9081eec1fb
have successfully built, booted, and run a number of different ELF kernel configurations, including GENERIC. LINT also builds and links cleanly, though I have not tried to boot it. The impact on developers is virtually nil, except for two things. All linker sets that might possibly be present in the kernel must be listed in "sys/i386/i386/setdefs.h". And all C symbols that are also referenced from assembly language code must be listed in "sys/i386/include/asnames.h". It so happens that failure to do these things will have no impact on the a.out kernel. But it will break the build of the ELF kernel. The ELF bootloader works, but it is not ready to commit quite yet.
293 lines
6.9 KiB
ArmAsm
293 lines
6.9 KiB
ArmAsm
.file "reg_div.S"
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/*
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* reg_div.S
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*
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* Divide one FPU_REG by another and put the result in a destination FPU_REG.
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*
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* Call from C as:
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* void reg_div(FPU_REG *a, FPU_REG *b, FPU_REG *dest,
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*
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*
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* Copyright (C) 1992,1993,1994
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* W. Metzenthen, 22 Parker St, Ormond, Vic 3163,
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* Australia. E-mail billm@vaxc.cc.monash.edu.au
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* All rights reserved.
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*
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* This copyright notice covers the redistribution and use of the
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* FPU emulator developed by W. Metzenthen. It covers only its use
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* in the 386BSD, FreeBSD and NetBSD operating systems. Any other
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* use is not permitted under this copyright.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must include information specifying
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* that source code for the emulator is freely available and include
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* either:
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* a) an offer to provide the source code for a nominal distribution
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* fee, or
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* b) list at least two alternative methods whereby the source
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* can be obtained, e.g. a publically accessible bulletin board
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* and an anonymous ftp site from which the software can be
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* downloaded.
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* 3. All advertising materials specifically mentioning features or use of
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* this emulator must acknowledge that it was developed by W. Metzenthen.
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* 4. The name of W. Metzenthen may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
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* W. METZENTHEN BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*
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* The purpose of this copyright, based upon the Berkeley copyright, is to
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* ensure that the covered software remains freely available to everyone.
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*
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* The software (with necessary differences) is also available, but under
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* the terms of the GNU copyleft, for the Linux operating system and for
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* the djgpp ms-dos extender.
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*
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* W. Metzenthen June 1994.
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*
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*
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* $Id: reg_div.s,v 1.6 1997/02/22 09:29:22 peter Exp $
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*
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*/
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#include <gnu/i386/fpemul/exception.h>
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#include <gnu/i386/fpemul/fpu_asm.h>
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#include <gnu/i386/fpemul/control_w.h>
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.text
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ENTRY(reg_div)
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pushl %ebp
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movl %esp,%ebp
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pushl %esi
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pushl %edi
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pushl %ebx
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movl PARAM1,%esi
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movl PARAM2,%ebx
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movl PARAM3,%edi
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movb TAG(%esi),%al
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orb TAG(%ebx),%al
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jne L_div_special /* Not (both numbers TW_Valid) */
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#ifdef DENORM_OPERAND
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/* Check for denormals */
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cmpl EXP_UNDER,EXP(%esi)
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jg xL_arg1_not_denormal
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call _denormal_operand
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orl %eax,%eax
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jnz FPU_Arith_exit
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xL_arg1_not_denormal:
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cmpl EXP_UNDER,EXP(%ebx)
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jg xL_arg2_not_denormal
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call _denormal_operand
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orl %eax,%eax
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jnz FPU_Arith_exit
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xL_arg2_not_denormal:
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#endif DENORM_OPERAND
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/* Both arguments are TW_Valid */
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movb TW_Valid,TAG(%edi)
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movb SIGN(%esi),%cl
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cmpb %cl,SIGN(%ebx)
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setne (%edi) /* Set the sign, requires SIGN_NEG=1, SIGN_POS=0 */
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movl EXP(%esi),%edx
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movl EXP(%ebx),%eax
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subl %eax,%edx
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addl EXP_BIAS,%edx
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movl %edx,EXP(%edi)
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jmp _divide_kernel
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/*-----------------------------------------------------------------------*/
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L_div_special:
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cmpb TW_NaN,TAG(%esi) /* A NaN with anything to give NaN */
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je L_arg1_NaN
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cmpb TW_NaN,TAG(%ebx) /* A NaN with anything to give NaN */
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jne L_no_NaN_arg
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/* Operations on NaNs */
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L_arg1_NaN:
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L_arg2_NaN:
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pushl %edi /* Destination */
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pushl %ebx
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pushl %esi
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call _real_2op_NaN
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jmp LDiv_exit
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/* Invalid operations */
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L_zero_zero:
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L_inf_inf:
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pushl %edi /* Destination */
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call _arith_invalid /* 0/0 or Infinity/Infinity */
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jmp LDiv_exit
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L_no_NaN_arg:
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cmpb TW_Infinity,TAG(%esi)
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jne L_arg1_not_inf
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cmpb TW_Infinity,TAG(%ebx)
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je L_inf_inf /* invalid operation */
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cmpb TW_Valid,TAG(%ebx)
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je L_inf_valid
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#ifdef PARANOID
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/* arg2 must be zero or valid */
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cmpb TW_Zero,TAG(%ebx)
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ja L_unknown_tags
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#endif PARANOID
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/* Note that p16-9 says that infinity/0 returns infinity */
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jmp L_copy_arg1 /* Answer is Inf */
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L_inf_valid:
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#ifdef DENORM_OPERAND
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cmpl EXP_UNDER,EXP(%ebx)
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jg L_copy_arg1 /* Answer is Inf */
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call _denormal_operand
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orl %eax,%eax
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jnz FPU_Arith_exit
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#endif DENORM_OPERAND
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jmp L_copy_arg1 /* Answer is Inf */
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L_arg1_not_inf:
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cmpb TW_Zero,TAG(%ebx) /* Priority to div-by-zero error */
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jne L_arg2_not_zero
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cmpb TW_Zero,TAG(%esi)
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je L_zero_zero /* invalid operation */
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#ifdef PARANOID
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/* arg1 must be valid */
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cmpb TW_Valid,TAG(%esi)
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ja L_unknown_tags
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#endif PARANOID
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/* Division by zero error */
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pushl %edi /* destination */
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movb SIGN(%esi),%al
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xorb SIGN(%ebx),%al
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pushl %eax /* lower 8 bits have the sign */
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call _divide_by_zero
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jmp LDiv_exit
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L_arg2_not_zero:
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cmpb TW_Infinity,TAG(%ebx)
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jne L_arg2_not_inf
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#ifdef DENORM_OPERAND
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cmpb TW_Valid,TAG(%esi)
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jne L_return_zero
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cmpl EXP_UNDER,EXP(%esi)
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jg L_return_zero /* Answer is zero */
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call _denormal_operand
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orl %eax,%eax
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jnz FPU_Arith_exit
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#endif DENORM_OPERAND
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jmp L_return_zero /* Answer is zero */
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L_arg2_not_inf:
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#ifdef PARANOID
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cmpb TW_Zero,TAG(%esi)
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jne L_unknown_tags
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#endif PARANOID
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/* arg1 is zero, arg2 is not Infinity or a NaN */
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#ifdef DENORM_OPERAND
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cmpl EXP_UNDER,EXP(%ebx)
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jg L_copy_arg1 /* Answer is zero */
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call _denormal_operand
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orl %eax,%eax
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jnz FPU_Arith_exit
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#endif DENORM_OPERAND
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L_copy_arg1:
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movb TAG(%esi),%ax
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movb %ax,TAG(%edi)
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movl EXP(%esi),%eax
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movl %eax,EXP(%edi)
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movl SIGL(%esi),%eax
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movl %eax,SIGL(%edi)
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movl SIGH(%esi),%eax
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movl %eax,SIGH(%edi)
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movb SIGN(%esi),%cl
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cmpb %cl,SIGN(%ebx)
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jne LDiv_negative_result
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movb SIGN_POS,SIGN(%edi)
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jmp LDiv_exit
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LDiv_set_result_sign:
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movb SIGN(%esi),%cl
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cmpb %cl,SIGN(%edi)
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jne LDiv_negative_result
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movb SIGN_POS,SIGN(%ebx)
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jmp LDiv_exit
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LDiv_negative_result:
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movb SIGN_NEG,SIGN(%edi)
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LDiv_exit:
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leal -12(%ebp),%esp
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popl %ebx
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popl %edi
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popl %esi
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leave
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ret
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L_return_zero:
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movb TW_Zero,TAG(%edi)
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jmp LDiv_set_result_sign
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#ifdef PARANOID
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L_unknown_tags:
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push EX_INTERNAL | 0x208
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call EXCEPTION
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/* Generate a NaN for unknown tags */
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movl _CONST_QNaN,%eax
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movl %eax,(%edi)
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movl _CONST_QNaN+4,%eax
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movl %eax,SIGL(%edi)
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movl _CONST_QNaN+8,%eax
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movl %eax,SIGH(%edi)
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jmp LDiv_exit
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#endif PARANOID
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