ARM: Fix memcpy computed-jump calculations for ARM_ALWAYS_BX case.
This commit is contained in:
parent
12e0e8c65d
commit
068dcfd675
|
@ -1,3 +1,11 @@
|
||||||
|
2013-11-22 Roland McGrath <roland@hack.frob.com>
|
||||||
|
|
||||||
|
* sysdeps/arm/armv7/multiarch/memcpy_impl.S
|
||||||
|
[ARM_ALWAYS_BX] (dispatch_helper): Fix PC computation to properly
|
||||||
|
account for instructions after the reference to PC given that 'bx'
|
||||||
|
might actually be expanded to multiple instructions.
|
||||||
|
* sysdeps/arm/arm-features.h (ARM_BX_NINSNS): Macro removed.
|
||||||
|
|
||||||
2013-10-30 Mike Frysinger <vapier@gentoo.org>
|
2013-10-30 Mike Frysinger <vapier@gentoo.org>
|
||||||
|
|
||||||
* sysdeps/arm/configure.in: Moved to ...
|
* sysdeps/arm/configure.in: Moved to ...
|
||||||
|
|
|
@ -53,14 +53,6 @@
|
||||||
# define ARM_BX_ALIGN_LOG2 2
|
# define ARM_BX_ALIGN_LOG2 2
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
/* The number of instructions that 'bx' expands to. A more-specific
|
|
||||||
arm-features.h that defines 'bx' as a macro should define this to the
|
|
||||||
number instructions it expands to. This is used only in a context
|
|
||||||
where the 'bx' expansion won't cross an ARM_BX_ALIGN_LOG2 boundary. */
|
|
||||||
#ifndef ARM_BX_NINSNS
|
|
||||||
# define ARM_BX_NINSNS 1
|
|
||||||
#endif
|
|
||||||
|
|
||||||
/* An OS-specific arm-features.h file may define ARM_NO_INDEX_REGISTER to
|
/* An OS-specific arm-features.h file may define ARM_NO_INDEX_REGISTER to
|
||||||
indicate that the two-register addressing modes must never be used. */
|
indicate that the two-register addressing modes must never be used. */
|
||||||
|
|
||||||
|
|
|
@ -127,25 +127,26 @@
|
||||||
.purgem dispatch_step
|
.purgem dispatch_step
|
||||||
.endm
|
.endm
|
||||||
#else
|
#else
|
||||||
# if ARM_BX_ALIGN_LOG2 < 4
|
# if ARM_BX_ALIGN_LOG2 < 3
|
||||||
# error case not handled
|
# error case not handled
|
||||||
# endif
|
# endif
|
||||||
.macro dispatch_helper steps, log2_bytes_per_step
|
.macro dispatch_helper steps, log2_bytes_per_step
|
||||||
.p2align ARM_BX_ALIGN_LOG2
|
|
||||||
/* TMP1 gets (max_bytes - bytes_to_copy), where max_bytes is
|
/* TMP1 gets (max_bytes - bytes_to_copy), where max_bytes is
|
||||||
(STEPS << LOG2_BYTES_PER_STEP).
|
(STEPS << LOG2_BYTES_PER_STEP).
|
||||||
So this is (steps_to_skip << LOG2_BYTES_PER_STEP). */
|
So this is (steps_to_skip << LOG2_BYTES_PER_STEP).
|
||||||
rsb tmp1, tmp1, #(\steps << \log2_bytes_per_step)
|
Then it needs further adjustment to compensate for the
|
||||||
/* Pad so that the add;bx pair immediately precedes an alignment
|
distance between the PC value taken below (0f + PC_OFS)
|
||||||
boundary. Hence, TMP1=0 will run all the steps. */
|
and the first step's instructions (1f). */
|
||||||
.rept (1 << (ARM_BX_ALIGN_LOG2 - 2)) - (2 + ARM_BX_NINSNS)
|
rsb tmp1, tmp1, #((\steps << \log2_bytes_per_step) \
|
||||||
nop
|
+ ((1f - PC_OFS - 0f) \
|
||||||
.endr
|
>> (ARM_BX_ALIGN_LOG2 - \log2_bytes_per_step)))
|
||||||
/* Shifting down LOG2_BYTES_PER_STEP gives us the number of
|
/* Shifting down LOG2_BYTES_PER_STEP gives us the number of
|
||||||
steps to skip, then shifting up ARM_BX_ALIGN_LOG2 gives us
|
steps to skip, then shifting up ARM_BX_ALIGN_LOG2 gives us
|
||||||
the (byte) distance to add to the PC. */
|
the (byte) distance to add to the PC. */
|
||||||
add tmp1, pc, tmp1, lsl #(ARM_BX_ALIGN_LOG2 - \log2_bytes_per_step)
|
0: add tmp1, pc, tmp1, lsl #(ARM_BX_ALIGN_LOG2 - \log2_bytes_per_step)
|
||||||
bx tmp1
|
bx tmp1
|
||||||
|
.p2align ARM_BX_ALIGN_LOG2
|
||||||
|
1:
|
||||||
.endm
|
.endm
|
||||||
|
|
||||||
.macro dispatch_7_dword
|
.macro dispatch_7_dword
|
||||||
|
|
Loading…
Reference in New Issue