| 1 | ; $Id: logl.asm 98103 2023-01-17 14:15:46Z vboxsync $
|
|---|
| 2 | ;; @file
|
|---|
| 3 | ; IPRT - No-CRT logl - AMD64 & X86.
|
|---|
| 4 | ;
|
|---|
| 5 |
|
|---|
| 6 | ;
|
|---|
| 7 | ; Copyright (C) 2006-2023 Oracle and/or its affiliates.
|
|---|
| 8 | ;
|
|---|
| 9 | ; This file is part of VirtualBox base platform packages, as
|
|---|
| 10 | ; available from https://www.virtualbox.org.
|
|---|
| 11 | ;
|
|---|
| 12 | ; This program is free software; you can redistribute it and/or
|
|---|
| 13 | ; modify it under the terms of the GNU General Public License
|
|---|
| 14 | ; as published by the Free Software Foundation, in version 3 of the
|
|---|
| 15 | ; License.
|
|---|
| 16 | ;
|
|---|
| 17 | ; This program is distributed in the hope that it will be useful, but
|
|---|
| 18 | ; WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 19 | ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|---|
| 20 | ; General Public License for more details.
|
|---|
| 21 | ;
|
|---|
| 22 | ; You should have received a copy of the GNU General Public License
|
|---|
| 23 | ; along with this program; if not, see <https://www.gnu.org/licenses>.
|
|---|
| 24 | ;
|
|---|
| 25 | ; The contents of this file may alternatively be used under the terms
|
|---|
| 26 | ; of the Common Development and Distribution License Version 1.0
|
|---|
| 27 | ; (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
|
|---|
| 28 | ; in the VirtualBox distribution, in which case the provisions of the
|
|---|
| 29 | ; CDDL are applicable instead of those of the GPL.
|
|---|
| 30 | ;
|
|---|
| 31 | ; You may elect to license modified versions of this file under the
|
|---|
| 32 | ; terms and conditions of either the GPL or the CDDL or both.
|
|---|
| 33 | ;
|
|---|
| 34 | ; SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
|
|---|
| 35 | ;
|
|---|
| 36 |
|
|---|
| 37 |
|
|---|
| 38 | %define RT_ASM_WITH_SEH64
|
|---|
| 39 | %include "iprt/asmdefs.mac"
|
|---|
| 40 | %include "iprt/x86.mac"
|
|---|
| 41 |
|
|---|
| 42 |
|
|---|
| 43 | BEGINCODE
|
|---|
| 44 |
|
|---|
| 45 | ;;
|
|---|
| 46 | ; compute the natural logarithm of lrd
|
|---|
| 47 | ; @returns st(0)
|
|---|
| 48 | ; @param lrd [rbp + xCB*2]
|
|---|
| 49 | RT_NOCRT_BEGINPROC logl
|
|---|
| 50 | push xBP
|
|---|
| 51 | SEH64_PUSH_xBP
|
|---|
| 52 | mov xBP, xSP
|
|---|
| 53 | SEH64_SET_FRAME_xBP 0
|
|---|
| 54 | SEH64_END_PROLOGUE
|
|---|
| 55 |
|
|---|
| 56 | fldln2 ; st0=log(2)
|
|---|
| 57 | fld tword [xBP + xCB*2] ; st1=log(2) st0=lrd
|
|---|
| 58 | fld st0 ; st1=log(2) st0=lrd st0=lrd
|
|---|
| 59 | fsub qword [.one xWrtRIP] ; st2=log(2) st1=lrd st0=lrd-1.0
|
|---|
| 60 | fld st0 ; st3=log(2) st2=lrd st1=lrd-1.0 st0=lrd-1.0
|
|---|
| 61 |
|
|---|
| 62 | fabs ; st3=log(2) st2=lrd st1=lrd-1.0 st0=abs(lrd-1.0)
|
|---|
| 63 | fcomp qword [.limit xWrtRIP] ; st2=log(2) st1=lrd st0=lrd-1.0
|
|---|
| 64 | fnstsw ax
|
|---|
| 65 | and eax, X86_FSW_C3 | X86_FSW_C2 | X86_FSW_C0
|
|---|
| 66 | jnz .use_st1
|
|---|
| 67 |
|
|---|
| 68 | fstp st0 ; st1=log(2) st0=lrd
|
|---|
| 69 | fyl2x ; log(lrd)
|
|---|
| 70 | jmp .done
|
|---|
| 71 |
|
|---|
| 72 | .use_st1:
|
|---|
| 73 | fstp st1 ; st1=log(2) st0=lrd-1.0
|
|---|
| 74 | fyl2xp1 ; log(lrd)
|
|---|
| 75 |
|
|---|
| 76 | .done:
|
|---|
| 77 | leave
|
|---|
| 78 | ret
|
|---|
| 79 |
|
|---|
| 80 | ALIGNCODE(8)
|
|---|
| 81 | .one: dq 1.0
|
|---|
| 82 | .limit: dq 0.29
|
|---|
| 83 | ENDPROC RT_NOCRT(logl)
|
|---|
| 84 |
|
|---|
