blob: 93df552dc922f63019f782c225be9104ca9cffe8 [file] [log] [blame]
// Copyright 2010 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.
// func Asin(x float64) float64
TEXT ·Asin(SB),7,$0
FMOVD x+0(FP), F0 // F0=sin(x)
FMOVD F0, F1 // F0=sin(x), F1=sin(x)
FMULD F0, F0 // F0=sin(x)*sin(x), F1=sin(x)
FLD1 // F0=1, F1=sin(x)*sin(x), F2=sin(x)
FSUBRDP F0, F1 // F0=1-sin(x)*sin(x) (=cos(x)*cos(x)), F1=sin(x)
FSQRT // F0=cos(x), F1=sin(x)
FPATAN // F0=arcsin(sin(x))=x
FMOVDP F0, r+8(FP)
// func Acos(x float64) float64
TEXT ·Acos(SB),7,$0
FMOVD x+0(FP), F0 // F0=cos(x)
FMOVD F0, F1 // F0=cos(x), F1=cos(x)
FMULD F0, F0 // F0=cos(x)*cos(x), F1=cos(x)
FLD1 // F0=1, F1=cos(x)*cos(x), F2=cos(x)
FSUBRDP F0, F1 // F0=1-cos(x)*cos(x) (=sin(x)*sin(x)), F1=cos(x)
FSQRT // F0=sin(x), F1=cos(x)
FXCHD F0, F1 // F0=cos(x), F1=sin(x)
FPATAN // F0=arccos(cos(x))=x
FMOVDP F0, r+8(FP)