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Diffstat (limited to 'sys/gnu/arch/i386/fpemul/reg_div.s')
| -rw-r--r-- | sys/gnu/arch/i386/fpemul/reg_div.s | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/sys/gnu/arch/i386/fpemul/reg_div.s b/sys/gnu/arch/i386/fpemul/reg_div.s new file mode 100644 index 00000000000..c6970d236d8 --- /dev/null +++ b/sys/gnu/arch/i386/fpemul/reg_div.s @@ -0,0 +1,298 @@ + .file "reg_div.S" +/* $OpenBSD: reg_div.s,v 1.1 1996/08/27 10:32:58 downsj Exp $ */ +/* + * 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: reg_div.s,v 1.3 1994/06/10 07:44:50 rich Exp $ + * + */ + +#include <machine/asm.h> + +#include <gnu/arch/i386/fpemul/exception.h> +#include <gnu/arch/i386/fpemul/fpu_asm.h> +#include <gnu/arch/i386/fpemul/control_w.h> + +.text + .align 2 + +.globl _reg_div +_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),%ax + movb %ax,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 |