1 // Copyright 2010 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 #include "textflag.h" 6 7 // func Asin(x float64) float64 8 TEXT Asin(SB),NOSPLIT,$0 9 FMOVD x+0(FP), F0 // F0=sin(x) 10 FMOVD F0, F1 // F0=sin(x), F1=sin(x) 11 FMULD F0, F0 // F0=sin(x)*sin(x), F1=sin(x) 12 FLD1 // F0=1, F1=sin(x)*sin(x), F2=sin(x) 13 FSUBRDP F0, F1 // F0=1-sin(x)*sin(x) (=cos(x)*cos(x)), F1=sin(x) 14 FSQRT // F0=cos(x), F1=sin(x) 15 FPATAN // F0=arcsin(sin(x))=x 16 FMOVDP F0, ret+8(FP) 17 RET 18 19 // func Acos(x float64) float64 20 TEXT Acos(SB),NOSPLIT,$0 21 FMOVD x+0(FP), F0 // F0=cos(x) 22 FMOVD F0, F1 // F0=cos(x), F1=cos(x) 23 FMULD F0, F0 // F0=cos(x)*cos(x), F1=cos(x) 24 FLD1 // F0=1, F1=cos(x)*cos(x), F2=cos(x) 25 FSUBRDP F0, F1 // F0=1-cos(x)*cos(x) (=sin(x)*sin(x)), F1=cos(x) 26 FSQRT // F0=sin(x), F1=cos(x) 27 FXCHD F0, F1 // F0=cos(x), F1=sin(x) 28 FPATAN // F0=arccos(cos(x))=x 29 FMOVDP F0, ret+8(FP) 30 RET 31
