void fmulp_(void)
{
/* fmulp st(i),st */
clear_C1();
if (FPU_mul(&st(0), FPU_gettag0(), FPU_rm, control_word) >= 0)
FPU_pop();
}
int FPU_add(FPU_REG const *b, u_char tagb, int deststnr, int control_w)
{
FPU_REG *a = &st(0);
FPU_REG *dest = &st(deststnr);
u_char signb = getsign(b);
u_char taga = FPU_gettag0();
u_char signa = getsign(a);
u_char saved_sign = getsign(dest);
int diff, tag, expa, expb;
if (!(taga | tagb)) {
expa = exponent(a);
expb = exponent(b);
valid_add:
if (!(signa ^ signb)) {
tag =
FPU_u_add(a, b, dest, control_w, signa, expa, expb);
} else {
diff = expa - expb;
if (!diff) {
diff = a->sigh - b->sigh;
if (!diff) {
diff = a->sigl > b->sigl;
if (!diff)
diff = -(a->sigl < b->sigl);
}
}
if (diff > 0) {
tag =
FPU_u_sub(a, b, dest, control_w, signa,
expa, expb);
} else if (diff < 0) {
tag =
FPU_u_sub(b, a, dest, control_w, signb,
expb, expa);
} else {
FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
setsign(dest, ((control_w & CW_RC) != RC_DOWN)
? SIGN_POS : SIGN_NEG);
return TAG_Zero;
}
}
if (tag < 0) {
setsign(dest, saved_sign);
return tag;
}
FPU_settagi(deststnr, tag);
return tag;
}
if (taga == TAG_Special)
taga = FPU_Special(a);
if (tagb == TAG_Special)
tagb = FPU_Special(b);
if (((taga == TAG_Valid) && (tagb == TW_Denormal))
|| ((taga == TW_Denormal) && (tagb == TAG_Valid))
|| ((taga == TW_Denormal) && (tagb == TW_Denormal))) {
FPU_REG x, y;
if (denormal_operand() < 0)
return FPU_Exception;
FPU_to_exp16(a, &x);
FPU_to_exp16(b, &y);
a = &x;
b = &y;
expa = exponent16(a);
expb = exponent16(b);
goto valid_add;
}
if ((taga == TW_NaN) || (tagb == TW_NaN)) {
if (deststnr == 0)
return real_2op_NaN(b, tagb, deststnr, a);
else
return real_2op_NaN(a, taga, deststnr, a);
}
return add_sub_specials(a, taga, signa, b, tagb, signb,
dest, deststnr, control_w);
}
int FPU_sub(int flags, int rm, int control_w)
{
FPU_REG const *a, *b;
FPU_REG *dest;
u_char taga, tagb, signa, signb, saved_sign, sign;
int diff, tag = 0, expa, expb, deststnr;
a = &st(0);
taga = FPU_gettag0();
deststnr = 0;
if (flags & LOADED) {
b = (FPU_REG *) rm;
tagb = flags & 0x0f;
} else {
b = &st(rm);
tagb = FPU_gettagi(rm);
if (flags & DEST_RM)
deststnr = rm;
}
signa = getsign(a);
signb = getsign(b);
if (flags & REV) {
signa ^= SIGN_NEG;
signb ^= SIGN_NEG;
}
dest = &st(deststnr);
saved_sign = getsign(dest);
if (!(taga | tagb)) {
expa = exponent(a);
expb = exponent(b);
valid_subtract:
diff = expa - expb;
if (!diff) {
diff = a->sigh - b->sigh;
if (!diff) {
diff = a->sigl > b->sigl;
if (!diff)
diff = -(a->sigl < b->sigl);
}
}
switch ((((int)signa) * 2 + signb) / SIGN_NEG) {
case 0:
case 3:
if (diff > 0) {
tag =
FPU_u_sub(a, b, dest, control_w, signa,
expa, expb);
} else if (diff == 0) {
FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
setsign(dest, ((control_w & CW_RC) != RC_DOWN)
? SIGN_POS : SIGN_NEG);
return TAG_Zero;
} else {
sign = signa ^ SIGN_NEG;
tag =
FPU_u_sub(b, a, dest, control_w, sign, expb,
expa);
}
break;
case 1:
tag =
FPU_u_add(a, b, dest, control_w, SIGN_POS, expa,
expb);
break;
case 2:
tag =
FPU_u_add(a, b, dest, control_w, SIGN_NEG, expa,
expb);
break;
#ifdef PARANOID
default:
EXCEPTION(EX_INTERNAL | 0x111);
return -1;
#endif
}
if (tag < 0) {
setsign(dest, saved_sign);
return tag;
}
FPU_settagi(deststnr, tag);
return tag;
}
if (taga == TAG_Special)
taga = FPU_Special(a);
if (tagb == TAG_Special)
tagb = FPU_Special(b);
if (((taga == TAG_Valid) && (tagb == TW_Denormal))
|| ((taga == TW_Denormal) && (tagb == TAG_Valid))
|| ((taga == TW_Denormal) && (tagb == TW_Denormal))) {
FPU_REG x, y;
if (denormal_operand() < 0)
return FPU_Exception;
FPU_to_exp16(a, &x);
FPU_to_exp16(b, &y);
a = &x;
b = &y;
expa = exponent16(a);
expb = exponent16(b);
goto valid_subtract;
}
if ((taga == TW_NaN) || (tagb == TW_NaN)) {
FPU_REG const *d1, *d2;
if (flags & REV) {
d1 = b;
d2 = a;
} else {
d1 = a;
d2 = b;
}
if (flags & LOADED)
return real_2op_NaN(b, tagb, deststnr, d1);
if (flags & DEST_RM)
return real_2op_NaN(a, taga, deststnr, d2);
else
return real_2op_NaN(b, tagb, deststnr, d2);
}
return add_sub_specials(a, taga, signa, b, tagb, signb ^ SIGN_NEG,
dest, deststnr, control_w);
}
void FPU_etc(void)
{
(fp_etc_table[FPU_rm]) (&st(0), FPU_gettag0());
}
int FPU_load_store(u_char type, fpu_addr_modes addr_modes,
void __user *data_address)
{
FPU_REG loaded_data;
FPU_REG *st0_ptr;
u_char st0_tag = TAG_Empty; /* This is just to stop a gcc warning. */
u_char loaded_tag;
st0_ptr = NULL; /* Initialized just to stop compiler warnings. */
if ( addr_modes.default_mode & PROTECTED )
{
if ( addr_modes.default_mode == SEG32 )
{
if ( access_limit < data_sizes_32[type] )
math_abort(FPU_info,SIGSEGV);
}
else if ( addr_modes.default_mode == PM16 )
{
if ( access_limit < data_sizes_16[type] )
math_abort(FPU_info,SIGSEGV);
}
#ifdef PARANOID
else
EXCEPTION(EX_INTERNAL|0x140);
#endif /* PARANOID */
}
switch ( type_table[type] )
{
case _NONE_:
break;
case _REG0_:
st0_ptr = &st(0); /* Some of these instructions pop after
storing */
st0_tag = FPU_gettag0();
break;
case _PUSH_:
{
if ( FPU_gettagi(-1) != TAG_Empty )
{ FPU_stack_overflow(); return 0; }
top--;
st0_ptr = &st(0);
}
break;
case _null_:
FPU_illegal();
return 0;
#ifdef PARANOID
default:
EXCEPTION(EX_INTERNAL|0x141);
return 0;
#endif /* PARANOID */
}
switch ( type )
{
case 000: /* fld m32real */
clear_C1();
loaded_tag = FPU_load_single((float __user *)data_address, &loaded_data);
if ( (loaded_tag == TAG_Special)
&& isNaN(&loaded_data)
&& (real_1op_NaN(&loaded_data) < 0) )
{
top++;
break;
}
FPU_copy_to_reg0(&loaded_data, loaded_tag);
break;
case 001: /* fild m32int */
clear_C1();
loaded_tag = FPU_load_int32((long __user *)data_address, &loaded_data);
FPU_copy_to_reg0(&loaded_data, loaded_tag);
break;
case 002: /* fld m64real */
clear_C1();
loaded_tag = FPU_load_double((double __user *)data_address, &loaded_data);
if ( (loaded_tag == TAG_Special)
&& isNaN(&loaded_data)
&& (real_1op_NaN(&loaded_data) < 0) )
{
top++;
break;
}
FPU_copy_to_reg0(&loaded_data, loaded_tag);
break;
case 003: /* fild m16int */
clear_C1();
loaded_tag = FPU_load_int16((short __user *)data_address, &loaded_data);
FPU_copy_to_reg0(&loaded_data, loaded_tag);
break;
case 010: /* fst m32real */
clear_C1();
FPU_store_single(st0_ptr, st0_tag, (float __user *)data_address);
break;
case 011: /* fist m32int */
clear_C1();
FPU_store_int32(st0_ptr, st0_tag, (long __user *)data_address);
break;
case 012: /* fst m64real */
clear_C1();
FPU_store_double(st0_ptr, st0_tag, (double __user *)data_address);
break;
case 013: /* fist m16int */
clear_C1();
FPU_store_int16(st0_ptr, st0_tag, (short __user *)data_address);
break;
case 014: /* fstp m32real */
clear_C1();
if ( FPU_store_single(st0_ptr, st0_tag, (float __user *)data_address) )
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
break;
case 015: /* fistp m32int */
clear_C1();
if ( FPU_store_int32(st0_ptr, st0_tag, (long __user *)data_address) )
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
break;
case 016: /* fstp m64real */
clear_C1();
if ( FPU_store_double(st0_ptr, st0_tag, (double __user *)data_address) )
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
break;
case 017: /* fistp m16int */
clear_C1();
if ( FPU_store_int16(st0_ptr, st0_tag, (short __user *)data_address) )
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
break;
case 020: /* fldenv m14/28byte */
fldenv(addr_modes, (u_char __user *)data_address);
/* Ensure that the values just loaded are not changed by
fix-up operations. */
return 1;
case 022: /* frstor m94/108byte */
frstor(addr_modes, (u_char __user *)data_address);
/* Ensure that the values just loaded are not changed by
fix-up operations. */
return 1;
case 023: /* fbld m80dec */
clear_C1();
loaded_tag = FPU_load_bcd((u_char __user *)data_address);
FPU_settag0(loaded_tag);
break;
case 024: /* fldcw */
RE_ENTRANT_CHECK_OFF;
FPU_verify_area(VERIFY_READ, data_address, 2);
FPU_get_user(control_word, (unsigned short __user *) data_address);
RE_ENTRANT_CHECK_ON;
if ( partial_status & ~control_word & CW_Exceptions )
partial_status |= (SW_Summary | SW_Backward);
else
partial_status &= ~(SW_Summary | SW_Backward);
#ifdef PECULIAR_486
control_word |= 0x40; /* An 80486 appears to always set this bit */
#endif /* PECULIAR_486 */
return 1;
case 025: /* fld m80real */
clear_C1();
loaded_tag = FPU_load_extended((long double __user *)data_address, 0);
FPU_settag0(loaded_tag);
break;
case 027: /* fild m64int */
clear_C1();
loaded_tag = FPU_load_int64((long long __user *)data_address);
FPU_settag0(loaded_tag);
break;
case 030: /* fstenv m14/28byte */
fstenv(addr_modes, (u_char __user *)data_address);
return 1;
case 032: /* fsave */
fsave(addr_modes, (u_char __user *)data_address);
return 1;
case 033: /* fbstp m80dec */
clear_C1();
if ( FPU_store_bcd(st0_ptr, st0_tag, (u_char __user *)data_address) )
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
break;
case 034: /* fstcw m16int */
RE_ENTRANT_CHECK_OFF;
FPU_verify_area(VERIFY_WRITE,data_address,2);
FPU_put_user(control_word, (unsigned short __user *) data_address);
RE_ENTRANT_CHECK_ON;
return 1;
case 035: /* fstp m80real */
clear_C1();
if ( FPU_store_extended(st0_ptr, st0_tag, (long double __user *)data_address) )
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
break;
case 036: /* fstsw m2byte */
RE_ENTRANT_CHECK_OFF;
FPU_verify_area(VERIFY_WRITE,data_address,2);
FPU_put_user(status_word(),(unsigned short __user *) data_address);
RE_ENTRANT_CHECK_ON;
return 1;
case 037: /* fistp m64int */
clear_C1();
if ( FPU_store_int64(st0_ptr, st0_tag, (long long __user *)data_address) )
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
break;
}
return 0;
}
void fmul_i(void)
{
/* fmul st(i),st */
clear_C1();
FPU_mul(&st(0), FPU_gettag0(), FPU_rm, control_word);
}
/*
Divide one register by another and put the result into a third register.
*/
int FPU_div(int flags, int rm, int control_w)
{
FPU_REG x, y;
FPU_REG const *a, *b, *st0_ptr, *st_ptr;
FPU_REG *dest;
u_char taga, tagb, signa, signb, sign, saved_sign;
int tag, deststnr;
if (flags & DEST_RM)
deststnr = rm;
else
deststnr = 0;
if (flags & REV) {
b = &st(0);
st0_ptr = b;
tagb = FPU_gettag0();
if (flags & LOADED) {
a = (FPU_REG *) rm;
taga = flags & 0x0f;
} else {
a = &st(rm);
st_ptr = a;
taga = FPU_gettagi(rm);
}
} else {
a = &st(0);
st0_ptr = a;
taga = FPU_gettag0();
if (flags & LOADED) {
b = (FPU_REG *) rm;
tagb = flags & 0x0f;
} else {
b = &st(rm);
st_ptr = b;
tagb = FPU_gettagi(rm);
}
}
signa = getsign(a);
signb = getsign(b);
sign = signa ^ signb;
dest = &st(deststnr);
saved_sign = getsign(dest);
if (!(taga | tagb)) {
/* Both regs Valid, this should be the most common case. */
reg_copy(a, &x);
reg_copy(b, &y);
setpositive(&x);
setpositive(&y);
tag = FPU_u_div(&x, &y, dest, control_w, sign);
if (tag < 0)
return tag;
FPU_settagi(deststnr, tag);
return tag;
}
if (taga == TAG_Special)
taga = FPU_Special(a);
if (tagb == TAG_Special)
tagb = FPU_Special(b);
if (((taga == TAG_Valid) && (tagb == TW_Denormal))
|| ((taga == TW_Denormal) && (tagb == TAG_Valid))
|| ((taga == TW_Denormal) && (tagb == TW_Denormal))) {
if (denormal_operand() < 0)
return FPU_Exception;
FPU_to_exp16(a, &x);
FPU_to_exp16(b, &y);
tag = FPU_u_div(&x, &y, dest, control_w, sign);
if (tag < 0)
return tag;
FPU_settagi(deststnr, tag);
return tag;
} else if ((taga <= TW_Denormal) && (tagb <= TW_Denormal)) {
if (tagb != TAG_Zero) {
/* Want to find Zero/Valid */
if (tagb == TW_Denormal) {
if (denormal_operand() < 0)
return FPU_Exception;
}
/* The result is zero. */
FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
setsign(dest, sign);
return TAG_Zero;
}
/* We have an exception condition, either 0/0 or Valid/Zero. */
if (taga == TAG_Zero) {
/* 0/0 */
return arith_invalid(deststnr);
}
/* Valid/Zero */
return FPU_divide_by_zero(deststnr, sign);
}
/* Must have infinities, NaNs, etc */
else if ((taga == TW_NaN) || (tagb == TW_NaN)) {
if (flags & LOADED)
return real_2op_NaN((FPU_REG *) rm, flags & 0x0f, 0,
st0_ptr);
if (flags & DEST_RM) {
int tag;
tag = FPU_gettag0();
if (tag == TAG_Special)
tag = FPU_Special(st0_ptr);
return real_2op_NaN(st0_ptr, tag, rm,
(flags & REV) ? st0_ptr : &st(rm));
} else {
int tag;
tag = FPU_gettagi(rm);
if (tag == TAG_Special)
tag = FPU_Special(&st(rm));
return real_2op_NaN(&st(rm), tag, 0,
(flags & REV) ? st0_ptr : &st(rm));
}
} else if (taga == TW_Infinity) {
if (tagb == TW_Infinity) {
/* infinity/infinity */
return arith_invalid(deststnr);
} else {
/* tagb must be Valid or Zero */
if ((tagb == TW_Denormal) && (denormal_operand() < 0))
return FPU_Exception;
/* Infinity divided by Zero or Valid does
not raise and exception, but returns Infinity */
FPU_copy_to_regi(a, TAG_Special, deststnr);
setsign(dest, sign);
return taga;
}
} else if (tagb == TW_Infinity) {
if ((taga == TW_Denormal) && (denormal_operand() < 0))
return FPU_Exception;
/* The result is zero. */
FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
setsign(dest, sign);
return TAG_Zero;
}
#ifdef PARANOID
else {
EXCEPTION(EX_INTERNAL | 0x102);
return FPU_Exception;
}
#endif /* PARANOID */
return 0;
}
static int compare(FPU_REG const *b, int tagb)
{
int diff, exp0, expb;
u_char st0_tag;
FPU_REG *st0_ptr;
FPU_REG x, y;
u_char st0_sign, signb = getsign(b);
st0_ptr = &st(0);
st0_tag = FPU_gettag0();
st0_sign = getsign(st0_ptr);
if (tagb == TAG_Special)
tagb = FPU_Special(b);
if (st0_tag == TAG_Special)
st0_tag = FPU_Special(st0_ptr);
if (((st0_tag != TAG_Valid) && (st0_tag != TW_Denormal))
|| ((tagb != TAG_Valid) && (tagb != TW_Denormal))) {
if (st0_tag == TAG_Zero) {
if (tagb == TAG_Zero)
return COMP_A_eq_B;
if (tagb == TAG_Valid)
return ((signb ==
SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B);
if (tagb == TW_Denormal)
return ((signb ==
SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B)
| COMP_Denormal;
} else if (tagb == TAG_Zero) {
if (st0_tag == TAG_Valid)
return ((st0_sign ==
SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B);
if (st0_tag == TW_Denormal)
return ((st0_sign ==
SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B)
| COMP_Denormal;
}
if (st0_tag == TW_Infinity) {
if ((tagb == TAG_Valid) || (tagb == TAG_Zero))
return ((st0_sign ==
SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B);
else if (tagb == TW_Denormal)
return ((st0_sign ==
SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B)
| COMP_Denormal;
else if (tagb == TW_Infinity) {
/* */
return (st0_sign == signb) ? COMP_A_eq_B :
((st0_sign ==
SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B);
}
/* */
} else if (tagb == TW_Infinity) {
if ((st0_tag == TAG_Valid) || (st0_tag == TAG_Zero))
return ((signb ==
SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B);
if (st0_tag == TW_Denormal)
return ((signb ==
SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B)
| COMP_Denormal;
/* */
}
/*
*/
if ((st0_tag == TW_NaN) || (tagb == TW_NaN)) {
int signalling = 0, unsupported = 0;
if (st0_tag == TW_NaN) {
signalling =
(st0_ptr->sigh & 0xc0000000) == 0x80000000;
unsupported = !((exponent(st0_ptr) == EXP_OVER)
&& (st0_ptr->
sigh & 0x80000000));
}
if (tagb == TW_NaN) {
signalling |=
(b->sigh & 0xc0000000) == 0x80000000;
unsupported |= !((exponent(b) == EXP_OVER)
&& (b->sigh & 0x80000000));
}
if (signalling || unsupported)
return COMP_No_Comp | COMP_SNaN | COMP_NaN;
else
/* */
return COMP_No_Comp | COMP_NaN;
}
EXCEPTION(EX_Invalid);
}
if (st0_sign != signb) {
return ((st0_sign == SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B)
| (((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) ?
COMP_Denormal : 0);
}
if ((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) {
FPU_to_exp16(st0_ptr, &x);
FPU_to_exp16(b, &y);
st0_ptr = &x;
b = &y;
exp0 = exponent16(st0_ptr);
expb = exponent16(b);
} else {
exp0 = exponent(st0_ptr);
expb = exponent(b);
}
#ifdef PARANOID
if (!(st0_ptr->sigh & 0x80000000))
EXCEPTION(EX_Invalid);
if (!(b->sigh & 0x80000000))
EXCEPTION(EX_Invalid);
#endif /* */
diff = exp0 - expb;
if (diff == 0) {
diff = st0_ptr->sigh - b->sigh; /*
*/
if (diff == 0) {
diff = st0_ptr->sigl > b->sigl;
if (diff == 0)
diff = -(st0_ptr->sigl < b->sigl);
}
}
if (diff > 0) {
return ((st0_sign == SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B)
| (((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) ?
COMP_Denormal : 0);
}
if (diff < 0) {
return ((st0_sign == SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B)
| (((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) ?
COMP_Denormal : 0);
}
return COMP_A_eq_B
| (((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) ?
COMP_Denormal : 0);
}
/*
Operates on st(0) and st(n), or on st(0) and temporary data.
The destination must be one of the source st(x).
*/
int FPU_add(FPU_REG const *b, u_char tagb, int deststnr, u16 control_w)
{
FPU_REG *a = &st(0);
FPU_REG *dest = &st(deststnr);
u_char signb = getsign(b);
u_char taga = FPU_gettag0();
u_char signa = getsign(a);
u_char saved_sign = getsign(dest);
int diff, tag, expa, expb;
if ( !(taga | tagb) )
{
expa = exponent(a);
expb = exponent(b);
valid_add:
/* Both registers are valid */
if (!(signa ^ signb))
{
/* signs are the same */
tag = FPU_u_add(a, b, dest, control_w, signa, expa, expb);
}
else
{
/* The signs are different, so do a subtraction */
diff = expa - expb;
if (!diff)
{
diff = a->sigh - b->sigh; /* This works only if the ms bits
are identical. */
if (!diff)
{
diff = a->sigl > b->sigl;
if (!diff)
diff = -(a->sigl < b->sigl);
}
}
if (diff > 0)
{
tag = FPU_u_sub(a, b, dest, control_w, signa, expa, expb);
}
else if ( diff < 0 )
{
tag = FPU_u_sub(b, a, dest, control_w, signb, expb, expa);
}
else
{
FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
/* sign depends upon rounding mode */
setsign(dest, ((control_w & CW_RC) != RC_DOWN)
? SIGN_POS : SIGN_NEG);
return TAG_Zero;
}
}
if ( tag < 0 )
{
setsign(dest, saved_sign);
return tag;
}
FPU_settagi(deststnr, tag);
return tag;
}
if ( taga == TAG_Special )
taga = FPU_Special(a);
if ( tagb == TAG_Special )
tagb = FPU_Special(b);
if ( ((taga == TAG_Valid) && (tagb == TW_Denormal))
|| ((taga == TW_Denormal) && (tagb == TAG_Valid))
|| ((taga == TW_Denormal) && (tagb == TW_Denormal)) )
{
FPU_REG x, y;
if ( denormal_operand() < 0 )
return FPU_Exception;
FPU_to_exp16(a, &x);
FPU_to_exp16(b, &y);
a = &x;
b = &y;
expa = exponent16(a);
expb = exponent16(b);
goto valid_add;
}
if ( (taga == TW_NaN) || (tagb == TW_NaN) )
{
if ( deststnr == 0 )
return real_2op_NaN(b, tagb, deststnr, a);
else
return real_2op_NaN(a, taga, deststnr, a);
}
return add_sub_specials(a, taga, signa, b, tagb, signb,
dest, deststnr, control_w);
}
int FPU_div(int flags, int rm, int control_w)
{
FPU_REG x, y;
FPU_REG const *a, *b, *st0_ptr, *st_ptr;
FPU_REG *dest;
u_char taga, tagb, signa, signb, sign, saved_sign;
int tag, deststnr;
if (flags & DEST_RM)
deststnr = rm;
else
deststnr = 0;
if (flags & REV) {
b = &st(0);
st0_ptr = b;
tagb = FPU_gettag0();
if (flags & LOADED) {
a = (FPU_REG *) rm;
taga = flags & 0x0f;
} else {
a = &st(rm);
st_ptr = a;
taga = FPU_gettagi(rm);
}
} else {
a = &st(0);
st0_ptr = a;
taga = FPU_gettag0();
if (flags & LOADED) {
b = (FPU_REG *) rm;
tagb = flags & 0x0f;
} else {
b = &st(rm);
st_ptr = b;
tagb = FPU_gettagi(rm);
}
}
signa = getsign(a);
signb = getsign(b);
sign = signa ^ signb;
dest = &st(deststnr);
saved_sign = getsign(dest);
if (!(taga | tagb)) {
reg_copy(a, &x);
reg_copy(b, &y);
setpositive(&x);
setpositive(&y);
tag = FPU_u_div(&x, &y, dest, control_w, sign);
if (tag < 0)
return tag;
FPU_settagi(deststnr, tag);
return tag;
}
if (taga == TAG_Special)
taga = FPU_Special(a);
if (tagb == TAG_Special)
tagb = FPU_Special(b);
if (((taga == TAG_Valid) && (tagb == TW_Denormal))
|| ((taga == TW_Denormal) && (tagb == TAG_Valid))
|| ((taga == TW_Denormal) && (tagb == TW_Denormal))) {
if (denormal_operand() < 0)
return FPU_Exception;
FPU_to_exp16(a, &x);
FPU_to_exp16(b, &y);
tag = FPU_u_div(&x, &y, dest, control_w, sign);
if (tag < 0)
return tag;
FPU_settagi(deststnr, tag);
return tag;
} else if ((taga <= TW_Denormal) && (tagb <= TW_Denormal)) {
if (tagb != TAG_Zero) {
if (tagb == TW_Denormal) {
if (denormal_operand() < 0)
return FPU_Exception;
}
FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
setsign(dest, sign);
return TAG_Zero;
}
if (taga == TAG_Zero) {
return arith_invalid(deststnr);
}
return FPU_divide_by_zero(deststnr, sign);
}
else if ((taga == TW_NaN) || (tagb == TW_NaN)) {
if (flags & LOADED)
return real_2op_NaN((FPU_REG *) rm, flags & 0x0f, 0,
st0_ptr);
if (flags & DEST_RM) {
int tag;
tag = FPU_gettag0();
if (tag == TAG_Special)
tag = FPU_Special(st0_ptr);
return real_2op_NaN(st0_ptr, tag, rm,
(flags & REV) ? st0_ptr : &st(rm));
} else {
int tag;
tag = FPU_gettagi(rm);
if (tag == TAG_Special)
tag = FPU_Special(&st(rm));
return real_2op_NaN(&st(rm), tag, 0,
(flags & REV) ? st0_ptr : &st(rm));
}
} else if (taga == TW_Infinity) {
if (tagb == TW_Infinity) {
return arith_invalid(deststnr);
} else {
if ((tagb == TW_Denormal) && (denormal_operand() < 0))
return FPU_Exception;
FPU_copy_to_regi(a, TAG_Special, deststnr);
setsign(dest, sign);
return taga;
}
} else if (tagb == TW_Infinity) {
if ((taga == TW_Denormal) && (denormal_operand() < 0))
return FPU_Exception;
FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
setsign(dest, sign);
return TAG_Zero;
}
#ifdef PARANOID
else {
EXCEPTION(EX_INTERNAL | 0x102);
return FPU_Exception;
}
#endif
return 0;
}
