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" 32 .weak __expm1l 33 .type __expm1l,@function 34 35 .data 36 .align 16 37ln2_hi: .4byte 0xd1d00000, 0xb17217f7, 0x3ffe, 0x0 38ln2_lo: .4byte 0x4c67fc0d, 0x8654361c, 0xbfce, 0x0 39 40 ENTRY(expm1l) 41 movl 16(%rsp),%ecx # cx <--sign&bexp(x) 42 movl %ecx,%eax # ax <--sign&bexp(x) 43 andl $0x7fff,%ecx # ecx <-- zero_xtnd(bexp(x)) 44 cmpl $0x3ffe,%ecx # Is |x| < ln(2)? 45 jb .shortcut # If so, take a shortcut. 46 je .check_tail # |x| may be only slightly < ln(2) 47.general_case: # Here, |x| > ln(2) or x is NaN 48 cmpl $0x7fff,%ecx # bexp(|x|) = bexp(INF)? 49 je .not_finite # if so, x is not finite 50 andl $0xffff,%eax # eax <-- sign&bexp(x) 51 cmpl $0xc006,%eax # x <= -128? 52 jae 1f # if so, simply return -1 53 cmpl $0x400d,%ecx # |x| < 16384 = 2^14? 54 jb .finite_non_special # if so, proceed with argument reduction 55 fldt 8(%rsp) # x >= 16384; x 56 fld1 # 1, x 57 fscale # +Inf, x 58 fstp %st(1) # +Inf 59 ret 60 61.finite_non_special: # -128 < x < -ln(2) || ln(2) < x < 2^14 62 fldt 8(%rsp) # x 63 fld %st(0) # x, x 64 fldl2e # log2(e), x, x 65 fmulp # z := x*log2(e), x 66 frndint # [z], x 67 fst %st(2) # [z], x, [z] 68#ifdef PIC /* PIC-L macro */ 69 fldt ln2_hi(%rip) # ln2_hi, [z], x, [z] 70#else 71 fldt ln2_hi # ln2_hi, [z], x, [z] 72#endif 73 fmulp # [z]*ln2_hi, x, [z] 74 fsubrp %st,%st(1) # x-[z]*ln2_hi, [z] 75#ifdef PIC /* PIC-L macro */ 76 fldt ln2_lo(%rip) # ln2_lo, x-[z]*ln2_hi, [z] 77#else 78 fldt ln2_lo # ln2_lo, x-[z]*ln2_hi, [z] 79#endif 80 fmulp %st,%st(2) # [z]*ln2_lo, x-[z]*ln2_hi, [z] 81 fsubrp %st,%st(1) # r := x-[z]*ln(2), [z] 82 fldl2e # log2(e), r, [z] 83 fmulp # f := r*log2(e), [z] 84 f2xm1 # 2^f-1,[z] 85 fld1 # 1, 2^f-1, [z] 86 faddp %st,%st(1) # 2^f, [z] 87 fscale # e^x, [z] 88 fstp %st(1) # e^x 89 fld1 # 1, e^x 90 fsubrp %st,%st(1) # e^x-1 91 ret 92 93.check_tail: 94 movl 12(%rsp),%ecx # ecx <-- hi_32(sgnfcnd(x)) 95 cmpl $0xb17217f7,%ecx # Is |x| < ln(2)? 96 ja .finite_non_special 97 jb .shortcut 98 movl 8(%rsp),%edx # edx <-- lo_32(x) 99 cmpl $0xd1cf79ab,%edx # Is |x| slightly < ln(2)? 100 ja .finite_non_special # branch if |x| slightly > ln(2) 101.shortcut: 102 # Here, |x| < ln(2), so |z| = |x/ln(2)| < 1, 103 # whence z is in f2xm1's domain. 104 fldt 8(%rsp) # x 105 fldl2e # log2(e), x 106 fmulp # z := x*log2(e) 107 f2xm1 # 2^(x*log2(e))-1 = e^x-1 108 ret 109 110.not_finite: 111 movl 12(%rsp),%ecx # ecx <-- hi_32(sgnfcnd(x)) 112 cmpl $0x80000000,%ecx # hi_32(|x|) = hi_32(INF)? 113 jne .NaN_or_pinf # if not, x is NaN 114 movl 8(%rsp),%edx # edx <-- lo_32(x) 115 cmpl $0,%edx # lo_32(x) = 0? 116 jne .NaN_or_pinf # if not, x is NaN 117 movl 16(%rsp),%eax # ax <-- sign&bexp((x)) 118 andl $0x8000,%eax # here, x is infinite, but +/-? 119 jz .NaN_or_pinf # branch if x = +INF 1201: 121 fld1 # Here, x = -inf, so return -1 122 fchs 123 ret 124 125.NaN_or_pinf: 126 # Here, x = NaN or +inf, so load x and return immediately. 127 fldt 8(%rsp) 128 ret 129 .align 16 130 SET_SIZE(expm1l) 131 .section .note.GNU-stack,"",%progbits 132