qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-18 00:54:45 -07:00
Code Releases Activity

math: optimize Ceil, Floor and Trunc on s390x

Browse Source 
Use the FIDBR instruction to round floating-point numbers to integers.

name   old time/op  new time/op  delta
Ceil   14.1ns ± 0%   3.0ns ± 0%  -78.89%  (p=0.000 n=10+10)
Floor  6.42ns ± 0%  3.03ns ± 0%  -52.80%  (p=0.000 n=10+10)
Trunc  6.67ns ± 0%  3.03ns ± 0%  -54.57%   (p=0.000 n=10+9)

Change-Id: I3b416f6d0bccaaa9b547de86356471365862399c
Reviewed-on: https://go-review.googlesource.com/27827
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This commit is contained in:
Michael Munday 2016-08-26 11:39:47 -04:00
parent d2dd0dfda8
commit 9f7ea61674
2 changed files with 26 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
src/math/floor_s390x.s Normal file
View File

@ -0,0 +1,26 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "textflag.h"
// func Floor(x float64) float64
TEXT ·Floor(SB),NOSPLIT,$0
FMOVD x+0(FP), F0
FIDBR $7, F0, F0
FMOVD F0, ret+8(FP)
RET
// func Ceil(x float64) float64
TEXT ·Ceil(SB),NOSPLIT,$0
FMOVD x+0(FP), F0
FIDBR $6, F0, F0
FMOVD F0, ret+8(FP)
RET
// func Trunc(x float64) float64
TEXT ·Trunc(SB),NOSPLIT,$0
FMOVD x+0(FP), F0
FIDBR $5, F0, F0
FMOVD F0, ret+8(FP)
RET

9
src/math/stubs_s390x.s
View File

@ -25,15 +25,6 @@ TEXT ·Expm1(SB),NOSPLIT,$0
TEXT ·Exp(SB),NOSPLIT,$0
BR ·exp(SB)
TEXT ·Floor(SB),NOSPLIT,$0
BR ·floor(SB)
TEXT ·Ceil(SB),NOSPLIT,$0
BR ·ceil(SB)
TEXT ·Trunc(SB),NOSPLIT,$0
BR ·trunc(SB)
TEXT ·Frexp(SB),NOSPLIT,$0
BR ·frexp(SB)