262 lines
7.8 KiB
ArmAsm
262 lines
7.8 KiB
ArmAsm
.file "wm_shrx.S"
|
|
/*
|
|
* wm_shrx.S
|
|
*
|
|
* 64 bit right shift functions
|
|
*
|
|
* Call from C as:
|
|
* unsigned shrx(void *arg1, unsigned arg2)
|
|
* and
|
|
* unsigned shrxs(void *arg1, unsigned arg2)
|
|
*
|
|
*
|
|
* Copyright (C) 1992,1993,1994
|
|
* W. Metzenthen, 22 Parker St, Ormond, Vic 3163,
|
|
* Australia. E-mail billm@vaxc.cc.monash.edu.au
|
|
* All rights reserved.
|
|
*
|
|
* This copyright notice covers the redistribution and use of the
|
|
* FPU emulator developed by W. Metzenthen. It covers only its use
|
|
* in the 386BSD, FreeBSD and NetBSD operating systems. Any other
|
|
* use is not permitted under this copyright.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must include information specifying
|
|
* that source code for the emulator is freely available and include
|
|
* either:
|
|
* a) an offer to provide the source code for a nominal distribution
|
|
* fee, or
|
|
* b) list at least two alternative methods whereby the source
|
|
* can be obtained, e.g. a publically accessible bulletin board
|
|
* and an anonymous ftp site from which the software can be
|
|
* downloaded.
|
|
* 3. All advertising materials specifically mentioning features or use of
|
|
* this emulator must acknowledge that it was developed by W. Metzenthen.
|
|
* 4. The name of W. Metzenthen may not be used to endorse or promote
|
|
* products derived from this software without specific prior written
|
|
* permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
|
|
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
|
|
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
|
|
* W. METZENTHEN BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
*
|
|
* The purpose of this copyright, based upon the Berkeley copyright, is to
|
|
* ensure that the covered software remains freely available to everyone.
|
|
*
|
|
* The software (with necessary differences) is also available, but under
|
|
* the terms of the GNU copyleft, for the Linux operating system and for
|
|
* the djgpp ms-dos extender.
|
|
*
|
|
* W. Metzenthen June 1994.
|
|
*
|
|
*
|
|
* $Id: wm_shrx.s,v 1.3 1994/06/10 07:45:03 rich Exp $
|
|
*
|
|
*/
|
|
|
|
|
|
#include <gnu/i386/fpemul/fpu_asm.h>
|
|
|
|
.text
|
|
.align 2,144
|
|
|
|
/*---------------------------------------------------------------------------+
|
|
| unsigned shrx(void *arg1, unsigned arg2) |
|
|
| |
|
|
| Extended shift right function. |
|
|
| Fastest for small shifts. |
|
|
| Shifts the 64 bit quantity pointed to by the first arg (arg1) |
|
|
| right by the number of bits specified by the second arg (arg2). |
|
|
| Forms a 96 bit quantity from the 64 bit arg and eax: |
|
|
| [ 64 bit arg ][ eax ] |
|
|
| shift right ---------> |
|
|
| The eax register is initialized to 0 before the shifting. |
|
|
| Results returned in the 64 bit arg and eax. |
|
|
+---------------------------------------------------------------------------*/
|
|
|
|
.globl _shrx
|
|
|
|
_shrx:
|
|
push %ebp
|
|
movl %esp,%ebp
|
|
pushl %esi
|
|
movl PARAM2,%ecx
|
|
movl PARAM1,%esi
|
|
cmpl $32,%ecx /* shrd only works for 0..31 bits */
|
|
jnc L_more_than_31
|
|
|
|
/* less than 32 bits */
|
|
pushl %ebx
|
|
movl (%esi),%ebx /* lsl */
|
|
movl 4(%esi),%edx /* msl */
|
|
xorl %eax,%eax /* extension */
|
|
shrd %cl,%ebx,%eax
|
|
shrd %cl,%edx,%ebx
|
|
shr %cl,%edx
|
|
movl %ebx,(%esi)
|
|
movl %edx,4(%esi)
|
|
popl %ebx
|
|
popl %esi
|
|
leave
|
|
ret
|
|
|
|
L_more_than_31:
|
|
cmpl $64,%ecx
|
|
jnc L_more_than_63
|
|
|
|
subb $32,%cl
|
|
movl (%esi),%eax /* lsl */
|
|
movl 4(%esi),%edx /* msl */
|
|
shrd %cl,%edx,%eax
|
|
shr %cl,%edx
|
|
movl %edx,(%esi)
|
|
movl $0,4(%esi)
|
|
popl %esi
|
|
leave
|
|
ret
|
|
|
|
L_more_than_63:
|
|
cmpl $96,%ecx
|
|
jnc L_more_than_95
|
|
|
|
subb $64,%cl
|
|
movl 4(%esi),%eax /* msl */
|
|
shr %cl,%eax
|
|
xorl %edx,%edx
|
|
movl %edx,(%esi)
|
|
movl %edx,4(%esi)
|
|
popl %esi
|
|
leave
|
|
ret
|
|
|
|
L_more_than_95:
|
|
xorl %eax,%eax
|
|
movl %eax,(%esi)
|
|
movl %eax,4(%esi)
|
|
popl %esi
|
|
leave
|
|
ret
|
|
|
|
|
|
/*---------------------------------------------------------------------------+
|
|
| unsigned shrxs(void *arg1, unsigned arg2) |
|
|
| |
|
|
| Extended shift right function (optimized for small floating point |
|
|
| integers). |
|
|
| Shifts the 64 bit quantity pointed to by the first arg (arg1) |
|
|
| right by the number of bits specified by the second arg (arg2). |
|
|
| Forms a 96 bit quantity from the 64 bit arg and eax: |
|
|
| [ 64 bit arg ][ eax ] |
|
|
| shift right ---------> |
|
|
| The eax register is initialized to 0 before the shifting. |
|
|
| The lower 8 bits of eax are lost and replaced by a flag which is |
|
|
| set (to 0x01) if any bit, apart from the first one, is set in the |
|
|
| part which has been shifted out of the arg. |
|
|
| Results returned in the 64 bit arg and eax. |
|
|
+---------------------------------------------------------------------------*/
|
|
.globl _shrxs
|
|
_shrxs:
|
|
push %ebp
|
|
movl %esp,%ebp
|
|
pushl %esi
|
|
pushl %ebx
|
|
movl PARAM2,%ecx
|
|
movl PARAM1,%esi
|
|
cmpl $64,%ecx /* shrd only works for 0..31 bits */
|
|
jnc Ls_more_than_63
|
|
|
|
cmpl $32,%ecx /* shrd only works for 0..31 bits */
|
|
jc Ls_less_than_32
|
|
|
|
/* We got here without jumps by assuming that the most common requirement
|
|
is for small integers */
|
|
/* Shift by [32..63] bits */
|
|
subb $32,%cl
|
|
movl (%esi),%eax /* lsl */
|
|
movl 4(%esi),%edx /* msl */
|
|
xorl %ebx,%ebx
|
|
shrd %cl,%eax,%ebx
|
|
shrd %cl,%edx,%eax
|
|
shr %cl,%edx
|
|
orl %ebx,%ebx /* test these 32 bits */
|
|
setne %bl
|
|
test $0x7fffffff,%eax /* and 31 bits here */
|
|
setne %bh
|
|
orw %bx,%bx /* Any of the 63 bit set ? */
|
|
setne %al
|
|
movl %edx,(%esi)
|
|
movl $0,4(%esi)
|
|
popl %ebx
|
|
popl %esi
|
|
leave
|
|
ret
|
|
|
|
/* Shift by [0..31] bits */
|
|
Ls_less_than_32:
|
|
movl (%esi),%ebx /* lsl */
|
|
movl 4(%esi),%edx /* msl */
|
|
xorl %eax,%eax /* extension */
|
|
shrd %cl,%ebx,%eax
|
|
shrd %cl,%edx,%ebx
|
|
shr %cl,%edx
|
|
test $0x7fffffff,%eax /* only need to look at eax here */
|
|
setne %al
|
|
movl %ebx,(%esi)
|
|
movl %edx,4(%esi)
|
|
popl %ebx
|
|
popl %esi
|
|
leave
|
|
ret
|
|
|
|
/* Shift by [64..95] bits */
|
|
Ls_more_than_63:
|
|
cmpl $96,%ecx
|
|
jnc Ls_more_than_95
|
|
|
|
subb $64,%cl
|
|
movl (%esi),%ebx /* lsl */
|
|
movl 4(%esi),%eax /* msl */
|
|
xorl %edx,%edx /* extension */
|
|
shrd %cl,%ebx,%edx
|
|
shrd %cl,%eax,%ebx
|
|
shr %cl,%eax
|
|
orl %ebx,%edx
|
|
setne %bl
|
|
test $0x7fffffff,%eax /* only need to look at eax here */
|
|
setne %bh
|
|
orw %bx,%bx
|
|
setne %al
|
|
xorl %edx,%edx
|
|
movl %edx,(%esi) /* set to zero */
|
|
movl %edx,4(%esi) /* set to zero */
|
|
popl %ebx
|
|
popl %esi
|
|
leave
|
|
ret
|
|
|
|
Ls_more_than_95:
|
|
/* Shift by [96..inf) bits */
|
|
xorl %eax,%eax
|
|
movl (%esi),%ebx
|
|
orl 4(%esi),%ebx
|
|
setne %al
|
|
xorl %ebx,%ebx
|
|
movl %ebx,(%esi)
|
|
movl %ebx,4(%esi)
|
|
popl %ebx
|
|
popl %esi
|
|
leave
|
|
ret
|