/*---------------------------------------------------------------------------+ | reg_ld_str.c | | | | All of the functions which transfer data between user memory and FPU_REGs.| | | | Copyright (C) 1992,1993,1994,1996 | | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | | E-mail billm@jacobi.maths.monash.edu.au | | | | | +---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------+ | 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 "fpu_system.h" #include "exception.h" #include "reg_constant.h" #include "fpu_emu.h" #include "control_w.h" #include "status_w.h" #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 */ static void write_to_extended(FPU_REG *rp, char *d); /* Get a long double from user memory */ int reg_load_extended(long double *s, FPU_REG *loaded_data) { unsigned long sigl, sigh, exp; RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_READ, s, 10); get_user(sigl, (unsigned long *) s); get_user(sigh, 1 + (unsigned long *) s); get_user(exp, 4 + (unsigned short *) s); RE_ENTRANT_CHECK_ON; loaded_data->tag = TW_Valid; /* Default */ loaded_data->sigl = sigl; loaded_data->sigh = sigh; if (exp & 0x8000) loaded_data->sign = SIGN_NEG; else loaded_data->sign = SIGN_POS; exp &= 0x7fff; loaded_data->exp = exp - EXTENDED_Ebias + EXP_BIAS; if ( exp == 0 ) { if ( !(sigh | sigl) ) { loaded_data->tag = TW_Zero; return 0; } /* The number is a de-normal or pseudodenormal. */ if (sigh & 0x80000000) { /* Is a pseudodenormal. */ /* Convert it for internal use. */ /* This is non-80486 behaviour because the number loses its 'denormal' identity. */ loaded_data->exp++; return 1; } else { /* Is a denormal. */ /* Convert it for internal use. */ loaded_data->exp++; normalize_nuo(loaded_data); return 0; } } else if ( exp == 0x7fff ) { if ( !((sigh ^ 0x80000000) | sigl) ) { /* Matches the bit pattern for Infinity. */ loaded_data->exp = EXP_Infinity; loaded_data->tag = TW_Infinity; return 0; } loaded_data->exp = EXP_NaN; loaded_data->tag = TW_NaN; if ( !(sigh & 0x80000000) ) { /* NaNs have the ms bit set to 1. */ /* This is therefore an Unsupported NaN data type. */ /* This is non 80486 behaviour */ /* This should generate an Invalid Operand exception later, so we convert it to a SNaN */ loaded_data->sigh = 0x80000000; loaded_data->sigl = 0x00000001; loaded_data->sign = SIGN_NEG; return 1; } return 0; } if ( !(sigh & 0x80000000) ) { /* Unsupported data type. */ /* Valid numbers have the ms bit set to 1. */ /* Unnormal. */ /* Convert it for internal use. */ /* This is non-80486 behaviour */ /* This should generate an Invalid Operand exception later, so we convert it to a SNaN */ loaded_data->sigh = 0x80000000; loaded_data->sigl = 0x00000001; loaded_data->sign = SIGN_NEG; loaded_data->exp = EXP_NaN; loaded_data->tag = TW_NaN; return 1; } return 0; } /* Get a double from user memory */ int reg_load_double(double *dfloat, FPU_REG *loaded_data) { int exp; unsigned m64, l64; RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_READ, dfloat, 8); get_user(m64, 1 + (unsigned long *) dfloat); get_user(l64, (unsigned long *) dfloat); RE_ENTRANT_CHECK_ON; if (m64 & 0x80000000) loaded_data->sign = SIGN_NEG; else 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 */ loaded_data->sigh = 0x80000000; loaded_data->sigl = 0x00000000; loaded_data->exp = EXP_Infinity; loaded_data->tag = TW_Infinity; return 0; } else { /* Must be a signaling or quiet NaN */ loaded_data->exp = EXP_NaN; loaded_data->tag = TW_NaN; loaded_data->sigh = (m64 << 11) | 0x80000000; loaded_data->sigh |= l64 >> 21; loaded_data->sigl = l64 << 11; return 0; /* The calling function must look for NaNs */ } } else if ( exp < DOUBLE_Emin ) { /* Zero or de-normal */ if ((m64 == 0) && (l64 == 0)) { /* Zero */ int c = loaded_data->sign; reg_move(&CONST_Z, loaded_data); loaded_data->sign = c; return 0; } else { /* De-normal */ loaded_data->exp = DOUBLE_Emin + EXP_BIAS; loaded_data->tag = TW_Valid; loaded_data->sigh = m64 << 11; loaded_data->sigh |= l64 >> 21; loaded_data->sigl = l64 << 11; normalize_nuo(loaded_data); return denormal_operand(); } } else { loaded_data->exp = exp + EXP_BIAS; loaded_data->tag = TW_Valid; loaded_data->sigh = (m64 << 11) | 0x80000000; loaded_data->sigh |= l64 >> 21; loaded_data->sigl = l64 << 11; return 0; } } /* Get a float from user memory */ int reg_load_single(float *single, FPU_REG *loaded_data) { unsigned m32; int exp; RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_READ, single, 4); get_user(m32, (unsigned long *) single); RE_ENTRANT_CHECK_ON; if (m32 & 0x80000000) loaded_data->sign = SIGN_NEG; else loaded_data->sign = SIGN_POS; if (!(m32 & 0x7fffffff)) { /* Zero */ int c = loaded_data->sign; reg_move(&CONST_Z, loaded_data); loaded_data->sign = c; return 0; } exp = ((m32 & 0x7f800000) >> 23) - SINGLE_Ebias; m32 = (m32 & 0x7fffff) << 8; if ( exp < SINGLE_Emin ) { /* De-normals */ loaded_data->exp = SINGLE_Emin + EXP_BIAS; loaded_data->tag = TW_Valid; loaded_data->sigh = m32; loaded_data->sigl = 0; normalize_nuo(loaded_data); return denormal_operand(); } else if ( exp > SINGLE_Emax ) { /* Infinity or NaN */ if ( m32 == 0 ) { /* +- infinity */ loaded_data->sigh = 0x80000000; loaded_data->sigl = 0x00000000; loaded_data->exp = EXP_Infinity; loaded_data->tag = TW_Infinity; return 0; } else { /* Must be a signaling or quiet NaN */ loaded_data->exp = EXP_NaN; loaded_data->tag = TW_NaN; loaded_data->sigh = m32 | 0x80000000; loaded_data->sigl = 0; return 0; /* The calling function must look for NaNs */ } } else { loaded_data->exp = exp + EXP_BIAS; loaded_data->sigh = m32 | 0x80000000; loaded_data->sigl = 0; loaded_data->tag = TW_Valid; return 0; } } /* Get a long long from user memory */ void reg_load_int64(long long *_s, FPU_REG *loaded_data) { int e; long long s; RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_READ, _s, 8); copy_from_user(&s,_s,8); RE_ENTRANT_CHECK_ON; if (s == 0) { reg_move(&CONST_Z, loaded_data); return; } if (s > 0) loaded_data->sign = SIGN_POS; else { s = -s; loaded_data->sign = SIGN_NEG; } e = EXP_BIAS + 63; significand(loaded_data) = s; loaded_data->exp = e; loaded_data->tag = TW_Valid; normalize_nuo(loaded_data); } /* Get a long from user memory */ void reg_load_int32(long *_s, FPU_REG *loaded_data) { long s; int e; RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_READ, _s, 4); get_user(s, _s); RE_ENTRANT_CHECK_ON; if (s == 0) { reg_move(&CONST_Z, loaded_data); return; } if (s > 0) loaded_data->sign = SIGN_POS; else { s = -s; loaded_data->sign = SIGN_NEG; } e = EXP_BIAS + 31; loaded_data->sigh = s; loaded_data->sigl = 0; loaded_data->exp = e; loaded_data->tag = TW_Valid; normalize_nuo(loaded_data); } /* Get a short from user memory */ void reg_load_int16(short *_s, FPU_REG *loaded_data) { int s, e; RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_READ, _s, 2); /* Cast as short to get the sign extended. */ get_user(s, _s); RE_ENTRANT_CHECK_ON; if (s == 0) { reg_move(&CONST_Z, loaded_data); return; } if (s > 0) loaded_data->sign = SIGN_POS; else { s = -s; loaded_data->sign = SIGN_NEG; } e = EXP_BIAS + 15; loaded_data->sigh = s << 16; loaded_data->sigl = 0; loaded_data->exp = e; loaded_data->tag = TW_Valid; normalize_nuo(loaded_data); } /* Get a packed bcd array from user memory */ void reg_load_bcd(char *s, FPU_REG *loaded_data) { int pos; unsigned char bcd; long long l=0; RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_READ, s, 10); RE_ENTRANT_CHECK_ON; for ( pos = 8; pos >= 0; pos--) { l *= 10; RE_ENTRANT_CHECK_OFF; get_user(bcd, (unsigned char *) s+pos); RE_ENTRANT_CHECK_ON; l += bcd >> 4; l *= 10; l += bcd & 0x0f; } RE_ENTRANT_CHECK_OFF; { unsigned char sign; get_user(sign, (unsigned char *) s+9); loaded_data->sign = (sign & 0x80) ? SIGN_NEG : SIGN_POS; } RE_ENTRANT_CHECK_ON; if (l == 0) { char sign = loaded_data->sign; reg_move(&CONST_Z, loaded_data); loaded_data->sign = sign; } else { significand(loaded_data) = l; loaded_data->exp = EXP_BIAS + 63; loaded_data->tag = TW_Valid; normalize_nuo(loaded_data); } } /*===========================================================================*/ /* Put a long double into user memory */ int reg_store_extended(long double *d, FPU_REG *st0_ptr) { /* The only exception raised by an attempt to store to an extended format is the Invalid Stack exception, i.e. attempting to store from an empty register. */ if ( st0_ptr->tag != TW_Empty ) { RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE, d, 10); RE_ENTRANT_CHECK_ON; write_to_extended(st0_ptr, (char *) d); return 1; } /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); if ( control_word & CW_Invalid ) { /* The masked response */ /* Put out the QNaN indefinite */ RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,d,10); put_user(0, (unsigned long *) d); put_user(0xc0000000, 1 + (unsigned long *) d); put_user(0xffff, 4 + (short *) d); RE_ENTRANT_CHECK_ON; return 1; } else return 0; } /* Put a double into user memory */ int reg_store_double(double *dfloat, FPU_REG *st0_ptr) { unsigned long l[2]; unsigned long increment = 0; /* avoid gcc warnings */ char st0_tag = st0_ptr->tag; if (st0_tag == TW_Valid) { int precision_loss; int exp; FPU_REG tmp; reg_move(st0_ptr, &tmp); exp = tmp.exp - EXP_BIAS; if ( exp < DOUBLE_Emin ) /* It may be a denormal */ { /* A denormal will always underflow. */ #ifndef PECULIAR_486 /* An 80486 is supposed to be able to generate a denormal exception here, but... */ if ( st0_ptr->exp <= EXP_UNDER ) { /* Underflow has priority. */ if ( control_word & CW_Underflow ) denormal_operand(); } #endif PECULIAR_486 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) && (st0_ptr->sigl & 0x000007ff)) ) #endif PECULIAR_486 { EXCEPTION(EX_Underflow); /* This is a special case: see sec 16.2.5.1 of the 80486 book */ if ( !(control_word & CW_Underflow) ) return 0; } EXCEPTION(precision_loss); if ( !(control_word & CW_Precision) ) return 0; } l[0] = tmp.sigl; l[1] = tmp.sigh; } else { if ( tmp.sigl & 0x000007ff ) { precision_loss = 1; 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 ) { 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 precision_loss = 0; l[0] = (tmp.sigl >> 11) | (tmp.sigh << 21); l[1] = ((tmp.sigh >> 11) & 0xfffff); if ( exp > DOUBLE_Emax ) { overflow: EXCEPTION(EX_Overflow); if ( !(control_word & CW_Overflow) ) return 0; set_precision_flag_up(); if ( !(control_word & CW_Precision) ) return 0; /* This is a special case: see sec 16.2.5.1 of the 80486 book */ /* Overflow to infinity */ l[0] = 0x00000000; /* Set to */ l[1] = 0x7ff00000; /* + INF */ } else { if ( precision_loss ) { if ( increment ) set_precision_flag_up(); else set_precision_flag_down(); } /* Add the exponent */ l[1] |= (((exp+DOUBLE_Ebias) & 0x7ff) << 20); } } } else if (st0_tag == TW_Zero) { /* Number is zero */ l[0] = 0; l[1] = 0; } else if (st0_tag == TW_Infinity) { l[0] = 0; l[1] = 0x7ff00000; } else if (st0_tag == TW_NaN) { /* See if we can get a valid NaN from the FPU_REG */ l[0] = (st0_ptr->sigl >> 11) | (st0_ptr->sigh << 21); l[1] = ((st0_ptr->sigh >> 11) & 0xfffff); if ( !(st0_ptr->sigh & 0x40000000) ) { /* It is a signalling NaN */ EXCEPTION(EX_Invalid); if ( !(control_word & CW_Invalid) ) return 0; l[1] |= (0x40000000 >> 11); } l[1] |= 0x7ff00000; } else if ( st0_tag == TW_Empty ) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); if ( control_word & CW_Invalid ) { /* The masked response */ /* Put out the QNaN indefinite */ RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,(void *)dfloat,8); put_user(0, (unsigned long *) dfloat); put_user(0xfff80000, 1 + (unsigned long *) dfloat); RE_ENTRANT_CHECK_ON; return 1; } else return 0; } if ( st0_ptr->sign ) l[1] |= 0x80000000; RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,(void *)dfloat,8); put_user(l[0], (unsigned long *)dfloat); put_user(l[1], 1 + (unsigned long *)dfloat); RE_ENTRANT_CHECK_ON; return 1; } /* Put a float into user memory */ int reg_store_single(float *single, FPU_REG *st0_ptr) { long templ; unsigned long increment = 0; /* avoid gcc warnings */ char st0_tag = st0_ptr->tag; if (st0_tag == TW_Valid) { int precision_loss; int exp; FPU_REG tmp; reg_move(st0_ptr, &tmp); exp = tmp.exp - EXP_BIAS; if ( exp < SINGLE_Emin ) { /* A denormal will always underflow. */ #ifndef PECULIAR_486 /* An 80486 is supposed to be able to generate a denormal exception here, but... */ if ( st0_ptr->exp <= EXP_UNDER ) { /* Underflow has priority. */ if ( control_word & CW_Underflow ) denormal_operand(); } #endif PECULIAR_486 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) && ((st0_ptr->sigh & 0x000000ff) || st0_ptr->sigl)) ) #endif PECULIAR_486 { EXCEPTION(EX_Underflow); /* This is a special case: see sec 16.2.5.1 of the 80486 book */ if ( !(control_word & EX_Underflow) ) return 0; } EXCEPTION(precision_loss); if ( !(control_word & EX_Precision) ) return 0; } templ = tmp.sigl; } else { if ( tmp.sigl | (tmp.sigh & 0x000000ff) ) { unsigned long sigh = tmp.sigh; unsigned long sigl = tmp.sigl; precision_loss = 1; 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) { 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 { tmp.sigh &= 0xffffff00; /* Finish the truncation */ } } else precision_loss = 0; templ = (tmp.sigh >> 8) & 0x007fffff; if ( exp > SINGLE_Emax ) { overflow: EXCEPTION(EX_Overflow); if ( !(control_word & CW_Overflow) ) return 0; set_precision_flag_up(); if ( !(control_word & CW_Precision) ) return 0; /* This is a special case: see sec 16.2.5.1 of the 80486 book. */ /* Masked response is overflow to infinity. */ templ = 0x7f800000; } else { if ( precision_loss ) { if ( increment ) set_precision_flag_up(); else set_precision_flag_down(); } /* Add the exponent */ templ |= ((exp+SINGLE_Ebias) & 0xff) << 23; } } } else if (st0_tag == TW_Zero) { templ = 0; } else if (st0_tag == TW_Infinity) { templ = 0x7f800000; } else if (st0_tag == TW_NaN) { /* See if we can get a valid NaN from the FPU_REG */ templ = st0_ptr->sigh >> 8; if ( !(st0_ptr->sigh & 0x40000000) ) { /* It is a signalling NaN */ EXCEPTION(EX_Invalid); if ( !(control_word & CW_Invalid) ) return 0; templ |= (0x40000000 >> 8); } templ |= 0x7f800000; } else if ( st0_tag == TW_Empty ) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); if ( control_word & EX_Invalid ) { /* The masked response */ /* Put out the QNaN indefinite */ RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,(void *)single,4); put_user(0xffc00000, (unsigned long *) single); RE_ENTRANT_CHECK_ON; return 1; } else return 0; } #ifdef PARANOID else { EXCEPTION(EX_INTERNAL|0x163); return 0; } #endif if (st0_ptr->sign) templ |= 0x80000000; RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,(void *)single,4); put_user(templ,(unsigned long *) single); RE_ENTRANT_CHECK_ON; return 1; } /* Put a long long into user memory */ int reg_store_int64(long long *d, FPU_REG *st0_ptr) { FPU_REG t; long long tll; int precision_loss; char st0_tag = st0_ptr->tag; if ( st0_tag == TW_Empty ) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); goto invalid_operand; } else if ( (st0_tag == TW_Infinity) || (st0_tag == TW_NaN) ) { EXCEPTION(EX_Invalid); goto invalid_operand; } reg_move(st0_ptr, &t); precision_loss = round_to_int(&t); ((long *)&tll)[0] = t.sigl; ((long *)&tll)[1] = t.sigh; if ( (precision_loss == 1) || ((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 */ invalid_operand: if ( control_word & EX_Invalid ) { /* Produce something like QNaN "indefinite" */ tll = 0x8000000000000000LL; } else return 0; } else { if ( precision_loss ) set_precision_flag(precision_loss); if ( t.sign ) tll = - tll; } RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,(void *)d,8); copy_to_user(d, &tll, 8); RE_ENTRANT_CHECK_ON; return 1; } /* Put a long into user memory */ int reg_store_int32(long *d, FPU_REG *st0_ptr) { FPU_REG t; int precision_loss; char st0_tag = st0_ptr->tag; if ( st0_tag == TW_Empty ) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); goto invalid_operand; } else if ( (st0_tag == TW_Infinity) || (st0_tag == TW_NaN) ) { EXCEPTION(EX_Invalid); goto invalid_operand; } reg_move(st0_ptr, &t); precision_loss = 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 */ invalid_operand: if ( control_word & EX_Invalid ) { /* Produce something like QNaN "indefinite" */ t.sigl = 0x80000000; } else return 0; } else { if ( precision_loss ) set_precision_flag(precision_loss); if ( t.sign ) t.sigl = -(long)t.sigl; } RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,d,4); put_user(t.sigl, (unsigned long *) d); RE_ENTRANT_CHECK_ON; return 1; } /* Put a short into user memory */ int reg_store_int16(short *d, FPU_REG *st0_ptr) { FPU_REG t; int precision_loss; char st0_tag = st0_ptr->tag; if ( st0_tag == TW_Empty ) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); goto invalid_operand; } else if ( (st0_tag == TW_Infinity) || (st0_tag == TW_NaN) ) { EXCEPTION(EX_Invalid); goto invalid_operand; } reg_move(st0_ptr, &t); precision_loss = 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 */ invalid_operand: if ( control_word & EX_Invalid ) { /* Produce something like QNaN "indefinite" */ t.sigl = 0x8000; } else return 0; } else { if ( precision_loss ) set_precision_flag(precision_loss); if ( t.sign ) t.sigl = -t.sigl; } RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,d,2); put_user((short)t.sigl,(short *) d); RE_ENTRANT_CHECK_ON; return 1; } /* Put a packed bcd array into user memory */ int reg_store_bcd(char *d, FPU_REG *st0_ptr) { FPU_REG t; unsigned long long ll; unsigned char b; int i, precision_loss; unsigned char sign = (st0_ptr->sign == SIGN_NEG) ? 0x80 : 0; char st0_tag = st0_ptr->tag; if ( st0_tag == TW_Empty ) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); goto invalid_operand; } reg_move(st0_ptr, &t); precision_loss = round_to_int(&t); ll = significand(&t); /* 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 */ invalid_operand: if ( control_word & CW_Invalid ) { /* Produce the QNaN "indefinite" */ RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,d,10); for ( i = 0; i < 7; i++) put_user(0, (unsigned char *) d+i); /* These bytes "undefined" */ put_user(0xc0, (unsigned char *) d+7); /* This byte "undefined" */ put_user(0xff, (unsigned char *) d+8); put_user(0xff, (unsigned char *) d+9); RE_ENTRANT_CHECK_ON; return 1; } else return 0; } else if ( precision_loss ) { /* Precision loss doesn't stop the data transfer */ set_precision_flag(precision_loss); } RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,d,10); RE_ENTRANT_CHECK_ON; for ( i = 0; i < 9; i++) { b = div_small(&ll, 10); b |= (div_small(&ll, 10)) << 4; RE_ENTRANT_CHECK_OFF; put_user(b,(unsigned char *) d+i); RE_ENTRANT_CHECK_ON; } RE_ENTRANT_CHECK_OFF; put_user(sign,(unsigned char *) d+9); RE_ENTRANT_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 largest possible value */ int round_to_int(FPU_REG *r) { char very_big; unsigned eax; if (r->tag == TW_Zero) { /* Make sure that zero is returned */ significand(r) = 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 */ significand(r) ++; return PRECISION_LOST_UP; } break; case RC_DOWN: if (frac_part && r->sign) { if ( very_big ) return 1; /* overflow */ significand(r) ++; return PRECISION_LOST_UP; } break; case RC_UP: if (frac_part && !r->sign) { if ( very_big ) return 1; /* overflow */ significand(r) ++; return PRECISION_LOST_UP; } break; case RC_CHOP: break; } return eax ? PRECISION_LOST_DOWN : 0; } /*===========================================================================*/ char *fldenv(fpu_addr_modes addr_modes, char *s) { unsigned short tag_word = 0; unsigned char tag; int i; if ( (addr_modes.default_mode == VM86) || ((addr_modes.default_mode == PM16) ^ (addr_modes.override.operand_size == OP_SIZE_PREFIX)) ) { RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_READ, s, 0x0e); get_user(control_word, (unsigned short *) s); get_user(partial_status, (unsigned short *) (s+2)); get_user(tag_word, (unsigned short *) (s+4)); get_user(instruction_address.offset, (unsigned short *) (s+6)); get_user(instruction_address.selector, (unsigned short *) (s+8)); get_user(operand_address.offset, (unsigned short *) (s+0x0a)); get_user(operand_address.selector, (unsigned short *) (s+0x0c)); RE_ENTRANT_CHECK_ON; s += 0x0e; if ( addr_modes.default_mode == VM86 ) { instruction_address.offset += (instruction_address.selector & 0xf000) << 4; operand_address.offset += (operand_address.selector & 0xf000) << 4; } } else { RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_READ, s, 0x1c); get_user(control_word, (unsigned short *) s); get_user(partial_status, (unsigned short *) (s+4)); get_user(tag_word, (unsigned short *) (s+8)); get_user(instruction_address.offset, (unsigned long *) (s+0x0c)); get_user(instruction_address.selector, (unsigned short *) (s+0x10)); get_user(instruction_address.opcode, (unsigned short *) (s+0x12)); get_user(operand_address.offset, (unsigned long *) (s+0x14)); get_user(operand_address.selector, (unsigned long *) (s+0x18)); RE_ENTRANT_CHECK_ON; s += 0x1c; } #ifdef PECULIAR_486 control_word &= ~0xe080; #endif PECULIAR_486 top = (partial_status >> SW_Top_Shift) & 7; if ( partial_status & ~control_word & CW_Exceptions ) partial_status |= (SW_Summary | SW_Backward); else partial_status &= ~(SW_Summary | SW_Backward); for ( i = 0; i < 8; i++ ) { tag = tag_word & 3; tag_word >>= 2; if ( tag == 3 ) /* New tag is empty. Accept it */ regs[i].tag = TW_Empty; else if ( regs[i].tag == TW_Empty ) { /* Old tag is empty and new tag is not empty. New tag is determined by old reg contents */ if ( regs[i].exp == EXP_BIAS - EXTENDED_Ebias ) { if ( !(regs[i].sigl | regs[i].sigh) ) regs[i].tag = TW_Zero; else regs[i].tag = TW_Valid; } else if ( regs[i].exp == 0x7fff + EXP_BIAS - EXTENDED_Ebias ) { if ( !((regs[i].sigh & ~0x80000000) | regs[i].sigl) ) regs[i].tag = TW_Infinity; else regs[i].tag = TW_NaN; } else regs[i].tag = TW_Valid; } /* Else old tag is not empty and new tag is not empty. Old tag remains correct */ } return s; } void frstor(fpu_addr_modes addr_modes, char *data_address) { int i, stnr; unsigned char tag; char *s = fldenv(addr_modes, data_address); for ( i = 0; i < 8; i++ ) { /* Load each register. */ stnr = (i+top) & 7; tag = regs[stnr].tag; /* Derived from the fldenv() loaded tag word. */ reg_load_extended((long double *)(s+i*10), ®s[stnr]); if ( tag == TW_Empty ) /* The loaded data over-rides all other cases. */ regs[stnr].tag = tag; } } 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 ) { 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_Zero already has the correct value */ } word <<= 2; word |= tag; } return word; } char *fstenv(fpu_addr_modes addr_modes, char *d) { if ( (addr_modes.default_mode == VM86) || ((addr_modes.default_mode == PM16) ^ (addr_modes.override.operand_size == OP_SIZE_PREFIX)) ) { RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,d,14); #ifdef PECULIAR_486 put_user(control_word & ~0xe080, (unsigned long *) d); #else put_user(control_word, (unsigned short *) d); #endif PECULIAR_486 put_user(status_word(), (unsigned short *) (d+2)); put_user(tag_word(), (unsigned short *) (d+4)); put_user(instruction_address.offset, (unsigned short *) (d+6)); put_user(operand_address.offset, (unsigned short *) (d+0x0a)); if ( addr_modes.default_mode == VM86 ) { put_user((instruction_address.offset & 0xf0000) >> 4, (unsigned short *) (d+8)); put_user((operand_address.offset & 0xf0000) >> 4, (unsigned short *) (d+0x0c)); } else { put_user(instruction_address.selector, (unsigned short *) (d+8)); put_user(operand_address.selector, (unsigned short *) (d+0x0c)); } RE_ENTRANT_CHECK_ON; d += 0x0e; } else { RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,d,28); #ifdef PECULIAR_486 /* An 80486 sets all the reserved bits to 1. */ put_user(0xffff0040 | (control_word & ~0xe080), (unsigned long *) d); put_user(0xffff0000 | status_word(), (unsigned long *) (d+4)); put_user(0xffff0000 | tag_word(), (unsigned long *) (d+8)); #else put_user(control_word, (unsigned short *) d); put_user(status_word(), (unsigned short *) (d+4)); put_user(tag_word(), (unsigned short *) (d+8)); #endif PECULIAR_486 put_user(instruction_address.offset, (unsigned long *) (d+0x0c)); put_user(instruction_address.selector, (unsigned short *) (d+0x10)); put_user(instruction_address.opcode, (unsigned short *) (d+0x12)); put_user(operand_address.offset, (unsigned long *) (d+0x14)); #ifdef PECULIAR_486 /* An 80486 sets all the reserved bits to 1. */ put_user(operand_address.selector, (unsigned short *) (d+0x18)); put_user(0xffff, (unsigned short *) (d+0x1a)); #else put_user(operand_address.selector, (unsigned long *) (d+0x18)); #endif PECULIAR_486 RE_ENTRANT_CHECK_ON; d += 0x1c; } control_word |= CW_Exceptions; partial_status &= ~(SW_Summary | SW_Backward); return d; } void fsave(fpu_addr_modes addr_modes, char *data_address) { char *d; int i; d = fstenv(addr_modes, data_address); RE_ENTRANT_CHECK_OFF; FPU_verify_area(VERIFY_WRITE,d,80); RE_ENTRANT_CHECK_ON; for ( i = 0; i < 8; i++ ) write_to_extended(®s[(top + i) & 7], d + 10 * i); finit(); } /*===========================================================================*/ /* A call to this function must be preceded by a call to FPU_verify_area() to verify access to the 10 bytes at d */ static void write_to_extended(FPU_REG *rp, char *d) { long e; FPU_REG tmp; e = rp->exp - EXP_BIAS + EXTENDED_Ebias; #ifdef PARANOID switch ( rp->tag ) { case TW_Zero: if ( rp->sigh | rp->sigl | e ) EXCEPTION(EX_INTERNAL | 0x160); break; case TW_Infinity: case TW_NaN: if ( (e ^ 0x7fff) | !(rp->sigh & 0x80000000) ) EXCEPTION(EX_INTERNAL | 0x161); break; default: if (e > 0x7fff || e < -63) EXCEPTION(EX_INTERNAL | 0x162); } #endif PARANOID /* All numbers except denormals are stored internally in a format which is compatible with the extended real number format. */ if ( e > 0 ) { /* just copy the reg */ RE_ENTRANT_CHECK_OFF; put_user(rp->sigl, (unsigned long *) d); put_user(rp->sigh, (unsigned long *) (d + 4)); RE_ENTRANT_CHECK_ON; } else { /* The number is a de-normal stored as a normal using our extra exponent range, or is Zero. Convert it back to a de-normal, or leave it as Zero. */ reg_move(rp, &tmp); tmp.exp += -EXTENDED_Emin + 63; /* largest exp to be 63 */ round_to_int(&tmp); e = 0; RE_ENTRANT_CHECK_OFF; put_user(tmp.sigl, (unsigned long *) d); put_user(tmp.sigh, (unsigned long *) (d + 4)); RE_ENTRANT_CHECK_ON; } e |= rp->sign == SIGN_POS ? 0 : 0x8000; RE_ENTRANT_CHECK_OFF; put_user(e, (unsigned short *) (d + 8)); RE_ENTRANT_CHECK_ON; }