/*---------------------------------------------------------------------------+ | reg_ld_str.c | | | | All of the functions which transfer data between user memory and FPU_REGs.| | | | Copyright (C) 1992,1993,1994,1996,1997 | | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | | E-mail billm@suburbia.net | | | | | +---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------+ | 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 "fpu_emu.h" #include <asm/uaccess.h> #include "fpu_system.h" #include "exception.h" #include "reg_constant.h" #include "control_w.h" #include "status_w.h" #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 u_char normalize_no_excep(FPU_REG *r, int exp, int sign) { u_char tag; setexponent16(r, exp); tag = FPU_normalize_nuo(r); stdexp(r); if ( sign ) setnegative(r); return tag; } int FPU_tagof(FPU_REG *ptr) { int exp; exp = exponent16(ptr) & 0x7fff; if ( exp == 0 ) { if ( !(ptr->sigh | ptr->sigl) ) { return TAG_Zero; } /* The number is a de-normal or pseudodenormal. */ return TAG_Special; } if ( exp == 0x7fff ) { /* Is an Infinity, a NaN, or an unsupported data type. */ return TAG_Special; } if ( !(ptr->sigh & 0x80000000) ) { /* Unsupported data type. */ /* Valid numbers have the ms bit set to 1. */ /* Unnormal. */ return TAG_Special; } return TAG_Valid; } /* Get a long double from user memory */ int FPU_load_extended(long double __user *s, int stnr) { FPU_REG *sti_ptr = &st(stnr); RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_READ, s, 10); __copy_from_user(sti_ptr, s, 10); RE_ENTRANT_CHECK_ON; return FPU_tagof(sti_ptr); } /* Get a double from user memory */ int FPU_load_double(double __user *dfloat, FPU_REG *loaded_data) { int exp, tag, negative; unsigned m64, l64; RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_READ, dfloat, 8); FPU_get_user(m64, 1 + (unsigned long __user *) dfloat); FPU_get_user(l64, (unsigned long __user *) dfloat); RE_ENTRANT_CHECK_ON; negative = (m64 & 0x80000000) ? SIGN_Negative : SIGN_Positive; exp = ((m64 & 0x7ff00000) >> 20) - DOUBLE_Ebias + EXTENDED_Ebias; m64 &= 0xfffff; if ( exp > DOUBLE_Emax + EXTENDED_Ebias ) { /* Infinity or NaN */ if ((m64 == 0) && (l64 == 0)) { /* +- infinity */ loaded_data->sigh = 0x80000000; loaded_data->sigl = 0x00000000; exp = EXP_Infinity + EXTENDED_Ebias; tag = TAG_Special; } else { /* Must be a signaling or quiet NaN */ exp = EXP_NaN + EXTENDED_Ebias; loaded_data->sigh = (m64 << 11) | 0x80000000; loaded_data->sigh |= l64 >> 21; loaded_data->sigl = l64 << 11; tag = TAG_Special; /* The calling function must look for NaNs */ } } else if ( exp < DOUBLE_Emin + EXTENDED_Ebias ) { /* Zero or de-normal */ if ((m64 == 0) && (l64 == 0)) { /* Zero */ reg_copy(&CONST_Z, loaded_data); exp = 0; tag = TAG_Zero; } else { /* De-normal */ loaded_data->sigh = m64 << 11; loaded_data->sigh |= l64 >> 21; loaded_data->sigl = l64 << 11; return normalize_no_excep(loaded_data, DOUBLE_Emin, negative) | (denormal_operand() < 0 ? FPU_Exception : 0); } } else { loaded_data->sigh = (m64 << 11) | 0x80000000; loaded_data->sigh |= l64 >> 21; loaded_data->sigl = l64 << 11; tag = TAG_Valid; } setexponent16(loaded_data, exp | negative); return tag; } /* Get a float from user memory */ int FPU_load_single(float __user *single, FPU_REG *loaded_data) { unsigned m32; int exp, tag, negative; RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_READ, single, 4); FPU_get_user(m32, (unsigned long __user *) single); RE_ENTRANT_CHECK_ON; negative = (m32 & 0x80000000) ? SIGN_Negative : SIGN_Positive; if (!(m32 & 0x7fffffff)) { /* Zero */ reg_copy(&CONST_Z, loaded_data); addexponent(loaded_data, negative); return TAG_Zero; } exp = ((m32 & 0x7f800000) >> 23) - SINGLE_Ebias + EXTENDED_Ebias; m32 = (m32 & 0x7fffff) << 8; if ( exp < SINGLE_Emin + EXTENDED_Ebias ) { /* De-normals */ loaded_data->sigh = m32; loaded_data->sigl = 0; return normalize_no_excep(loaded_data, SINGLE_Emin, negative) | (denormal_operand() < 0 ? FPU_Exception : 0); } else if ( exp > SINGLE_Emax + EXTENDED_Ebias ) { /* Infinity or NaN */ if ( m32 == 0 ) { /* +- infinity */ loaded_data->sigh = 0x80000000; loaded_data->sigl = 0x00000000; exp = EXP_Infinity + EXTENDED_Ebias; tag = TAG_Special; } else { /* Must be a signaling or quiet NaN */ exp = EXP_NaN + EXTENDED_Ebias; loaded_data->sigh = m32 | 0x80000000; loaded_data->sigl = 0; tag = TAG_Special; /* The calling function must look for NaNs */ } } else { loaded_data->sigh = m32 | 0x80000000; loaded_data->sigl = 0; tag = TAG_Valid; } setexponent16(loaded_data, exp | negative); /* Set the sign. */ return tag; } /* Get a long long from user memory */ int FPU_load_int64(long long __user *_s) { long long s; int sign; FPU_REG *st0_ptr = &st(0); RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_READ, _s, 8); if (copy_from_user(&s,_s,8)) FPU_abort; RE_ENTRANT_CHECK_ON; if (s == 0) { reg_copy(&CONST_Z, st0_ptr); return TAG_Zero; } if (s > 0) sign = SIGN_Positive; else { s = -s; sign = SIGN_Negative; } significand(st0_ptr) = s; return normalize_no_excep(st0_ptr, 63, sign); } /* Get a long from user memory */ int FPU_load_int32(long __user *_s, FPU_REG *loaded_data) { long s; int negative; RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_READ, _s, 4); FPU_get_user(s, _s); RE_ENTRANT_CHECK_ON; if (s == 0) { reg_copy(&CONST_Z, loaded_data); return TAG_Zero; } if (s > 0) negative = SIGN_Positive; else { s = -s; negative = SIGN_Negative; } loaded_data->sigh = s; loaded_data->sigl = 0; return normalize_no_excep(loaded_data, 31, negative); } /* Get a short from user memory */ int FPU_load_int16(short __user *_s, FPU_REG *loaded_data) { int s, negative; RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_READ, _s, 2); /* Cast as short to get the sign extended. */ FPU_get_user(s, _s); RE_ENTRANT_CHECK_ON; if (s == 0) { reg_copy(&CONST_Z, loaded_data); return TAG_Zero; } if (s > 0) negative = SIGN_Positive; else { s = -s; negative = SIGN_Negative; } loaded_data->sigh = s << 16; loaded_data->sigl = 0; return normalize_no_excep(loaded_data, 15, negative); } /* Get a packed bcd array from user memory */ int FPU_load_bcd(u_char __user *s) { FPU_REG *st0_ptr = &st(0); int pos; u_char bcd; long long l=0; int sign; RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_READ, s, 10); RE_ENTRANT_CHECK_ON; for ( pos = 8; pos >= 0; pos--) { l *= 10; RE_ENTRANT_CHECK_OFF; FPU_get_user(bcd, s+pos); RE_ENTRANT_CHECK_ON; l += bcd >> 4; l *= 10; l += bcd & 0x0f; } RE_ENTRANT_CHECK_OFF; FPU_get_user(sign, s+9); sign = sign & 0x80 ? SIGN_Negative : SIGN_Positive; RE_ENTRANT_CHECK_ON; if ( l == 0 ) { reg_copy(&CONST_Z, st0_ptr); addexponent(st0_ptr, sign); /* Set the sign. */ return TAG_Zero; } else { significand(st0_ptr) = l; return normalize_no_excep(st0_ptr, 63, sign); } } /*===========================================================================*/ /* Put a long double into user memory */ int FPU_store_extended(FPU_REG *st0_ptr, u_char st0_tag, long double __user *d) { /* 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_tag != TAG_Empty ) { RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_WRITE, d, 10); FPU_put_user(st0_ptr->sigl, (unsigned long __user *) d); FPU_put_user(st0_ptr->sigh, (unsigned long __user *) ((u_char __user *)d + 4)); FPU_put_user(exponent16(st0_ptr), (unsigned short __user *) ((u_char __user *)d + 8)); RE_ENTRANT_CHECK_ON; 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_access_ok(VERIFY_WRITE,d,10); FPU_put_user(0, (unsigned long __user *) d); FPU_put_user(0xc0000000, 1 + (unsigned long __user *) d); FPU_put_user(0xffff, 4 + (short __user *) d); RE_ENTRANT_CHECK_ON; return 1; } else return 0; } /* Put a double into user memory */ int FPU_store_double(FPU_REG *st0_ptr, u_char st0_tag, double __user *dfloat) { unsigned long l[2]; unsigned long increment = 0; /* avoid gcc warnings */ int precision_loss; int exp; FPU_REG tmp; if ( st0_tag == TAG_Valid ) { reg_copy(st0_ptr, &tmp); exp = exponent(&tmp); if ( exp < DOUBLE_Emin ) /* It may be a denormal */ { addexponent(&tmp, -DOUBLE_Emin + 52); /* largest exp to be 51 */ denormal_arg: if ( (precision_loss = FPU_round_to_int(&tmp, st0_tag)) ) { #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 = signpositive(&tmp) ? 0 : tmp.sigl & 0x7ff; break; case RC_UP: /* towards +infinity */ increment = signpositive(&tmp) ? 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 == TAG_Zero) { /* Number is zero */ l[0] = 0; l[1] = 0; } else if ( st0_tag == TAG_Special ) { st0_tag = FPU_Special(st0_ptr); if ( st0_tag == TW_Denormal ) { /* A denormal will always underflow. */ #ifndef PECULIAR_486 /* An 80486 is supposed to be able to generate a denormal exception here, but... */ /* Underflow has priority. */ if ( control_word & CW_Underflow ) denormal_operand(); #endif /* PECULIAR_486 */ reg_copy(st0_ptr, &tmp); goto denormal_arg; } else if (st0_tag == TW_Infinity) { l[0] = 0; l[1] = 0x7ff00000; } else if (st0_tag == TW_NaN) { /* Is it really a NaN ? */ if ( (exponent(st0_ptr) == EXP_OVER) && (st0_ptr->sigh & 0x80000000) ) { /* 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 { /* It is an unsupported data type */ EXCEPTION(EX_Invalid); if ( !(control_word & CW_Invalid) ) return 0; l[0] = 0; l[1] = 0xfff80000; } } } else if ( st0_tag == TAG_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_access_ok(VERIFY_WRITE,dfloat,8); FPU_put_user(0, (unsigned long __user *) dfloat); FPU_put_user(0xfff80000, 1 + (unsigned long __user *) dfloat); RE_ENTRANT_CHECK_ON; return 1; } else return 0; } if ( getsign(st0_ptr) ) l[1] |= 0x80000000; RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_WRITE,dfloat,8); FPU_put_user(l[0], (unsigned long __user *)dfloat); FPU_put_user(l[1], 1 + (unsigned long __user *)dfloat); RE_ENTRANT_CHECK_ON; return 1; } /* Put a float into user memory */ int FPU_store_single(FPU_REG *st0_ptr, u_char st0_tag, float __user *single) { long templ = 0; unsigned long increment = 0; /* avoid gcc warnings */ int precision_loss; int exp; FPU_REG tmp; if ( st0_tag == TAG_Valid ) { reg_copy(st0_ptr, &tmp); exp = exponent(&tmp); if ( exp < SINGLE_Emin ) { addexponent(&tmp, -SINGLE_Emin + 23); /* largest exp to be 22 */ denormal_arg: if ( (precision_loss = FPU_round_to_int(&tmp, st0_tag)) ) { #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 & CW_Underflow) ) return 0; } EXCEPTION(precision_loss); if ( !(control_word & CW_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 = signpositive(&tmp) ? 0 : (sigl | (sigh & 0xff)); break; case RC_UP: /* towards +infinity */ increment = signpositive(&tmp) ? (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 == TAG_Zero) { templ = 0; } else if ( st0_tag == TAG_Special ) { st0_tag = FPU_Special(st0_ptr); if (st0_tag == TW_Denormal) { reg_copy(st0_ptr, &tmp); /* A denormal will always underflow. */ #ifndef PECULIAR_486 /* An 80486 is supposed to be able to generate a denormal exception here, but... */ /* Underflow has priority. */ if ( control_word & CW_Underflow ) denormal_operand(); #endif /* PECULIAR_486 */ goto denormal_arg; } else if (st0_tag == TW_Infinity) { templ = 0x7f800000; } else if (st0_tag == TW_NaN) { /* Is it really a NaN ? */ if ( (exponent(st0_ptr) == EXP_OVER) && (st0_ptr->sigh & 0x80000000) ) { /* 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 { /* It is an unsupported data type */ EXCEPTION(EX_Invalid); if ( !(control_word & CW_Invalid) ) return 0; templ = 0xffc00000; } } #ifdef PARANOID else { EXCEPTION(EX_INTERNAL|0x164); return 0; } #endif } else if ( st0_tag == TAG_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_access_ok(VERIFY_WRITE,single,4); FPU_put_user(0xffc00000, (unsigned long __user *) single); RE_ENTRANT_CHECK_ON; return 1; } else return 0; } #ifdef PARANOID else { EXCEPTION(EX_INTERNAL|0x163); return 0; } #endif if ( getsign(st0_ptr) ) templ |= 0x80000000; RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_WRITE,single,4); FPU_put_user(templ,(unsigned long __user *) single); RE_ENTRANT_CHECK_ON; return 1; } /* Put a long long into user memory */ int FPU_store_int64(FPU_REG *st0_ptr, u_char st0_tag, long long __user *d) { FPU_REG t; long long tll; int precision_loss; if ( st0_tag == TAG_Empty ) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); goto invalid_operand; } else if ( st0_tag == TAG_Special ) { st0_tag = FPU_Special(st0_ptr); if ( (st0_tag == TW_Infinity) || (st0_tag == TW_NaN) ) { EXCEPTION(EX_Invalid); goto invalid_operand; } } reg_copy(st0_ptr, &t); precision_loss = FPU_round_to_int(&t, st0_tag); ((long *)&tll)[0] = t.sigl; ((long *)&tll)[1] = t.sigh; if ( (precision_loss == 1) || ((t.sigh & 0x80000000) && !((t.sigh == 0x80000000) && (t.sigl == 0) && signnegative(&t))) ) { 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 ( signnegative(&t) ) tll = - tll; } RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_WRITE,d,8); if (copy_to_user(d, &tll, 8)) FPU_abort; RE_ENTRANT_CHECK_ON; return 1; } /* Put a long into user memory */ int FPU_store_int32(FPU_REG *st0_ptr, u_char st0_tag, long __user *d) { FPU_REG t; int precision_loss; if ( st0_tag == TAG_Empty ) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); goto invalid_operand; } else if ( st0_tag == TAG_Special ) { st0_tag = FPU_Special(st0_ptr); if ( (st0_tag == TW_Infinity) || (st0_tag == TW_NaN) ) { EXCEPTION(EX_Invalid); goto invalid_operand; } } reg_copy(st0_ptr, &t); precision_loss = FPU_round_to_int(&t, st0_tag); if (t.sigh || ((t.sigl & 0x80000000) && !((t.sigl == 0x80000000) && signnegative(&t))) ) { 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 ( signnegative(&t) ) t.sigl = -(long)t.sigl; } RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_WRITE,d,4); FPU_put_user(t.sigl, (unsigned long __user *) d); RE_ENTRANT_CHECK_ON; return 1; } /* Put a short into user memory */ int FPU_store_int16(FPU_REG *st0_ptr, u_char st0_tag, short __user *d) { FPU_REG t; int precision_loss; if ( st0_tag == TAG_Empty ) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); goto invalid_operand; } else if ( st0_tag == TAG_Special ) { st0_tag = FPU_Special(st0_ptr); if ( (st0_tag == TW_Infinity) || (st0_tag == TW_NaN) ) { EXCEPTION(EX_Invalid); goto invalid_operand; } } reg_copy(st0_ptr, &t); precision_loss = FPU_round_to_int(&t, st0_tag); if (t.sigh || ((t.sigl & 0xffff8000) && !((t.sigl == 0x8000) && signnegative(&t))) ) { 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 ( signnegative(&t) ) t.sigl = -t.sigl; } RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_WRITE,d,2); FPU_put_user((short)t.sigl, d); RE_ENTRANT_CHECK_ON; return 1; } /* Put a packed bcd array into user memory */ int FPU_store_bcd(FPU_REG *st0_ptr, u_char st0_tag, u_char __user *d) { FPU_REG t; unsigned long long ll; u_char b; int i, precision_loss; u_char sign = (getsign(st0_ptr) == SIGN_NEG) ? 0x80 : 0; if ( st0_tag == TAG_Empty ) { /* Empty register (stack underflow) */ EXCEPTION(EX_StackUnder); goto invalid_operand; } else if ( st0_tag == TAG_Special ) { st0_tag = FPU_Special(st0_ptr); if ( (st0_tag == TW_Infinity) || (st0_tag == TW_NaN) ) { EXCEPTION(EX_Invalid); goto invalid_operand; } } reg_copy(st0_ptr, &t); precision_loss = FPU_round_to_int(&t, st0_tag); 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_access_ok(VERIFY_WRITE,d,10); for ( i = 0; i < 7; i++) FPU_put_user(0, d+i); /* These bytes "undefined" */ FPU_put_user(0xc0, d+7); /* This byte "undefined" */ FPU_put_user(0xff, d+8); FPU_put_user(0xff, 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_access_ok(VERIFY_WRITE,d,10); RE_ENTRANT_CHECK_ON; for ( i = 0; i < 9; i++) { b = FPU_div_small(&ll, 10); b |= (FPU_div_small(&ll, 10)) << 4; RE_ENTRANT_CHECK_OFF; FPU_put_user(b, d+i); RE_ENTRANT_CHECK_ON; } RE_ENTRANT_CHECK_OFF; FPU_put_user(sign, 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 FPU_round_to_int(FPU_REG *r, u_char tag) { u_char very_big; unsigned eax; if (tag == TAG_Zero) { /* Make sure that zero is returned */ significand(r) = 0; return 0; /* o.k. */ } if (exponent(r) > 63) { r->sigl = r->sigh = ~0; /* The largest representable number */ return 1; /* overflow */ } eax = FPU_shrxs(&r->sigl, 63 - exponent(r)); 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 && getsign(r)) { if ( very_big ) return 1; /* overflow */ significand(r) ++; return PRECISION_LOST_UP; } break; case RC_UP: if (frac_part && !getsign(r)) { if ( very_big ) return 1; /* overflow */ significand(r) ++; return PRECISION_LOST_UP; } break; case RC_CHOP: break; } return eax ? PRECISION_LOST_DOWN : 0; } /*===========================================================================*/ u_char __user *fldenv(fpu_addr_modes addr_modes, u_char __user *s) { unsigned short tag_word = 0; u_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_access_ok(VERIFY_READ, s, 0x0e); FPU_get_user(control_word, (unsigned short __user *) s); FPU_get_user(partial_status, (unsigned short __user *) (s+2)); FPU_get_user(tag_word, (unsigned short __user *) (s+4)); FPU_get_user(instruction_address.offset, (unsigned short __user *) (s+6)); FPU_get_user(instruction_address.selector, (unsigned short __user *) (s+8)); FPU_get_user(operand_address.offset, (unsigned short __user *) (s+0x0a)); FPU_get_user(operand_address.selector, (unsigned short __user *) (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_access_ok(VERIFY_READ, s, 0x1c); FPU_get_user(control_word, (unsigned short __user *) s); FPU_get_user(partial_status, (unsigned short __user *) (s+4)); FPU_get_user(tag_word, (unsigned short __user *) (s+8)); FPU_get_user(instruction_address.offset, (unsigned long __user *) (s+0x0c)); FPU_get_user(instruction_address.selector, (unsigned short __user *) (s+0x10)); FPU_get_user(instruction_address.opcode, (unsigned short __user *) (s+0x12)); FPU_get_user(operand_address.offset, (unsigned long __user *) (s+0x14)); FPU_get_user(operand_address.selector, (unsigned long __user *) (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 == TAG_Empty ) /* New tag is empty. Accept it */ FPU_settag(i, TAG_Empty); else if ( FPU_gettag(i) == TAG_Empty ) { /* Old tag is empty and new tag is not empty. New tag is determined by old reg contents */ if ( exponent(&fpu_register(i)) == - EXTENDED_Ebias ) { if ( !(fpu_register(i).sigl | fpu_register(i).sigh) ) FPU_settag(i, TAG_Zero); else FPU_settag(i, TAG_Special); } else if ( exponent(&fpu_register(i)) == 0x7fff - EXTENDED_Ebias ) { FPU_settag(i, TAG_Special); } else if ( fpu_register(i).sigh & 0x80000000 ) FPU_settag(i, TAG_Valid); else FPU_settag(i, TAG_Special); /* An Un-normal */ } /* 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, u_char __user *data_address) { int i, regnr; u_char __user *s = fldenv(addr_modes, data_address); int offset = (top & 7) * 10, other = 80 - offset; /* Copy all registers in stack order. */ RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_READ,s,80); __copy_from_user(register_base+offset, s, other); if ( offset ) __copy_from_user(register_base, s+other, offset); RE_ENTRANT_CHECK_ON; for ( i = 0; i < 8; i++ ) { regnr = (i+top) & 7; if ( FPU_gettag(regnr) != TAG_Empty ) /* The loaded data over-rides all other cases. */ FPU_settag(regnr, FPU_tagof(&st(i))); } } u_char __user *fstenv(fpu_addr_modes addr_modes, u_char __user *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_access_ok(VERIFY_WRITE,d,14); #ifdef PECULIAR_486 FPU_put_user(control_word & ~0xe080, (unsigned long __user *) d); #else FPU_put_user(control_word, (unsigned short __user *) d); #endif /* PECULIAR_486 */ FPU_put_user(status_word(), (unsigned short __user *) (d+2)); FPU_put_user(fpu_tag_word, (unsigned short __user *) (d+4)); FPU_put_user(instruction_address.offset, (unsigned short __user *) (d+6)); FPU_put_user(operand_address.offset, (unsigned short __user *) (d+0x0a)); if ( addr_modes.default_mode == VM86 ) { FPU_put_user((instruction_address.offset & 0xf0000) >> 4, (unsigned short __user *) (d+8)); FPU_put_user((operand_address.offset & 0xf0000) >> 4, (unsigned short __user *) (d+0x0c)); } else { FPU_put_user(instruction_address.selector, (unsigned short __user *) (d+8)); FPU_put_user(operand_address.selector, (unsigned short __user *) (d+0x0c)); } RE_ENTRANT_CHECK_ON; d += 0x0e; } else { RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_WRITE, d, 7*4); #ifdef PECULIAR_486 control_word &= ~0xe080; /* An 80486 sets nearly all of the reserved bits to 1. */ control_word |= 0xffff0040; partial_status = status_word() | 0xffff0000; fpu_tag_word |= 0xffff0000; I387.soft.fcs &= ~0xf8000000; I387.soft.fos |= 0xffff0000; #endif /* PECULIAR_486 */ if (__copy_to_user(d, &control_word, 7*4)) FPU_abort; 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, u_char __user *data_address) { u_char __user *d; int offset = (top & 7) * 10, other = 80 - offset; d = fstenv(addr_modes, data_address); RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_WRITE,d,80); /* Copy all registers in stack order. */ if (__copy_to_user(d, register_base+offset, other)) FPU_abort; if ( offset ) if (__copy_to_user(d+other, register_base, offset)) FPU_abort; RE_ENTRANT_CHECK_ON; finit(); } /*===========================================================================*/