/* $OpenBSD: reg_ld_str.c,v 1.1 1996/08/27 10:32:59 downsj Exp $ */ /* * reg_ld_str.c * * All of the functions which transfer data between user memory and FPU_REGs. * * * 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_ld_str.c,v 1.6 1996/06/25 20:29:26 bde Exp $ * */ /*---------------------------------------------------------------------------+ | Note: | | The file contains code which accesses user memory. | | Emulator static data may change when user memory is accessed, due to | | other processes using the emulator while swapping is in progress. | +---------------------------------------------------------------------------*/ #include #include #include #include #if defined(__FreeBSD__) #include #endif #include #include #include #include #include #include #include #define EXTENDED_Emax 0x3fff /* largest valid exponent */ #define EXTENDED_Ebias 0x3fff #define EXTENDED_Emin (-0x3ffe) /* smallest valid exponent */ #define DOUBLE_Emax 1023 /* largest valid exponent */ #define DOUBLE_Ebias 1023 #define DOUBLE_Emin (-1022) /* smallest valid exponent */ #define SINGLE_Emax 127 /* largest valid exponent */ #define SINGLE_Ebias 127 #define SINGLE_Emin (-126) /* smallest valid exponent */ #define LOST_UP (EX_Precision | SW_C1) #define LOST_DOWN EX_Precision FPU_REG FPU_loaded_data; /* Get a long double from user memory */ void reg_load_extended(void) { long double *s = (long double *) FPU_data_address; unsigned long sigl, sigh, exp; REENTRANT_CHECK(OFF); /* Use temporary variables here because FPU_loaded data is static and * hence re-entrancy problems can arise */ sigl = fuword((unsigned long *) s); sigh = fuword(1 + (unsigned long *) s); exp = fusword(4 + (unsigned short *) s); REENTRANT_CHECK(ON); FPU_loaded_data.sigl = sigl; FPU_loaded_data.sigh = sigh; FPU_loaded_data.exp = exp; if (FPU_loaded_data.exp & 0x8000) FPU_loaded_data.sign = SIGN_NEG; else FPU_loaded_data.sign = SIGN_POS; if ((FPU_loaded_data.exp &= 0x7fff) == 0) { if (!(FPU_loaded_data.sigl | FPU_loaded_data.sigh)) { FPU_loaded_data.tag = TW_Zero; return; } /* The number is a de-normal or pseudodenormal. */ /* The 80486 doesn't regard pseudodenormals as denormals here. */ if (!(FPU_loaded_data.sigh & 0x80000000)) EXCEPTION(EX_Denormal); FPU_loaded_data.exp++; /* The default behaviour will now take care of it. */ } else if (FPU_loaded_data.exp == 0x7fff) { FPU_loaded_data.exp = EXTENDED_Emax; if ((FPU_loaded_data.sigh == 0x80000000) && (FPU_loaded_data.sigl == 0)) { FPU_loaded_data.tag = TW_Infinity; return; } else if (!(FPU_loaded_data.sigh & 0x80000000)) { /* Unsupported NaN data type */ EXCEPTION(EX_Invalid); FPU_loaded_data.tag = TW_NaN; return; } FPU_loaded_data.tag = TW_NaN; return; } FPU_loaded_data.exp = (FPU_loaded_data.exp & 0x7fff) - EXTENDED_Ebias + EXP_BIAS; FPU_loaded_data.tag = TW_Valid; if (!(sigh & 0x80000000)) { /* Unsupported data type */ EXCEPTION(EX_Invalid); normalize_nuo(&FPU_loaded_data); } } /* Get a double from user memory */ void reg_load_double(void) { double *dfloat = (double *) FPU_data_address; int exp; unsigned m64, l64; REENTRANT_CHECK(OFF); m64 = fuword(1 + (unsigned long *) dfloat); l64 = fuword((unsigned long *) dfloat); REENTRANT_CHECK(ON); if (m64 & 0x80000000) FPU_loaded_data.sign = SIGN_NEG; else FPU_loaded_data.sign = SIGN_POS; exp = ((m64 & 0x7ff00000) >> 20) - DOUBLE_Ebias; m64 &= 0xfffff; if (exp > DOUBLE_Emax) { /* Infinity or NaN */ if ((m64 == 0) && (l64 == 0)) { /* +- infinity */ FPU_loaded_data.exp = EXTENDED_Emax; FPU_loaded_data.tag = TW_Infinity; return; } else { /* Must be a signaling or quiet NaN */ FPU_loaded_data.exp = EXTENDED_Emax; FPU_loaded_data.tag = TW_NaN; FPU_loaded_data.sigh = (m64 << 11) | 0x80000000; FPU_loaded_data.sigh |= l64 >> 21; FPU_loaded_data.sigl = l64 << 11; return; } } else if (exp < DOUBLE_Emin) { /* Zero or de-normal */ if ((m64 == 0) && (l64 == 0)) { /* Zero */ int c = FPU_loaded_data.sign; reg_move(&CONST_Z, &FPU_loaded_data); FPU_loaded_data.sign = c; return; } else { /* De-normal */ EXCEPTION(EX_Denormal); FPU_loaded_data.exp = DOUBLE_Emin + EXP_BIAS; FPU_loaded_data.tag = TW_Valid; FPU_loaded_data.sigh = m64 << 11; FPU_loaded_data.sigh |= l64 >> 21; FPU_loaded_data.sigl = l64 << 11; normalize_nuo(&FPU_loaded_data); return; } } else { FPU_loaded_data.exp = exp + EXP_BIAS; FPU_loaded_data.tag = TW_Valid; FPU_loaded_data.sigh = (m64 << 11) | 0x80000000; FPU_loaded_data.sigh |= l64 >> 21; FPU_loaded_data.sigl = l64 << 11; return; } } /* Get a float from user memory */ void reg_load_single(void) { float *single = (float *) FPU_data_address; unsigned m32; int exp; REENTRANT_CHECK(OFF); m32 = fuword((unsigned long *) single); REENTRANT_CHECK(ON); if (m32 & 0x80000000) FPU_loaded_data.sign = SIGN_NEG; else FPU_loaded_data.sign = SIGN_POS; if (!(m32 & 0x7fffffff)) { /* Zero */ int c = FPU_loaded_data.sign; reg_move(&CONST_Z, &FPU_loaded_data); FPU_loaded_data.sign = c; return; } exp = ((m32 & 0x7f800000) >> 23) - SINGLE_Ebias; m32 = (m32 & 0x7fffff) << 8; if (exp < SINGLE_Emin) { /* De-normals */ EXCEPTION(EX_Denormal); FPU_loaded_data.exp = SINGLE_Emin + EXP_BIAS; FPU_loaded_data.tag = TW_Valid; FPU_loaded_data.sigh = m32; FPU_loaded_data.sigl = 0; normalize_nuo(&FPU_loaded_data); return; } else if (exp > SINGLE_Emax) { /* Infinity or NaN */ if (m32 == 0) { /* +- infinity */ FPU_loaded_data.exp = EXTENDED_Emax; FPU_loaded_data.tag = TW_Infinity; return; } else { /* Must be a signaling or quiet NaN */ FPU_loaded_data.exp = EXTENDED_Emax; FPU_loaded_data.tag = TW_NaN; FPU_loaded_data.sigh = m32 | 0x80000000; FPU_loaded_data.sigl = 0; return; } } else { FPU_loaded_data.exp = exp + EXP_BIAS; FPU_loaded_data.sigh = m32 | 0x80000000; FPU_loaded_data.sigl = 0; FPU_loaded_data.tag = TW_Valid; } } /* Get a long long from user memory */ void reg_load_int64(void) { long long *_s = (long long *) FPU_data_address; int e; long long s; REENTRANT_CHECK(OFF); ((unsigned long *) &s)[0] = fuword((unsigned long *) _s); ((unsigned long *) &s)[1] = fuword(1 + (unsigned long *) _s); REENTRANT_CHECK(ON); if (s == 0) { reg_move(&CONST_Z, &FPU_loaded_data); return; } if (s > 0) FPU_loaded_data.sign = SIGN_POS; else { s = -s; FPU_loaded_data.sign = SIGN_NEG; } e = EXP_BIAS + 63; *((long long *) &FPU_loaded_data.sigl) = s; FPU_loaded_data.exp = e; FPU_loaded_data.tag = TW_Valid; normalize_nuo(&FPU_loaded_data); } /* Get a long from user memory */ void reg_load_int32(void) { long *_s = (long *) FPU_data_address; long s; int e; REENTRANT_CHECK(OFF); s = (long) fuword((unsigned long *) _s); REENTRANT_CHECK(ON); if (s == 0) { reg_move(&CONST_Z, &FPU_loaded_data); return; } if (s > 0) FPU_loaded_data.sign = SIGN_POS; else { s = -s; FPU_loaded_data.sign = SIGN_NEG; } e = EXP_BIAS + 31; FPU_loaded_data.sigh = s; FPU_loaded_data.sigl = 0; FPU_loaded_data.exp = e; FPU_loaded_data.tag = TW_Valid; normalize_nuo(&FPU_loaded_data); } /* Get a short from user memory */ void reg_load_int16(void) { short *_s = (short *) FPU_data_address; int s, e; REENTRANT_CHECK(OFF); /* Cast as short to get the sign extended. */ s = (short) fusword((unsigned short *) _s); REENTRANT_CHECK(ON); if (s == 0) { reg_move(&CONST_Z, &FPU_loaded_data); return; } if (s > 0) FPU_loaded_data.sign = SIGN_POS; else { s = -s; FPU_loaded_data.sign = SIGN_NEG; } e = EXP_BIAS + 15; FPU_loaded_data.sigh = s << 16; FPU_loaded_data.sigl = 0; FPU_loaded_data.exp = e; FPU_loaded_data.tag = TW_Valid; normalize_nuo(&FPU_loaded_data); } /* Get a packed bcd array from user memory */ void reg_load_bcd(void) { char *s = (char *) FPU_data_address; int pos; unsigned char bcd; long long l = 0; for (pos = 8; pos >= 0; pos--) { l *= 10; REENTRANT_CHECK(OFF); bcd = (unsigned char) fubyte((unsigned char *) s + pos); REENTRANT_CHECK(ON); l += bcd >> 4; l *= 10; l += bcd & 0x0f; } /* Finish all access to user memory before putting stuff into the * static FPU_loaded_data */ REENTRANT_CHECK(OFF); FPU_loaded_data.sign = ((unsigned char) fubyte((unsigned char *) s + 9)) & 0x80 ? SIGN_NEG : SIGN_POS; REENTRANT_CHECK(ON); if (l == 0) { char sign = FPU_loaded_data.sign; reg_move(&CONST_Z, &FPU_loaded_data); FPU_loaded_data.sign = sign; } else { *((long long *) &FPU_loaded_data.sigl) = l; FPU_loaded_data.exp = EXP_BIAS + 63; FPU_loaded_data.tag = TW_Valid; normalize_nuo(&FPU_loaded_data); } } /*===========================================================================*/ /* Put a long double into user memory */ int reg_store_extended(void) { long double *d = (long double *) FPU_data_address; long e = FPU_st0_ptr->exp - EXP_BIAS + EXTENDED_Ebias; unsigned short sign = FPU_st0_ptr->sign * 0x8000; unsigned long ls, ms; if (FPU_st0_tag == TW_Valid) { if (e >= 0x7fff) { EXCEPTION(EX_Overflow); /* Overflow */ /* This is a special case: see sec 16.2.5.1 of the * 80486 book */ if (control_word & EX_Overflow) { /* Overflow to infinity */ ls = 0; ms = 0x80000000; e = 0x7fff; } else return 0; } else if (e <= 0) { if (e > -63) { /* Correctly format the de-normal */ int precision_loss; FPU_REG tmp; EXCEPTION(EX_Denormal); reg_move(FPU_st0_ptr, &tmp); tmp.exp += -EXTENDED_Emin + 63; /* largest exp to be 62 */ if ((precision_loss = round_to_int(&tmp))) { EXCEPTION(EX_Underflow | precision_loss); /* This is a special case: see * sec 16.2.5.1 of the 80486 * book */ if (!(control_word & EX_Underflow)) return 0; } e = 0; ls = tmp.sigl; ms = tmp.sigh; } else { /* ****** ??? This should not be * possible */ EXCEPTION(EX_Underflow); /* Underflow */ /* This is a special case: see sec * 16.2.5.1 of the 80486 book */ if (control_word & EX_Underflow) { /* Underflow to zero */ ls = 0; ms = 0; e = FPU_st0_ptr->sign == SIGN_POS ? 0x7fff : 0xffff; } else return 0; } } else { ls = FPU_st0_ptr->sigl; ms = FPU_st0_ptr->sigh; } } else if (FPU_st0_tag == TW_Zero) { ls = ms = 0; e = 0; } else if (FPU_st0_tag == TW_Infinity) { ls = 0; ms = 0x80000000; e = 0x7fff; } else if (FPU_st0_tag == TW_NaN) { ls = FPU_st0_ptr->sigl; ms = FPU_st0_ptr->sigh; e = 0x7fff; } else if (FPU_st0_tag == TW_Empty) { /* Empty register (stack * underflow) */ EXCEPTION(EX_StackUnder); if (control_word & EX_Invalid) { /* The masked response */ /* Put out the QNaN * indefinite */ ls = 0; ms = 0xc0000000; e = 0xffff; } else return 0; } else { /* We don't use TW_Denormal * yet ... perhaps never! */ EXCEPTION(EX_Invalid); /* Store a NaN */ e = 0x7fff; ls = 1; ms = 0x80000000; } REENTRANT_CHECK(OFF); /* verify_area(VERIFY_WRITE, d, 10); */ suword((unsigned long *) d, ls); suword(1 + (unsigned long *) d, ms); susword(4 + (short *) d, (unsigned short) e | sign); REENTRANT_CHECK(ON); return 1; } /* Put a double into user memory */ int reg_store_double(void) { double *dfloat = (double *) FPU_data_address; unsigned long l[2]; if (FPU_st0_tag == TW_Valid) { int exp; FPU_REG tmp; reg_move(FPU_st0_ptr, &tmp); exp = tmp.exp - EXP_BIAS; if (exp < DOUBLE_Emin) { /* It may be a denormal */ /* Make a de-normal */ int precision_loss; if (exp <= -EXTENDED_Ebias) EXCEPTION(EX_Denormal); tmp.exp += -DOUBLE_Emin + 52; /* largest exp to be 51 */ if ((precision_loss = round_to_int(&tmp))) { #ifdef PECULIAR_486 /* Did it round to a non-denormal ? */ /* This behaviour might be regarded as * peculiar, it appears that the 80486 rounds * to the dest precision, then converts to * decide underflow. */ if ((tmp.sigh == 0x00100000) && (tmp.sigl == 0) && (FPU_st0_ptr->sigl & 0x000007ff)) EXCEPTION(precision_loss); else #endif /* PECULIAR_486 */ { EXCEPTION(EX_Underflow | precision_loss); /* This is a special case: see sec * 16.2.5.1 of the 80486 book */ if (!(control_word & EX_Underflow)) return 0; } } l[0] = tmp.sigl; l[1] = tmp.sigh; } else { if (tmp.sigl & 0x000007ff) { unsigned long increment = 0; /* avoid gcc warnings */ switch (control_word & CW_RC) { case RC_RND: /* Rounding can get a little messy.. */ increment = ((tmp.sigl & 0x7ff) > 0x400) | /* nearest */ ((tmp.sigl & 0xc00) == 0xc00); /* odd -> even */ break; case RC_DOWN: /* towards -infinity */ increment = (tmp.sign == SIGN_POS) ? 0 : tmp.sigl & 0x7ff; break; case RC_UP: /* towards +infinity */ increment = (tmp.sign == SIGN_POS) ? tmp.sigl & 0x7ff : 0; break; case RC_CHOP: increment = 0; break; } /* Truncate the mantissa */ tmp.sigl &= 0xfffff800; if (increment) { set_precision_flag_up(); if (tmp.sigl >= 0xfffff800) { /* the sigl part overflows */ if (tmp.sigh == 0xffffffff) { /* The sigh part * overflows */ tmp.sigh = 0x80000000; exp++; if (exp >= EXP_OVER) goto overflow; } else { tmp.sigh++; } tmp.sigl = 0x00000000; } else { /* We only need to increment * sigl */ tmp.sigl += 0x00000800; } } else set_precision_flag_down(); } l[0] = (tmp.sigl >> 11) | (tmp.sigh << 21); l[1] = ((tmp.sigh >> 11) & 0xfffff); if (exp > DOUBLE_Emax) { overflow: EXCEPTION(EX_Overflow); /* This is a special case: see sec 16.2.5.1 of * the 80486 book */ if (control_word & EX_Overflow) { /* Overflow to infinity */ l[0] = 0x00000000; /* Set to */ l[1] = 0x7ff00000; /* + INF */ } else return 0; } else { /* Add the exponent */ l[1] |= (((exp + DOUBLE_Ebias) & 0x7ff) << 20); } } } else if (FPU_st0_tag == TW_Zero) { /* Number is zero */ l[0] = 0; l[1] = 0; } else if (FPU_st0_tag == TW_Infinity) { l[0] = 0; l[1] = 0x7ff00000; } else if (FPU_st0_tag == TW_NaN) { /* See if we can get a valid NaN from * the FPU_REG */ l[0] = (FPU_st0_ptr->sigl >> 11) | (FPU_st0_ptr->sigh << 21); l[1] = ((FPU_st0_ptr->sigh >> 11) & 0xfffff); if (!(l[0] | l[1])) { /* This case does not seem to * be handled by the 80486 * specs */ EXCEPTION(EX_Invalid); /* Make the quiet NaN "real * indefinite" */ goto put_indefinite; } l[1] |= 0x7ff00000; } else if (FPU_st0_tag == TW_Empty) { /* Empty register (stack * underflow) */ EXCEPTION(EX_StackUnder); if (control_word & EX_Invalid) { /* The masked response */ /* Put out the QNaN * indefinite */ put_indefinite: REENTRANT_CHECK(OFF); /* verify_area(VERIFY_W * RITE, (void *) * dfloat, 8); */ suword((unsigned long *) dfloat, 0); suword(1 + (unsigned long *) dfloat, 0xfff80000); REENTRANT_CHECK(ON); return 1; } else return 0; } #if 0 /* TW_Denormal is not used yet, and probably * won't be */ else if (FPU_st0_tag == TW_Denormal) { /* Extended real -> * double real will * always underflow */ l[0] = l[1] = 0; EXCEPTION(EX_Underflow); } #endif if (FPU_st0_ptr->sign) l[1] |= 0x80000000; REENTRANT_CHECK(OFF); /* verify_area(VERIFY_WRITE, (void *) dfloat, 8);*/ suword((u_long *) dfloat, l[0]); suword((u_long *) dfloat + 1, l[1]); /* suword(l[0], (unsigned long *) dfloat); suword(l[1], 1 + (unsigned long *) dfloat);*/ REENTRANT_CHECK(ON); return 1; } /* Put a float into user memory */ int reg_store_single(void) { float *single = (float *) FPU_data_address; long templ = 0; if (FPU_st0_tag == TW_Valid) { int exp; FPU_REG tmp; reg_move(FPU_st0_ptr, &tmp); exp = tmp.exp - EXP_BIAS; if (exp < SINGLE_Emin) { /* Make a de-normal */ int precision_loss; if (exp <= -EXTENDED_Ebias) EXCEPTION(EX_Denormal); tmp.exp += -SINGLE_Emin + 23; /* largest exp to be 22 */ if ((precision_loss = round_to_int(&tmp))) { #ifdef PECULIAR_486 /* Did it round to a non-denormal ? */ /* This behaviour might be regarded as * peculiar, it appears that the 80486 rounds * to the dest precision, then converts to * decide underflow. */ if ((tmp.sigl == 0x00800000) && ((FPU_st0_ptr->sigh & 0x000000ff) || FPU_st0_ptr->sigl)) EXCEPTION(precision_loss); else #endif /* PECULIAR_486 */ { EXCEPTION(EX_Underflow | precision_loss); /* This is a special case: see sec * 16.2.5.1 of the 80486 book */ if (!(control_word & EX_Underflow)) return 0; } } templ = tmp.sigl; } else { if (tmp.sigl | (tmp.sigh & 0x000000ff)) { unsigned long increment = 0; /* avoid gcc warnings */ unsigned long sigh = tmp.sigh; unsigned long sigl = tmp.sigl; switch (control_word & CW_RC) { case RC_RND: increment = ((sigh & 0xff) > 0x80) /* more than half */ ||(((sigh & 0xff) == 0x80) && sigl) /* more than half */ ||((sigh & 0x180) == 0x180); /* round to even */ break; case RC_DOWN: /* towards -infinity */ increment = (tmp.sign == SIGN_POS) ? 0 : (sigl | (sigh & 0xff)); break; case RC_UP: /* towards +infinity */ increment = (tmp.sign == SIGN_POS) ? (sigl | (sigh & 0xff)) : 0; break; case RC_CHOP: increment = 0; break; } /* Truncate part of the mantissa */ tmp.sigl = 0; if (increment) { set_precision_flag_up(); if (sigh >= 0xffffff00) { /* The sigh part overflows */ tmp.sigh = 0x80000000; exp++; if (exp >= EXP_OVER) goto overflow; } else { tmp.sigh &= 0xffffff00; tmp.sigh += 0x100; } } else { set_precision_flag_down(); tmp.sigh &= 0xffffff00; /* Finish the truncation */ } } templ = (tmp.sigh >> 8) & 0x007fffff; if (exp > SINGLE_Emax) { overflow: EXCEPTION(EX_Overflow); /* This is a special case: see sec 16.2.5.1 of * the 80486 book */ if (control_word & EX_Overflow) { /* Overflow to infinity */ templ = 0x7f800000; } else return 0; } else templ |= ((exp + SINGLE_Ebias) & 0xff) << 23; } } else if (FPU_st0_tag == TW_Zero) { templ = 0; } else if (FPU_st0_tag == TW_Infinity) { templ = 0x7f800000; } else if (FPU_st0_tag == TW_NaN) { /* See if we can get a valid NaN from * the FPU_REG */ templ = FPU_st0_ptr->sigh >> 8; if (!(templ & 0x3fffff)) { /* This case does not seem to * be handled by the 80486 * specs */ EXCEPTION(EX_Invalid); /* Make the quiet NaN "real * indefinite" */ goto put_indefinite; } templ |= 0x7f800000; } else if (FPU_st0_tag == TW_Empty) { /* Empty register (stack * underflow) */ EXCEPTION(EX_StackUnder); if (control_word & EX_Invalid) { /* The masked response */ /* Put out the QNaN * indefinite */ put_indefinite: REENTRANT_CHECK(OFF); /* verify_area(VERIFY_WRITE, (void *) single, 4); */ suword((unsigned long *) single, 0xffc00000); REENTRANT_CHECK(ON); return 1; } else return 0; } #if 0 /* TW_Denormal is not used yet, and probably * won't be */ else if (FPU_st0_tag == TW_Denormal) { /* Extended real -> * real will always * underflow */ templ = 0; EXCEPTION(EX_Underflow); } #endif #ifdef PARANOID else { EXCEPTION(EX_INTERNAL | 0x106); return 0; } #endif if (FPU_st0_ptr->sign) templ |= 0x80000000; REENTRANT_CHECK(OFF); /* verify_area(VERIFY_WRITE, (void *) single, 4); */ suword((unsigned long *) single, templ); REENTRANT_CHECK(ON); return 1; } /* Put a long long into user memory */ int reg_store_int64(void) { long long *d = (long long *) FPU_data_address; FPU_REG t; long long tll; if (FPU_st0_tag == TW_Empty) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); if (control_word & EX_Invalid) { /* The masked response */ /* Put out the QNaN indefinite */ goto put_indefinite; } else return 0; } reg_move(FPU_st0_ptr, &t); round_to_int(&t); ((long *) &tll)[0] = t.sigl; ((long *) &tll)[1] = t.sigh; if ((t.sigh & 0x80000000) && !((t.sigh == 0x80000000) && (t.sigl == 0) && (t.sign == SIGN_NEG))) { EXCEPTION(EX_Invalid); /* This is a special case: see sec 16.2.5.1 of the 80486 book */ if (control_word & EX_Invalid) { /* Produce "indefinite" */ put_indefinite: ((long *) &tll)[1] = 0x80000000; ((long *) &tll)[0] = 0; } else return 0; } else if (t.sign) tll = -tll; REENTRANT_CHECK(OFF); /* verify_area(VERIFY_WRITE, (void *) d, 8); */ suword((unsigned long *) d, ((long *) &tll)[0]); suword(1 + (unsigned long *) d, ((long *) &tll)[1]); REENTRANT_CHECK(ON); return 1; } /* Put a long into user memory */ int reg_store_int32(void) { long *d = (long *) FPU_data_address; FPU_REG t; if (FPU_st0_tag == TW_Empty) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); if (control_word & EX_Invalid) { /* The masked response */ /* Put out the QNaN indefinite */ REENTRANT_CHECK(OFF); /* verify_area(VERIFY_WRITE, d, 4);*/ suword((unsigned long *) d, 0x80000000); REENTRANT_CHECK(ON); return 1; } else return 0; } reg_move(FPU_st0_ptr, &t); round_to_int(&t); if (t.sigh || ((t.sigl & 0x80000000) && !((t.sigl == 0x80000000) && (t.sign == SIGN_NEG)))) { EXCEPTION(EX_Invalid); /* This is a special case: see sec 16.2.5.1 of the 80486 book */ if (control_word & EX_Invalid) { /* Produce "indefinite" */ t.sigl = 0x80000000; } else return 0; } else if (t.sign) t.sigl = -(long) t.sigl; REENTRANT_CHECK(OFF); /* verify_area(VERIFY_WRITE, d, 4); */ suword((unsigned long *) d, t.sigl); REENTRANT_CHECK(ON); return 1; } /* Put a short into user memory */ int reg_store_int16(void) { short *d = (short *) FPU_data_address; FPU_REG t; short ts; if (FPU_st0_tag == TW_Empty) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); if (control_word & EX_Invalid) { /* The masked response */ /* Put out the QNaN indefinite */ REENTRANT_CHECK(OFF); /* verify_area(VERIFY_WRITE, d, 2);*/ susword((unsigned short *) d, 0x8000); REENTRANT_CHECK(ON); return 1; } else return 0; } reg_move(FPU_st0_ptr, &t); round_to_int(&t); if (t.sigh || ((t.sigl & 0xffff8000) && !((t.sigl == 0x8000) && (t.sign == SIGN_NEG)))) { EXCEPTION(EX_Invalid); /* This is a special case: see sec 16.2.5.1 of the 80486 book */ if (control_word & EX_Invalid) { /* Produce "indefinite" */ ts = 0x8000; } else return 0; } else if (t.sign) t.sigl = -t.sigl; REENTRANT_CHECK(OFF); /* verify_area(VERIFY_WRITE, d, 2); */ susword((short *) d, (short) t.sigl); REENTRANT_CHECK(ON); return 1; } /* Put a packed bcd array into user memory */ int reg_store_bcd(void) { char *d = (char *) FPU_data_address; FPU_REG t; long long ll; unsigned char b; int i; unsigned char sign = (FPU_st0_ptr->sign == SIGN_NEG) ? 0x80 : 0; if (FPU_st0_tag == TW_Empty) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); if (control_word & EX_Invalid) { /* The masked response */ /* Put out the QNaN indefinite */ goto put_indefinite; } else return 0; } reg_move(FPU_st0_ptr, &t); round_to_int(&t); ll = *(long long *) (&t.sigl); /* Check for overflow, by comparing with 999999999999999999 decimal. */ if ((t.sigh > 0x0de0b6b3) || ((t.sigh == 0x0de0b6b3) && (t.sigl > 0xa763ffff))) { EXCEPTION(EX_Invalid); /* This is a special case: see sec 16.2.5.1 of the 80486 book */ if (control_word & EX_Invalid) { put_indefinite: /* Produce "indefinite" */ REENTRANT_CHECK(OFF); /* verify_area(VERIFY_WRITE, d, 10);*/ subyte((unsigned char *) d + 7, 0xff); subyte((unsigned char *) d + 8, 0xff); subyte((unsigned char *) d + 9, 0xff); REENTRANT_CHECK(ON); return 1; } else return 0; } /* verify_area(VERIFY_WRITE, d, 10);*/ for (i = 0; i < 9; i++) { b = div_small(&ll, 10); b |= (div_small(&ll, 10)) << 4; REENTRANT_CHECK(OFF); subyte((unsigned char *) d + i, b); REENTRANT_CHECK(ON); } REENTRANT_CHECK(OFF); subyte((unsigned char *) d + 9, sign); REENTRANT_CHECK(ON); return 1; } /*===========================================================================*/ /* r gets mangled such that sig is int, sign: it is NOT normalized */ /* The return value (in eax) is zero if the result is exact, if bits are changed due to rounding, truncation, etc, then a non-zero value is returned */ /* Overflow is signalled by a non-zero return value (in eax). In the case of overflow, the returned significand always has the the largest possible value */ /* The value returned in eax is never actually needed :-) */ int round_to_int(FPU_REG * r) { char very_big; unsigned eax; if (r->tag == TW_Zero) { /* Make sure that zero is returned */ *(long long *) &r->sigl = 0; return 0; /* o.k. */ } if (r->exp > EXP_BIAS + 63) { r->sigl = r->sigh = ~0; /* The largest representable number */ return 1; /* overflow */ } eax = shrxs(&r->sigl, EXP_BIAS + 63 - r->exp); very_big = !(~(r->sigh) | ~(r->sigl)); /* test for 0xfff...fff */ #define half_or_more (eax & 0x80000000) #define frac_part (eax) #define more_than_half ((eax & 0x80000001) == 0x80000001) switch (control_word & CW_RC) { case RC_RND: if (more_than_half /* nearest */ || (half_or_more && (r->sigl & 1))) { /* odd -> even */ if (very_big) return 1; /* overflow */ (*(long long *) (&r->sigl))++; return LOST_UP; } break; case RC_DOWN: if (frac_part && r->sign) { if (very_big) return 1; /* overflow */ (*(long long *) (&r->sigl))++; return LOST_UP; } break; case RC_UP: if (frac_part && !r->sign) { if (very_big) return 1; /* overflow */ (*(long long *) (&r->sigl))++; return LOST_UP; } break; case RC_CHOP: break; } return eax ? LOST_DOWN : 0; } /*===========================================================================*/ char * fldenv(void) { char *s = (char *) FPU_data_address; unsigned short tag_word = 0; unsigned char tag; int i; REENTRANT_CHECK(OFF); control_word = fusword((unsigned short *) s); status_word = fusword((unsigned short *) (s + 4)); tag_word = fusword((unsigned short *) (s + 8)); ip_offset = fuword((unsigned long *) (s + 0x0c)); cs_selector = fuword((unsigned long *) (s + 0x10)); data_operand_offset = fuword((unsigned long *) (s + 0x14)); operand_selector = fuword((unsigned long *) (s + 0x18)); REENTRANT_CHECK(ON); top = (status_word >> SW_Top_Shift) & 7; for (i = 0; i < 8; i++) { tag = tag_word & 3; tag_word >>= 2; switch (tag) { case 0: regs[i].tag = TW_Valid; break; case 1: regs[i].tag = TW_Zero; break; case 2: regs[i].tag = TW_NaN; break; case 3: regs[i].tag = TW_Empty; break; } } FPU_data_address = (void *) data_operand_offset; /* We want no net effect */ FPU_entry_eip = ip_offset; /* We want no net effect */ return s + 0x1c; } void frstor(void) { int i, stnr; unsigned char tag; unsigned short saved_status, saved_control; char *s = (char *) fldenv(); saved_status = status_word; saved_control = control_word; control_word = 0x037f; /* Mask all interrupts while we load. */ for (i = 0; i < 8; i++) { /* load each register */ FPU_data_address = (void *) (s + i * 10); reg_load_extended(); stnr = (i + top) & 7; tag = regs[stnr].tag; /* derived from the loaded tag word */ reg_move(&FPU_loaded_data, ®s[stnr]); if (tag == TW_NaN) { /* The current data is a special, i.e. NaN, * unsupported, infinity, or denormal */ unsigned char t = regs[stnr].tag; /* derived from the new * data */ if ( /* (t == TW_Valid) || *** */ (t == TW_Zero)) regs[stnr].tag = TW_NaN; } else regs[stnr].tag = tag; } control_word = saved_control; status_word = saved_status; FPU_data_address = (void *) data_operand_offset; /* We want no net effect */ } unsigned short tag_word(void) { unsigned short word = 0; unsigned char tag; int i; for (i = 7; i >= 0; i--) { switch (tag = regs[i].tag) { #if 0 /* TW_Denormal is not used yet, and probably * won't be */ case TW_Denormal: #endif case TW_Valid: if (regs[i].exp <= (EXP_BIAS - EXTENDED_Ebias)) tag = 2; break; case TW_Infinity: case TW_NaN: tag = 2; break; case TW_Empty: tag = 3; break; /* TW_Valid and TW_Zero already have the correct value */ } word <<= 2; word |= tag; } return word; } char * fstenv(void) { char *d = (char *) FPU_data_address; /* verify_area(VERIFY_WRITE, d, 28);*/ #if 0 /****/ *(unsigned short *) &cs_selector = fpu_cs; *(unsigned short *) &operand_selector = fpu_os; #endif /****/ REENTRANT_CHECK(OFF); susword((unsigned short *) d, control_word); susword((unsigned short *) (d + 4), (status_word & ~SW_Top) | ((top & 7) << SW_Top_Shift)); susword((unsigned short *) (d + 8), tag_word()); suword((unsigned long *) (d + 0x0c), ip_offset); suword((unsigned long *) (d + 0x10), cs_selector); suword((unsigned long *) (d + 0x14), data_operand_offset); suword((unsigned long *) (d + 0x18), operand_selector); REENTRANT_CHECK(ON); return d + 0x1c; } void fsave(void) { char *d; FPU_REG tmp, *rp; int i; short e; d = fstenv(); /* verify_area(VERIFY_WRITE, d, 80);*/ for (i = 0; i < 8; i++) { /* Store each register in the order: st(0), st(1), ... */ rp = ®s[(top + i) & 7]; e = rp->exp - EXP_BIAS + EXTENDED_Ebias; if (rp->tag == TW_Valid) { if (e >= 0x7fff) { /* Overflow to infinity */ REENTRANT_CHECK(OFF); suword((unsigned long *) (d + i * 10), 0); suword((unsigned long *) (d + i * 10 + 4), 0); REENTRANT_CHECK(ON); e = 0x7fff; } else if (e <= 0) { if (e > -63) { /* Make a de-normal */ reg_move(rp, &tmp); tmp.exp += -EXTENDED_Emin + 63; /* largest exp to be 62 */ round_to_int(&tmp); REENTRANT_CHECK(OFF); suword((unsigned long *) (d + i * 10), tmp.sigl); suword((unsigned long *) (d + i * 10 + 4), tmp.sigh); REENTRANT_CHECK(ON); } else { /* Underflow to zero */ REENTRANT_CHECK(OFF); suword((unsigned long *) (d + i * 10), 0); suword((unsigned long *) (d + i * 10 + 4), 0); REENTRANT_CHECK(ON); } e = 0; } else { REENTRANT_CHECK(OFF); suword((unsigned long *) (d + i * 10), rp->sigl); suword((unsigned long *) (d + i * 10 + 4), rp->sigh); REENTRANT_CHECK(ON); } } else if (rp->tag == TW_Zero) { REENTRANT_CHECK(OFF); suword((unsigned long *) (d + i * 10), 0); suword((unsigned long *) (d + i * 10 + 4), 0); REENTRANT_CHECK(ON); e = 0; } else if (rp->tag == TW_Infinity) { REENTRANT_CHECK(OFF); suword((unsigned long *) (d + i * 10), 0); suword((unsigned long *) (d + i * 10 + 4), 0x80000000); REENTRANT_CHECK(ON); e = 0x7fff; } else if (rp->tag == TW_NaN) { REENTRANT_CHECK(OFF); suword((unsigned long *) (d + i * 10), rp->sigl); suword((unsigned long *) (d + i * 10 + 4), rp->sigh); REENTRANT_CHECK(ON); e = 0x7fff; } else if (rp->tag == TW_Empty) { /* just copy the reg */ REENTRANT_CHECK(OFF); suword((unsigned long *) (d + i * 10), rp->sigl); suword((unsigned long *) (d + i * 10 + 4), rp->sigh); REENTRANT_CHECK(ON); } e |= rp->sign == SIGN_POS ? 0 : 0x8000; REENTRANT_CHECK(OFF); susword((unsigned short *) (d + i * 10 + 8), e); REENTRANT_CHECK(ON); } finit(); } /*===========================================================================*/