1/*- 2 * Copyright (c) 2011 The NetBSD Foundation, Inc. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to The NetBSD Foundation 6 * by Matt Thomas of 3am Software Foundry. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30#include <machine/asm.h> 31#include <sys/errno.h> 32 33RCSID("$NetBSD: n_scalbn.S,v 1.8 2024/05/07 15:15:31 riastradh Exp $") 34 35WEAK_ALIAS(scalbn,_scalbn) 36WEAK_ALIAS(scalbnl,_scalbnl) 37WEAK_ALIAS(scalbnf,_scalbnf) 38WEAK_ALIAS(ldexp,_scalbn) 39WEAK_ALIAS(ldexpf,_scalbnf) 40WEAK_ALIAS(ldexpl,_scalbnl) 41 42ENTRY(_scalbnf, 0) 43 cvtfd 4(%ap), %r0 44 movl 8(%ap), %r2 45 jr 1f 46END(_scalbnf) 47 48STRONG_ALIAS(_scalbnl, _scalbn) 49ENTRY(_scalbn, 0) 50 movd 4(%ap), %r0 51 movl 12(%ap), %r2 52 53 /* 54 * First see if the result will be within bounds 55 */ 561: cmpl %r2,$(256+55) 57 jgeq overflow 58 cmpl %r2,$-(256+55) 59 jleq underflow 60 61 extzv $7, $9, %r0, %r3 /* extract exponent */ 62 jneq 5f /* 0 * N is still 0 */ 63 cmpw %r3, $-256 /* is this a NAN? */ 64 jgtr 2f /* nope */ 65 ret 66 672: movzbl %r3, %r3 /* clear sign bit */ 68 addl2 %r2, %r3 /* add to exponent */ 69 jleq underflow /* <= 0? */ 70 713: jbs $8, %r3, overflow /* did exponent overflow? */ 72 insv $7, $8, %r3, %r0 /* replace exponent */ 73 ret 74 75underflow: 76 clrq %r0 /* return 0.0 */ 77 jr copysign /* or maybe -0.0 */ 78overflow: 79 pushl $ERANGE /* overflow */ 80 calls $1, _C_LABEL(infnan) /* possibly signal */ 81copysign: 82 jbc $15, 4(%ap), 5f /* if clear, don't set sign-bit */ 83 bisw2 $0x8000, %r0 /* preserve sign-bit */ 845: 85 ret 86END(_scalbn) 87