1*25c28e83SPiotr Jasiukajtis/* 2*25c28e83SPiotr Jasiukajtis * CDDL HEADER START 3*25c28e83SPiotr Jasiukajtis * 4*25c28e83SPiotr Jasiukajtis * The contents of this file are subject to the terms of the 5*25c28e83SPiotr Jasiukajtis * Common Development and Distribution License (the "License"). 6*25c28e83SPiotr Jasiukajtis * You may not use this file except in compliance with the License. 7*25c28e83SPiotr Jasiukajtis * 8*25c28e83SPiotr Jasiukajtis * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9*25c28e83SPiotr Jasiukajtis * or http://www.opensolaris.org/os/licensing. 10*25c28e83SPiotr Jasiukajtis * See the License for the specific language governing permissions 11*25c28e83SPiotr Jasiukajtis * and limitations under the License. 12*25c28e83SPiotr Jasiukajtis * 13*25c28e83SPiotr Jasiukajtis * When distributing Covered Code, include this CDDL HEADER in each 14*25c28e83SPiotr Jasiukajtis * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15*25c28e83SPiotr Jasiukajtis * If applicable, add the following below this CDDL HEADER, with the 16*25c28e83SPiotr Jasiukajtis * fields enclosed by brackets "[]" replaced with your own identifying 17*25c28e83SPiotr Jasiukajtis * information: Portions Copyright [yyyy] [name of copyright owner] 18*25c28e83SPiotr Jasiukajtis * 19*25c28e83SPiotr Jasiukajtis * CDDL HEADER END 20*25c28e83SPiotr Jasiukajtis */ 21*25c28e83SPiotr Jasiukajtis/* 22*25c28e83SPiotr Jasiukajtis * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 23*25c28e83SPiotr Jasiukajtis */ 24*25c28e83SPiotr Jasiukajtis/* 25*25c28e83SPiotr Jasiukajtis * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 26*25c28e83SPiotr Jasiukajtis * Use is subject to license terms. 27*25c28e83SPiotr Jasiukajtis */ 28*25c28e83SPiotr Jasiukajtis 29*25c28e83SPiotr Jasiukajtis .file "expl.s" 30*25c28e83SPiotr Jasiukajtis 31*25c28e83SPiotr Jasiukajtis#include "libm.h" 32*25c28e83SPiotr JasiukajtisLIBM_ANSI_PRAGMA_WEAK(expl,function) 33*25c28e83SPiotr Jasiukajtis 34*25c28e83SPiotr Jasiukajtis .data 35*25c28e83SPiotr Jasiukajtis .align 16 36*25c28e83SPiotr Jasiukajtisln2_hi: .4byte 0xd1d00000, 0xb17217f7, 0x3ffe, 0x0 37*25c28e83SPiotr Jasiukajtisln2_lo: .4byte 0x4c67fc0d, 0x8654361c, 0xbfce, 0x0 38*25c28e83SPiotr Jasiukajtis 39*25c28e83SPiotr Jasiukajtis ENTRY(expl) 40*25c28e83SPiotr Jasiukajtis movl 16(%rsp),%ecx / cx <--sign&bexp(x) 41*25c28e83SPiotr Jasiukajtis andl $0x7fff,%ecx / ecx <-- zero_xtnd(bexp(x)) 42*25c28e83SPiotr Jasiukajtis cmpl $0x3ffe,%ecx / Is |x| < 0.5? 43*25c28e83SPiotr Jasiukajtis jb 2f / If so, see which shortcut to take 44*25c28e83SPiotr Jasiukajtis je .check_tail / More checking if 0.5 <= |x| < 1 45*25c28e83SPiotr Jasiukajtis.general_case: / Here, |x| >= 1 or x is NaN 46*25c28e83SPiotr Jasiukajtis cmpl $0x7fff,%ecx / bexp(|x|) = bexp(INF)? 47*25c28e83SPiotr Jasiukajtis je .not_finite / if so, x is not finite 48*25c28e83SPiotr Jasiukajtis cmpl $0x400e,%ecx / |x| < 32768 = 2^15? 49*25c28e83SPiotr Jasiukajtis jb .finite_non_special / if so, proceed with argument reduction 50*25c28e83SPiotr Jasiukajtis fldt 8(%rsp) / x 51*25c28e83SPiotr Jasiukajtis fld1 / 1, x 52*25c28e83SPiotr Jasiukajtis jmp 1f 53*25c28e83SPiotr Jasiukajtis.finite_non_special: / Here, ln(2) < |x| < 2^15 54*25c28e83SPiotr Jasiukajtis fldt 8(%rsp) / x 55*25c28e83SPiotr Jasiukajtis fld %st(0) / x, x 56*25c28e83SPiotr Jasiukajtis fldl2e / log2(e), x, x 57*25c28e83SPiotr Jasiukajtis fmulp / z := x*log2(e), x 58*25c28e83SPiotr Jasiukajtis frndint / [z], x 59*25c28e83SPiotr Jasiukajtis fst %st(2) / [z], x, [z] 60*25c28e83SPiotr Jasiukajtis PIC_SETUP(1) 61*25c28e83SPiotr Jasiukajtis fldt PIC_L(ln2_hi) / ln2_hi, [z], x, [z] 62*25c28e83SPiotr Jasiukajtis fmulp / [z]*ln2_hi, x, [z] 63*25c28e83SPiotr Jasiukajtis fsubrp %st,%st(1) / x-[z]*ln2_hi, [z] 64*25c28e83SPiotr Jasiukajtis fldt PIC_L(ln2_lo) / ln2_lo, x-[z]*ln2_hi, [z] 65*25c28e83SPiotr Jasiukajtis PIC_WRAPUP 66*25c28e83SPiotr Jasiukajtis fmul %st(2),%st / [z]*ln2_lo, x-[z]*ln2_hi, [z] 67*25c28e83SPiotr Jasiukajtis fsubrp %st,%st(1) / r := x-[z]*ln(2), [z] 68*25c28e83SPiotr Jasiukajtis fldl2e / log2(e), r, [z] 69*25c28e83SPiotr Jasiukajtis fmulp / f := r*log2(e), [z] 70*25c28e83SPiotr Jasiukajtis f2xm1 / 2^f-1,[z] 71*25c28e83SPiotr Jasiukajtis fld1 / 1, 2^f-1, [z] 72*25c28e83SPiotr Jasiukajtis faddp %st,%st(1) / 2^f, [z] 73*25c28e83SPiotr Jasiukajtis1: 74*25c28e83SPiotr Jasiukajtis fscale / e^x, [z] 75*25c28e83SPiotr Jasiukajtis fstp %st(1) 76*25c28e83SPiotr Jasiukajtis ret 77*25c28e83SPiotr Jasiukajtis 78*25c28e83SPiotr Jasiukajtis2: / Here, |x| < 0.5 79*25c28e83SPiotr Jasiukajtis cmpl $0x3fbe,%ecx / Is |x| >= 2^-65? 80*25c28e83SPiotr Jasiukajtis jae .shortcut / If so, take a shortcut 81*25c28e83SPiotr Jasiukajtis fldt 8(%rsp) / x 82*25c28e83SPiotr Jasiukajtis fld1 / 1, x 83*25c28e83SPiotr Jasiukajtis faddp %st,%st(1) / 1+x (for inexact & directed rounding) 84*25c28e83SPiotr Jasiukajtis ret 85*25c28e83SPiotr Jasiukajtis 86*25c28e83SPiotr Jasiukajtis.check_tail: 87*25c28e83SPiotr Jasiukajtis movl 12(%rsp),%ecx / ecx <-- hi_32(sgnfcnd(x)) 88*25c28e83SPiotr Jasiukajtis cmpl $0xb17217f7,%ecx / Is |x| < ln(2)? 89*25c28e83SPiotr Jasiukajtis ja .finite_non_special 90*25c28e83SPiotr Jasiukajtis jb .shortcut 91*25c28e83SPiotr Jasiukajtis movl 8(%rsp),%edx / edx <-- lo_32(x) 92*25c28e83SPiotr Jasiukajtis cmpl $0xd1cf79ab,%edx / Is |x| slightly < ln(2)? 93*25c28e83SPiotr Jasiukajtis ja .finite_non_special / branch if |x| slightly > ln(2) 94*25c28e83SPiotr Jasiukajtis.shortcut: 95*25c28e83SPiotr Jasiukajtis / Here, |x| < ln(2), so |z| = |x/ln(2)| < 1, 96*25c28e83SPiotr Jasiukajtis / whence z is in f2xm1's domain. 97*25c28e83SPiotr Jasiukajtis fldt 8(%rsp) / x 98*25c28e83SPiotr Jasiukajtis fldl2e / log2(e), x 99*25c28e83SPiotr Jasiukajtis fmulp / x*log2(e) 100*25c28e83SPiotr Jasiukajtis f2xm1 / 2^(x*log2(e))-1 = e^x-1 101*25c28e83SPiotr Jasiukajtis fld1 / 1, e^x-1 102*25c28e83SPiotr Jasiukajtis faddp %st,%st(1) / e^x 103*25c28e83SPiotr Jasiukajtis ret 104*25c28e83SPiotr Jasiukajtis 105*25c28e83SPiotr Jasiukajtis.not_finite: 106*25c28e83SPiotr Jasiukajtis movl 12(%rsp),%ecx / ecx <-- hi_32(sgnfcnd(x)) 107*25c28e83SPiotr Jasiukajtis cmpl $0x80000000,%ecx / hi_32(|x|) = hi_32(INF)? 108*25c28e83SPiotr Jasiukajtis jne .NaN_or_pinf / if not, x is NaN 109*25c28e83SPiotr Jasiukajtis movl 8(%rsp),%edx / edx <-- lo_32(x) 110*25c28e83SPiotr Jasiukajtis cmpl $0,%edx / lo_32(x) = 0? 111*25c28e83SPiotr Jasiukajtis jne .NaN_or_pinf / if not, x is NaN 112*25c28e83SPiotr Jasiukajtis movl 16(%rsp),%eax / ax <-- sign&bexp((x)) 113*25c28e83SPiotr Jasiukajtis andl $0x8000,%eax / here, x is infinite, but +/-? 114*25c28e83SPiotr Jasiukajtis jz .NaN_or_pinf / branch if x = +INF 115*25c28e83SPiotr Jasiukajtis fldz / Here, x = -inf, so return 0 116*25c28e83SPiotr Jasiukajtis ret 117*25c28e83SPiotr Jasiukajtis 118*25c28e83SPiotr Jasiukajtis.NaN_or_pinf: 119*25c28e83SPiotr Jasiukajtis / Here, x = NaN or +inf, so load x and return immediately. 120*25c28e83SPiotr Jasiukajtis fldt 8(%rsp) 121*25c28e83SPiotr Jasiukajtis fadd %st(0),%st / quiet SNaN 122*25c28e83SPiotr Jasiukajtis ret 123*25c28e83SPiotr Jasiukajtis .align 16 124*25c28e83SPiotr Jasiukajtis SET_SIZE(expl) 125