| 0,0 → 1,171 |
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| ;***************************************************************************** |
| ;* |
| ;* Open Watcom Project |
| ;* |
| ;* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved. |
| ;* |
| ;* ======================================================================== |
| ;* |
| ;* This file contains Original Code and/or Modifications of Original |
| ;* Code as defined in and that are subject to the Sybase Open Watcom |
| ;* Public License version 1.0 (the 'License'). You may not use this file |
| ;* except in compliance with the License. BY USING THIS FILE YOU AGREE TO |
| ;* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is |
| ;* provided with the Original Code and Modifications, and is also |
| ;* available at www.sybase.com/developer/opensource. |
| ;* |
| ;* The Original Code and all software distributed under the License are |
| ;* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
| ;* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM |
| ;* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF |
| ;* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR |
| ;* NON-INFRINGEMENT. Please see the License for the specific language |
| ;* governing rights and limitations under the License. |
| ;* |
| ;* ======================================================================== |
| ;* |
| ;* Description: WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE |
| ;* DESCRIBE IT HERE! |
| ;* |
| ;***************************************************************************** |
| |
| |
| ;======================================================================== |
| ;== Name: FSI4, FSU4, FSI2, FSU2, FSI1, FSU1 == |
| ;== Operation: Convert single precision to integer == |
| ;== Inputs: EAX single precision floating point == |
| ;== Outputs: EAX integer value == |
| ;== Volatile: none == |
| ;== == |
| ;== == |
| ;== handle -1.0 -> 0xffffffff == |
| ;======================================================================== |
| include mdef.inc |
| include struct.inc |
| |
| modstart fsi4386 |
| |
| xdefp __FSI4 |
| xdefp __FSU4 |
| xdefp __FSI2 |
| xdefp __FSU2 |
| xdefp __FSI1 |
| xdefp __FSU1 |
| |
| defpe __FSI4 |
| push ECX ; save cx |
| mov cl,7fh+31 ; maximum number 2^31-1 |
| call __FSI ; convert to integer |
| pop ECX ; restore cx |
| ret ; return (overflow already handled |
| endproc __FSI4 |
| |
| defpe __FSU4 |
| push ECX ; save cx |
| mov cl,7fh+32 ; maximum number 2^32-1 |
| call __FSU ; convert to integer |
| pop ECX ; restore cx |
| ret ; return if no overflow |
| endproc __FSU4 |
| |
| defpe __FSI2 |
| push ECX ; save cx |
| mov cl,7fh+15 ; maximum number 2^15-1 |
| call __FSI ; convert to integer |
| pop ECX ; restore cx |
| ret ; return (overflow already handled |
| endproc __FSI2 |
| |
| defpe __FSU2 |
| push ECX ; save cx |
| mov cl,7fh+16 ; maximum number 2^16-1 |
| call __FSU ; convert to integer |
| pop ECX ; restore cx |
| ret ; return if no overflow |
| endproc __FSU2 |
| |
| defpe __FSI1 |
| push ECX ; save cx |
| mov cl,7fh+7 ; maximum number 2^7-1 |
| call __FSI ; convert to integer |
| pop ECX ; restore cx |
| ret ; return (overflow already handled |
| endproc __FSI1 |
| |
| |
| defpe __FSU1 |
| push ECX ; save cx |
| mov cl,7fh+8 ; maximum number 2^8-1 |
| call __FSU ; convert to integer |
| pop ECX ; restore cx |
| ret ; return if no overflow |
| endproc __FSU1 |
| |
| __FSI proc near |
| __FSU: |
| or EAX,EAX ; check sign bit |
| jns short __FSAbs ; treat as unsigned if positive |
| call __FSAbs ; otherwise convert number |
| neg EAX ; negate the result |
| ret ; and return |
| endproc __FSI |
| |
| ; 18-nov-87 AFS (for WATCOM C) |
| ;__FSU proc near |
| ; jmp |
| ; or dx,dx ; check sign bit |
| ; jns __FSAbs ; just convert if positive |
| ; sub ax,ax ; return 0 if negative |
| ; sub dx,dx ; ... |
| ; ret |
| ; endproc __FSU |
| |
| ;======================================================================== |
| ;== Name: FSAbs_ == |
| ;== Inputs: EAX float == |
| ;== CL maximum exponent excess $7f == |
| ;== Outputs: EAX integer, absolute value of float == |
| ;== if exponent >= maximum then 2^max - 1 == |
| ;== returned == |
| ;======================================================================== |
| |
| __FSAbs proc near |
| or EAX,EAX ; check if number 0 |
| je short retzero ; if so, just return it |
| _shl EAX,1 ; shift mantissa over |
| rol EAX,8 ; get exponent to bottom |
| cmp AL,7fh ; quit if number < 1.0 15-apr-91 |
| jb short uflow ; ... |
| mov CH,AL ; save exponent |
| stc ; set carry for implied bit |
| rcr EAX,1 ; put implied '1' bit in |
| shr EAX,8 ; remove exponent |
| cmp CH,CL ; check if exponent exceeds maximum |
| jae short retmax ; return maximum value if so |
| sub CH,7fh+23 ; calculate amount to shift (+ve -> left) |
| jae short m_left ; jump if left shift/no shift |
| xchg CH,CL ; get shift count |
| neg CL ; make positive |
| shr EAX,CL ; shift mantissa |
| ret ; return with number |
| |
| m_left: |
| _if ne ; done if exponent exactly 23 |
| mov CL,CH ; - get shift count |
| shl EAX,CL ; - shift number left |
| _endif ; endif |
| ret ; return |
| |
| retmax: mov EAX,0FFFFFFFFh ; return maximum value |
| sub CL,7Fh+32 ; subtract bias + 32 |
| neg CL ; get shift count |
| shr EAX,CL ; compute value |
| ret ; return |
| |
| uflow: |
| retzero:sub EAX,EAX ; ensure entire number 0 |
| ret ; return |
| endproc __FSAbs |
| |
| endmod |
| end |