define __get_tls() \
    /* On mips32r1, this goes via a kernel illegal instruction trap that's optimized for v1. */ \
    ({ register void** __val asm("v1"); \
       __asm__(".set    push\n" \
               ".set    mips32r2\n" \
               "rdhwr   %0,$29\n" \
               ".set    pop\n" : "=r"(__val)); \
       __val; })
#elif defined(__i386__)
# define __get_tls() \
    ({ void** __val; \
       __asm__("movl %%gs:0, %0" : "=r"(__val)); \
       __val; })
#elif defined(__x86_64__)
# define __get_tls() \
    ({ void** __val; \
       __asm__("mov %%fs:0, %0" : "=r"(__val)); \
       __val; })
#else
#error unsupported architecture
#endif

#endif /* __BIONIC_PRIVATE_GET_TLS_H_ */