glibc/sysdeps/unix/sysv/linux/arm/aeabi_read_tp.S

/* Copyright (C) 2005-2016 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.

   In addition to the permissions in the GNU Lesser General Public
   License, the Free Software Foundation gives you unlimited
   permission to link the compiled version of this file with other
   programs, and to distribute those programs without any restriction
   coming from the use of this file. (The GNU Lesser General Public
   License restrictions do apply in other respects; for example, they
   cover modification of the file, and distribution when not linked
   into another program.)

   Note that people who make modified versions of this file are not
   obligated to grant this special exception for their modified
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   version without this exception; this exception also makes it
   possible to release a modified version which carries forward this
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#include <sysdep.h>

/* GCC will emit calls to this routine under -mtp=soft.  Linux has an
   equivalent helper function (which clobbers fewer registers than
   a normal function call) in a high page of memory; tail call to the
   helper.  */

	.hidden __aeabi_read_tp
ENTRY (__aeabi_read_tp)
#ifdef ARCH_HAS_HARD_TP
	mrc	p15, 0, r0, c13, c0, 3
	bx	lr
#elif defined(__thumb2__)
	movw	r0, #0x0fe0
	movt	r0, #0xffff
	bx	r0
#else
	mov	r0, #0xffff0fff
	sub	pc, r0, #31
#endif
END (__aeabi_read_tp)