| 1 | ; $Id: floorl.asm 28800 2010-04-27 08:22:32Z vboxsync $
|
|---|
| 2 | ;; @file
|
|---|
| 3 | ; IPRT - No-CRT floorl - AMD64 & X86.
|
|---|
| 4 | ;
|
|---|
| 5 |
|
|---|
| 6 | ;
|
|---|
| 7 | ; Copyright (C) 2006-2007 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 | %include "iprt/asmdefs.mac"
|
|---|
| 28 |
|
|---|
| 29 | BEGINCODE
|
|---|
| 30 |
|
|---|
| 31 | ;;
|
|---|
| 32 | ; Compute the largest integral value not greater than lrd.
|
|---|
| 33 | ; @returns st(0)
|
|---|
| 34 | ; @param lrd [rbp + 8]
|
|---|
| 35 | BEGINPROC RT_NOCRT(floorl)
|
|---|
| 36 | push xBP
|
|---|
| 37 | mov xBP, xSP
|
|---|
| 38 | sub xSP, 10h
|
|---|
| 39 |
|
|---|
| 40 | fld tword [xBP + xS*2]
|
|---|
| 41 |
|
|---|
| 42 | ; Make it round down by modifying the fpu control word.
|
|---|
| 43 | fstcw [xBP - 10h]
|
|---|
| 44 | mov eax, [xBP - 10h]
|
|---|
| 45 | or eax, 00400h
|
|---|
| 46 | and eax, 0f7ffh
|
|---|
| 47 | mov [xBP - 08h], eax
|
|---|
| 48 | fldcw [xBP - 08h]
|
|---|
| 49 |
|
|---|
| 50 | ; Round ST(0) to integer.
|
|---|
| 51 | frndint
|
|---|
| 52 |
|
|---|
| 53 | ; Restore the fpu control word.
|
|---|
| 54 | fldcw [xBP - 10h]
|
|---|
| 55 |
|
|---|
| 56 | leave
|
|---|
| 57 | ret
|
|---|
| 58 | ENDPROC RT_NOCRT(floorl)
|
|---|
| 59 |
|
|---|
