Tue Ly
4973eee122
[libc][math] Improve tanhf performance.
...
Optimize the core part of `tanhf` implementation that is to compute `e^x`
similar to https://reviews.llvm.org/D133870 . Factor the constants and
polynomial approximation out so that it can be used for `exp10f`
Performance benchmark using perf tool from the CORE-MATH project on Ryzen 1700:
```
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh tanhf
GNU libc version: 2.35
GNU libc release: stable
CORE-MATH reciprocal throughput : 13.377
System LIBC reciprocal throughput : 55.046
BEFORE:
LIBC reciprocal throughput : 75.674
LIBC reciprocal throughput : 33.242 (with `-msse4.2` flag)
LIBC reciprocal throughput : 25.927 (with `-mfma` flag)
AFTER:
LIBC reciprocal throughput : 26.359
LIBC reciprocal throughput : 18.888 (with `-msse4.2` flag)
LIBC reciprocal throughput : 14.243 (with `-mfma` flag)
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh tanhf --latency
GNU libc version: 2.35
GNU libc release: stable
CORE-MATH latency : 43.365
System LIBC latency : 123.499
BEFORE
LIBC latency : 112.968
LIBC latency : 104.908 (with `-msse4.2` flag)
LIBC latency : 92.310 (with `-mfma` flag)
AFTER
LIBC latency : 69.828
LIBC latency : 63.874 (with `-msse4.2` flag)
LIBC latency : 57.427 (with `-mfma` flag)
```
Reviewed By: orex, zimmermann6
Differential Revision: https://reviews.llvm.org/D134002
2022-09-19 08:43:03 -04:00
Kirill Okhotnikov
89ed5b7c50
[libc][math] Added auxiliary function log2_eval for asinhf/acoshf/atanhf.
...
1) `double log2_eval(double)` function added with better than float precision is added.
2) Some refactoring done to put all auxiliary functions and corresponding data
to one place to reuse the code.
3) Added tests for new functions.
4) Performance and precision tests of the function shows, that it more precise than exiting log2,
(no exceptional cases), but timing is ~5% higer that on current one.
Differential Revision: https://reviews.llvm.org/D132809
2022-08-30 22:39:54 +02:00
