According to ISO C23 (7.6.4.4), fesetexcept is supposed to set
floating-point exception flags without raising a trap (unlike
feraiseexcept, which is supposed to raise a trap if feenableexcept
was called with the appropriate argument).
The flags can be set in the 387 unit or in the SSE unit. When we need
to clear a flag, we need to do so in both units, due to the way
fetestexcept is implemented.
When we need to set a flag, it is sufficient to do it in the SSE unit,
because that is guaranteed to not trap. However, on i386 CPUs that have
only a 387 unit, set the flags in the 387, as long as this cannot trap.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
On Skylake, it changes log1p bench performance by:
Before After Improvement
max 63.349 58.347 8%
min 4.448 5.651 -30%
mean 12.0674 10.336 14%
The minimum code path is
if (hx < 0x3FDA827A) /* x < 0.41422 */
{
if (__glibc_unlikely (ax >= 0x3ff00000)) /* x <= -1.0 */
{
...
}
if (__glibc_unlikely (ax < 0x3e200000)) /* |x| < 2**-29 */
{
math_force_eval (two54 + x); /* raise inexact */
if (ax < 0x3c900000) /* |x| < 2**-54 */
{
...
}
else
return x - x * x * 0.5;
FMA and non-FMA code sequences look similar. Non-FMA version is slightly
faster. Since log1p is called by asinh and atanh, it improves asinh
performance by:
Before After Improvement
max 75.645 63.135 16%
min 10.074 10.071 0%
mean 15.9483 14.9089 6%
and improves atanh performance by:
Before After Improvement
max 91.768 75.081 18%
min 15.548 13.883 10%
mean 18.3713 16.8011 8%
On Skylake, it improves expm1 bench performance by:
Before After Improvement
max 70.204 68.054 3%
min 20.709 16.2 22%
mean 22.1221 16.7367 24%
NB: Add
extern long double __expm1l (long double);
extern long double __expm1f128 (long double);
for __typeof (__expm1l) and __typeof (__expm1f128) when __expm1 is
defined since __expm1 may be expanded in their declarations which
causes the build failure.
Based on feedback by Mike Gilbert <floppym@gentoo.org>
Linux-6.1.38-dist x86_64 AMD Phenom-tm- II X6 1055T Processor
-march=amdfam10
failures occur for x32 ABI
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
Applying this commit results in a bit-identical rebuild of
mathvec/libmvec.so.1 (which is the only binary that gets rebuilt).
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This patch enables libmvec on AArch64. The proposed change is mainly
implementing build infrastructure to add the new routines to ABI,
tests and benchmarks. I have demonstrated how this all fits together
by adding implementations for vector cos, in both single and double
precision, targeting both Advanced SIMD and SVE.
The implementations of the routines themselves are just loops over the
scalar routine from libm for now, as we are more concerned with
getting the plumbing right at this point. We plan to contribute vector
routines from the Arm Optimized Routines repo that are compliant with
requirements described in the libmvec wiki.
Building libmvec requires minimum GCC 10 for SVE ACLE. To avoid raising
the minimum GCC by such a big jump, we allow users to disable libmvec
if their compiler is too old.
Note that at this point users have to manually call the vector math
functions. This seems to be acceptable to some downstream users.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
The divss instruction clobbers its first argument, and the constraints
need to reflect that. Fortunately, with GCC 12, generated code does
not actually change, so there is no externally visible bug.
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This allows other targets to use the same inputs for their own libmvec
microbenchmarks without having to duplicate them in their own
subdirectory.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Update libm test ulps for
commit 3efbf11fdf
Author: Paul Zimmermann <Paul.Zimmermann@inria.fr>
Date: Tue Feb 14 11:24:59 2023 +0100
update auto-libm-test-out-hypot
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
vfprintf is entangled with vfwprintf (of course), __printf_fp,
__printf_fphex, __vstrfmon_l_internal, and the strfrom family of
functions. The latter use the internal snprintf functionality,
so vsnprintf is converted as well.
The simples conversion is __printf_fphex, followed by
__vstrfmon_l_internal and __printf_fp, and finally
__vfprintf_internal and __vfwprintf_internal. __vsnprintf_internal
and strfrom* are mostly consuming the new interfaces, so they
are comparatively simple.
__printf_fp is a public symbol, so the FILE *-based interface
had to preserved.
The __printf_fp rewrite does not change the actual binary-to-decimal
conversion algorithm, and digits are still not emitted directly to
the target buffer. However, the staging buffer now uses bytes
instead of wide characters, and one buffer copy is eliminated.
The changes are at least performance-neutral in my testing.
Floating point printing and snprintf improved measurably, so that
this Lua script
for i=1,5000000 do
print(i, i * math.pi)
end
runs about 5% faster for me. To preserve fprintf performance for
a simple "%d" format, this commit has some logic changes under
LABEL (unsigned_number) to avoid additional function calls. There
are certainly some very easy performance improvements here: binary,
octal and hexadecimal formatting can easily avoid the temporary work
buffer (the number of digits can be computed ahead-of-time using one
of the __builtin_clz* built-ins). Decimal formatting can use a
specialized version of _itoa_word for base 10.
The existing (inconsistent) width handling between strfmon and printf
is preserved here. __print_fp_buffer_1 would have to use
__translated_number_width to achieve ISO conformance for printf.
Test expectations in libio/tst-vtables-common.c are adjusted because
the internal staging buffer merges all virtual function calls into
one.
In general, stack buffer usage is greatly reduced, particularly for
unbuffered input streams. __printf_fp can still use a large buffer
in binary128 mode for %g, though.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Most of these don't really matter as there was no dirty upper state
but we should generally avoid stray sse when its not needed.
The one case that really matters is in svml_d_tanh4_core_avx2.S:
blendvps %xmm0, %xmm8, %xmm7
When there was a dirty upper state.
Tested on x86_64-linux
Optimizations are:
1. Reduce code size (-112 bytes).
2. Remove redundant move instructions.
3. Slightly improve instruction selection/scheduling where
possible.
4. Prefer registers which get short instruction encoding.
5. Reduce rodata size (-4k+ rodata is shared with avx2).
Result is roughly a 15-16% speedup:
Function, New Time, Old Time, New / Old
_ZGVbN4v_tanhf, 3.158, 3.749, 0.842
Optimizations are:
1. Reduce code size (-81 bytes).
2. Remove redundant move instructions.
3. Slightly improve instruction selection/scheduling where
possible.
4. Prefer registers which get short instruction encoding.
5. Reduce rodata size (-32 bytes).
Result is roughly a 17-18% speedup:
Function, New Time, Old Time, New / Old
_ZGVdN8v_tanhf, 1.977, 2.402, 0.823
tanhf-avx2 and tanhf-sse4 use the same data tables so we can save
over 4kb using a shared datatable. This does increase the memory
footprint of the sse4 version (as now all the targets are 32 bytes
instead of 16), generally it seems worth the code size save.
NB: This patch doesn't do anything itself, it is setup for future
patches.
Optimizations are:
1. Reduce code size (-67 bytes).
2. Remove redundant move instructions.
3. Slightly improve instruction selection/scheduling where
possible.
4. Reduce rodata usage (-448 bytes).
Result is roughly a 14% speedup:
Function, New Time, Old Time, New / Old
_ZGVeN16v_tanhf, 0.649, 0.752, 0.863
Improvements are:
1. Reduce code size (-62 bytes).
2. Remove redundant move instructions.
3. Slightly improve instruction selection/scheduling where
possible.
4. Prefer registers which get short instruction encoding.
5. Reduce rodata usage (-16 bytes).
The throughput improvement is not significant as the port 0 bottleneck
is unavoidable.
Function, New Time, Old Time, New / Old
_ZGVbN4v_atanhf, 8.821, 8.903, 0.991
Improvements are:
1. Reduce code size (-60 bytes).
2. Remove redundant move instructions.
3. Slightly improve instruction selection/scheduling where
possible.
4. Prefer registers which get short instruction encoding.
5. Shrink rodata usage (-32 bytes).
The throughput improvement is not that significant (3-5%) as the
port 0 bottleneck is unavoidable.
Function, New Time, Old Time, New / Old
_ZGVdN8v_atanhf, 2.799, 2.923, 0.958
Improvements are:
1. Reduce code size (-64 bytes).
2. Remove redundant move instructions.
3. Slightly improve instruction selection/scheduling where
possible.
4. Reduce rodata size ([-128, -188] bytes).
The throughput improvement is not significant as the port 0 bottleneck
is unavoidable.
Function, New Time, Old Time, New / Old
_ZGVeN16v_atanhf, 1.39, 1.408, 0.987
The compiler may substitute calls to sin or cos with calls to sincos, thus
we should have the same optimized implementations for sincos. The
optimized implementations may produce results that differ, that also makes
sure that the sincos call aggrees with the sin and cos calls.
Both float, double, and _Float128 are assumed to be supported
(float and double already only uses builtins). Only long double
is parametrized due GCC bug 29253 which prevents its usage on
powerpc.
It allows to remove i686, ia64, x86_64, powerpc, and sparc arch
specific implementation.
On ia64 it also fixes the sNAN handling:
math/test-float64x-fabs
math/test-ldouble-fabs
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc-linux-gnu,
powerpc64-linux-gnu, sparc64-linux-gnu, and ia64-linux-gnu.
Improve libmvec benchmark integration so that in future other
architectures may be able to run their libmvec benchmarks as well. This
now allows libmvec benchmarks to be run with `make BENCHSET=bench-math`.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
The libmvec benchmarks print a message indicating that a certain CPU
feature is unsupported and exit prematurelyi, which breaks the JSON in
bench.out.
Handle this more elegantly in the bench makefile target by adding
support for an UNSUPPORTED exit status (77) so that bench.out continues
to have output for valid tests.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
This commit contains following formatting changes
1. Instructions proceeded by a tab.
2. Instruction less than 8 characters in length have a tab
between it and the first operand.
3. Instruction greater than 7 characters in length have a
space between it and the first operand.
4. Tabs after `#define`d names and their value.
5. 8 space at the beginning of line replaced by tab.
6. Indent comments with code.
7. Remove redundent .text section.
8. 1 space between line content and line comment.
9. Space after all commas.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
