void
fmulp_()
{
/* fmulp st(i),st */
reg_mul(&st(FPU_rm), FPU_st0_ptr, &st(FPU_rm), control_word);
pop();
}
static void
f2xm1(void)
{
switch (FPU_st0_tag) {
case TW_Valid:
{
FPU_REG rv, tmp;
#ifdef DENORM_OPERAND
if ((FPU_st0_ptr->exp <= EXP_UNDER) && (denormal_operand()))
return;
#endif /* DENORM_OPERAND */
if (FPU_st0_ptr->sign == SIGN_POS) {
/* poly_2xm1(x) requires 0 < x < 1. */
if (poly_2xm1(FPU_st0_ptr, &rv))
return; /* error */
reg_mul(&rv, FPU_st0_ptr, FPU_st0_ptr, FULL_PRECISION);
} else {
/* **** Should change poly_2xm1() to at least handle numbers near 0 */
/* poly_2xm1(x) doesn't handle negative
* numbers. */
/* So we compute (poly_2xm1(x+1)-1)/2, for -1
* < x < 0 */
reg_add(FPU_st0_ptr, &CONST_1, &tmp, FULL_PRECISION);
poly_2xm1(&tmp, &rv);
reg_mul(&rv, &tmp, &tmp, FULL_PRECISION);
reg_sub(&tmp, &CONST_1, FPU_st0_ptr, FULL_PRECISION);
FPU_st0_ptr->exp--;
if (FPU_st0_ptr->exp <= EXP_UNDER)
arith_underflow(FPU_st0_ptr);
}
return;
}
case TW_Zero:
return;
case TW_Infinity:
if (FPU_st0_ptr->sign == SIGN_NEG) {
/* -infinity gives -1 (p16-10) */
reg_move(&CONST_1, FPU_st0_ptr);
FPU_st0_ptr->sign = SIGN_NEG;
}
return;
default:
single_arg_error();
}
}
static int
math_emulate(struct trapframe * tframe)
{
unsigned char FPU_modrm;
unsigned short code;
#ifdef LOOKAHEAD_LIMIT
int lookahead_limit = LOOKAHEAD_LIMIT;
#endif
#ifdef PARANOID
if (emulating) {
printf("ERROR: wm-FPU-emu is not RE-ENTRANT!\n");
}
REENTRANT_CHECK(ON);
#endif /* PARANOID */
if ((((struct pcb *) curproc->p_addr)->pcb_flags & FP_SOFTFP) == 0) {
finit();
control_word = __INITIAL_NPXCW__;
((struct pcb *) curproc->p_addr)->pcb_flags |= FP_SOFTFP;
}
FPU_info = tframe;
FPU_ORIG_EIP = FPU_EIP; /* --pink-- */
if (FPU_CS != 0x001f) {
printf("math_emulate: %x : %x\n", FPU_CS, FPU_EIP);
panic("FPU emulation in kernel");
}
#ifdef notyet
/* We cannot handle emulation in v86-mode */
if (FPU_EFLAGS & 0x00020000) {
FPU_ORIG_EIP = FPU_EIP;
math_abort(FPU_info, SIGILL);
}
#endif
FPU_lookahead = FPU_LOOKAHEAD;
if (curproc->p_flag & P_TRACED)
FPU_lookahead = 0;
do_another_FPU_instruction:
REENTRANT_CHECK(OFF);
code = fuword((u_int *) FPU_EIP);
REENTRANT_CHECK(ON);
if ((code & 0xff) == 0x9b) { /* fwait */
if (status_word & SW_Summary)
goto do_the_FPU_interrupt;
else {
FPU_EIP++;
goto FPU_instruction_done;
}
}
if (status_word & SW_Summary) {
/* Ignore the error for now if the current instruction is a
* no-wait control instruction */
/* The 80486 manual contradicts itself on this topic, so I use
* the following list of such instructions until I can check
* on a real 80486: fninit, fnstenv, fnsave, fnstsw, fnstenv,
* fnclex. */
if (!((((code & 0xf803) == 0xe003) || /* fnclex, fninit,
* fnstsw */
(((code & 0x3003) == 0x3001) && /* fnsave, fnstcw,
* fnstenv, fnstsw */
((code & 0xc000) != 0xc000))))) {
/* This is a guess about what a real FPU might do to
* this bit: */
/* status_word &= ~SW_Summary; ****/
/* We need to simulate the action of the kernel to FPU
* interrupts here. Currently, the "real FPU" part of
* the kernel (0.99.10) clears the exception flags,
* sets the registers to empty, and passes information
* back to the interrupted process via the cs selector
* and operand selector, so we do the same. */
do_the_FPU_interrupt:
cs_selector &= 0xffff0000;
cs_selector |= (status_word & ~SW_Top) | ((top & 7) << SW_Top_Shift);
operand_selector = tag_word();
status_word = 0;
top = 0;
{
int r;
for (r = 0; r < 8; r++) {
regs[r].tag = TW_Empty;
}
}
REENTRANT_CHECK(OFF);
math_abort(SIGFPE);
}
}
FPU_entry_eip = FPU_ORIG_EIP = FPU_EIP;
if ((code & 0xff) == 0x66) { /* size prefix */
FPU_EIP++;
REENTRANT_CHECK(OFF);
code = fuword((u_int *) FPU_EIP);
REENTRANT_CHECK(ON);
}
FPU_EIP += 2;
FPU_modrm = code >> 8;
FPU_rm = FPU_modrm & 7;
if (FPU_modrm < 0300) {
/* All of these instructions use the mod/rm byte to get a data
* address */
get_address(FPU_modrm);
if (!(code & 1)) {
unsigned short status1 = status_word;
FPU_st0_ptr = &st(0);
FPU_st0_tag = FPU_st0_ptr->tag;
/* Stack underflow has priority */
if (NOT_EMPTY_0) {
switch ((code >> 1) & 3) {
case 0:
reg_load_single();
break;
case 1:
reg_load_int32();
break;
case 2:
reg_load_double();
break;
case 3:
reg_load_int16();
break;
}
/* No more access to user memory, it is safe
* to use static data now */
FPU_st0_ptr = &st(0);
FPU_st0_tag = FPU_st0_ptr->tag;
/* NaN operands have the next priority. */
/* We have to delay looking at st(0) until
* after loading the data, because that data
* might contain an SNaN */
if ((FPU_st0_tag == TW_NaN) ||
(FPU_loaded_data.tag == TW_NaN)) {
/* Restore the status word; we might
* have loaded a denormal. */
status_word = status1;
if ((FPU_modrm & 0x30) == 0x10) {
/* fcom or fcomp */
EXCEPTION(EX_Invalid);
setcc(SW_C3 | SW_C2 | SW_C0);
if (FPU_modrm & 0x08)
pop(); /* fcomp, so we pop. */
} else
real_2op_NaN(FPU_st0_ptr, &FPU_loaded_data, FPU_st0_ptr);
goto reg_mem_instr_done;
}
switch ((FPU_modrm >> 3) & 7) {
case 0: /* fadd */
reg_add(FPU_st0_ptr, &FPU_loaded_data, FPU_st0_ptr, control_word);
break;
case 1: /* fmul */
reg_mul(FPU_st0_ptr, &FPU_loaded_data, FPU_st0_ptr, control_word);
break;
case 2: /* fcom */
compare_st_data();
break;
case 3: /* fcomp */
compare_st_data();
pop();
break;
case 4: /* fsub */
reg_sub(FPU_st0_ptr, &FPU_loaded_data, FPU_st0_ptr, control_word);
break;
case 5: /* fsubr */
reg_sub(&FPU_loaded_data, FPU_st0_ptr, FPU_st0_ptr, control_word);
break;
case 6: /* fdiv */
reg_div(FPU_st0_ptr, &FPU_loaded_data, FPU_st0_ptr, control_word);
break;
case 7: /* fdivr */
if (FPU_st0_tag == TW_Zero)
status_word = status1; /* Undo any denorm tag,
* zero-divide has
* priority. */
reg_div(&FPU_loaded_data, FPU_st0_ptr, FPU_st0_ptr, control_word);
break;
}
} else {
if ((FPU_modrm & 0x30) == 0x10) {
/*--- poly_sine() -----------------------------------------------------------+
| |
+---------------------------------------------------------------------------*/
void poly_sine(FPU_REG const *arg, FPU_REG *result)
{
short exponent;
FPU_REG fixed_arg, arg_sqrd, arg_to_4, accum, negaccum;
exponent = arg->exp - EXP_BIAS;
if ( arg->tag == TW_Zero )
{
/* Return 0.0 */
reg_move(&CONST_Z, result);
return;
}
#ifdef PARANOID
if ( arg->sign != 0 ) /* Can't hack a number < 0.0 */
{
EXCEPTION(EX_Invalid);
reg_move(&CONST_QNaN, result);
return;
}
if ( exponent >= 0 ) /* Can't hack a number > 1.0 */
{
if ( (exponent == 0) && (arg->sigl == 0) && (arg->sigh == 0x80000000) )
{
reg_move(&CONST_1, result);
return;
}
EXCEPTION(EX_Invalid);
reg_move(&CONST_QNaN, result);
return;
}
#endif PARANOID
fixed_arg.sigl = arg->sigl;
fixed_arg.sigh = arg->sigh;
if ( exponent < -1 )
{
/* shift the argument right by the required places */
if ( shrx(&(fixed_arg.sigl), -1-exponent) >= 0x80000000U )
significand(&fixed_arg)++; /* round up */
}
mul64(&significand(&fixed_arg), &significand(&fixed_arg),
&significand(&arg_sqrd));
mul64(&significand(&arg_sqrd), &significand(&arg_sqrd),
&significand(&arg_to_4));
/* will be a valid positive nr with expon = 0 */
*(short *)&(accum.sign) = 0;
accum.exp = 0;
/* Do the basic fixed point polynomial evaluation */
polynomial(&(accum.sigl), &(arg_to_4.sigl), lterms, HIPOWER-1);
/* will be a valid positive nr with expon = 0 */
*(short *)&(negaccum.sign) = 0;
negaccum.exp = 0;
/* Do the basic fixed point polynomial evaluation */
polynomial(&(negaccum.sigl), &(arg_to_4.sigl), negterms, HIPOWER-1);
mul64(&significand(&arg_sqrd), &significand(&negaccum),
&significand(&negaccum));
/* Subtract the mantissas */
significand(&accum) -= significand(&negaccum);
/* Convert to 64 bit signed-compatible */
accum.exp = EXP_BIAS - 1 + accum.exp;
reg_move(&accum, result);
normalize(result);
reg_mul(result, arg, result, FULL_PRECISION);
reg_u_add(result, arg, result, FULL_PRECISION);
if ( result->exp >= EXP_BIAS )
{
/* A small overflow may be possible... but an illegal result. */
if ( (result->exp > EXP_BIAS) /* Larger or equal 2.0 */
|| (result->sigl > 1) /* Larger than 1.0+msb */
|| (result->sigh != 0x80000000) /* Much > 1.0 */
)
{
#ifdef DEBUGGING
RE_ENTRANT_CHECK_OFF;
printk("\nEXP=%d, MS=%08x, LS=%08x\n", result->exp,
result->sigh, result->sigl);
RE_ENTRANT_CHECK_ON;
#endif DEBUGGING
EXCEPTION(EX_INTERNAL|0x103);
}
#ifdef DEBUGGING
RE_ENTRANT_CHECK_OFF;
printk("\n***CORRECTING ILLEGAL RESULT*** in poly_sin() computation\n");
printk("EXP=%d, MS=%08x, LS=%08x\n", result->exp,
result->sigh, result->sigl);
RE_ENTRANT_CHECK_ON;
#endif DEBUGGING
result->sigl = 0; /* Truncate the result to 1.00 */
}
}
void
fmul__()
{
/* fmul st,st(i) */
reg_mul(FPU_st0_ptr, &st(FPU_rm), FPU_st0_ptr, control_word);
}
void
fmul_i()
{
/* fmul st(i),st */
reg_mul(&st(FPU_rm), FPU_st0_ptr, &st(FPU_rm), control_word);
}
/*--- poly_tan() ------------------------------------------------------------+
| |
+---------------------------------------------------------------------------*/
void
poly_tan(FPU_REG * arg, FPU_REG * y_reg)
{
char invert = 0;
short exponent;
FPU_REG odd_poly, even_poly, pos_poly, neg_poly;
FPU_REG argSq;
long long arg_signif, argSqSq;
exponent = arg->exp - EXP_BIAS;
if (arg->tag == TW_Zero) {
/* Return 0.0 */
reg_move(&CONST_Z, y_reg);
return;
}
if (exponent >= -1) {
/* argument is in the range [0.5 .. 1.0] */
if (exponent >= 0) {
#ifdef PARANOID
if ((exponent == 0) &&
(arg->sigl == 0) && (arg->sigh == 0x80000000))
#endif /* PARANOID */
{
arith_overflow(y_reg);
return;
}
#ifdef PARANOID
EXCEPTION(EX_INTERNAL | 0x104); /* There must be a logic
* error */
return;
#endif /* PARANOID */
}
/* The argument is in the range [0.5 .. 1.0) */
/* Convert the argument to a number in the range (0.0 .. 0.5] */
*((long long *) (&arg->sigl)) = -*((long long *) (&arg->sigl));
normalize(arg); /* Needed later */
exponent = arg->exp - EXP_BIAS;
invert = 1;
}
#ifdef PARANOID
if (arg->sign != 0) { /* Can't hack a number < 0.0 */
arith_invalid(y_reg);
return;
} /* Need a positive number */
#endif /* PARANOID */
*(long long *) &arg_signif = *(long long *) &(arg->sigl);
if (exponent < -1) {
/* shift the argument right by the required places */
if (shrx(&arg_signif, -1 - exponent) >= (unsigned)0x80000000)
arg_signif++; /* round up */
}
mul64(&arg_signif, &arg_signif, (long long *) (&argSq.sigl));
mul64((long long *) (&argSq.sigl), (long long *) (&argSq.sigl), &argSqSq);
/* will be a valid positive nr with expon = 0 */
*(short *) &(pos_poly.sign) = 0;
pos_poly.exp = EXP_BIAS;
/* Do the basic fixed point polynomial evaluation */
polynomial((u_int *) &pos_poly.sigl, (unsigned *) &argSqSq, oddplterms, HIPOWERop - 1);
/* will be a valid positive nr with expon = 0 */
*(short *) &(neg_poly.sign) = 0;
neg_poly.exp = EXP_BIAS;
/* Do the basic fixed point polynomial evaluation */
polynomial((u_int *) &neg_poly.sigl, (unsigned *) &argSqSq, oddnegterms, HIPOWERon - 1);
mul64((long long *) (&argSq.sigl), (long long *) (&neg_poly.sigl),
(long long *) (&neg_poly.sigl));
/* Subtract the mantissas */
*((long long *) (&pos_poly.sigl)) -= *((long long *) (&neg_poly.sigl));
/* Convert to 64 bit signed-compatible */
pos_poly.exp -= 1;
reg_move(&pos_poly, &odd_poly);
normalize(&odd_poly);
reg_mul(&odd_poly, arg, &odd_poly, FULL_PRECISION);
reg_u_add(&odd_poly, arg, &odd_poly, FULL_PRECISION); /* This is just the odd
* polynomial */
/* will be a valid positive nr with expon = 0 */
*(short *) &(pos_poly.sign) = 0;
pos_poly.exp = EXP_BIAS;
/* Do the basic fixed point polynomial evaluation */
polynomial((u_int *) &pos_poly.sigl, (unsigned *) &argSqSq, evenplterms, HIPOWERep - 1);
mul64((long long *) (&argSq.sigl),
(long long *) (&pos_poly.sigl), (long long *) (&pos_poly.sigl));
/* will be a valid positive nr with expon = 0 */
*(short *) &(neg_poly.sign) = 0;
neg_poly.exp = EXP_BIAS;
/* Do the basic fixed point polynomial evaluation */
polynomial((u_int *) &neg_poly.sigl, (unsigned *) &argSqSq, evennegterms, HIPOWERen - 1);
/* Subtract the mantissas */
*((long long *) (&neg_poly.sigl)) -= *((long long *) (&pos_poly.sigl));
/* and multiply by argSq */
/* Convert argSq to a valid reg number */
*(short *) &(argSq.sign) = 0;
argSq.exp = EXP_BIAS - 1;
normalize(&argSq);
/* Convert to 64 bit signed-compatible */
neg_poly.exp -= 1;
reg_move(&neg_poly, &even_poly);
normalize(&even_poly);
reg_mul(&even_poly, &argSq, &even_poly, FULL_PRECISION);
reg_add(&even_poly, &argSq, &even_poly, FULL_PRECISION);
reg_sub(&CONST_1, &even_poly, &even_poly, FULL_PRECISION); /* This is just the even
* polynomial */
/* Now ready to copy the results */
if (invert) {
reg_div(&even_poly, &odd_poly, y_reg, FULL_PRECISION);
} else {
reg_div(&odd_poly, &even_poly, y_reg, FULL_PRECISION);
}
}
