291 lines
6.8 KiB
ArmAsm
291 lines
6.8 KiB
ArmAsm
.file "reg_div.S"
|
|
/*
|
|
* reg_div.S
|
|
*
|
|
* Divide one FPU_REG by another and put the result in a destination FPU_REG.
|
|
*
|
|
* Call from C as:
|
|
* void reg_div(FPU_REG *a, FPU_REG *b, FPU_REG *dest,
|
|
*
|
|
*
|
|
* 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.
|
|
*
|
|
*
|
|
* $FreeBSD$
|
|
*
|
|
*/
|
|
|
|
#include <gnu/i386/fpemul/fpu_asm.h>
|
|
|
|
.text
|
|
ENTRY(reg_div)
|
|
pushl %ebp
|
|
movl %esp,%ebp
|
|
|
|
pushl %esi
|
|
pushl %edi
|
|
pushl %ebx
|
|
|
|
movl PARAM1,%esi
|
|
movl PARAM2,%ebx
|
|
movl PARAM3,%edi
|
|
|
|
movb TAG(%esi),%al
|
|
orb TAG(%ebx),%al
|
|
|
|
jne L_div_special /* Not (both numbers TW_Valid) */
|
|
|
|
#ifdef DENORM_OPERAND
|
|
/* Check for denormals */
|
|
cmpl EXP_UNDER,EXP(%esi)
|
|
jg xL_arg1_not_denormal
|
|
|
|
call denormal_operand
|
|
orl %eax,%eax
|
|
jnz FPU_Arith_exit
|
|
|
|
xL_arg1_not_denormal:
|
|
cmpl EXP_UNDER,EXP(%ebx)
|
|
jg xL_arg2_not_denormal
|
|
|
|
call denormal_operand
|
|
orl %eax,%eax
|
|
jnz FPU_Arith_exit
|
|
|
|
xL_arg2_not_denormal:
|
|
#endif /* DENORM_OPERAND */
|
|
|
|
/* Both arguments are TW_Valid */
|
|
movb TW_Valid,TAG(%edi)
|
|
|
|
movb SIGN(%esi),%cl
|
|
cmpb %cl,SIGN(%ebx)
|
|
setne (%edi) /* Set the sign, requires SIGN_NEG=1, SIGN_POS=0 */
|
|
|
|
movl EXP(%esi),%edx
|
|
movl EXP(%ebx),%eax
|
|
subl %eax,%edx
|
|
addl EXP_BIAS,%edx
|
|
movl %edx,EXP(%edi)
|
|
|
|
jmp divide_kernel
|
|
|
|
|
|
/*-----------------------------------------------------------------------*/
|
|
L_div_special:
|
|
cmpb TW_NaN,TAG(%esi) /* A NaN with anything to give NaN */
|
|
je L_arg1_NaN
|
|
|
|
cmpb TW_NaN,TAG(%ebx) /* A NaN with anything to give NaN */
|
|
jne L_no_NaN_arg
|
|
|
|
/* Operations on NaNs */
|
|
L_arg1_NaN:
|
|
L_arg2_NaN:
|
|
pushl %edi /* Destination */
|
|
pushl %ebx
|
|
pushl %esi
|
|
call real_2op_NaN
|
|
jmp LDiv_exit
|
|
|
|
/* Invalid operations */
|
|
L_zero_zero:
|
|
L_inf_inf:
|
|
pushl %edi /* Destination */
|
|
call arith_invalid /* 0/0 or Infinity/Infinity */
|
|
jmp LDiv_exit
|
|
|
|
L_no_NaN_arg:
|
|
cmpb TW_Infinity,TAG(%esi)
|
|
jne L_arg1_not_inf
|
|
|
|
cmpb TW_Infinity,TAG(%ebx)
|
|
je L_inf_inf /* invalid operation */
|
|
|
|
cmpb TW_Valid,TAG(%ebx)
|
|
je L_inf_valid
|
|
|
|
#ifdef PARANOID
|
|
/* arg2 must be zero or valid */
|
|
cmpb TW_Zero,TAG(%ebx)
|
|
ja L_unknown_tags
|
|
#endif /* PARANOID */
|
|
|
|
/* Note that p16-9 says that infinity/0 returns infinity */
|
|
jmp L_copy_arg1 /* Answer is Inf */
|
|
|
|
L_inf_valid:
|
|
#ifdef DENORM_OPERAND
|
|
cmpl EXP_UNDER,EXP(%ebx)
|
|
jg L_copy_arg1 /* Answer is Inf */
|
|
|
|
call denormal_operand
|
|
orl %eax,%eax
|
|
jnz FPU_Arith_exit
|
|
#endif /* DENORM_OPERAND */
|
|
|
|
jmp L_copy_arg1 /* Answer is Inf */
|
|
|
|
L_arg1_not_inf:
|
|
cmpb TW_Zero,TAG(%ebx) /* Priority to div-by-zero error */
|
|
jne L_arg2_not_zero
|
|
|
|
cmpb TW_Zero,TAG(%esi)
|
|
je L_zero_zero /* invalid operation */
|
|
|
|
#ifdef PARANOID
|
|
/* arg1 must be valid */
|
|
cmpb TW_Valid,TAG(%esi)
|
|
ja L_unknown_tags
|
|
#endif /* PARANOID */
|
|
|
|
/* Division by zero error */
|
|
pushl %edi /* destination */
|
|
movb SIGN(%esi),%al
|
|
xorb SIGN(%ebx),%al
|
|
pushl %eax /* lower 8 bits have the sign */
|
|
call divide_by_zero
|
|
jmp LDiv_exit
|
|
|
|
L_arg2_not_zero:
|
|
cmpb TW_Infinity,TAG(%ebx)
|
|
jne L_arg2_not_inf
|
|
|
|
#ifdef DENORM_OPERAND
|
|
cmpb TW_Valid,TAG(%esi)
|
|
jne L_return_zero
|
|
|
|
cmpl EXP_UNDER,EXP(%esi)
|
|
jg L_return_zero /* Answer is zero */
|
|
|
|
call denormal_operand
|
|
orl %eax,%eax
|
|
jnz FPU_Arith_exit
|
|
#endif /* DENORM_OPERAND */
|
|
|
|
jmp L_return_zero /* Answer is zero */
|
|
|
|
L_arg2_not_inf:
|
|
|
|
#ifdef PARANOID
|
|
cmpb TW_Zero,TAG(%esi)
|
|
jne L_unknown_tags
|
|
#endif /* PARANOID */
|
|
|
|
/* arg1 is zero, arg2 is not Infinity or a NaN */
|
|
|
|
#ifdef DENORM_OPERAND
|
|
cmpl EXP_UNDER,EXP(%ebx)
|
|
jg L_copy_arg1 /* Answer is zero */
|
|
|
|
call denormal_operand
|
|
orl %eax,%eax
|
|
jnz FPU_Arith_exit
|
|
#endif /* DENORM_OPERAND */
|
|
|
|
L_copy_arg1:
|
|
movb TAG(%esi),%al
|
|
movb %al,TAG(%edi)
|
|
movl EXP(%esi),%eax
|
|
movl %eax,EXP(%edi)
|
|
movl SIGL(%esi),%eax
|
|
movl %eax,SIGL(%edi)
|
|
movl SIGH(%esi),%eax
|
|
movl %eax,SIGH(%edi)
|
|
|
|
movb SIGN(%esi),%cl
|
|
cmpb %cl,SIGN(%ebx)
|
|
jne LDiv_negative_result
|
|
|
|
movb SIGN_POS,SIGN(%edi)
|
|
jmp LDiv_exit
|
|
|
|
LDiv_set_result_sign:
|
|
movb SIGN(%esi),%cl
|
|
cmpb %cl,SIGN(%edi)
|
|
jne LDiv_negative_result
|
|
|
|
movb SIGN_POS,SIGN(%ebx)
|
|
jmp LDiv_exit
|
|
|
|
LDiv_negative_result:
|
|
movb SIGN_NEG,SIGN(%edi)
|
|
|
|
LDiv_exit:
|
|
leal -12(%ebp),%esp
|
|
|
|
popl %ebx
|
|
popl %edi
|
|
popl %esi
|
|
leave
|
|
ret
|
|
|
|
|
|
L_return_zero:
|
|
movb TW_Zero,TAG(%edi)
|
|
jmp LDiv_set_result_sign
|
|
|
|
#ifdef PARANOID
|
|
L_unknown_tags:
|
|
push EX_INTERNAL | 0x208
|
|
call EXCEPTION
|
|
|
|
/* Generate a NaN for unknown tags */
|
|
movl _CONST_QNaN,%eax
|
|
movl %eax,(%edi)
|
|
movl _CONST_QNaN+4,%eax
|
|
movl %eax,SIGL(%edi)
|
|
movl _CONST_QNaN+8,%eax
|
|
movl %eax,SIGH(%edi)
|
|
jmp LDiv_exit
|
|
#endif /* PARANOID */
|