| 0,0 → 1,144 |
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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! |
| ;* |
| ;***************************************************************************** |
| |
| |
| ; |
| include mdef.inc |
| include struct.inc |
| |
| modstart fdi4386 |
| |
| xdefp __FDI4 |
| xdefp __RDI4 |
| |
| xdefp __FDU4 |
| xdefp __RDU4 |
| |
| ;[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][] |
| ;[] |
| ;[] __FDU4 convert double float EDX:EAX into 32-bit integer EAX |
| ;[] Input: EDX:EAX - double precision floating point number |
| ;[] Output: EAX - 32-bit integer |
| ;[] |
| ;[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][] |
| ; convert floating double to 4-byte integer with rounding |
| |
| defpe __RDU4 |
| mov AL,80h+20h ; indicate we are rounding |
| jmp short DtoI ; do it |
| |
| defpe __RDI4 |
| mov AL,80h+1Fh ; indicate we are rounding |
| jmp short DtoI ; do it |
| |
| defpe __FDI4 |
| mov AL,1Fh ; indicate we are truncating |
| jmp short DtoI ; do it |
| |
| ; convert floating double to 4-byte integer with truncation |
| |
| defpe __FDU4 |
| mov AL,20h ; indicate we are truncating |
| |
| DtoI: _shl EDX,1 ; get sign |
| rcr AH,1 ; AH <-- sign |
| shr AH,1 ; shift sign bit over 1 |
| or AH,AL ; get rounding bit |
| shr EDX,1 ; restore exponent to its place |
| |
| ; high bit of AH is rounding bit |
| ; next bit is the sign bit |
| |
| ;<~> Shift real right four places so that exponent occupies an entire |
| ;<~> word and the mantissa occupies the remaining words. We do not need |
| ;<~> AX because we only need 32 sig digits |
| |
| push ECX ; save ECX |
| mov ECX,EDX ; get high part |
| sar ECX,20 ; get exponent to the bottom |
| and CX,07FFh ; isolate exponent |
| sub CX,03FEh ; remove bias from exponent |
| jl short DIzero ; if |real| < .5 goto DIzero |
| cmp CX,20h ; if exponent > 32 |
| jg short DIo_f ; goto DIo_flow |
| and AL,3Fh ; isolate # of significant bits |
| cmp CL,AL ; quit if number too big |
| jg short DIo_f ; goto DIo_flow |
| mov CH,AH ; save rounding/truncation bit |
| and EDX,000FFFFFh ; isolate top 20 bits of fraction |
| and EAX,0FFF00000h ; isolate next 12 bits of fraction |
| or EDX,EAX ; glue them together |
| rol EDX,12 ; and rotate into position |
| |
| stc ; set carry and |
| rcr EDX,1 ; restore implied 1/2 bit |
| |
| rcr CH,1 ; save rounding bit |
| cmp CL,32 ; if want 32 bits |
| _if e ; then |
| mov EAX,EDX ; - get them |
| _shl CH,1 ; - get rounding bit |
| _else ; else |
| sub EAX,EAX ; - zero result register |
| shld EAX,EDX,CL ; - shift answer into EAX |
| shl EDX,CL ; - shift rounding bit into position |
| _shl CH,1 ; - get rid of rounding bit from CH |
| _shl EDX,1 ; - get proper rounding bit |
| _endif ; endif |
| mov CL,0FFh ; get mask |
| rcr CL,1 ; get rounding bit |
| and CH,CL ; mask it with rounding control bit |
| _shl CH,1 ; get rounding bit |
| adc EAX,0 ; add it to the integer to round it up |
| _shl CH,1 ; get sign |
| _if c ; if negative |
| neg EAX ; - negate integer |
| _endif ; endif |
| pop ECX ; restore ECX |
| ret ; return |
| |
| DIo_f: |
| mov EAX,80000000h ; set answer to largest negative number |
| pop ECX ; restore ECX |
| ret ; return |
| ; jmp I4OverFlow ; report overflow |
| |
| DIzero: sub EAX,EAX ; set result to zero |
| pop ECX ; restore ECX |
| ret |
| |
| endproc __FDU4 |
| endproc __FDI4 |
| endproc __RDI4 |
| endproc __RDU4 |
| |
| endmod |
| end |