| 1 | /** |
| 2 | * This file has no copyright assigned and is placed in the Public Domain. |
| 3 | * This file is part of the mingw-w64 runtime package. |
| 4 | * No warranty is given; refer to the file DISCLAIMER.PD within this package. |
| 5 | */ |
| 6 | /* |
| 7 | * Written by J.T. Conklin <jtc@netbsd.org>. |
| 8 | * Public domain. |
| 9 | * Adapted for long double type by Danny Smith <dannysmith@users.sourceforge.net>. |
| 10 | */ |
| 11 | |
| 12 | /* asin = atan (x / sqrt(1 - x^2)) */ |
| 13 | long double asinl (long double x); |
| 14 | |
| 15 | long double asinl (long double x) |
| 16 | { |
| 17 | long double res = 0.0L; |
| 18 | |
| 19 | asm volatile ( |
| 20 | 	"fld	%%st\n\t" |
| 21 | 	"fmul	%%st(0)\n\t"			/* x^2 */ |
| 22 | 	"fld1\n\t" |
| 23 | 	"fsubp\n\t"				/* 1 - x^2 */ |
| 24 | 	"fsqrt\n\t"				/* sqrt (1 - x^2) */ |
| 25 | 	"fpatan" |
| 26 | 	: "=t" (res) : "0" (x) : "st(1)"); |
| 27 | return res; |
| 28 | } |