| 1 | ; $Id: logl.asm 96220 2022-08-15 13:03:25Z vboxsync $
|
|---|
| 2 | ;; @file
|
|---|
| 3 | ; IPRT - No-CRT logl - AMD64 & X86.
|
|---|
| 4 | ;
|
|---|
| 5 |
|
|---|
| 6 | ;
|
|---|
| 7 | ; Copyright (C) 2006-2022 Oracle Corporation
|
|---|
| 8 | ;
|
|---|
| 9 | ; This file is part of VirtualBox Open Source Edition (OSE), as
|
|---|
| 10 | ; available from http://www.virtualbox.org. This file is free software;
|
|---|
| 11 | ; you can redistribute it and/or modify it under the terms of the GNU
|
|---|
| 12 | ; General Public License (GPL) as published by the Free Software
|
|---|
| 13 | ; Foundation, in version 2 as it comes in the "COPYING" file of the
|
|---|
| 14 | ; VirtualBox OSE distribution. VirtualBox OSE is distributed in the
|
|---|
| 15 | ; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
|
|---|
| 16 | ;
|
|---|
| 17 | ; The contents of this file may alternatively be used under the terms
|
|---|
| 18 | ; of the Common Development and Distribution License Version 1.0
|
|---|
| 19 | ; (CDDL) only, as it comes in the "COPYING.CDDL" file of the
|
|---|
| 20 | ; VirtualBox OSE distribution, in which case the provisions of the
|
|---|
| 21 | ; CDDL are applicable instead of those of the GPL.
|
|---|
| 22 | ;
|
|---|
| 23 | ; You may elect to license modified versions of this file under the
|
|---|
| 24 | ; terms and conditions of either the GPL or the CDDL or both.
|
|---|
| 25 | ;
|
|---|
| 26 |
|
|---|
| 27 |
|
|---|
| 28 | %define RT_ASM_WITH_SEH64
|
|---|
| 29 | %include "iprt/asmdefs.mac"
|
|---|
| 30 | %include "iprt/x86.mac"
|
|---|
| 31 |
|
|---|
| 32 |
|
|---|
| 33 | BEGINCODE
|
|---|
| 34 |
|
|---|
| 35 | ;;
|
|---|
| 36 | ; compute the natural logarithm of lrd
|
|---|
| 37 | ; @returns st(0)
|
|---|
| 38 | ; @param lrd [rbp + xCB*2]
|
|---|
| 39 | RT_NOCRT_BEGINPROC logl
|
|---|
| 40 | push xBP
|
|---|
| 41 | SEH64_PUSH_xBP
|
|---|
| 42 | mov xBP, xSP
|
|---|
| 43 | SEH64_SET_FRAME_xBP 0
|
|---|
| 44 | SEH64_END_PROLOGUE
|
|---|
| 45 |
|
|---|
| 46 | fldln2 ; st0=log(2)
|
|---|
| 47 | fld tword [xBP + xCB*2] ; st1=log(2) st0=lrd
|
|---|
| 48 | fld st0 ; st1=log(2) st0=lrd st0=lrd
|
|---|
| 49 | fsub qword [.one xWrtRIP] ; st2=log(2) st1=lrd st0=lrd-1.0
|
|---|
| 50 | fld st0 ; st3=log(2) st2=lrd st1=lrd-1.0 st0=lrd-1.0
|
|---|
| 51 |
|
|---|
| 52 | fabs ; st3=log(2) st2=lrd st1=lrd-1.0 st0=abs(lrd-1.0)
|
|---|
| 53 | fcomp qword [.limit xWrtRIP] ; st2=log(2) st1=lrd st0=lrd-1.0
|
|---|
| 54 | fnstsw ax
|
|---|
| 55 | and eax, X86_FSW_C3 | X86_FSW_C2 | X86_FSW_C0
|
|---|
| 56 | jnz .use_st1
|
|---|
| 57 |
|
|---|
| 58 | fstp st0 ; st1=log(2) st0=lrd
|
|---|
| 59 | fyl2x ; log(lrd)
|
|---|
| 60 | jmp .done
|
|---|
| 61 |
|
|---|
| 62 | .use_st1:
|
|---|
| 63 | fstp st1 ; st1=log(2) st0=lrd-1.0
|
|---|
| 64 | fyl2xp1 ; log(lrd)
|
|---|
| 65 |
|
|---|
| 66 | .done:
|
|---|
| 67 | leave
|
|---|
| 68 | ret
|
|---|
| 69 |
|
|---|
| 70 | ALIGNCODE(8)
|
|---|
| 71 | .one: dq 1.0
|
|---|
| 72 | .limit: dq 0.29
|
|---|
| 73 | ENDPROC RT_NOCRT(logl)
|
|---|
| 74 |
|
|---|
