glibc/sysdeps/arm/eabi/__longjmp.S
Andrew Stubbs fbc4c20a80 Fix register conflicts and avoid deprecated instructions in ARM EABI setjmp/longjmp.
* setjmp and longjmp were using the obsolete fstmiax and fldmiax
  instructions.

* Because of a confusion with two different sets of names for the same
  registers (r0...r3 and a1...a4), if VFP was present then the
  subsequent check for iWMMXt support would use a register that had
  been clobbered by saving/restoring the VFP registers.  (The bit
  being checked was clobbered by a reserved bit of FPSCR that it
  always 0 on present hardware, and no present hardware has both VFP
  and iWMMXt, so this did not cause visible problems.)

2009-10-22  Andrew Stubbs  <ams@codesourcery.com>
            Julian Brown  <julian@codesourcery.com>

	* sysdeps/arm/eabi/setjmp.S (__sigsetjmp): Replace deprecated
	instruction fstmiax with vstmia.
	Correct register conflict and comment.
	* sysdeps/arm/eabi/__longjmp.S (__longjmp): Use vldmia not fldmiax.
	Don't clobber r1/a2 register before testing IWMMXT hwcap.
2009-10-22 19:35:53 +00:00

101 lines
2.5 KiB
ArmAsm

/* longjmp for ARM.
Copyright (C) 1997, 1998, 2005, 2006, 2009 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 General Public License
along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA. */
#include <sysdep.h>
#define _SETJMP_H
#define _ASM
#include <bits/setjmp.h>
#include <rtld-global-offsets.h>
/* __longjmp(jmpbuf, val) */
ENTRY (__longjmp)
mov ip, r0
movs r0, r1 /* get the return value in place */
moveq r0, #1 /* can't let setjmp() return zero! */
#ifdef CHECK_SP
ldr r4, [ip, #32]
CHECK_SP (r4)
#endif
LOADREGS(ia, ip!, {v1-v6, sl, fp, sp, lr})
#ifdef IS_IN_rtld
ldr a2, 1f
ldr a3, Lrtld_local_ro
0: add a2, pc, a2
add a2, a2, a3
ldr a2, [a2, #RTLD_GLOBAL_RO_DL_HWCAP_OFFSET]
#else
#ifdef PIC
ldr a2, 1f
ldr a3, Lrtld_global_ro
0: add a2, pc, a2
ldr a2, [a2, a3]
ldr a2, [a2, #RTLD_GLOBAL_RO_DL_HWCAP_OFFSET]
#else
ldr a2, Lhwcap
ldr a2, [a2, #0]
#endif
#endif
tst a2, #HWCAP_ARM_VFP
beq Lno_vfp
/* Restore the VFP registers. */
/* Following instruction is vldmia ip!, {d8-d15}. */
ldc p11, cr8, [r12], #64
/* Restore the floating-point status register. */
ldr a3, [ip], #4
/* Following instruction is fmxr fpscr, a3. */
mcr p10, 7, a3, cr1, cr0, 0
Lno_vfp:
tst a2, #HWCAP_ARM_IWMMXT
beq Lno_iwmmxt
/* Restore the call-preserved iWMMXt registers. */
/* Following instructions are wldrd wr10, [ip], #8 (etc.) */
ldcl p1, cr10, [r12], #8
ldcl p1, cr11, [r12], #8
ldcl p1, cr12, [r12], #8
ldcl p1, cr13, [r12], #8
ldcl p1, cr14, [r12], #8
ldcl p1, cr15, [r12], #8
Lno_iwmmxt:
DO_RET(lr)
#ifdef IS_IN_rtld
1: .long _GLOBAL_OFFSET_TABLE_ - 0b - 8
Lrtld_local_ro:
.long C_SYMBOL_NAME(_rtld_local_ro)(GOTOFF)
#else
#ifdef PIC
1: .long _GLOBAL_OFFSET_TABLE_ - 0b - 8
Lrtld_global_ro:
.long C_SYMBOL_NAME(_rtld_global_ro)(GOT)
#else
Lhwcap:
.long C_SYMBOL_NAME(_dl_hwcap)
#endif
#endif
END (__longjmp)