Commit Graph

80 Commits

Author SHA1 Message Date
Amrita H S
23f0d81608 powerpc: Optimized strncmp for power10
This patch is based on __strcmp_power10.

Improvements from __strncmp_power9:

    1. Uses new POWER10 instructions
       - This code uses lxvp to decrease contention on load
	 by loading 32 bytes per instruction.

    2. Performance implication
       - This version has around 38% better performance on average.
       - Minor performance regression is seen for few small sizes
	 and specific combination of alignments.

Signed-off-by: Amrita H S <amritahs@linux.ibm.com>
Reviewed-by: Peter Bergner <bergner@linux.ibm.com>
2024-05-06 09:01:29 -05:00
Amrita H S
1ea0511456 powerpc: Placeholder and infrastructure/build support to add Power11 related changes.
The following three changes have been added to provide initial Power11 support.
    1. Add the directories to hold Power11 files.
    2. Add support to select Power11 libraries based on AT_PLATFORM.
    3. Let submachine=power11 be set automatically.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
Reviewed-by: Peter Bergner <bergner@linux.ibm.com>
2024-03-19 21:11:34 -05:00
Joseph Myers
83d8d289b2 Rename c2x / gnu2x tests to c23 / gnu23
Complete the internal renaming from "C2X" and related names in GCC by
renaming *-c2x and *-gnu2x tests to *-c23 and *-gnu23.

Tested for x86_64, and with build-many-glibcs.py for powerpc64le.
2024-02-01 17:55:57 +00:00
Paul Eggert
dff8da6b3e Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
Amrita H S
90bcc8721e powerpc: Fix performance issues of strcmp power10
Current implementation of strcmp for power10 has
performance regression for multiple small sizes
and alignment combination.

Most of these performance issues are fixed by this
patch. The compare loop is unrolled and page crosses
of unrolled loop is handled.

Thanks to Paul E. Murphy for helping in fixing the
performance issues.

Signed-off-by: Amrita H S <amritahs@linux.vnet.ibm.com>
Co-Authored-By: Paul E. Murphy <murphyp@linux.ibm.com>
Reviewed-by: Rajalakshmi Srinivasaraghavan <rajis@linux.ibm.com>
2023-12-15 16:42:40 -06:00
MAHESH BODAPATI
b9182c793c powerpc : Add optimized memchr for POWER10
Optimized memchr for POWER10 based on existing rawmemchr and strlen.
Reordering instructions and loop unrolling helped in getting better performance.
Reviewed-by: Rajalakshmi Srinivasaraghavan <rajis@linux.ibm.com>
2023-12-14 14:40:14 -06:00
Amrita H S
3367d8e180 powerpc: Optimized strcmp for power10
This patch is based on __strcmp_power9 and __strlen_power10.

Improvements from __strcmp_power9:

    1. Uses new POWER10 instructions
       - This code uses lxvp to decrease contention on load
         by loading 32 bytes per instruction.

    2. Performance implication
       - This version has around 30% better performance on average.
       - Performance regression is seen for a specific combination
         of sizes and alignments. Some of them is observed without
         changes also, while rest may be induced by the patch.

Signed-off-by: Amrita H S <amritahs@linux.vnet.ibm.com>
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
2023-12-07 11:10:40 -06:00
Siddhesh Poyarekar
c6cb8783b5 configure: Use autoconf 2.71
Bump autoconf requirement to 2.71 to allow regenerating configure on
more recent distributions.  autoconf 2.71 has been in Fedora since F36
and is the current version in Debian stable (bookworm).  It appears to
be current in Gentoo as well.

All sysdeps configure and preconfigure scripts have also been
regenerated; all changes are trivial transformations that do not affect
functionality.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-07-17 10:08:10 -04:00
Paul Pluzhnikov
0b25c28e02 Fix misspellings in sysdeps/powerpc -- BZ 25337
All fixes are in comments, so the binaries should be identical
before/after this commit, but I can't verify this.

Reviewed-by: Rajalakshmi Srinivasaraghavan <rajis@linux.ibm.com>
2023-05-23 15:23:09 +00:00
Mahesh Bodapati
36cc908ed5 powerpc:GCC(<10) doesn't allow -mlong-double-64 after -mabi=ieeelongdouble
Removed -mabi=ieeelongdouble on failing tests. It resolves the error.
error: ‘-mabi=ieeelongdouble’ requires ‘-mlong-double-128’
2023-05-19 17:35:01 -05:00
Sachin Monga
1a57ab0c92 Added Redirects to longdouble error functions [BZ #29033]
This patch redirects the error functions to the appropriate
longdouble variants which enables the compiler to optimize
for the abi ieeelongdouble.

Signed-off-by: Sachin Monga <smonga@linux.ibm.com>
2023-05-10 13:59:48 -05:00
Joseph Myers
6d7e8eda9b Update copyright dates with scripts/update-copyrights 2023-01-06 21:14:39 +00:00
Adhemerval Zanella
5c5a8b99cf Disable use of -fsignaling-nans if compiler does not support it
Reviewed-by: Fangrui Song <maskray@google.com>
2022-11-01 09:46:08 -03:00
Joseph Myers
f66780ba46 Fix build with GCC 13 _FloatN, _FloatNx built-in functions
GCC 13 has added more _FloatN and _FloatNx versions of existing
<math.h> and <complex.h> built-in functions, for use in libstdc++-v3.

This breaks the glibc build because of how those functions are defined
as aliases to functions with the same ABI but different types.  Add
appropriate -fno-builtin-* options for compiling relevant files, as
already done for the case of long double functions aliasing double
ones and based on the list of files used there.

I fixed some mistakes in that list of double files that I noticed
while implementing this fix, but there may well be more such
(harmless) cases, in this list or the new one (files that don't
actually exist or don't define the named functions as aliases so don't
need the options).  I did try to exclude cases where glibc doesn't
define certain functions for _FloatN or _FloatNx types at all from the
new uses of -fno-builtin-* options.  As with the options for double
files (see the commit message for commit
49348beafe, "Fix build with GCC 10 when
long double = double."), it's deliberate that the options are used
even if GCC currently doesn't have a built-in version of a given
functions, so providing some level of future-proofing against more
such built-in functions being added in future.

Tested with build-many-glibcs.py for aarch64-linux-gnu
powerpc-linux-gnu powerpc64le-linux-gnu x86_64-linux-gnu (compilers
and glibcs builds) with GCC mainline.
2022-10-31 23:20:08 +00:00
Adhemerval Zanella
5355f9ca7b elf: Remove -fno-tree-loop-distribute-patterns usage on dl-support
Besides the option being gcc specific, this approach is still fragile
and not future proof since we do not know if this will be the only
optimization option gcc will add that transforms loops to memset
(or any libcall).

This patch adds a new header, dl-symbol-redir-ifunc.h, that can b
used to redirect the compiler generated libcalls to port the generic
memset implementation if required.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-10-10 10:32:28 -03:00
Matheus Castanho
0218463dd8 powerpc: Fix VSX register number on __strncpy_power9 [BZ #29197]
__strncpy_power9 initializes VR 18 with zeroes to be used throughout the
code, including when zero-padding the destination string. However, the
v18 reference was mistakenly being used for stxv and stxvl, which take a
VSX vector as operand. The code ended up using the uninitialized VSR 18
register by mistake.

Both occurrences have been changed to use the proper VSX number for VR 18
(i.e. VSR 50).

Tested on powerpc, powerpc64 and powerpc64le.

Signed-off-by: Kewen Lin <linkw@gcc.gnu.org>
2022-06-07 15:07:25 -03:00
Sam James
cb7b1c9014 configure.ac: fix bashisms in configure.ac
configure scripts need to be runnable with a POSIX-compliant /bin/sh.

On many (but not all!) systems, /bin/sh is provided by Bash, so errors
like this aren't spotted. Notably Debian defaults to /bin/sh provided
by dash which doesn't tolerate such bashisms as '=='.

This retains compatibility with bash.

Fixes configure warnings/errors like:
```
checking if compiler warns about alias for function with incompatible types... yes
/var/tmp/portage/sys-libs/glibc-2.34-r10/work/glibc-2.34/configure: 4209: test: xyes: unexpected operator
```

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Sam James <sam@gentoo.org>
2022-03-22 21:53:43 -04:00
Adhemerval Zanella
4e81019f30 powerpc: Remove powerpc64 bzero optimizations
The symbol is not present in current POSIX specification and compiler
already generates memset call.
2022-02-23 14:18:18 -03:00
Adhemerval Zanella
86a82cd57c powerpc: Remove bcopy optimizations
The symbols is not present in current POSIX specification and compiler
already generates memmove call.
2022-02-23 14:06:49 -03:00
Florian Weimer
5501164866 powerpc64le: Use <gcc-macros.h> in early HWCAP check
This is required so that the checks still work if $(early-cflags)
selects a different ISA level.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2022-01-14 20:17:40 +01:00
Paul Eggert
581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00
Noah Goldstein
9894127d20 String: Add hidden defs for __memcmpeq() to enable internal usage
No bug.

This commit adds hidden defs for all declarations of __memcmpeq. This
enables usage of __memcmpeq without the PLT for usage internal to
GLIBC.
2021-10-26 16:51:29 -05:00
Noah Goldstein
44829b3ddb String: Add support for __memcmpeq() ABI on all targets
No bug.

This commit adds support for __memcmpeq() as a new ABI for all
targets. In this commit __memcmpeq() is implemented only as an alias
to the corresponding targets memcmp() implementation. __memcmpeq() is
added as a new symbol starting with GLIBC_2.35 and defined in string.h
with comments explaining its behavior. Basic tests that it is callable
and works where added in string/tester.c

As discussed in the proposal "Add new ABI '__memcmpeq()' to libc"
__memcmpeq() is essentially a reserved namespace for bcmp(). The means
is shares the same specifications as memcmp() except the return value
for non-equal byte sequences is any non-zero value. This is less
strict than memcmp()'s return value specification and can be better
optimized when a boolean return is all that is needed.

__memcmpeq() is meant to only be called by compilers if they can prove
that the return value of a memcmp() call is only used for its boolean
value.

All tests in string/tester.c passed. As well build succeeds on
x86_64-linux-gnu target.
2021-10-26 16:51:29 -05:00
Joseph Myers
b3f27d8150 Add narrowing fma functions
This patch adds the narrowing fused multiply-add functions from TS
18661-1 / TS 18661-3 / C2X to glibc's libm: ffma, ffmal, dfmal,
f32fmaf64, f32fmaf32x, f32xfmaf64 for all configurations; f32fmaf64x,
f32fmaf128, f64fmaf64x, f64fmaf128, f32xfmaf64x, f32xfmaf128,
f64xfmaf128 for configurations with _Float64x and _Float128;
__f32fmaieee128 and __f64fmaieee128 aliases in the powerpc64le case
(for calls to ffmal and dfmal when long double is IEEE binary128).
Corresponding tgmath.h macro support is also added.

The changes are mostly similar to those for the other narrowing
functions previously added, especially that for sqrt, so the
description of those generally applies to this patch as well.  As with
sqrt, I reused the same test inputs in auto-libm-test-in as for
non-narrowing fma rather than adding extra or separate inputs for
narrowing fma.  The tests in libm-test-narrow-fma.inc also follow
those for non-narrowing fma.

The non-narrowing fma has a known bug (bug 6801) that it does not set
errno on errors (overflow, underflow, Inf * 0, Inf - Inf).  Rather
than fixing this or having narrowing fma check for errors when
non-narrowing does not (complicating the cases when narrowing fma can
otherwise be an alias for a non-narrowing function), this patch does
not attempt to check for errors from narrowing fma and set errno; the
CHECK_NARROW_FMA macro is still present, but as a placeholder that
does nothing, and this missing errno setting is considered to be
covered by the existing bug rather than needing a separate open bug.
missing-errno annotations are duly added to many of the
auto-libm-test-in test inputs for fma.

This completes adding all the new functions from TS 18661-1 to glibc,
so will be followed by corresponding stdc-predef.h changes to define
__STDC_IEC_60559_BFP__ and __STDC_IEC_60559_COMPLEX__, as the support
for TS 18661-1 will be at a similar level to that for C standard
floating-point facilities up to C11 (pragmas not implemented, but
library functions done).  (There are still further changes to be done
to implement changes to the types of fromfp functions from N2548.)

Tested as followed: natively with the full glibc testsuite for x86_64
(GCC 11, 7, 6) and x86 (GCC 11); with build-many-glibcs.py with GCC
11, 7 and 6; cross testing of math/ tests for powerpc64le, powerpc32
hard float, mips64 (all three ABIs, both hard and soft float).  The
different GCC versions are to cover the different cases in tgmath.h
and tgmath.h tests properly (GCC 6 has _Float* only as typedefs in
glibc headers, GCC 7 has proper _Float* support, GCC 8 adds
__builtin_tgmath).
2021-09-22 21:25:31 +00:00
Joseph Myers
abd383584b Add narrowing square root functions
This patch adds the narrowing square root functions from TS 18661-1 /
TS 18661-3 / C2X to glibc's libm: fsqrt, fsqrtl, dsqrtl, f32sqrtf64,
f32sqrtf32x, f32xsqrtf64 for all configurations; f32sqrtf64x,
f32sqrtf128, f64sqrtf64x, f64sqrtf128, f32xsqrtf64x, f32xsqrtf128,
f64xsqrtf128 for configurations with _Float64x and _Float128;
__f32sqrtieee128 and __f64sqrtieee128 aliases in the powerpc64le case
(for calls to fsqrtl and dsqrtl when long double is IEEE binary128).
Corresponding tgmath.h macro support is also added.

The changes are mostly similar to those for the other narrowing
functions previously added, so the description of those generally
applies to this patch as well.  However, the not-actually-narrowing
cases (where the two types involved in the function have the same
floating-point format) are aliased to sqrt, sqrtl or sqrtf128 rather
than needing a separately built not-actually-narrowing function such
as was needed for add / sub / mul / div.  Thus, there is no
__nldbl_dsqrtl name for ldbl-opt because no such name was needed
(whereas the other functions needed such a name since the only other
name for that entry point was e.g. f32xaddf64, not reserved by TS
18661-1); the headers are made to arrange for sqrt to be called in
that case instead.

The DIAG_* calls in sysdeps/ieee754/soft-fp/s_dsqrtl.c are because
they were observed to be needed in GCC 7 testing of
riscv32-linux-gnu-rv32imac-ilp32.  The other sysdeps/ieee754/soft-fp/
files added didn't need such DIAG_* in any configuration I tested with
build-many-glibcs.py, but if they do turn out to be needed in more
files with some other configuration / GCC version, they can always be
added there.

I reused the same test inputs in auto-libm-test-in as for
non-narrowing sqrt rather than adding extra or separate inputs for
narrowing sqrt.  The tests in libm-test-narrow-sqrt.inc also follow
those for non-narrowing sqrt.

Tested as followed: natively with the full glibc testsuite for x86_64
(GCC 11, 7, 6) and x86 (GCC 11); with build-many-glibcs.py with GCC
11, 7 and 6; cross testing of math/ tests for powerpc64le, powerpc32
hard float, mips64 (all three ABIs, both hard and soft float).  The
different GCC versions are to cover the different cases in tgmath.h
and tgmath.h tests properly (GCC 6 has _Float* only as typedefs in
glibc headers, GCC 7 has proper _Float* support, GCC 8 adds
__builtin_tgmath).
2021-09-10 20:56:22 +00:00
Anton Blanchard
01d7806282 powerpc64le: Fix typo in configure
The configure script checks for -mlong-double-128 but mentions -mlongdouble
when it fails.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-07-08 21:59:28 -03:00
Pedro Franco de Carvalho
813c6ec808 powerpc: optimize strcpy/stpcpy for POWER9/10
This patch modifies the current POWER9 implementation of strcpy and
stpcpy to optimize it for POWER9/10.

Since no new POWER10 instructions are used, the original POWER9 strcpy is
modified instead of creating a new implementation for POWER10.  This
implementation is based on both the original POWER9 implementation of
strcpy and the preamble of the new POWER10 implementation of strlen.

The changes also affect stpcpy, which uses the same implementation with
some additional code before returning.

On POWER9, averaging improvements across the benchmark
inputs (length/source alignment/destination alignment), for an
experiment that ran the benchmark five times, bench-strcpy showed an
improvement of 5.23%, and bench-stpcpy showed an improvement of 6.59%.

On POWER10, bench-strcpy showed 13.16%, and bench-stpcpy showed 13.59%.

The changes are:

1. Removed the null string optimization.

   Although this results in a few extra cycles for the null string, in
   combination with the second change, this resulted in improvements for
   for other cases.

2. Adapted the preamble from strlen for POWER10.

   This is the part of the function that handles up to the first 16 bytes
   of the string.

3. Increased number of unrolled iterations in the main loop to 6.

Reviewed-by: Matheus Castanho <msc@linux.ibm.com>
Tested-by: Matheus Castanho <msc@linux.ibm.com>
2021-07-01 17:58:53 -03:00
Lucas A. M. Magalhaes
a55e2da270 powerpc: Optimized memcmp for power10
This patch was based on the __memcmp_power8 and the recent
__strlen_power10.

Improvements from __memcmp_power8:

1. Don't need alignment code.

   On POWER10 lxvp and lxvl do not generate alignment interrupts, so
they are safe for use on caching-inhibited memory.  Notice that the
comparison on the main loop will wait for both VSR to be ready.
Therefore aligning one of the input address does not improve
performance.  In order to align both registers a vperm is necessary
which add too much overhead.

2. Uses new POWER10 instructions

   This code uses lxvp to decrease contention on load by loading 32 bytes
per instruction.
   The vextractbm is used to have a smaller tail code for calculating the
return value.

3. Performance improvement

   This version has around 35% better performance on average. I saw no
performance regressions for any length or alignment.

Thanks Matheus for helping me out with some details.

Co-authored-by: Matheus Castanho <msc@linux.ibm.com>
Reviewed-by: Raphael M Zinsly <rzinsly@linux.ibm.com>
2021-05-31 18:00:20 -03:00
Florian Weimer
d337345ce1 powerpc64le: Check HWCAP bits against compiler build flags
When built with GCC 11.1 and -mcpu=power9, ld.so prints this error
message when running on POWER8:

Fatal glibc error: CPU lacks ISA 3.00 support (POWER9 or later required)
2021-05-19 11:09:57 +02:00
Matheus Castanho
1a594aa986 powerpc: Add optimized rawmemchr for POWER10
Reuse code for optimized strlen to implement a faster version of rawmemchr.
This takes advantage of the same benefits provided by the strlen implementation,
but needs some extra steps. __strlen_power10 code should be unchanged after this
change.

rawmemchr returns a pointer to the char found, while strlen returns only the
length, so we have to take that into account when preparing the return value.

To quickly check 64B, the loop on __strlen_power10 merges the whole block into
16B by using unsigned minimum vector operations (vminub) and checks if there are
any \0 on the resulting vector. The same code is used by rawmemchr if the char c
is 0. However, this approach does not work when c != 0.  We first need to
subtract each byte by c, so that the value we are looking for is converted to a
0, then taking the minimum and checking for nulls works again.

The new code branches after it has compared ~256 bytes and chooses which of the
two strategies above will be used in the main loop, based on the char c. This
extra branch adds some overhead (~5%) for length ~256, but is quickly amortized
by the faster loop for larger sizes.

Compared to __rawmemchr_power9, this version is ~20% faster for length < 256.
Because of the optimized main loop, the improvement becomes ~35% for c != 0
and ~50% for c = 0 for strings longer than 256.

Reviewed-by: Lucas A. M. Magalhaes <lamm@linux.ibm.com>
Reviewed-by: Raphael M Zinsly <rzinsly@linux.ibm.com>
2021-05-17 10:30:35 -03:00
Raoni Fassina Firmino
23fdf8178c powerpc64le: Optimize memset for POWER10
This implementation is based on __memset_power8 and integrates a lot
of suggestions from Anton Blanchard.

The biggest difference is that it makes extensive use of stxvl to
alignment and tail code to avoid branches and small stores.  It has
three main execution paths:

a) "Short lengths" for lengths up to 64 bytes, avoiding as many
   branches as possible.

b) "General case" for larger lengths, it has an alignment section
   using stxvl to avoid branches, a 128 bytes loop and then a tail
   code, again using stxvl with few branches.

c) "Zeroing cache blocks" for lengths from 256 bytes upwards and set
   value being zero.  It is mostly the __memset_power8 code but the
   alignment phase was simplified because, at this point, address is
   already 16-bytes aligned and also changed to use vector stores.
   The tail code was also simplified to reuse the general case tail.

All unaligned stores use stxvl instructions that do not generate
alignment interrupts on POWER10, making it safe to use on
caching-inhibited memory.

On average, this implementation provides something around 30%
improvement when compared to __memset_power8.

Reviewed-by: Matheus Castanho <msc@linux.ibm.com>
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2021-04-30 18:12:08 -03:00
Tulio Magno Quites Machado Filho
e941e0ae80 powerpc64le: Optimize memcpy for POWER10
This implementation is based on __memcpy_power8_cached and integrates
suggestions from Anton Blanchard.
It benefits from loads and stores with length for short lengths and for
tail code, simplifying the code.

All unaligned memory accesses use instructions that do not generate
alignment interrupts on POWER10, making it safe to use on
caching-inhibited memory.

The main loop has also been modified in order to increase instruction
throughput by reducing the dependency on updates from previous iterations.

On average, this implementation provides around 30% improvement when
compared to __memcpy_power7 and 10% improvement in comparison to
__memcpy_power8_cached.
2021-04-30 18:12:08 -03:00
Lucas A. M. Magalhaes
dd59655e93 powerpc64le: Optimized memmove for POWER10
This patch was initially based on the __memmove_power7 with some ideas
from strncpy implementation for Power 9.

Improvements from __memmove_power7:

1. Use lxvl/stxvl for alignment code.

   The code for Power 7 uses branches when the input is not naturally
   aligned to the width of a vector. The new implementation uses
   lxvl/stxvl instead which reduces pressure on GPRs. It also allows
   the removal of branch instructions, implicitly removing branch stalls
   and mispredictions.

2. Use of lxv/stxv and lxvl/stxvl pair is safe to use on Cache Inhibited
   memory.

   On Power 10 vector load and stores are safe to use on CI memory for
   addresses unaligned to 16B. This code takes advantage of this to
   do unaligned loads.

   The unaligned loads don't have a significant performance impact by
   themselves. However doing so decreases register pressure on GPRs
   and interdependence stalls on load/store pairs. This also improved
   readability as there are now less code paths for different alignments.
   Finally this reduces the overall code size.

3. Improved performance.

   This version runs on average about 30% better than memmove_power7
   for lengths  larger than 8KB. For input lengths shorter than 8KB
   the improvement is smaller, it has on average about 17% better
   performance.

   This version has a degradation of about 50% for input lengths
   in the 0 to 31 bytes range when dest is unaligned.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2021-04-30 18:12:08 -03:00
Raphael Moreira Zinsly
25cb72820a powerpc: Add log IFUNC multiarch support for POWER10
Checked on ppc64le built without --with-cpu, with --with-cpu=power9
and with --disable-multi-arch.

Reviewed-by: Matheus Castanho <msc@linux.ibm.com>
2021-04-26 10:10:29 -03:00
Matheus Castanho
10624a97e8 powerpc: Add optimized strlen for POWER10
Improvements compared to POWER9 version:

1. Take into account first 16B comparison for aligned strings

   The previous version compares the first 16B and increments r4 by the number
   of bytes until the address is 16B-aligned, then starts doing aligned loads at
   that address. For aligned strings, this causes the first 16B to be compared
   twice, because the increment is 0. Here we calculate the next 16B-aligned
   address differently, which avoids that issue.

2. Use simple comparisons for the first ~192 bytes

   The main loop is good for big strings, but comparing 16B each time is better
   for smaller strings.  So after aligning the address to 16 Bytes, we check
   more 176B in 16B chunks.  There may be some overlaps with the main loop for
   unaligned strings, but we avoid using the more aggressive strategy too soon,
   and also allow the loop to start at a 64B-aligned address.  This greatly
   benefits smaller strings and avoids overlapping checks if the string is
   already aligned at a 64B boundary.

3. Reduce dependencies between load blocks caused by address calculation on loop

   Doing a precise time tracing on the code showed many loads in the loop were
   stalled waiting for updates to r4 from previous code blocks.  This
   implementation avoids that as much as possible by using 2 registers (r4 and
   r5) to hold addresses to be used by different parts of the code.

   Also, the previous code aligned the address to 16B, then to 64B by doing a
   few 48B loops (if needed) until the address was aligned. The main loop could
   not start until that 48B loop had finished and r4 was updated with the
   current address. Here we calculate the address used by the loop very early,
   so it can start sooner.

   The main loop now uses 2 pointers 128B apart to make pointer updates less
   frequent, and also unrolls 1 iteration to guarantee there is enough time
   between iterations to update the pointers, reducing stalled cycles.

4. Use new P10 instructions

   lxvp is used to load 32B with a single instruction, reducing contention in
   the load queue.

   vextractbm allows simplifying the tail code for the loop, replacing
   vbpermq and avoiding having to generate a permute control vector.

Reviewed-by: Paul E Murphy <murphyp@linux.ibm.com>
Reviewed-by: Raphael M Zinsly <rzinsly@linux.ibm.com>
Reviewed-by: Lucas A. M. Magalhaes <lamm@linux.ibm.com>
2021-04-22 16:18:06 -03:00
Andreas Schwab
5ccea9a011 powerpc64le: Use ifunc for _Float128 functions also in libc
This fixes missing definition of math functions in libc in a static link
that are no longer built for libm after commit 4898d9712b ("Avoid adding
duplicated symbols into static libraries").
2021-04-01 10:55:42 +02:00
Raphael Moreira Zinsly
a7d88506c2 powerpc: Add optimized llogb* for POWER9
The POWER9 builtins used to improve the ilogb* functions can be
used in the llogb* functions as well.
2021-03-16 12:19:09 -03:00
Raphael Moreira Zinsly
56c81132cc powerpc: Add optimized ilogb* for POWER9
The instructions xsxexpdp and xsxexpqp introduced on POWER9 extract
the exponent from a double-precision and quad-precision floating-point
respectively, thus they can be used to improve ilogb, ilogbf and ilogbf128.
2021-03-16 12:19:09 -03:00
Paul Eggert
2b778ceb40 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
2021-01-02 12:17:34 -08:00
Florian Weimer
4c38c1a229 powerpc64le: Add glibc-hwcaps support
The "power10" and "power9" subdirectories are selected in a way
that matches the -mcpu=power10 and -mcpu=power9 options of GCC.
2020-12-04 14:50:49 +01:00
Paul E. Murphy
33fc34521d powerpc64le: ifunc select *f128 routines in multiarch mode
Programatically generate simple wrappers for interesting libm *f128
objects.  Selected functions are transcendental functions or
those with trivial compiler builtins.  This can result in a 2-3x
speedup (e.g logf128 and expf128).

A second set of implementation files are generated which include
the first implementation encountered along the search path.  This
usually works, except when a wrapper is overriden and makefile
search order slightly diverges from include order.  Likewise,
wrapper object files are created for each generated file.  These
hold the ifunc selection routines which export ABI.

Next, several shared headers are intercepted to control renaming of
asm function redirects are used first, and sometimes macro renames
if the former is impractical.

Notably, if the request machine supports hardware IEEE128 (i.e POWER9
and newer) this ifunc machinery is disabled.  Likewise existing
ifunc support for float128 is consolidated into this (e.g sqrtf128
and fmaf128).

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-11-30 09:56:14 -06:00
Raphael M Zinsly
7beee7b39a powerpc: Add optimized stpncpy for POWER9
Add stpncpy support into the POWER9 strncpy.

Reviewed-by: Matheus Castanho <msc@linux.ibm.com>
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-11-12 13:16:36 -03:00
Raphael M Zinsly
b9d83bf3eb powerpc: Add optimized strncpy for POWER9
Similar to the strcpy P9 optimization, this version uses VSX to improve
performance.

Reviewed-by: Matheus Castanho <msc@linux.ibm.com>
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-11-12 13:12:24 -03:00
Paul E. Murphy
c79607a474 powerpc64le: guarantee a .gnu.attributes section [BZ #26220]
Upstream GCC 11 development is now building the ibm128 runtime
support (in libgcc) without a .gnu.attributes section on ppc64le.
Ensure we have one to replace by building one ibm128 file in
libc and libm with attributes.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-07-21 09:03:01 -05:00
Tulio Magno Quites Machado Filho
d2ba3677da powerpc: Add support for POWER10
1. Add the directories to hold POWER10 files.

2. Add support to select POWER10 libraries based on AT_PLATFORM.

3. Let submachine=power10 be set automatically.
2020-06-29 10:08:38 -03:00
Paul E. Murphy
b637306d3e powerpc64le: refactor e_sqrtf128.c
Combine both implementations into a single file to allow
building twice with appropriate multiarch support when possible.
2020-06-16 13:50:44 -05:00
Paul E. Murphy
a23bd00f9d powerpc64le: add optimized strlen for P9
This started as a trivial change to Anton's rawmemchr.  I got
carried away.  This is a hybrid between P8's asympotically
faster 64B checks with extremely efficient small string checks
e.g <64B (and sometimes a little bit more depending on alignment).

The second trick is to align to 64B by running a 48B checking loop
16B at a time until we naturally align to 64B (i.e checking 48/96/144
bytes/iteration based on the alignment after the first 5 comparisons).
This allieviates the need to check page boundaries.

Finally, explicly use the P7 strlen with the runtime loader when building
P9.  We need to be cautious about vector/vsx extensions here on P9 only
builds.
2020-06-05 15:30:00 -05:00
Paul E. Murphy
6ef4227509 powerpc64le: use common fmaf128 implementation
This defines the macro such that it should behave best on all
supported powerpc targets.  Likewise, this allows us to remove the
ppc64le specific s_fmaf128.c.

I have verified powerpc64le multiarch and powerpc64le power9
no-multiarch builds continue to generate optimize fmaf128.
2020-06-05 15:29:44 -05:00
Anton Blanchard
765de945ef powerpc: Optimized rawmemchr for POWER9
This version uses vector instructions and is up to 60% faster on medium
matches and up to 90% faster on long matches, compared to the POWER7
version. A few examples:

                            __rawmemchr_power9  __rawmemchr_power7
Length   32, alignment  0:   2.27566             3.77765
Length   64, alignment  2:   2.46231             3.51064
Length 1024, alignment  0:  17.3059             32.6678
2020-05-18 17:08:54 -05:00
Anton Blanchard via Libc-alpha
aa70d05632 powerpc: Optimized stpcpy for POWER9
Add stpcpy support to the POWER9 strcpy. This is up to 40% faster on
small strings and up to 90% faster on long relatively unaligned strings,
compared to the POWER8 version. A few examples:

                                        __stpcpy_power9  __stpcpy_power8
Length   20, alignments in bytes  4/ 4:  2.58246          4.8788
Length 1024, alignments in bytes  1/ 6: 24.8186          47.8528
2020-05-18 08:26:22 -05:00