http://sourceware.org/ml/libc-alpha/2013-08/msg00102.html
This is a rather large patch due to formatting and renaming. The
formatting changes were to make it possible to compare power7 and
power4 versions of memcmp. Using different register defines came
about while I was wrestling with the code, trying to find spare
registers at one stage. I found it much simpler if we refer to a reg
by the same name throughout a function, so it's better if short-term
multiple use regs like rTMP are referred to using their register
number. I made the cr field usage changes when attempting to reload
rWORDn regs in the exit path to byte swap before comparing when
little-endian. That proved a bad idea due to the pipelining involved
in the main loop; Offsets to reload the regs were different first
time around the loop.. Anyway, I left the cr field usage changes in
place for consistency.
Aside from these more-or-less cosmetic changes, I fixed a number of
places where an early exit path restores regs unnecessarily, removed
some dead code, and optimised one or two exits.
* sysdeps/powerpc/powerpc64/power7/memcmp.S: Add little-endian support.
Formatting. Consistently use rXXX register defines or rN defines.
Use early exit labels that avoid restoring unused non-volatile regs.
Make cr field use more consistent with rWORDn compares. Rename
regs used as shift registers for unaligned loop, using rN defines
for short lifetime/multiple use regs.
* sysdeps/powerpc/powerpc64/power4/memcmp.S: Likewise.
* sysdeps/powerpc/powerpc32/power7/memcmp.S: Likewise. Exit with
addi 1,1,64 to pop stack frame. Simplify return value code.
* sysdeps/powerpc/powerpc32/power4/memcmp.S: Likewise.
http://sourceware.org/ml/libc-alpha/2013-08/msg00101.html
Adds little-endian support to optimised strchr assembly. I've also
tweaked the big-endian code a little. In power7/strchr.S there's a
check in the tail of the function that we didn't match 0 before
finding a c match, done by comparing leading zero counts. It's just
as valid, and quicker, to compare the raw output from cmpb.
Another little tweak is to use rldimi/insrdi in place of rlwimi for
the power7 strchr functions. Since rlwimi is cracked, it is a few
cycles slower. rldimi can be used on the 32-bit power7 functions
too.
* sysdeps/powerpc/powerpc64/power7/strchr.S (strchr): Add little-endian
support. Correct typos, formatting. Optimize tail. Use insrdi
rather than rlwimi.
* sysdeps/powerpc/powerpc32/power7/strchr.S: Likewise.
* sysdeps/powerpc/powerpc64/power7/strchrnul.S (__strchrnul): Add
little-endian support. Correct typos.
* sysdeps/powerpc/powerpc32/power7/strchrnul.S: Likewise. Use insrdi
rather than rlwimi.
* sysdeps/powerpc/powerpc64/strchr.S (rTMP4, rTMP5): Define. Use
in loop and entry code to keep "and." results.
(strchr): Add little-endian support. Comment. Move cntlzd
earlier in tail.
* sysdeps/powerpc/powerpc32/strchr.S: Likewise.
http://sourceware.org/ml/libc-alpha/2013-08/msg00100.html
The strcpy changes for little-endian are quite straight-forward, just
a matter of rotating the last word differently.
I'll note that the powerpc64 version of stpcpy is just begging to be
converted to use 64-bit loads and stores..
* sysdeps/powerpc/powerpc64/strcpy.S: Add little-endian support:
* sysdeps/powerpc/powerpc32/strcpy.S: Likewise.
* sysdeps/powerpc/powerpc64/stpcpy.S: Likewise.
* sysdeps/powerpc/powerpc32/stpcpy.S: Likewise.
http://sourceware.org/ml/libc-alpha/2013-08/msg00099.html
More little-endian support. I leave the main strcmp loops unchanged,
(well, except for renumbering rTMP to something other than r0 since
it's needed in an addi insn) and modify the tail for little-endian.
I noticed some of the big-endian tail code was a little untidy so have
cleaned that up too.
* sysdeps/powerpc/powerpc64/strcmp.S (rTMP2): Define as r0.
(rTMP): Define as r11.
(strcmp): Add little-endian support. Optimise tail.
* sysdeps/powerpc/powerpc32/strcmp.S: Similarly.
* sysdeps/powerpc/powerpc64/strncmp.S: Likewise.
* sysdeps/powerpc/powerpc32/strncmp.S: Likewise.
* sysdeps/powerpc/powerpc64/power4/strncmp.S: Likewise.
* sysdeps/powerpc/powerpc32/power4/strncmp.S: Likewise.
* sysdeps/powerpc/powerpc64/power7/strncmp.S: Likewise.
* sysdeps/powerpc/powerpc32/power7/strncmp.S: Likewise.
http://sourceware.org/ml/libc-alpha/2013-08/msg00098.html
The existing strnlen code has a number of defects, so this patch is more
than just adding little-endian support. The changes here are similar to
those for memchr.
* sysdeps/powerpc/powerpc64/power7/strnlen.S (strnlen): Add
little-endian support. Remove unnecessary "are we done" tests.
Handle "s" wrapping around zero and extremely large "size".
Correct main loop count. Handle single left-over word from main
loop inline rather than by using small_loop. Correct comments.
Delete "zero" tail, use "end_max" instead.
* sysdeps/powerpc/powerpc32/power7/strnlen.S: Likewise.
http://sourceware.org/ml/libc-alpha/2013-08/msg00097.html
This is the first of nine patches adding little-endian support to the
existing optimised string and memory functions. I did spend some
time with a power7 simulator looking at cycle by cycle behaviour for
memchr, but most of these patches have not been run on cpu simulators
to check that we are going as fast as possible. I'm sure PowerPC can
do better. However, the little-endian support mostly leaves main
loops unchanged, so I'm banking on previous authors having done a
good job on big-endian.. As with most code you stare at long enough,
I found some improvements for big-endian too.
Little-endian support for strlen. Like most of the string functions,
I leave the main word or multiple-word loops substantially unchanged,
just needing to modify the tail.
Removing the branch in the power7 functions is just a tidy. .align
produces a branch anyway. Modifying regs in the non-power7 functions
is to suit the new little-endian tail.
* sysdeps/powerpc/powerpc64/power7/strlen.S (strlen): Add little-endian
support. Don't branch over align.
* sysdeps/powerpc/powerpc32/power7/strlen.S: Likewise.
* sysdeps/powerpc/powerpc64/strlen.S (strlen): Add little-endian support.
Rearrange tmp reg use to suit. Comment.
* sysdeps/powerpc/powerpc32/strlen.S: Likewise.
http://sourceware.org/ml/libc-alpha/2013-08/msg00090.html
This patch fixes symbol versioning in setjmp/longjmp. The existing
code uses raw versions, which results in wrong symbol versioning when
you want to build glibc with a base version of 2.19 for LE.
Note that the merging the 64-bit and 32-bit versions in novmx-lonjmp.c
and pt-longjmp.c doesn't result in GLIBC_2.0 versions for 64-bit, due
to the base in shlib_versions.
* sysdeps/powerpc/longjmp.c: Use proper symbol versioning macros.
* sysdeps/powerpc/novmx-longjmp.c: Likewise.
* sysdeps/powerpc/powerpc32/bsd-_setjmp.S: Likewise.
* sysdeps/powerpc/powerpc32/bsd-setjmp.S: Likewise.
* sysdeps/powerpc/powerpc32/fpu/__longjmp.S: Likewise.
* sysdeps/powerpc/powerpc32/fpu/setjmp.S: Likewise.
* sysdeps/powerpc/powerpc32/mcount.c: Likewise.
* sysdeps/powerpc/powerpc32/setjmp.S: Likewise.
* sysdeps/powerpc/powerpc64/setjmp.S: Likewise.
* nptl/sysdeps/unix/sysv/linux/powerpc/pt-longjmp.c: Likewise.
http://sourceware.org/ml/libc-alpha/2013-08/msg00089.html
Little-endian fixes for setjmp/longjmp. When writing these I noticed
the setjmp code corrupts the non volatile VMX registers when using an
unaligned buffer. Anton fixed this, and also simplified it quite a
bit.
The current code uses boilerplate for the case where we want to store
16 bytes to an unaligned address. For that we have to do a
read/modify/write of two aligned 16 byte quantities. In our case we
are storing a bunch of back to back data (consective VMX registers),
and only the start and end of the region need the read/modify/write.
[BZ #15723]
* sysdeps/powerpc/jmpbuf-offsets.h: Comment fix.
* sysdeps/powerpc/powerpc32/fpu/__longjmp-common.S: Correct
_dl_hwcap access for little-endian.
* sysdeps/powerpc/powerpc32/fpu/setjmp-common.S: Likewise. Don't
destroy vmx regs when saving unaligned.
* sysdeps/powerpc/powerpc64/__longjmp-common.S: Correct CR load.
* sysdeps/powerpc/powerpc64/setjmp-common.S: Likewise CR save. Don't
destroy vmx regs when saving unaligned.
The pointer guard used for pointer mangling was not initialized for
static applications resulting in the security feature being disabled.
The pointer guard is now correctly initialized to a random value for
static applications. Existing static applications need to be
recompiled to take advantage of the fix.
The test tst-ptrguard1-static and tst-ptrguard1 add regression
coverage to ensure the pointer guards are sufficiently random
and initialized to a default value.
This patch fixes backtrace for PPC32 and PPC64 to correctly handle
signal trampolines. The 'debug/tst-backtrace6.c' also check for
SA_SIGINFO handling, where is triggers another vDSO symbols for PPC32.
Resolves: #15465
The program name may be unavailable if the user application tampers
with argc and argv[]. Some parts of the dynamic linker caters for
this while others don't, so this patch consolidates the check and
fallback into a single macro and updates all users.
This patch fix the 3c0265394d commits
by correctly setting minimum architecture for modf PPC optimization
to power5+ instead of power5 (since only on power5+ round/ceil will
be inline to inline assembly).
The branch prediction hints is actually hurts performance in this case.
The assembly implementation make two assumptions: 1. 'fabs (x) < 2^52'
is unlikely and 2. 'x > 0.0' is unlike (if 1. is true). Since it a
general floating point function, expected input is not bounded and then
it is better to let the hardware handle the branches.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_ceil.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_finite.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_floor.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_frexp.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_isinf.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_isnan.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_llround.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_logb.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_lround.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_modf.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_nearbyint.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_remquo.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_rint.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_round.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_scalbln.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_scalbn.c: New file.
* sysdeps/ieee754/ldbl-opt/wordsize-64/s_trunc.c: New file.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/Implies: Add
ieee754/ldbl-opt/wordsize-64.
* sysdeps/powerpc/powerpc64/Implies: Add
ieee754/dbl-64/wordsize-64.
