1/* Compute the hypothenuse of X and Y. 2 Copyright (C) 1998 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, write to the Free 18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 19 02111-1307 USA. */ 20 21#include <sysdep.h> 22 23 .text 24ENTRY(__ieee754_hypot) 25 fldl 4(%esp) // x 26 fxam 27 fnstsw 28 fldl 12(%esp) // y : x 29 movb %ah, %ch 30 fxam 31 fnstsw 32 movb %ah, %al 33 orb %ch, %ah 34 sahf 35 jc 1f 36 fmul %st(0) // y * y : x 37 fxch // x : y * y 38 fmul %st(0) // x * x : y * y 39 faddp // x * x + y * y 40 fsqrt 412: ret 42 43 // We have to test whether any of the parameters is Inf. 44 // In this case the result is infinity. 451: andb $0x45, %al 46 cmpb $5, %al 47 je 3f // jump if y is Inf 48 andb $0x45, %ch 49 cmpb $5, %ch 50 jne 4f // jump if x is not Inf 51 fxch 523: fstp %st(1) 53 fabs 54 jmp 2b 55 564: testb $1, %al 57 jnz 5f // y is NaN 58 fxch 595: fstp %st(1) 60 jmp 2b 61 62END(__ieee754_hypot) 63