Hi Severin, On 09/11/2018 09:02 AM, Severin Gehwolf wrote:

Micro-benchmark results from running [1] for x86_64 and ppc64le are here (-O2 is sufficient it seems):

http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8210416/microbenchmarks_res...

More thoughts?

Thanks a lot for checking it on PPC64. I did additional tests on a POWER8 using the same microbench. I share the results below. The numbers are the arithmetic mean of 10 runs. Unit is second. 1 O3 | O2 2 Math StrictMath | Math StrictMath 3 | 4 acos: 3.0728 3.0728 | acos: 3.07325 3.07375 5 asin: 3.0933 3.0916 | asin: 3.09337 3.0915 6 atan2: 10.9743 10.9759 | atan2: 11.2994 11.2977 7 atan: 7.653 7.6602 | atan: 7.48463 7.48225 8 cbrt: 13.444 13.4433 | cbrt: 13.4535 13.4527 9 cos: 30.1561 33.9689 | cos: 30.157 35.1162 10 cosh: 3.0911 3.1074 | cosh: 3.09975 3.09088 11 exp: 1.413 3.0572 | exp: 1.41313 3.09737 12 expm1: 3.0281 3.0349 | expm1: 2.98813 2.98913 13 hypot: 33.7668 33.7471 | hypot: 27.9664 27.9675 14 log10: 4.2213 10.0832 | log10: 4.221 10.1109 15 log1p: 9.2886 9.2888 | log1p: 9.08713 9.08075 16 log: 3.1362 7.6327 | log: 3.136 7.633 17 pow: 13.7787 17.4739 | pow: 13.7829 17.483 18 sin: 30.216 33.9733 | sin: 30.2163 35.1684 19 sinh: 3.1478 3.152 | sinh: 3.18638 3.18375 20 sqrt: 0.665 0.6714 | sqrt: 0.665 0.671 21 tan: 31.6409 36.461 | tan: 31.6385 37.7166 22 tanh: 3.0753 3.0925 | tanh: 3.11088 3.10675 Based upon that, it looks like that O3 is better for most of the functions, specially for sin, cos, and tan. On the other hand, it looks like that O3 hurts hypot. Thus it seems -O2 is not quite the same as -O3, but it's not straightforward to decide which one is better too. Maybe Andrew can enlight us. I also CC:ed ppc-aix-port in case somebody there wishes to comment on that. Thank you. Best regards, Gustavo

Thanks, Severin

[1] https://github.com/gromero/strictmath/