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Fix register conflicts and avoid deprecated instructions in ARM EABI setjmp/longjmp.

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* 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.
This commit is contained in:
Andrew Stubbs 2009-10-22 19:35:53 +00:00 committed by Joseph Myers
parent b5c2620bee
commit fbc4c20a80
3 changed files with 22 additions and 11 deletions
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9
ChangeLog.arm
View File

@ -1,3 +1,12 @@
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 Julian Brown <julian@codesourcery.com>
* sysdeps/arm/elf/start.S (_start): Avoid dependency on PC pipeline

10
sysdeps/arm/eabi/__longjmp.S
View File

@ -59,12 +59,12 @@ ENTRY (__longjmp)
beq Lno_vfp
/* Restore the VFP registers. */
/* Following instruction is fldmiax ip!, {d8-d15}. */
ldc p11, cr8, [r12], #68
/* Following instruction is vldmia ip!, {d8-d15}. */
ldc p11, cr8, [r12], #64
/* Restore the floating-point status register. */
ldr r1, [ip], #4
/* Following instruction is fmxr fpscr, r1. */
mcr p10, 7, r1, cr1, cr0, 0
ldr a3, [ip], #4
/* Following instruction is fmxr fpscr, a3. */
mcr p10, 7, a3, cr1, cr0, 0
Lno_vfp:
tst a2, #HWCAP_ARM_IWMMXT

14
sysdeps/arm/eabi/setjmp.S
View File

@ -52,13 +52,15 @@ ENTRY (__sigsetjmp)
tst a3, #HWCAP_ARM_VFP
beq Lno_vfp
/* Store the VFP registers. */
/* Following instruction is fstmiax ip!, {d8-d15}. */
stc p11, cr8, [r12], #68
/* Store the VFP registers.
Don't use VFP instructions directly because this code
is used in non-VFP multilibs. */
/* Following instruction is vstmia ip!, {d8-d15}. */
stc p11, cr8, [ip], #64
/* Store the floating-point status register. */
/* Following instruction is fmrx r2, fpscr. */
mrc p10, 7, r2, cr1, cr0, 0
str r2, [ip], #4
/* Following instruction is vmrs a4, fpscr. */
mrc p10, 7, a4, cr1, cr0, 0
str a4, [ip], #4
Lno_vfp:
tst a3, #HWCAP_ARM_IWMMXT