1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21/* 22 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 23 */ 24/* 25 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 26 * Use is subject to license terms. 27 */ 28 29 .file "expm1l.s" 30 31#include "libm.h" 32LIBM_ANSI_PRAGMA_WEAK(expm1l,function) 33 34 .data 35 .align 16 36ln2_hi: .4byte 0xd1d00000, 0xb17217f7, 0x3ffe, 0x0 37ln2_lo: .4byte 0x4c67fc0d, 0x8654361c, 0xbfce, 0x0 38 39 ENTRY(expm1l) 40 movl 16(%rsp),%ecx / cx <--sign&bexp(x) 41 movl %ecx,%eax / ax <--sign&bexp(x) 42 andl $0x7fff,%ecx / ecx <-- zero_xtnd(bexp(x)) 43 cmpl $0x3ffe,%ecx / Is |x| < ln(2)? 44 jb .shortcut / If so, take a shortcut. 45 je .check_tail / |x| may be only slightly < ln(2) 46.general_case: / Here, |x| > ln(2) or x is NaN 47 cmpl $0x7fff,%ecx / bexp(|x|) = bexp(INF)? 48 je .not_finite / if so, x is not finite 49 andl $0xffff,%eax / eax <-- sign&bexp(x) 50 cmpl $0xc006,%eax / x <= -128? 51 jae 1f / if so, simply return -1 52 cmpl $0x400d,%ecx / |x| < 16384 = 2^14? 53 jb .finite_non_special / if so, proceed with argument reduction 54 fldt 8(%rsp) / x >= 16384; x 55 fld1 / 1, x 56 fscale / +Inf, x 57 fstp %st(1) / +Inf 58 ret 59 60.finite_non_special: / -128 < x < -ln(2) || ln(2) < x < 2^14 61 fldt 8(%rsp) / x 62 fld %st(0) / x, x 63 fldl2e / log2(e), x, x 64 fmulp / z := x*log2(e), x 65 frndint / [z], x 66 fst %st(2) / [z], x, [z] 67 PIC_SETUP(1) 68 fldt PIC_L(ln2_hi) / ln2_hi, [z], x, [z] 69 fmulp / [z]*ln2_hi, x, [z] 70 fsubrp %st,%st(1) / x-[z]*ln2_hi, [z] 71 fldt PIC_L(ln2_lo) / ln2_lo, x-[z]*ln2_hi, [z] 72 PIC_WRAPUP 73 fmul %st(2),%st / [z]*ln2_lo, x-[z]*ln2_hi, [z] 74 fsubrp %st,%st(1) / r := x-[z]*ln(2), [z] 75 fldl2e / log2(e), r, [z] 76 fmulp / f := r*log2(e), [z] 77 f2xm1 / 2^f-1,[z] 78 fld1 / 1, 2^f-1, [z] 79 faddp %st,%st(1) / 2^f, [z] 80 fscale / e^x, [z] 81 fstp %st(1) / e^x 82 fld1 / 1, e^x 83 fsubrp %st,%st(1) / e^x-1 84 ret 85 86.check_tail: 87 movl 12(%rsp),%ecx / ecx <-- hi_32(sgnfcnd(x)) 88 cmpl $0xb17217f7,%ecx / Is |x| < ln(2)? 89 ja .finite_non_special 90 jb .shortcut 91 movl 8(%rsp),%edx / edx <-- lo_32(x) 92 cmpl $0xd1cf79ab,%edx / Is |x| slightly < ln(2)? 93 ja .finite_non_special / branch if |x| slightly > ln(2) 94.shortcut: 95 / Here, |x| < ln(2), so |z| = |x/ln(2)| < 1, 96 / whence z is in f2xm1's domain. 97 fldt 8(%rsp) / x 98 fldl2e / log2(e), x 99 fmulp / z := x*log2(e) 100 f2xm1 / 2^(x*log2(e))-1 = e^x-1 101 ret 102 103.not_finite: 104 movl 12(%rsp),%ecx / ecx <-- hi_32(sgnfcnd(x)) 105 cmpl $0x80000000,%ecx / hi_32(|x|) = hi_32(INF)? 106 jne .NaN_or_pinf / if not, x is NaN 107 movl 8(%rsp),%edx / edx <-- lo_32(x) 108 cmpl $0,%edx / lo_32(x) = 0? 109 jne .NaN_or_pinf / if not, x is NaN 110 movl 16(%rsp),%eax / ax <-- sign&bexp((x)) 111 andl $0x8000,%eax / here, x is infinite, but +/-? 112 jz .NaN_or_pinf / branch if x = +INF 1131: 114 fld1 / Here, x = -inf, so return -1 115 fchs 116 ret 117 118.NaN_or_pinf: 119 / Here, x = NaN or +inf, so load x and return immediately. 120 fldt 8(%rsp) 121 ret 122 .align 16 123 SET_SIZE(expm1l) 124