n_scalbn.S revision 1.6
11.1Smatt/*- 21.1Smatt * Copyright (c) 2011 The NetBSD Foundation, Inc. 31.1Smatt * All rights reserved. 41.1Smatt * 51.1Smatt * This code is derived from software contributed to The NetBSD Foundation 61.1Smatt * by Matt Thomas of 3am Software Foundry. 71.1Smatt * 81.1Smatt * Redistribution and use in source and binary forms, with or without 91.1Smatt * modification, are permitted provided that the following conditions 101.1Smatt * are met: 111.1Smatt * 1. Redistributions of source code must retain the above copyright 121.1Smatt * notice, this list of conditions and the following disclaimer. 131.1Smatt * 2. Redistributions in binary form must reproduce the above copyright 141.1Smatt * notice, this list of conditions and the following disclaimer in the 151.1Smatt * documentation and/or other materials provided with the distribution. 161.1Smatt * 171.1Smatt * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 181.1Smatt * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 191.1Smatt * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 201.1Smatt * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 211.1Smatt * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 221.1Smatt * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 231.1Smatt * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 241.1Smatt * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 251.1Smatt * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 261.1Smatt * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 271.1Smatt * POSSIBILITY OF SUCH DAMAGE. 281.1Smatt */ 291.1Smatt 301.1Smatt#include <machine/asm.h> 311.1Smatt#include <sys/errno.h> 321.1Smatt 331.6SandvarRCSID("$NetBSD: n_scalbn.S,v 1.6 2022/04/04 19:33:44 andvar Exp $") 341.2Sjoerg 351.4SmartinWEAK_ALIAS(scalbn,_scalbn) 361.5SmartinWEAK_ALIAS(scalbnl,_scalbnl) 371.5SmartinWEAK_ALIAS(scalbnf,_scalbnf) 381.3SmlelstvWEAK_ALIAS(ldexp,_scalbn) 391.3SmlelstvWEAK_ALIAS(ldexpf,_scalbnf) 401.3SmlelstvWEAK_ALIAS(ldexpl,_scalbnl) 411.1Smatt 421.4SmartinENTRY(_scalbnf, 0) 431.1Smatt cvtfd 4(%ap), %r0 441.1Smatt movl 8(%ap), %r2 451.1Smatt jr 1f 461.1Smatt 471.4SmartinALTENTRY(_scalbnl) 481.4SmartinENTRY(_scalbn, 0) 491.1Smatt movd 4(%ap), %r0 501.1Smatt movl 12(%ap), %r2 511.1Smatt 521.1Smatt /* 531.1Smatt * First see if the result will be within bounds 541.1Smatt */ 551.1Smatt1: cmpl %r2,$(256+55) 561.1Smatt jgeq overflow 571.1Smatt cmpl %r2,$-(256+55) 581.1Smatt jleq underflow 591.1Smatt 601.1Smatt extzv $7, $9, %r0, %r3 /* extract exponent */ 611.1Smatt jneq 5f /* 0 * N is still 0 */ 621.1Smatt cmpw %r3, $-256 /* is this a NAN? */ 631.1Smatt jgtr 2f /* nope */ 641.1Smatt ret 651.1Smatt 661.1Smatt2: movzbl %r3, %r3 /* clear sign bit */ 671.1Smatt addl2 %r2, %r3 /* add to exponent */ 681.1Smatt jleq underflow /* <= 0? */ 691.1Smatt 701.1Smatt3: jbs $8, %r3, overflow /* did exponent overflow? */ 711.1Smatt insv $7, $8, %r3, %r0 /* replace exponent */ 721.1Smatt ret 731.1Smatt 741.1Smattunderflow: 751.1Smatt clrq %r0 /* return 0.0 */ 761.6Sandvar jr copysign /* or maybe -0.0 */ 771.1Smattoverflow: 781.1Smatt pushl $ERANGE /* overflow */ 791.1Smatt calls $1, _C_LABEL(infnan) /* possibly signal */ 801.1Smattcopysign: 811.1Smatt jbc $15, 4(%ap), 5f /* if clear, don't set sign-bit */ 821.1Smatt bisw2 $0x8000, %r0 /* preserve sign-bit */ 831.1Smatt5: 841.1Smatt ret 85