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Story
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Resolution: Unresolved
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Normal
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rhel-9.4, rhel-9.8
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None
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Patch
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1
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rhel-pt-c-libs
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ssg_platform_tools
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3
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True
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No
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Red Hat Enterprise Linux
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PT C Libraries Refinement
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None
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None
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x86_64
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Linux
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None
Performance testing indicates that we see some potential for benchmark improvement if we add variants of log2, asinh, atanh, sinh, tanh.
These changes would look similar to this one for log2f:
commit 5c7adbd8eded546eb6e17a82f5ab3b35def47f38
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Sun Oct 22 08:06:46 2017 -0700
x86-64: Add log2f with FMA
For workload-spec2017.wrf, on Skylake, it improves performance by:
Before After Improvement
reciprocal-throughput 16.5937 14.0789 17%
latency 41.7755 35.3586 18%
* sysdeps/x86_64/fpu/multiarch/Makefile (libm-sysdep_routines):
Add e_log2f-fma.
(CFLAGS-e_log2f-fma.c): New.
* sysdeps/x86_64/fpu/multiarch/e_log2f-fma.c: New file.
* sysdeps/x86_64/fpu/multiarch/e_log2f.c: Likewise.
Acceptance Criteria:
eu-readelf --symbols=.dynsym shows IFUNCs for the named functions, and performance of RHEL 9 glibc matches that of a glibc rebuild with -march=x86-64-v3.