235 lines
5.5 KiB
ArmAsm
235 lines
5.5 KiB
ArmAsm
.file "reg_u_add.S"
|
|
/*
|
|
* reg_u_add.S
|
|
*
|
|
* Add two valid (TW_Valid) FPU_REG numbers, of the same sign, and put the
|
|
* result in a destination FPU_REG.
|
|
*
|
|
* Call from C as:
|
|
* void reg_u_add(FPU_REG *arg1, FPU_REG *arg2, FPU_REG *answ,
|
|
* int control_w)
|
|
*
|
|
*
|
|
* Copyright (C) 1992, 1993 W. Metzenthen, 22 Parker St, Ormond,
|
|
* Vic 3163, Australia.
|
|
* E-mail apm233m@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 operating system. 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.
|
|
*
|
|
*
|
|
* $Id:$
|
|
*
|
|
*/
|
|
|
|
|
|
/*
|
|
| Kernel addition routine reg_u_add(reg *arg1, reg *arg2, reg *answ).
|
|
| Takes two valid reg f.p. numbers (TW_Valid), which are
|
|
| treated as unsigned numbers,
|
|
| and returns their sum as a TW_Valid or TW_S f.p. number.
|
|
| The returned number is normalized.
|
|
| Basic checks are performed if PARANOID is defined.
|
|
*/
|
|
|
|
#include "exception.h"
|
|
#include "fpu_asm.h"
|
|
#include "control_w.h"
|
|
|
|
.text
|
|
.align 2,144
|
|
.globl _reg_u_add
|
|
_reg_u_add:
|
|
pushl %ebp
|
|
movl %esp,%ebp
|
|
/* subl $16,%esp*/
|
|
pushl %esi
|
|
pushl %edi
|
|
pushl %ebx
|
|
|
|
movl PARAM1,%esi /* source 1 */
|
|
movl PARAM2,%edi /* source 2 */
|
|
|
|
#ifdef DENORM_OPERAND
|
|
cmpl EXP_UNDER,EXP(%esi)
|
|
jg xOp1_not_denorm
|
|
|
|
call _denormal_operand
|
|
orl %eax,%eax
|
|
jnz FPU_Arith_exit
|
|
|
|
xOp1_not_denorm:
|
|
cmpl EXP_UNDER,EXP(%edi)
|
|
jg xOp2_not_denorm
|
|
|
|
call _denormal_operand
|
|
orl %eax,%eax
|
|
jnz FPU_Arith_exit
|
|
|
|
xOp2_not_denorm:
|
|
#endif DENORM_OPERAND
|
|
|
|
/* xorl %ecx,%ecx*/
|
|
movl EXP(%esi),%ecx
|
|
subl EXP(%edi),%ecx /* exp1 - exp2 */
|
|
/* jnc L_arg1_larger*/
|
|
jge L_arg1_larger
|
|
|
|
/* num1 is smaller */
|
|
movl SIGL(%esi),%ebx
|
|
movl SIGH(%esi),%eax
|
|
|
|
movl %edi,%esi
|
|
negw %cx
|
|
jmp L_accum_loaded
|
|
|
|
L_arg1_larger:
|
|
/* num1 has larger or equal exponent */
|
|
movl SIGL(%edi),%ebx
|
|
movl SIGH(%edi),%eax
|
|
|
|
L_accum_loaded:
|
|
movl PARAM3,%edi /* destination */
|
|
movb SIGN(%esi),%dl
|
|
movb %dl,SIGN(%edi) /* Copy the sign from the first arg */
|
|
|
|
|
|
movl EXP(%esi),%edx
|
|
movl %edx,EXP(%edi) /* Copy exponent to destination */
|
|
|
|
xorl %edx,%edx /* clear the extension */
|
|
|
|
#ifdef PARANOID
|
|
testl $0x80000000,%eax
|
|
je L_bugged
|
|
|
|
testl $0x80000000,SIGH(%esi)
|
|
je L_bugged
|
|
#endif PARANOID
|
|
|
|
/* The number to be shifted is in %eax:%ebx:%edx*/
|
|
cmpw $32,%cx /* shrd only works for 0..31 bits */
|
|
jnc L_more_than_31
|
|
|
|
/* less than 32 bits */
|
|
shrd %cl,%ebx,%edx
|
|
shrd %cl,%eax,%ebx
|
|
shr %cl,%eax
|
|
jmp L_shift_done
|
|
|
|
L_more_than_31:
|
|
cmpw $64,%cx
|
|
jnc L_more_than_63
|
|
|
|
subb $32,%cl
|
|
jz L_exactly_32
|
|
|
|
shrd %cl,%eax,%edx
|
|
shr %cl,%eax
|
|
orl %ebx,%ebx
|
|
jz L_more_31_no_low /* none of the lowest bits is set*/
|
|
|
|
orl $1,%edx /* record the fact in the extension*/
|
|
|
|
L_more_31_no_low:
|
|
movl %eax,%ebx
|
|
xorl %eax,%eax
|
|
jmp L_shift_done
|
|
|
|
L_exactly_32:
|
|
movl %ebx,%edx
|
|
movl %eax,%ebx
|
|
xorl %eax,%eax
|
|
jmp L_shift_done
|
|
|
|
L_more_than_63:
|
|
cmpw $65,%cx
|
|
jnc L_more_than_64
|
|
|
|
movl %eax,%edx
|
|
orl %ebx,%ebx
|
|
jz L_more_63_no_low
|
|
|
|
orl $1,%edx
|
|
jmp L_more_63_no_low
|
|
|
|
L_more_than_64:
|
|
movl $1,%edx /* The shifted nr always at least one '1'*/
|
|
|
|
L_more_63_no_low:
|
|
xorl %ebx,%ebx
|
|
xorl %eax,%eax
|
|
|
|
L_shift_done:
|
|
/* Now do the addition */
|
|
addl SIGL(%esi),%ebx
|
|
adcl SIGH(%esi),%eax
|
|
jnc L_round_the_result
|
|
|
|
/* Overflow, adjust the result */
|
|
rcrl $1,%eax
|
|
rcrl $1,%ebx
|
|
rcrl $1,%edx
|
|
jnc L_no_bit_lost
|
|
|
|
orl $1,%edx
|
|
|
|
L_no_bit_lost:
|
|
incl EXP(%edi)
|
|
|
|
L_round_the_result:
|
|
jmp FPU_round /* Round the result*/
|
|
|
|
|
|
|
|
#ifdef PARANOID
|
|
/* If we ever get here then we have problems! */
|
|
L_bugged:
|
|
pushl EX_INTERNAL|0x201
|
|
call EXCEPTION
|
|
pop %ebx
|
|
jmp L_exit
|
|
#endif PARANOID
|
|
|
|
|
|
L_exit:
|
|
popl %ebx
|
|
popl %edi
|
|
popl %esi
|
|
leave
|
|
ret
|