forked from OSchip/llvm-project
a752460d73
Implement exp10f function correctly rounded to all rounding modes. Algorithm: perform range reduction to reduce ``` 10^x = 2^(hi + mid) * 10^lo ``` where: ``` hi is an integer, 0 <= mid * 2^5 < 2^5 -log10(2) / 2^6 <= lo <= log10(2) / 2^6 ``` Then `2^mid` is stored in a table of 32 entries and the product `2^hi * 2^mid` is performed by adding `hi` into the exponent field of `2^mid`. `10^lo` is then approximated by a degree-5 minimax polynomials generated by Sollya with: ``` > P = fpminimax((10^x - 1)/x, 4, [|D...|], [-log10(2)/64. log10(2)/64]); ``` Performance benchmark using perf tool from the CORE-MATH project on Ryzen 1700: ``` $ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh exp10f GNU libc version: 2.35 GNU libc release: stable CORE-MATH reciprocal throughput : 10.215 System LIBC reciprocal throughput : 7.944 LIBC reciprocal throughput : 38.538 LIBC reciprocal throughput : 12.175 (with `-msse4.2` flag) LIBC reciprocal throughput : 9.862 (with `-mfma` flag) $ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh exp10f --latency GNU libc version: 2.35 GNU libc release: stable CORE-MATH latency : 40.744 System LIBC latency : 37.546 BEFORE LIBC latency : 48.989 LIBC latency : 44.486 (with `-msse4.2` flag) LIBC latency : 40.221 (with `-mfma` flag) ``` This patch relies on https://reviews.llvm.org/D134002 Reviewed By: orex, zimmermann6 Differential Revision: https://reviews.llvm.org/D134104 |
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| HdrGen | ||
| IntegrationTest | ||
| LibcTableGenUtil | ||
| MPFRWrapper | ||
| UnitTest | ||
| buildbot | ||
| mathtools | ||
| testutils | ||
| tools | ||
| CMakeLists.txt | ||