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 "exp10l.s" 30 31#include "libm.h" 32 33 .data 34 .align 16 35lt2_hi: .4byte 0xfbd00000, 0x9a209a84, 0x3ffd, 0x0 36lt2_lo: .4byte 0x653f4837, 0x8677076a, 0xbfc9, 0x0 37 38 ENTRY(exp10l) 39 movl 16(%rsp),%ecx / cx <--sign&bexp(x) 40 andl $0x7fff,%ecx / ecx <-- zero_xtnd(bexp(x)) 41 cmpl $0x3ffd,%ecx / Is |x| < log10(2)? 42 jb .shortcut / If so, take a shortcut. 43 je .check_tail / maybe |x| only slightly < log10(2) 44.general_case: / Here, |x| > log10(2) or x is NaN 45 cmpl $0x7fff,%ecx / bexp(|x|) = bexp(INF)? 46 je .not_finite / if so, x is not finite 47 cmpl $0x400e,%ecx / |x| < 32768 = 2^15? 48 jb .finite_non_special / if so, proceed with argument reduction 49 fldt 8(%rsp) / x 50 fld1 / 1, x 51 jmp 1f 52.finite_non_special: / Here, log10(2) < |x| < 2^15 53 fldt 8(%rsp) / x 54 fld %st(0) / x, x 55 fldl2t / log2(10), x, x 56 fmulp / z := x*log2(10), x 57 frndint / [z], x 58 fst %st(2) / [z], x, [z] 59 PIC_SETUP(1) 60 fldt PIC_L(lt2_hi) / lt2_hi, [z], x, [z] 61 fmulp / [z]*lt2_hi, x, [z] 62 fsubrp %st,%st(1) / x-[z]*lt2_hi, [z] 63 fldt PIC_L(lt2_lo) / lt2_lo, x-[z]*lt2_hi, [z] 64 PIC_WRAPUP 65 fmul %st(2),%st / [z]*lt2_lo, x-[z]*lt2_hi, [z] 66 fsubrp %st,%st(1) / r := x-[z]*log10(2), [z] 67 fldl2t / log2(10), r, [z] 68 fmulp / f := r*log2(10), [z] 69 f2xm1 / 2^f-1,[z] 70 fld1 / 1, 2^f-1, [z] 71 faddp %st,%st(1) / 2^f, [z] 721: 73 fscale / 10^x, [z] 74 fstp %st(1) 75 ret 76 77.check_tail: 78 movl 12(%rsp),%ecx / ecx <-- hi_32(sgnfcnd(x)) 79 cmpl $0x9a209a84,%ecx / Is |x| < log10(2)? 80 ja .finite_non_special 81 jb .shortcut 82 movl 8(%rsp),%edx / edx <-- lo_32(sgnfcnd(x)) 83 cmpl $0xfbcff798,%edx / Is |x| slightly > log10(2)? 84 ja .finite_non_special / branch if |x| slightly > log10(2) 85.shortcut: 86 / Here, |x| < log10(2), so |z| = |x/log10(2)| < 1 87 / whence z is in f2xm1's domain. 88 fldt 8(%rsp) / x 89 fldl2t / log2(10), x 90 fmulp / z := x*log2(10) 91 f2xm1 / 2^z-1 92 fld1 / 1, 2^z-1 93 faddp %st,%st(1) / 10^x 94 ret 95 96.not_finite: 97 movl 12(%rsp),%ecx / ecx <-- hi_32(sgnfcnd(x)) 98 cmpl $0x80000000,%ecx / hi_32(sgnfcnd(x)) = hi_32(sgnfcnd(INF))? 99 jne .NaN_or_pinf / if not, x is NaN or unsupp. 100 movl 8(%rsp),%edx / edx <-- lo_32(sgnfcnd(x)) 101 cmpl $0,%edx / lo_32(sgnfcnd(x)) = 0? 102 jne .NaN_or_pinf / if not, x is NaN 103 movl 16(%rsp),%eax / ax <-- sign&bexp((x)) 104 andl $0x8000,%eax / here, x is infinite, but +/-? 105 jz .NaN_or_pinf / branch if x = +INF 106 fldz / Here, x = -inf, so return 0 107 ret 108 109.NaN_or_pinf: 110 / Here, x = NaN or +inf, so load x and return immediately. 111 fldt 8(%rsp) 112 ret 113 .align 16 114 SET_SIZE(exp10l) 115