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 2006 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 4 35lt2_hi: .long 0xfbd00000, 0x9a209a84, 0x00003ffd 36lt2_lo: .long 0x653f4837, 0x8677076a, 0x0000bfc9 37 38 ENTRY(exp10l) 39 movl 12(%esp),%ecx / cx <--sign&bexp(x) 40 andl $0x00007fff,%ecx / ecx <-- zero_xtnd(bexp(x)) 41 cmpl $0x00003ffd,%ecx / Is |x| < log10(2)? 42 jb .shortcut / If so, take a shortcut. 43 je .check_tail / maybe |x| only slightly < log10(2) 44 cmpl $0x00007fff,%ecx / bexp(|x|) = bexp(INF)? 45 je .not_finite / if so, x is not finite 46 cmpl $0x0000400e,%ecx / |x| < 32768 = 2^15? 47 jb .finite_non_special / if so, proceed with argument reduction 48 fldt 4(%esp) / x 49 fld1 / 1, x 50 jmp 1f 51.finite_non_special: / Here, log10(2) < |x| < 2^15 52 fldt 4(%esp) / x 53 fld %st(0) / x, x 54 fldl2t / log2(10), x, x 55 fmulp / z := x*log2(10), x 56 frndint / [z], x 57 fst %st(2) / [z], x, [z] 58 PIC_SETUP(1) 59 fldt PIC_L(lt2_hi) / lt2_hi, [z], x, [z] 60 fmulp / [z]*lt2_hi, x, [z] 61 fsubrp %st,%st(1) / x-[z]*lt2_hi, [z] 62 fldt PIC_L(lt2_lo) / lt2_lo, x-[z]*lt2_hi, [z] 63 PIC_WRAPUP 64 fmul %st(2),%st / [z]*lt2_lo, x-[z]*lt2_hi, [z] 65 fsubrp %st,%st(1) / r := x-[z]*log10(2), [z] 66 fldl2t / log2(10), r, [z] 67 fmulp / f := r*log2(10), [z] 68 f2xm1 / 2^f-1,[z] 69 fld1 / 1, 2^f-1, [z] 70 faddp %st,%st(1) / 2^f, [z] 711: 72 fscale / 10^x, [z] 73 fstp %st(1) 74 ret 75 76.check_tail: 77 movl 8(%esp),%ecx / ecx <-- hi_32(sgnfcnd(x)) 78 cmpl $0x9a209a84,%ecx / Is |x| < log10(2)? 79 ja .finite_non_special 80 jb .shortcut 81 movl 4(%esp),%edx / edx <-- lo_32(sgnfcnd(x)) 82 cmpl $0xfbcff798,%edx / Is |x| slightly > log10(2)? 83 ja .finite_non_special / branch if |x| slightly > log10(2) 84.shortcut: 85 / Here, |x| < log10(2), so |z| = |x/log10(2)| < 1 86 / whence z is in f2xm1's domain. 87 fldt 4(%esp) / x 88 fldl2t / log2(10), x 89 fmulp / z := x*log2(10) 90 f2xm1 / 2^z-1 91 fld1 / 1, 2^z-1 92 faddp %st,%st(1) / 10^x 93 ret 94 95.not_finite: 96 movl 8(%esp),%ecx / ecx <-- hi_32(sgnfcnd(x)) 97 cmpl $0x80000000,%ecx / hi_32(sgnfcnd(x)) = hi_32(sgnfcnd(INF))? 98 jne .NaN_or_pinf / if not, x is NaN or unsupp. 99 movl 4(%esp),%edx / edx <-- lo_32(sgnfcnd(x)) 100 cmpl $0,%edx / lo_32(sgnfcnd(x)) = 0? 101 jne .NaN_or_pinf / if not, x is NaN 102 movl 12(%esp),%eax / ax <-- sign&bexp((x)) 103 andl $0x00008000,%eax / here, x is infinite, but +/-? 104 jz .NaN_or_pinf / branch if x = +INF 105 fldz / Here, x = -inf, so return 0 106 ret 107 108.NaN_or_pinf: 109 / Here, x = NaN or +inf, so load x and return immediately. 110 fldt 4(%esp) 111 ret 112 .align 4 113 SET_SIZE(exp10l) 114