diff options
Diffstat (limited to 'sys/gnu/i386/fpemul/reg_add_sub.c')
-rw-r--r-- | sys/gnu/i386/fpemul/reg_add_sub.c | 300 |
1 files changed, 0 insertions, 300 deletions
diff --git a/sys/gnu/i386/fpemul/reg_add_sub.c b/sys/gnu/i386/fpemul/reg_add_sub.c deleted file mode 100644 index df08bcd..0000000 --- a/sys/gnu/i386/fpemul/reg_add_sub.c +++ /dev/null @@ -1,300 +0,0 @@ -/* - * reg_add_sub.c - * - * Functions to add or subtract two registers and put the result in a third. - * - * 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. - * - * - * $FreeBSD$ - * - */ - -/*---------------------------------------------------------------------------+ - | For each function, the destination may be any FPU_REG, including one of | - | the source FPU_REGs. | - +---------------------------------------------------------------------------*/ - -#include <gnu/i386/fpemul/reg_constant.h> -#include <gnu/i386/fpemul/control_w.h> - - -void -reg_add(FPU_REG * a, FPU_REG * b, FPU_REG * dest, int control_w) -{ - int diff; - - if (!(a->tag | b->tag)) { - /* Both registers are valid */ - if (!(a->sign ^ b->sign)) { - /* signs are the same */ - reg_u_add(a, b, dest, control_w); - dest->sign = a->sign; - return; - } - /* The signs are different, so do a subtraction */ - diff = a->exp - b->exp; - if (!diff) { - diff = a->sigh - b->sigh; /* Works only if ms bits - * are identical */ - if (!diff) { - diff = a->sigl > b->sigl; - if (!diff) - diff = -(a->sigl < b->sigl); - } - } - if (diff > 0) { - reg_u_sub(a, b, dest, control_w); - dest->sign = a->sign; - } else - if (diff == 0) { - reg_move(&CONST_Z, dest); - /* sign depends upon rounding mode */ - dest->sign = ((control_w & CW_RC) != RC_DOWN) - ? SIGN_POS : SIGN_NEG; - } else { - reg_u_sub(b, a, dest, control_w); - dest->sign = b->sign; - } - return; - } else { - if ((a->tag == TW_NaN) || (b->tag == TW_NaN)) { - real_2op_NaN(a, b, dest); - return; - } else - if (a->tag == TW_Zero) { - if (b->tag == TW_Zero) { - char different_signs = a->sign ^ b->sign; - /* Both are zero, result will be zero. */ - reg_move(a, dest); - if (different_signs) { - /* Signs are different. */ - /* Sign of answer depends upon - * rounding mode. */ - dest->sign = ((control_w & CW_RC) != RC_DOWN) - ? SIGN_POS : SIGN_NEG; - } - } else { -#ifdef DENORM_OPERAND - if ((b->tag == TW_Valid) && (b->exp <= EXP_UNDER) && - denormal_operand()) - return; -#endif /* DENORM_OPERAND */ - reg_move(b, dest); - } - return; - } else - if (b->tag == TW_Zero) { -#ifdef DENORM_OPERAND - if ((a->tag == TW_Valid) && (a->exp <= EXP_UNDER) && - denormal_operand()) - return; -#endif /* DENORM_OPERAND */ - reg_move(a, dest); - return; - } else - if (a->tag == TW_Infinity) { - if (b->tag != TW_Infinity) { -#ifdef DENORM_OPERAND - if ((b->tag == TW_Valid) && (b->exp <= EXP_UNDER) && - denormal_operand()) - return; -#endif /* DENORM_OPERAND */ - reg_move(a, dest); - return; - } - if (a->sign == b->sign) { - /* They are both + or - * - infinity */ - reg_move(a, dest); - return; - } - arith_invalid(dest); /* Infinity-Infinity is - * undefined. */ - return; - } else - if (b->tag == TW_Infinity) { -#ifdef DENORM_OPERAND - if ((a->tag == TW_Valid) && (a->exp <= EXP_UNDER) && - denormal_operand()) - return; -#endif /* DENORM_OPERAND */ - reg_move(b, dest); - return; - } - } -#ifdef PARANOID - EXCEPTION(EX_INTERNAL | 0x101); -#endif -} - - -/* Subtract b from a. (a-b) -> dest */ -void -reg_sub(FPU_REG * a, FPU_REG * b, FPU_REG * dest, int control_w) -{ - int diff; - - if (!(a->tag | b->tag)) { - /* Both registers are valid */ - diff = a->exp - b->exp; - if (!diff) { - diff = a->sigh - b->sigh; /* Works only if ms bits - * are identical */ - if (!diff) { - diff = a->sigl > b->sigl; - if (!diff) - diff = -(a->sigl < b->sigl); - } - } - switch (a->sign * 2 + b->sign) { - case 0: /* P - P */ - case 3: /* N - N */ - if (diff > 0) { - reg_u_sub(a, b, dest, control_w); - dest->sign = a->sign; - } else - if (diff == 0) { -#ifdef DENORM_OPERAND - if ((b->tag == TW_Valid) && (b->exp <= EXP_UNDER) && - denormal_operand()) - return; -#endif /* DENORM_OPERAND */ - reg_move(&CONST_Z, dest); - /* sign depends upon rounding mode */ - dest->sign = ((control_w & CW_RC) != RC_DOWN) - ? SIGN_POS : SIGN_NEG; - } else { - reg_u_sub(b, a, dest, control_w); - dest->sign = a->sign ^ SIGN_POS ^ SIGN_NEG; - } - return; - case 1: /* P - N */ - reg_u_add(a, b, dest, control_w); - dest->sign = SIGN_POS; - return; - case 2: /* N - P */ - reg_u_add(a, b, dest, control_w); - dest->sign = SIGN_NEG; - return; - } - } else { - if ((a->tag == TW_NaN) || (b->tag == TW_NaN)) { - real_2op_NaN(a, b, dest); - return; - } else - if (b->tag == TW_Zero) { - if (a->tag == TW_Zero) { - char same_signs = !(a->sign ^ b->sign); - /* Both are zero, result will be zero. */ - reg_move(a, dest); /* Answer for different - * signs. */ - if (same_signs) { - /* Sign depends upon rounding - * mode */ - dest->sign = ((control_w & CW_RC) != RC_DOWN) - ? SIGN_POS : SIGN_NEG; - } - } else { -#ifdef DENORM_OPERAND - if ((a->tag == TW_Valid) && (a->exp <= EXP_UNDER) && - denormal_operand()) - return; -#endif /* DENORM_OPERAND */ - reg_move(a, dest); - } - return; - } else - if (a->tag == TW_Zero) { -#ifdef DENORM_OPERAND - if ((b->tag == TW_Valid) && (b->exp <= EXP_UNDER) && - denormal_operand()) - return; -#endif /* DENORM_OPERAND */ - reg_move(b, dest); - dest->sign ^= SIGN_POS ^ SIGN_NEG; - return; - } else - if (a->tag == TW_Infinity) { - if (b->tag != TW_Infinity) { -#ifdef DENORM_OPERAND - if ((b->tag == TW_Valid) && (b->exp <= EXP_UNDER) && - denormal_operand()) - return; -#endif /* DENORM_OPERAND */ - reg_move(a, dest); - return; - } - /* Both args are Infinity */ - if (a->sign == b->sign) { - arith_invalid(dest); /* Infinity-Infinity is - * undefined. */ - return; - } - reg_move(a, dest); - return; - } else - if (b->tag == TW_Infinity) { -#ifdef DENORM_OPERAND - if ((a->tag == TW_Valid) && (a->exp <= EXP_UNDER) && - denormal_operand()) - return; -#endif /* DENORM_OPERAND */ - reg_move(b, dest); - dest->sign ^= SIGN_POS ^ SIGN_NEG; - return; - } - } -#ifdef PARANOID - EXCEPTION(EX_INTERNAL | 0x110); -#endif -} |