1/* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34#if defined(LIBC_SCCS) && !defined(lint) 35 /*.asciz "@(#)ldexp.s 8.1 (Berkeley) 6/4/93" */ 36 .asciz "$NetBSD: ldexp.S,v 1.5 2002/02/24 01:06:19 matt Exp $" 37#endif /* LIBC_SCCS and not lint */ 38 39/* 40 * double ldexp (value, exp) 41 * double value; 42 * int exp; 43 * 44 * Ldexp returns value*2**exp, if that result is in range. 45 * If underflow occurs, it returns zero. If overflow occurs, 46 * it returns a value of appropriate sign and largest 47 * possible magnitude. In case of either overflow or underflow, 48 * errno is set to ERANGE. Note that errno is not modified if 49 * no error occurs. 50 */ 51 52#include "DEFS.h" 53 54/* 55 * don't include errno.h, ANSI C says it defines errno. 56 * 57 * #include <errno.h> 58 */ 59#define ERANGE 34 60 61 .globl _C_LABEL(errno) 62 63ENTRY(ldexp, 0) 64 movd 4(%ap),%r0 /* fetch "value" */ 65 extzv $7,$8,%r0,%r2 /* %r2 := biased exponent */ 66 jeql 1f /* if zero, done */ 67 68 addl2 12(%ap),%r2 /* %r2 := new biased exponent */ 69 jleq 2f /* if <= 0, underflow */ 70 cmpl %r2,$256 /* otherwise check if too big */ 71 jgeq 3f /* jump if overflow */ 72 insv %r2,$7,$8,%r0 /* put exponent back in result */ 731: 74 ret 752: 76 clrd %r0 77 jbr 1f 783: 79 movd huge,%r0 /* largest possible floating magnitude */ 80 jbc $15,4(%ap),1f /* jump if argument was positive */ 81 mnegd %r0,%r0 /* if arg < 0, make result negative */ 821: 83#ifdef _REENTRANT 84 pushl %r0 85 calls $0,_C_LABEL(__errno) 86 movl $ ERANGE,(%r0) 87 movl (%sp)+,%r0 88#else 89 movl $ ERANGE,_C_LABEL(errno) 90#endif 91 ret 92 93 .data 94huge: .word 0x7fff /* the largest number that can */ 95 .word 0xffff /* be represented in a long floating */ 96 .word 0xffff /* number. This is given in hex in order */ 97 .word 0xffff /* to avoid floating conversions */ 98