125c28e83SPiotr Jasiukajtis/* 225c28e83SPiotr Jasiukajtis * CDDL HEADER START 325c28e83SPiotr Jasiukajtis * 425c28e83SPiotr Jasiukajtis * The contents of this file are subject to the terms of the 525c28e83SPiotr Jasiukajtis * Common Development and Distribution License (the "License"). 625c28e83SPiotr Jasiukajtis * You may not use this file except in compliance with the License. 725c28e83SPiotr Jasiukajtis * 825c28e83SPiotr Jasiukajtis * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 925c28e83SPiotr Jasiukajtis * or http://www.opensolaris.org/os/licensing. 1025c28e83SPiotr Jasiukajtis * See the License for the specific language governing permissions 1125c28e83SPiotr Jasiukajtis * and limitations under the License. 1225c28e83SPiotr Jasiukajtis * 1325c28e83SPiotr Jasiukajtis * When distributing Covered Code, include this CDDL HEADER in each 1425c28e83SPiotr Jasiukajtis * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 1525c28e83SPiotr Jasiukajtis * If applicable, add the following below this CDDL HEADER, with the 1625c28e83SPiotr Jasiukajtis * fields enclosed by brackets "[]" replaced with your own identifying 1725c28e83SPiotr Jasiukajtis * information: Portions Copyright [yyyy] [name of copyright owner] 1825c28e83SPiotr Jasiukajtis * 1925c28e83SPiotr Jasiukajtis * CDDL HEADER END 2025c28e83SPiotr Jasiukajtis */ 2125c28e83SPiotr Jasiukajtis/* 2225c28e83SPiotr Jasiukajtis * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 2325c28e83SPiotr Jasiukajtis */ 2425c28e83SPiotr Jasiukajtis/* 2525c28e83SPiotr Jasiukajtis * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 2625c28e83SPiotr Jasiukajtis * Use is subject to license terms. 2725c28e83SPiotr Jasiukajtis */ 2825c28e83SPiotr Jasiukajtis 2925c28e83SPiotr Jasiukajtis .file "ilogb.s" 3025c28e83SPiotr Jasiukajtis 3125c28e83SPiotr Jasiukajtis#include "libm.h" 3225c28e83SPiotr JasiukajtisLIBM_ANSI_PRAGMA_WEAK(ilogb,function) 3325c28e83SPiotr Jasiukajtis#include "xpg6.h" 3425c28e83SPiotr Jasiukajtis 3525c28e83SPiotr Jasiukajtis .data 3625c28e83SPiotr Jasiukajtis .align 8 3725c28e83SPiotr Jasiukajtistwo52: .long 0x0,0x43300000 / 2**52 3825c28e83SPiotr Jasiukajtis 3925c28e83SPiotr Jasiukajtis ENTRY(ilogb) 4025c28e83SPiotr Jasiukajtis movl 8(%esp),%eax / eax <-- hi_32(x) 4125c28e83SPiotr Jasiukajtis andl $0x7fffffff,%eax / eax <-- hi_32(abs(x)) 4225c28e83SPiotr Jasiukajtis testl $0x7ff00000,%eax / is bexp(x) 0? 4325c28e83SPiotr Jasiukajtis jz .bexp_0 / jump if x is 0 or subnormal 4425c28e83SPiotr Jasiukajtis / biased exponent is non-zero 4525c28e83SPiotr Jasiukajtis cmpl $0x7ff00000,%eax / is bexp(x) 0x7ff? 4625c28e83SPiotr Jasiukajtis jae .bexp_all_1 / jump if x is NaN or Inf 4725c28e83SPiotr Jasiukajtis shrl $20,%eax / eax <-- bexp(x) 4825c28e83SPiotr Jasiukajtis subl $1023,%eax / unbias exponent by 1023 4925c28e83SPiotr Jasiukajtis ret 5025c28e83SPiotr Jasiukajtis 5125c28e83SPiotr Jasiukajtis.bexp_all_1: 5225c28e83SPiotr Jasiukajtis movl $0x7fffffff,%eax / x is NaN or inf, so return 0x7fffffff 5325c28e83SPiotr Jasiukajtis jmp 0f 5425c28e83SPiotr Jasiukajtis 5525c28e83SPiotr Jasiukajtis.bexp_0: 5625c28e83SPiotr Jasiukajtis orl 4(%esp),%eax / test whether x is 0 5725c28e83SPiotr Jasiukajtis jnz .ilogb_subnorm 5825c28e83SPiotr Jasiukajtis movl $0x80000001,%eax / x is +/-0, so return 0x80000001 5925c28e83SPiotr Jasiukajtis0: 6025c28e83SPiotr Jasiukajtis PIC_SETUP(0) 6125c28e83SPiotr Jasiukajtis PIC_G_LOAD(movzwl,__xpg6,ecx) 6225c28e83SPiotr Jasiukajtis PIC_WRAPUP 6325c28e83SPiotr Jasiukajtis andl $_C99SUSv3_ilogb_0InfNaN_raises_invalid,%ecx 6425c28e83SPiotr Jasiukajtis cmpl $0,%ecx 6525c28e83SPiotr Jasiukajtis je 1f 6625c28e83SPiotr Jasiukajtis fldz 6725c28e83SPiotr Jasiukajtis fdivp %st,%st(0) / raise invalid as per SUSv3 6825c28e83SPiotr Jasiukajtis1: 6925c28e83SPiotr Jasiukajtis ret 7025c28e83SPiotr Jasiukajtis 7125c28e83SPiotr Jasiukajtis.ilogb_subnorm: / subnormal input 7225c28e83SPiotr Jasiukajtis fldl 4(%esp) / push x 7325c28e83SPiotr Jasiukajtis PIC_SETUP(1) 7425c28e83SPiotr Jasiukajtis fmull PIC_L(two52) / x*2**52 7525c28e83SPiotr Jasiukajtis PIC_WRAPUP 7625c28e83SPiotr Jasiukajtis subl $8,%esp / set up storage area 7725c28e83SPiotr Jasiukajtis fstpl (%esp) / store x*2**52 in storage are 7825c28e83SPiotr Jasiukajtis movl $0x7ff00000,%eax 7925c28e83SPiotr Jasiukajtis andl 4(%esp),%eax 8025c28e83SPiotr Jasiukajtis shrl $20,%eax / extract exponent of x*2**52 8125c28e83SPiotr Jasiukajtis subl $1075,%eax / unbias it by 1075 (= 1023 + 52) 8225c28e83SPiotr Jasiukajtis addl $8,%esp 8325c28e83SPiotr Jasiukajtis ret 8425c28e83SPiotr Jasiukajtis .align 4 8525c28e83SPiotr Jasiukajtis SET_SIZE(ilogb) 86