2 Commits

Author	SHA1	Message	Date
Martin Möhrmann	69972aea74	internal/cpu: new package to detect cpu features ... Implements detection of x86 cpu features that are used in the go standard library. Changes all standard library packages to use the new cpu package instead of using runtime internal variables to check x86 cpu features. Updates: #15403 Change-Id: I2999a10cb4d9ec4863ffbed72f4e021a1dbc4bb9 Reviewed-on: https://go-review.googlesource.com/41476 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>	2017-05-10 17:02:21 +00:00
Ilya Tocar	37cfb2e07e	math: optimize ceil/floor functions on amd64 ... Use SSE 4.1 rounding instruction to perform rounding Results (haswell): name old time/op new time/op delta Floor-48 2.71ns ± 0% 1.87ns ± 1% -31.17% (p=0.000 n=16+19) Ceil-48 3.09ns ± 3% 2.16ns ± 0% -30.16% (p=0.000 n=19+12) Change-Id: If63715879eed6530b1eb4fc96132d827f8f43909 Reviewed-on: https://go-review.googlesource.com/14561 Reviewed-by: Klaus Post <klauspost@gmail.com> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>	2015-10-03 15:55:08 +00:00