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Diffstat (limited to 'sys/gnu/fpemul/fpu_etc.c')
| -rw-r--r-- | sys/gnu/fpemul/fpu_etc.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/sys/gnu/fpemul/fpu_etc.c b/sys/gnu/fpemul/fpu_etc.c new file mode 100644 index 000000000000..9993d3bddfd4 --- /dev/null +++ b/sys/gnu/fpemul/fpu_etc.c @@ -0,0 +1,175 @@ +/* + * fpu_etc.c + * + * Implement a few FPU instructions. + * + * + * 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. + * + * + * $Id: fpu_etc.c,v 1.3 1994/06/10 07:44:24 rich Exp $ + * + */ + +#include "param.h" +#include "proc.h" +#include "machine/cpu.h" +#include "machine/pcb.h" + +#include "fpu_emu.h" +#include "fpu_system.h" +#include "exception.h" +#include "status_w.h" +#include "reg_constant.h" + + +static void +fchs(void) +{ + if (NOT_EMPTY_0) { + FPU_st0_ptr->sign ^= SIGN_POS ^ SIGN_NEG; + status_word &= ~SW_C1; + } else + stack_underflow(); +} + +static void +fabs(void) +{ + if (FPU_st0_tag ^ TW_Empty) { + FPU_st0_ptr->sign = SIGN_POS; + status_word &= ~SW_C1; + } else + stack_underflow(); +} + + +static void +ftst_(void) +{ + switch (FPU_st0_tag) { + case TW_Zero: + setcc(SW_C3); + break; + case TW_Valid: + +#ifdef DENORM_OPERAND + if ((FPU_st0_ptr->exp <= EXP_UNDER) && (denormal_operand())) + return; +#endif /* DENORM_OPERAND */ + + if (FPU_st0_ptr->sign == SIGN_POS) + setcc(0); + else + setcc(SW_C0); + break; + case TW_NaN: + setcc(SW_C0 | SW_C2 | SW_C3); /* Operand is not comparable */ + EXCEPTION(EX_Invalid); + break; + case TW_Infinity: + if (FPU_st0_ptr->sign == SIGN_POS) + setcc(0); + else + setcc(SW_C0); + EXCEPTION(EX_Invalid); + break; + case TW_Empty: + setcc(SW_C0 | SW_C2 | SW_C3); + EXCEPTION(EX_StackUnder); + break; + default: + setcc(SW_C0 | SW_C2 | SW_C3); /* Operand is not comparable */ + EXCEPTION(EX_INTERNAL | 0x14); + break; + } +} + +static void +fxam(void) +{ + int c = 0; + switch (FPU_st0_tag) { + case TW_Empty: + c = SW_C3 | SW_C0; + break; + case TW_Zero: + c = SW_C3; + break; + case TW_Valid: + /* This will need to be changed if TW_Denormal is ever used. */ + if (FPU_st0_ptr->exp <= EXP_UNDER) + c = SW_C2 | SW_C3; /* Denormal */ + else + c = SW_C3; + break; + case TW_NaN: + c = SW_C0; + break; + case TW_Infinity: + c = SW_C2 | SW_C0; + break; + } + if (FPU_st0_ptr->sign == SIGN_NEG) + c |= SW_C1; + setcc(c); +} + +static FUNC fp_etc_table[] = { + fchs, fabs, Un_impl, Un_impl, ftst_, fxam, Un_impl, Un_impl +}; + +void +fp_etc() +{ + (fp_etc_table[FPU_rm]) (); +} |