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-rw-r--r--arch/i386/math-emu/fpu_trig.c1845
1 files changed, 0 insertions, 1845 deletions
diff --git a/arch/i386/math-emu/fpu_trig.c b/arch/i386/math-emu/fpu_trig.c
deleted file mode 100644
index 403cbde1d42..00000000000
--- a/arch/i386/math-emu/fpu_trig.c
+++ /dev/null
@@ -1,1845 +0,0 @@
-/*---------------------------------------------------------------------------+
- | fpu_trig.c |
- | |
- | Implementation of the FPU "transcendental" functions. |
- | |
- | Copyright (C) 1992,1993,1994,1997,1999 |
- | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
- | Australia. E-mail billm@melbpc.org.au |
- | |
- | |
- +---------------------------------------------------------------------------*/
-
-#include "fpu_system.h"
-#include "exception.h"
-#include "fpu_emu.h"
-#include "status_w.h"
-#include "control_w.h"
-#include "reg_constant.h"
-
-static void rem_kernel(unsigned long long st0, unsigned long long *y,
- unsigned long long st1,
- unsigned long long q, int n);
-
-#define BETTER_THAN_486
-
-#define FCOS 4
-
-/* Used only by fptan, fsin, fcos, and fsincos. */
-/* This routine produces very accurate results, similar to
- using a value of pi with more than 128 bits precision. */
-/* Limited measurements show no results worse than 64 bit precision
- except for the results for arguments close to 2^63, where the
- precision of the result sometimes degrades to about 63.9 bits */
-static int trig_arg(FPU_REG *st0_ptr, int even)
-{
- FPU_REG tmp;
- u_char tmptag;
- unsigned long long q;
- int old_cw = control_word, saved_status = partial_status;
- int tag, st0_tag = TAG_Valid;
-
- if ( exponent(st0_ptr) >= 63 )
- {
- partial_status |= SW_C2; /* Reduction incomplete. */
- return -1;
- }
-
- control_word &= ~CW_RC;
- control_word |= RC_CHOP;
-
- setpositive(st0_ptr);
- tag = FPU_u_div(st0_ptr, &CONST_PI2, &tmp, PR_64_BITS | RC_CHOP | 0x3f,
- SIGN_POS);
-
- FPU_round_to_int(&tmp, tag); /* Fortunately, this can't overflow
- to 2^64 */
- q = significand(&tmp);
- if ( q )
- {
- rem_kernel(significand(st0_ptr),
- &significand(&tmp),
- significand(&CONST_PI2),
- q, exponent(st0_ptr) - exponent(&CONST_PI2));
- setexponent16(&tmp, exponent(&CONST_PI2));
- st0_tag = FPU_normalize(&tmp);
- FPU_copy_to_reg0(&tmp, st0_tag);
- }
-
- if ( (even && !(q & 1)) || (!even && (q & 1)) )
- {
- st0_tag = FPU_sub(REV|LOADED|TAG_Valid, (int)&CONST_PI2, FULL_PRECISION);
-
-#ifdef BETTER_THAN_486
- /* So far, the results are exact but based upon a 64 bit
- precision approximation to pi/2. The technique used
- now is equivalent to using an approximation to pi/2 which
- is accurate to about 128 bits. */
- if ( (exponent(st0_ptr) <= exponent(&CONST_PI2extra) + 64) || (q > 1) )
- {
- /* This code gives the effect of having pi/2 to better than
- 128 bits precision. */
-
- significand(&tmp) = q + 1;
- setexponent16(&tmp, 63);
- FPU_normalize(&tmp);
- tmptag =
- FPU_u_mul(&CONST_PI2extra, &tmp, &tmp, FULL_PRECISION, SIGN_POS,
- exponent(&CONST_PI2extra) + exponent(&tmp));
- setsign(&tmp, getsign(&CONST_PI2extra));
- st0_tag = FPU_add(&tmp, tmptag, 0, FULL_PRECISION);
- if ( signnegative(st0_ptr) )
- {
- /* CONST_PI2extra is negative, so the result of the addition
- can be negative. This means that the argument is actually
- in a different quadrant. The correction is always < pi/2,
- so it can't overflow into yet another quadrant. */
- setpositive(st0_ptr);
- q++;
- }
- }
-#endif /* BETTER_THAN_486 */
- }
-#ifdef BETTER_THAN_486
- else
- {
- /* So far, the results are exact but based upon a 64 bit
- precision approximation to pi/2. The technique used
- now is equivalent to using an approximation to pi/2 which
- is accurate to about 128 bits. */
- if ( ((q > 0) && (exponent(st0_ptr) <= exponent(&CONST_PI2extra) + 64))
- || (q > 1) )
- {
- /* This code gives the effect of having p/2 to better than
- 128 bits precision. */
-
- significand(&tmp) = q;
- setexponent16(&tmp, 63);
- FPU_normalize(&tmp); /* This must return TAG_Valid */
- tmptag = FPU_u_mul(&CONST_PI2extra, &tmp, &tmp, FULL_PRECISION,
- SIGN_POS,
- exponent(&CONST_PI2extra) + exponent(&tmp));
- setsign(&tmp, getsign(&CONST_PI2extra));
- st0_tag = FPU_sub(LOADED|(tmptag & 0x0f), (int)&tmp,
- FULL_PRECISION);
- if ( (exponent(st0_ptr) == exponent(&CONST_PI2)) &&
- ((st0_ptr->sigh > CONST_PI2.sigh)
- || ((st0_ptr->sigh == CONST_PI2.sigh)
- && (st0_ptr->sigl > CONST_PI2.sigl))) )
- {
- /* CONST_PI2extra is negative, so the result of the
- subtraction can be larger than pi/2. This means
- that the argument is actually in a different quadrant.
- The correction is always < pi/2, so it can't overflow
- into yet another quadrant. */
- st0_tag = FPU_sub(REV|LOADED|TAG_Valid, (int)&CONST_PI2,
- FULL_PRECISION);
- q++;
- }
- }
- }
-#endif /* BETTER_THAN_486 */
-
- FPU_settag0(st0_tag);
- control_word = old_cw;
- partial_status = saved_status & ~SW_C2; /* Reduction complete. */
-
- return (q & 3) | even;
-}
-
-
-/* Convert a long to register */
-static void convert_l2reg(long const *arg, int deststnr)
-{
- int tag;
- long num = *arg;
- u_char sign;
- FPU_REG *dest = &st(deststnr);
-
- if (num == 0)
- {
- FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
- return;
- }
-
- if (num > 0)
- { sign = SIGN_POS; }
- else
- { num = -num; sign = SIGN_NEG; }
-
- dest->sigh = num;
- dest->sigl = 0;
- setexponent16(dest, 31);
- tag = FPU_normalize(dest);
- FPU_settagi(deststnr, tag);
- setsign(dest, sign);
- return;
-}
-
-
-static void single_arg_error(FPU_REG *st0_ptr, u_char st0_tag)
-{
- if ( st0_tag == TAG_Empty )
- FPU_stack_underflow(); /* Puts a QNaN in st(0) */
- else if ( st0_tag == TW_NaN )
- real_1op_NaN(st0_ptr); /* return with a NaN in st(0) */
-#ifdef PARANOID
- else
- EXCEPTION(EX_INTERNAL|0x0112);
-#endif /* PARANOID */
-}
-
-
-static void single_arg_2_error(FPU_REG *st0_ptr, u_char st0_tag)
-{
- int isNaN;
-
- switch ( st0_tag )
- {
- case TW_NaN:
- isNaN = (exponent(st0_ptr) == EXP_OVER) && (st0_ptr->sigh & 0x80000000);
- if ( isNaN && !(st0_ptr->sigh & 0x40000000) ) /* Signaling ? */
- {
- EXCEPTION(EX_Invalid);
- if ( control_word & CW_Invalid )
- {
- /* The masked response */
- /* Convert to a QNaN */
- st0_ptr->sigh |= 0x40000000;
- push();
- FPU_copy_to_reg0(st0_ptr, TAG_Special);
- }
- }
- else if ( isNaN )
- {
- /* A QNaN */
- push();
- FPU_copy_to_reg0(st0_ptr, TAG_Special);
- }
- else
- {
- /* pseudoNaN or other unsupported */
- EXCEPTION(EX_Invalid);
- if ( control_word & CW_Invalid )
- {
- /* The masked response */
- FPU_copy_to_reg0(&CONST_QNaN, TAG_Special);
- push();
- FPU_copy_to_reg0(&CONST_QNaN, TAG_Special);
- }
- }
- break; /* return with a NaN in st(0) */
-#ifdef PARANOID
- default:
- EXCEPTION(EX_INTERNAL|0x0112);
-#endif /* PARANOID */
- }
-}
-
-
-/*---------------------------------------------------------------------------*/
-
-static void f2xm1(FPU_REG *st0_ptr, u_char tag)
-{
- FPU_REG a;
-
- clear_C1();
-
- if ( tag == TAG_Valid )
- {
- /* For an 80486 FPU, the result is undefined if the arg is >= 1.0 */
- if ( exponent(st0_ptr) < 0 )
- {
- denormal_arg:
-
- FPU_to_exp16(st0_ptr, &a);
-
- /* poly_2xm1(x) requires 0 < st(0) < 1. */
- poly_2xm1(getsign(st0_ptr), &a, st0_ptr);
- }
- set_precision_flag_up(); /* 80486 appears to always do this */
- return;
- }
-
- if ( tag == TAG_Zero )
- return;
-
- if ( tag == TAG_Special )
- tag = FPU_Special(st0_ptr);
-
- switch ( tag )
- {
- case TW_Denormal:
- if ( denormal_operand() < 0 )
- return;
- goto denormal_arg;
- case TW_Infinity:
- if ( signnegative(st0_ptr) )
- {
- /* -infinity gives -1 (p16-10) */
- FPU_copy_to_reg0(&CONST_1, TAG_Valid);
- setnegative(st0_ptr);
- }
- return;
- default:
- single_arg_error(st0_ptr, tag);
- }
-}
-
-
-static void fptan(FPU_REG *st0_ptr, u_char st0_tag)
-{
- FPU_REG *st_new_ptr;
- int q;
- u_char arg_sign = getsign(st0_ptr);
-
- /* Stack underflow has higher priority */
- if ( st0_tag == TAG_Empty )
- {
- FPU_stack_underflow(); /* Puts a QNaN in st(0) */
- if ( control_word & CW_Invalid )
- {
- st_new_ptr = &st(-1);
- push();
- FPU_stack_underflow(); /* Puts a QNaN in the new st(0) */
- }
- return;
- }
-
- if ( STACK_OVERFLOW )
- { FPU_stack_overflow(); return; }
-
- if ( st0_tag == TAG_Valid )
- {
- if ( exponent(st0_ptr) > -40 )
- {
- if ( (q = trig_arg(st0_ptr, 0)) == -1 )
- {
- /* Operand is out of range */
- return;
- }
-
- poly_tan(st0_ptr);
- setsign(st0_ptr, (q & 1) ^ (arg_sign != 0));
- set_precision_flag_up(); /* We do not really know if up or down */
- }
- else
- {
- /* For a small arg, the result == the argument */
- /* Underflow may happen */
-
- denormal_arg:
-
- FPU_to_exp16(st0_ptr, st0_ptr);
-
- st0_tag = FPU_round(st0_ptr, 1, 0, FULL_PRECISION, arg_sign);
- FPU_settag0(st0_tag);
- }
- push();
- FPU_copy_to_reg0(&CONST_1, TAG_Valid);
- return;
- }
-
- if ( st0_tag == TAG_Zero )
- {
- push();
- FPU_copy_to_reg0(&CONST_1, TAG_Valid);
- setcc(0);
- return;
- }
-
- if ( st0_tag == TAG_Special )
- st0_tag = FPU_Special(st0_ptr);
-
- if ( st0_tag == TW_Denormal )
- {
- if ( denormal_operand() < 0 )
- return;
-
- goto denormal_arg;
- }
-
- if ( st0_tag == TW_Infinity )
- {
- /* The 80486 treats infinity as an invalid operand */
- if ( arith_invalid(0) >= 0 )
- {
- st_new_ptr = &st(-1);
- push();
- arith_invalid(0);
- }
- return;
- }
-
- single_arg_2_error(st0_ptr, st0_tag);
-}
-
-
-static void fxtract(FPU_REG *st0_ptr, u_char st0_tag)
-{
- FPU_REG *st_new_ptr;
- u_char sign;
- register FPU_REG *st1_ptr = st0_ptr; /* anticipate */
-
- if ( STACK_OVERFLOW )
- { FPU_stack_overflow(); return; }
-
- clear_C1();
-
- if ( st0_tag == TAG_Valid )
- {
- long e;
-
- push();
- sign = getsign(st1_ptr);
- reg_copy(st1_ptr, st_new_ptr);
- setexponent16(st_new_ptr, exponent(st_new_ptr));
-
- denormal_arg:
-
- e = exponent16(st_new_ptr);
- convert_l2reg(&e, 1);
- setexponentpos(st_new_ptr, 0);
- setsign(st_new_ptr, sign);
- FPU_settag0(TAG_Valid); /* Needed if arg was a denormal */
- return;
- }
- else if ( st0_tag == TAG_Zero )
- {
- sign = getsign(st0_ptr);
-
- if ( FPU_divide_by_zero(0, SIGN_NEG) < 0 )
- return;
-
- push();
- FPU_copy_to_reg0(&CONST_Z, TAG_Zero);
- setsign(st_new_ptr, sign);
- return;
- }
-
- if ( st0_tag == TAG_Special )
- st0_tag = FPU_Special(st0_ptr);
-
- if ( st0_tag == TW_Denormal )
- {
- if (denormal_operand() < 0 )
- return;
-
- push();
- sign = getsign(st1_ptr);
- FPU_to_exp16(st1_ptr, st_new_ptr);
- goto denormal_arg;
- }
- else if ( st0_tag == TW_Infinity )
- {
- sign = getsign(st0_ptr);
- setpositive(st0_ptr);
- push();
- FPU_copy_to_reg0(&CONST_INF, TAG_Special);
- setsign(st_new_ptr, sign);
- return;
- }
- else if ( st0_tag == TW_NaN )
- {
- if ( real_1op_NaN(st0_ptr) < 0 )
- return;
-
- push();
- FPU_copy_to_reg0(st0_ptr, TAG_Special);
- return;
- }
- else if ( st0_tag == TAG_Empty )
- {
- /* Is this the correct behaviour? */
- if ( control_word & EX_Invalid )
- {
- FPU_stack_underflow();
- push();
- FPU_stack_underflow();
- }
- else
- EXCEPTION(EX_StackUnder);
- }
-#ifdef PARANOID
- else
- EXCEPTION(EX_INTERNAL | 0x119);
-#endif /* PARANOID */
-}
-
-
-static void fdecstp(void)
-{
- clear_C1();
- top--;
-}
-
-static void fincstp(void)
-{
- clear_C1();
- top++;
-}
-
-
-static void fsqrt_(FPU_REG *st0_ptr, u_char st0_tag)
-{
- int expon;
-
- clear_C1();
-
- if ( st0_tag == TAG_Valid )
- {
- u_char tag;
-
- if (signnegative(st0_ptr))
- {
- arith_invalid(0); /* sqrt(negative) is invalid */
- return;
- }
-
- /* make st(0) in [1.0 .. 4.0) */
- expon = exponent(st0_ptr);
-
- denormal_arg:
-
- setexponent16(st0_ptr, (expon & 1));
-
- /* Do the computation, the sign of the result will be positive. */
- tag = wm_sqrt(st0_ptr, 0, 0, control_word, SIGN_POS);
- addexponent(st0_ptr, expon >> 1);
- FPU_settag0(tag);
- return;
- }
-
- if ( st0_tag == TAG_Zero )
- return;
-
- if ( st0_tag == TAG_Special )
- st0_tag = FPU_Special(st0_ptr);
-
- if ( st0_tag == TW_Infinity )
- {
- if ( signnegative(st0_ptr) )
- arith_invalid(0); /* sqrt(-Infinity) is invalid */
- return;
- }
- else if ( st0_tag == TW_Denormal )
- {
- if (signnegative(st0_ptr))
- {
- arith_invalid(0); /* sqrt(negative) is invalid */
- return;
- }
-
- if ( denormal_operand() < 0 )
- return;
-
- FPU_to_exp16(st0_ptr, st0_ptr);
-
- expon = exponent16(st0_ptr);
-
- goto denormal_arg;
- }
-
- single_arg_error(st0_ptr, st0_tag);
-
-}
-
-
-static void frndint_(FPU_REG *st0_ptr, u_char st0_tag)
-{
- int flags, tag;
-
- if ( st0_tag == TAG_Valid )
- {
- u_char sign;
-
- denormal_arg:
-
- sign = getsign(st0_ptr);
-
- if (exponent(st0_ptr) > 63)
- return;
-
- if ( st0_tag == TW_Denormal )
- {
- if (denormal_operand() < 0 )
- return;
- }
-
- /* Fortunately, this can't overflow to 2^64 */
- if ( (flags = FPU_round_to_int(st0_ptr, st0_tag)) )
- set_precision_flag(flags);
-
- setexponent16(st0_ptr, 63);
- tag = FPU_normalize(st0_ptr);
- setsign(st0_ptr, sign);
- FPU_settag0(tag);
- return;
- }
-
- if ( st0_tag == TAG_Zero )
- return;
-
- if ( st0_tag == TAG_Special )
- st0_tag = FPU_Special(st0_ptr);
-
- if ( st0_tag == TW_Denormal )
- goto denormal_arg;
- else if ( st0_tag == TW_Infinity )
- return;
- else
- single_arg_error(st0_ptr, st0_tag);
-}
-
-
-static int fsin(FPU_REG *st0_ptr, u_char tag)
-{
- u_char arg_sign = getsign(st0_ptr);
-
- if ( tag == TAG_Valid )
- {
- int q;
-
- if ( exponent(st0_ptr) > -40 )
- {
- if ( (q = trig_arg(st0_ptr, 0)) == -1 )
- {
- /* Operand is out of range */
- return 1;
- }
-
- poly_sine(st0_ptr);
-
- if (q & 2)
- changesign(st0_ptr);
-
- setsign(st0_ptr, getsign(st0_ptr) ^ arg_sign);
-
- /* We do not really know if up or down */
- set_precision_flag_up();
- return 0;
- }
- else
- {
- /* For a small arg, the result == the argument */
- set_precision_flag_up(); /* Must be up. */
- return 0;
- }
- }
-
- if ( tag == TAG_Zero )
- {
- setcc(0);
- return 0;
- }
-
- if ( tag == TAG_Special )
- tag = FPU_Special(st0_ptr);
-
- if ( tag == TW_Denormal )
- {
- if ( denormal_operand() < 0 )
- return 1;
-
- /* For a small arg, the result == the argument */
- /* Underflow may happen */
- FPU_to_exp16(st0_ptr, st0_ptr);
-
- tag = FPU_round(st0_ptr, 1, 0, FULL_PRECISION, arg_sign);
-
- FPU_settag0(tag);
-
- return 0;
- }
- else if ( tag == TW_Infinity )
- {
- /* The 80486 treats infinity as an invalid operand */
- arith_invalid(0);
- return 1;
- }
- else
- {
- single_arg_error(st0_ptr, tag);
- return 1;
- }
-}
-
-
-static int f_cos(FPU_REG *st0_ptr, u_char tag)
-{
- u_char st0_sign;
-
- st0_sign = getsign(st0_ptr);
-
- if ( tag == TAG_Valid )
- {
- int q;
-
- if ( exponent(st0_ptr) > -40 )
- {
- if ( (exponent(st0_ptr) < 0)
- || ((exponent(st0_ptr) == 0)
- && (significand(st0_ptr) <= 0xc90fdaa22168c234LL)) )
- {
- poly_cos(st0_ptr);
-
- /* We do not really know if up or down */
- set_precision_flag_down();
-
- return 0;
- }
- else if ( (q = trig_arg(st0_ptr, FCOS)) != -1 )
- {
- poly_sine(st0_ptr);
-
- if ((q+1) & 2)
- changesign(st0_ptr);
-
- /* We do not really know if up or down */
- set_precision_flag_down();
-
- return 0;
- }
- else
- {
- /* Operand is out of range */
- return 1;
- }
- }
- else
- {
- denormal_arg:
-
- setcc(0);
- FPU_copy_to_reg0(&CONST_1, TAG_Valid);
-#ifdef PECULIAR_486
- set_precision_flag_down(); /* 80486 appears to do this. */
-#else
- set_precision_flag_up(); /* Must be up. */
-#endif /* PECULIAR_486 */
- return 0;
- }
- }
- else if ( tag == TAG_Zero )
- {
- FPU_copy_to_reg0(&CONST_1, TAG_Valid);
- setcc(0);
- return 0;
- }
-
- if ( tag == TAG_Special )
- tag = FPU_Special(st0_ptr);
-
- if ( tag == TW_Denormal )
- {
- if ( denormal_operand() < 0 )
- return 1;
-
- goto denormal_arg;
- }
- else if ( tag == TW_Infinity )
- {
- /* The 80486 treats infinity as an invalid operand */
- arith_invalid(0);
- return 1;
- }
- else
- {
- single_arg_error(st0_ptr, tag); /* requires st0_ptr == &st(0) */
- return 1;
- }
-}
-
-
-static void fcos(FPU_REG *st0_ptr, u_char st0_tag)
-{
- f_cos(st0_ptr, st0_tag);
-}
-
-
-static void fsincos(FPU_REG *st0_ptr, u_char st0_tag)
-{
- FPU_REG *st_new_ptr;
- FPU_REG arg;
- u_char tag;
-
- /* Stack underflow has higher priority */
- if ( st0_tag == TAG_Empty )
- {
- FPU_stack_underflow(); /* Puts a QNaN in st(0) */
- if ( control_word & CW_Invalid )
- {
- st_new_ptr = &st(-1);
- push();
- FPU_stack_underflow(); /* Puts a QNaN in the new st(0) */
- }
- return;
- }
-
- if ( STACK_OVERFLOW )
- { FPU_stack_overflow(); return; }
-
- if ( st0_tag == TAG_Special )
- tag = FPU_Special(st0_ptr);
- else
- tag = st0_tag;
-
- if ( tag == TW_NaN )
- {
- single_arg_2_error(st0_ptr, TW_NaN);
- return;
- }
- else if ( tag == TW_Infinity )
- {
- /* The 80486 treats infinity as an invalid operand */
- if ( arith_invalid(0) >= 0 )
- {
- /* Masked response */
- push();
- arith_invalid(0);
- }
- return;
- }
-
- reg_copy(st0_ptr, &arg);
- if ( !fsin(st0_ptr, st0_tag) )
- {
- push();
- FPU_copy_to_reg0(&arg, st0_tag);
- f_cos(&st(0), st0_tag);
- }
- else
- {
- /* An error, so restore st(0) */
- FPU_copy_to_reg0(&arg, st0_tag);
- }
-}
-
-
-/*---------------------------------------------------------------------------*/
-/* The following all require two arguments: st(0) and st(1) */
-
-/* A lean, mean kernel for the fprem instructions. This relies upon
- the division and rounding to an integer in do_fprem giving an
- exact result. Because of this, rem_kernel() needs to deal only with
- the least significant 64 bits, the more significant bits of the
- result must be zero.
- */
-static void rem_kernel(unsigned long long st0, unsigned long long *y,
- unsigned long long st1,
- unsigned long long q, int n)
-{
- int dummy;
- unsigned long long x;
-
- x = st0 << n;
-
- /* Do the required multiplication and subtraction in the one operation */
-
- /* lsw x -= lsw st1 * lsw q */
- asm volatile ("mull %4; subl %%eax,%0; sbbl %%edx,%1"
- :"=m" (((unsigned *)&x)[0]), "=m" (((unsigned *)&x)[1]),
- "=a" (dummy)
- :"2" (((unsigned *)&st1)[0]), "m" (((unsigned *)&q)[0])
- :"%dx");
- /* msw x -= msw st1 * lsw q */
- asm volatile ("mull %3; subl %%eax,%0"
- :"=m" (((unsigned *)&x)[1]), "=a" (dummy)
- :"1" (((unsigned *)&st1)[1]), "m" (((unsigned *)&q)[0])
- :"%dx");
- /* msw x -= lsw st1 * msw q */
- asm volatile ("mull %3; subl %%eax,%0"
- :"=m" (((unsigned *)&x)[1]), "=a" (dummy)
- :"1" (((unsigned *)&st1)[0]), "m" (((unsigned *)&q)[1])
- :"%dx");
-
- *y = x;
-}
-
-
-/* Remainder of st(0) / st(1) */
-/* This routine produces exact results, i.e. there is never any
- rounding or truncation, etc of the result. */
-static void do_fprem(FPU_REG *st0_ptr, u_char st0_tag, int round)
-{
- FPU_REG *st1_ptr = &st(1);
- u_char st1_tag = FPU_gettagi(1);
-
- if ( !((st0_tag ^ TAG_Valid) | (st1_tag ^ TAG_Valid)) )
- {
- FPU_REG tmp, st0, st1;
- u_char st0_sign, st1_sign;
- u_char tmptag;
- int tag;
- int old_cw;
- int expdif;
- long long q;
- unsigned short saved_status;
- int cc;
-
- fprem_valid:
- /* Convert registers for internal use. */
- st0_sign = FPU_to_exp16(st0_ptr, &st0);
- st1_sign = FPU_to_exp16(st1_ptr, &st1);
- expdif = exponent16(&st0) - exponent16(&st1);
-
- old_cw = control_word;
- cc = 0;
-
- /* We want the status following the denorm tests, but don't want
- the status changed by the arithmetic operations. */
- saved_status = partial_status;
- control_word &= ~CW_RC;
- control_word |= RC_CHOP;
-
- if ( expdif < 64 )
- {
- /* This should be the most common case */
-
- if ( expdif > -2 )
- {
- u_char sign = st0_sign ^ st1_sign;
- tag = FPU_u_div(&st0, &st1, &tmp,
- PR_64_BITS | RC_CHOP | 0x3f,
- sign);
- setsign(&tmp, sign);
-
- if ( exponent(&tmp) >= 0 )
- {
- FPU_round_to_int(&tmp, tag); /* Fortunately, this can't
- overflow to 2^64 */
- q = significand(&tmp);
-
- rem_kernel(significand(&st0),
- &significand(&tmp),
- significand(&st1),
- q, expdif);
-
- setexponent16(&tmp, exponent16(&st1));
- }
- else
- {
- reg_copy(&st0, &tmp);
- q = 0;
- }
-
- if ( (round == RC_RND) && (tmp.sigh & 0xc0000000) )
- {
- /* We may need to subtract st(1) once more,
- to get a result <= 1/2 of st(1). */
- unsigned long long x;
- expdif = exponent16(&st1) - exponent16(&tmp);
- if ( expdif <= 1 )
- {
- if ( expdif == 0 )
- x = significand(&st1) - significand(&tmp);
- else /* expdif is 1 */
- x = (significand(&st1) << 1) - significand(&tmp);
- if ( (x < significand(&tmp)) ||
- /* or equi-distant (from 0 & st(1)) and q is odd */
- ((x == significand(&tmp)) && (q & 1) ) )
- {
- st0_sign = ! st0_sign;
- significand(&tmp) = x;
- q++;
- }
- }
- }
-
- if (q & 4) cc |= SW_C0;
- if (q & 2) cc |= SW_C3;
- if (q & 1) cc |= SW_C1;
- }
- else
- {
- control_word = old_cw;
- setcc(0);
- return;
- }
- }
- else
- {
- /* There is a large exponent difference ( >= 64 ) */
- /* To make much sense, the code in this section should
- be done at high precision. */
- int exp_1, N;
- u_char sign;
-
- /* prevent overflow here */
- /* N is 'a number between 32 and 63' (p26-113) */
- reg_copy(&st0, &tmp);
- tmptag = st0_tag;
- N = (expdif & 0x0000001f) + 32; /* This choice gives results
- identical to an AMD 486 */
- setexponent16(&tmp, N);
- exp_1 = exponent16(&st1);
- setexponent16(&st1, 0);
- expdif -= N;
-
- sign = getsign(&tmp) ^ st1_sign;
- tag = FPU_u_div(&tmp, &st1, &tmp, PR_64_BITS | RC_CHOP | 0x3f,
- sign);
- setsign(&tmp, sign);
-
- FPU_round_to_int(&tmp, tag); /* Fortunately, this can't
- overflow to 2^64 */
-
- rem_kernel(significand(&st0),
- &significand(&tmp),
- significand(&st1),
- significand(&tmp),
- exponent(&tmp)
- );
- setexponent16(&tmp, exp_1 + expdif);
-
- /* It is possible for the operation to be complete here.
- What does the IEEE standard say? The Intel 80486 manual
- implies that the operation will never be completed at this
- point, and the behaviour of a real 80486 confirms this.
- */
- if ( !(tmp.sigh | tmp.sigl) )
- {
- /* The result is zero */
- control_word = old_cw;
- partial_status = saved_status;
- FPU_copy_to_reg0(&CONST_Z, TAG_Zero);
- setsign(&st0, st0_sign);
-#ifdef PECULIAR_486
- setcc(SW_C2);
-#else
- setcc(0);
-#endif /* PECULIAR_486 */
- return;
- }
- cc = SW_C2;
- }
-
- control_word = old_cw;
- partial_status = saved_status;
- tag = FPU_normalize_nuo(&tmp);
- reg_copy(&tmp, st0_ptr);
-
- /* The only condition to be looked for is underflow,
- and it can occur here only if underflow is unmasked. */
- if ( (exponent16(&tmp) <= EXP_UNDER) && (tag != TAG_Zero)
- && !(control_word & CW_Underflow) )
- {
- setcc(cc);
- tag = arith_underflow(st0_ptr);
- setsign(st0_ptr, st0_sign);
- FPU_settag0(tag);
- return;
- }
- else if ( (exponent16(&tmp) > EXP_UNDER) || (tag == TAG_Zero) )
- {
- stdexp(st0_ptr);
- setsign(st0_ptr, st0_sign);
- }
- else
- {
- tag = FPU_round(st0_ptr, 0, 0, FULL_PRECISION, st0_sign);
- }
- FPU_settag0(tag);
- setcc(cc);
-
- return;
- }
-
- if ( st0_tag == TAG_Special )
- st0_tag = FPU_Special(st0_ptr);
- if ( st1_tag == TAG_Special )
- st1_tag = FPU_Special(st1_ptr);
-
- if ( ((st0_tag == TAG_Valid) && (st1_tag == TW_Denormal))
- || ((st0_tag == TW_Denormal) && (st1_tag == TAG_Valid))
- || ((st0_tag == TW_Denormal) && (st1_tag == TW_Denormal)) )
- {
- if ( denormal_operand() < 0 )
- return;
- goto fprem_valid;
- }
- else if ( (st0_tag == TAG_Empty) || (st1_tag == TAG_Empty) )
- {
- FPU_stack_underflow();
- return;
- }
- else if ( st0_tag == TAG_Zero )
- {
- if ( st1_tag == TAG_Valid )
- {
- setcc(0); return;
- }
- else if ( st1_tag == TW_Denormal )
- {
- if ( denormal_operand() < 0 )
- return;
- setcc(0); return;
- }
- else if ( st1_tag == TAG_Zero )
- { arith_invalid(0); return; } /* fprem(?,0) always invalid */
- else if ( st1_tag == TW_Infinity )
- { setcc(0); return; }
- }
- else if ( (st0_tag == TAG_Valid) || (st0_tag == TW_Denormal) )
- {
- if ( st1_tag == TAG_Zero )
- {
- arith_invalid(0); /* fprem(Valid,Zero) is invalid */
- return;
- }
- else if ( st1_tag != TW_NaN )
- {
- if ( ((st0_tag == TW_Denormal) || (st1_tag == TW_Denormal))
- && (denormal_operand() < 0) )
- return;
-
- if ( st1_tag == TW_Infinity )
- {
- /* fprem(Valid,Infinity) is o.k. */
- setcc(0); return;
- }
- }
- }
- else if ( st0_tag == TW_Infinity )
- {
- if ( st1_tag != TW_NaN )
- {
- arith_invalid(0); /* fprem(Infinity,?) is invalid */
- return;
- }
- }
-
- /* One of the registers must contain a NaN if we got here. */
-
-#ifdef PARANOID
- if ( (st0_tag != TW_NaN) && (st1_tag != TW_NaN) )
- EXCEPTION(EX_INTERNAL | 0x118);
-#endif /* PARANOID */
-
- real_2op_NaN(st1_ptr, st1_tag, 0, st1_ptr);
-
-}
-
-
-/* ST(1) <- ST(1) * log ST; pop ST */
-static void fyl2x(FPU_REG *st0_ptr, u_char st0_tag)
-{
- FPU_REG *st1_ptr = &st(1), exponent;
- u_char st1_tag = FPU_gettagi(1);
- u_char sign;
- int e, tag;
-
- clear_C1();
-
- if ( (st0_tag == TAG_Valid) && (st1_tag == TAG_Valid) )
- {
- both_valid:
- /* Both regs are Valid or Denormal */
- if ( signpositive(st0_ptr) )
- {
- if ( st0_tag == TW_Denormal )
- FPU_to_exp16(st0_ptr, st0_ptr);
- else
- /* Convert st(0) for internal use. */
- setexponent16(st0_ptr, exponent(st0_ptr));
-
- if ( (st0_ptr->sigh == 0x80000000) && (st0_ptr->sigl == 0) )
- {
- /* Special case. The result can be precise. */
- u_char esign;
- e = exponent16(st0_ptr);
- if ( e >= 0 )
- {
- exponent.sigh = e;
- esign = SIGN_POS;
- }
- else
- {
- exponent.sigh = -e;
- esign = SIGN_NEG;
- }
- exponent.sigl = 0;
- setexponent16(&exponent, 31);
- tag = FPU_normalize_nuo(&exponent);
- stdexp(&exponent);
- setsign(&exponent, esign);
- tag = FPU_mul(&exponent, tag, 1, FULL_PRECISION);
- if ( tag >= 0 )
- FPU_settagi(1, tag);
- }
- else
- {
- /* The usual case */
- sign = getsign(st1_ptr);
- if ( st1_tag == TW_Denormal )
- FPU_to_exp16(st1_ptr, st1_ptr);
- else
- /* Convert st(1) for internal use. */
- setexponent16(st1_ptr, exponent(st1_ptr));
- poly_l2(st0_ptr, st1_ptr, sign);
- }
- }
- else
- {
- /* negative */
- if ( arith_invalid(1) < 0 )
- return;
- }
-
- FPU_pop();
-
- return;
- }
-
- if ( st0_tag == TAG_Special )
- st0_tag = FPU_Special(st0_ptr);
- if ( st1_tag == TAG_Special )
- st1_tag = FPU_Special(st1_ptr);
-
- if ( (st0_tag == TAG_Empty) || (st1_tag == TAG_Empty) )
- {
- FPU_stack_underflow_pop(1);
- return;
- }
- else if ( (st0_tag <= TW_Denormal) && (st1_tag <= TW_Denormal) )
- {
- if ( st0_tag == TAG_Zero )
- {
- if ( st1_tag == TAG_Zero )
- {
- /* Both args zero is invalid */
- if ( arith_invalid(1) < 0 )
- return;
- }
- else
- {
- u_char sign;
- sign = getsign(st1_ptr)^SIGN_NEG;
- if ( FPU_divide_by_zero(1, sign) < 0 )
- return;
-
- setsign(st1_ptr, sign);
- }
- }
- else if ( st1_tag == TAG_Zero )
- {
- /* st(1) contains zero, st(0) valid <> 0 */
- /* Zero is the valid answer */
- sign = getsign(st1_ptr);
-
- if ( signnegative(st0_ptr) )
- {
- /* log(negative) */
- if ( arith_invalid(1) < 0 )
- return;
- }
- else if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
- else
- {
- if ( exponent(st0_ptr) < 0 )
- sign ^= SIGN_NEG;
-
- FPU_copy_to_reg1(&CONST_Z, TAG_Zero);
- setsign(st1_ptr, sign);
- }
- }
- else
- {
- /* One or both operands are denormals. */
- if ( denormal_operand() < 0 )
- return;
- goto both_valid;
- }
- }
- else if ( (st0_tag == TW_NaN) || (st1_tag == TW_NaN) )
- {
- if ( real_2op_NaN(st0_ptr, st0_tag, 1, st0_ptr) < 0 )
- return;
- }
- /* One or both arg must be an infinity */
- else if ( st0_tag == TW_Infinity )
- {
- if ( (signnegative(st0_ptr)) || (st1_tag == TAG_Zero) )
- {
- /* log(-infinity) or 0*log(infinity) */
- if ( arith_invalid(1) < 0 )
- return;
- }
- else
- {
- u_char sign = getsign(st1_ptr);
-
- if ( (st1_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
-
- FPU_copy_to_reg1(&CONST_INF, TAG_Special);
- setsign(st1_ptr, sign);
- }
- }
- /* st(1) must be infinity here */
- else if ( ((st0_tag == TAG_Valid) || (st0_tag == TW_Denormal))
- && ( signpositive(st0_ptr) ) )
- {
- if ( exponent(st0_ptr) >= 0 )
- {
- if ( (exponent(st0_ptr) == 0) &&
- (st0_ptr->sigh == 0x80000000) &&
- (st0_ptr->sigl == 0) )
- {
- /* st(0) holds 1.0 */
- /* infinity*log(1) */
- if ( arith_invalid(1) < 0 )
- return;
- }
- /* else st(0) is positive and > 1.0 */
- }
- else
- {
- /* st(0) is positive and < 1.0 */
-
- if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
-
- changesign(st1_ptr);
- }
- }
- else
- {
- /* st(0) must be zero or negative */
- if ( st0_tag == TAG_Zero )
- {
- /* This should be invalid, but a real 80486 is happy with it. */
-
-#ifndef PECULIAR_486
- sign = getsign(st1_ptr);
- if ( FPU_divide_by_zero(1, sign) < 0 )
- return;
-#endif /* PECULIAR_486 */
-
- changesign(st1_ptr);
- }
- else if ( arith_invalid(1) < 0 ) /* log(negative) */
- return;
- }
-
- FPU_pop();
-}
-
-
-static void fpatan(FPU_REG *st0_ptr, u_char st0_tag)
-{
- FPU_REG *st1_ptr = &st(1);
- u_char st1_tag = FPU_gettagi(1);
- int tag;
-
- clear_C1();
- if ( !((st0_tag ^ TAG_Valid) | (st1_tag ^ TAG_Valid)) )
- {
- valid_atan:
-
- poly_atan(st0_ptr, st0_tag, st1_ptr, st1_tag);
-
- FPU_pop();
-
- return;
- }
-
- if ( st0_tag == TAG_Special )
- st0_tag = FPU_Special(st0_ptr);
- if ( st1_tag == TAG_Special )
- st1_tag = FPU_Special(st1_ptr);
-
- if ( ((st0_tag == TAG_Valid) && (st1_tag == TW_Denormal))
- || ((st0_tag == TW_Denormal) && (st1_tag == TAG_Valid))
- || ((st0_tag == TW_Denormal) && (st1_tag == TW_Denormal)) )
- {
- if ( denormal_operand() < 0 )
- return;
-
- goto valid_atan;
- }
- else if ( (st0_tag == TAG_Empty) || (st1_tag == TAG_Empty) )
- {
- FPU_stack_underflow_pop(1);
- return;
- }
- else if ( (st0_tag == TW_NaN) || (st1_tag == TW_NaN) )
- {
- if ( real_2op_NaN(st0_ptr, st0_tag, 1, st0_ptr) >= 0 )
- FPU_pop();
- return;
- }
- else if ( (st0_tag == TW_Infinity) || (st1_tag == TW_Infinity) )
- {
- u_char sign = getsign(st1_ptr);
- if ( st0_tag == TW_Infinity )
- {
- if ( st1_tag == TW_Infinity )
- {
- if ( signpositive(st0_ptr) )
- {
- FPU_copy_to_reg1(&CONST_PI4, TAG_Valid);
- }
- else
- {
- setpositive(st1_ptr);
- tag = FPU_u_add(&CONST_PI4, &CONST_PI2, st1_ptr,
- FULL_PRECISION, SIGN_POS,
- exponent(&CONST_PI4), exponent(&CONST_PI2));
- if ( tag >= 0 )
- FPU_settagi(1, tag);
- }
- }
- else
- {
- if ( (st1_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
-
- if ( signpositive(st0_ptr) )
- {
- FPU_copy_to_reg1(&CONST_Z, TAG_Zero);
- setsign(st1_ptr, sign); /* An 80486 preserves the sign */
- FPU_pop();
- return;
- }
- else
- {
- FPU_copy_to_reg1(&CONST_PI, TAG_Valid);
- }
- }
- }
- else
- {
- /* st(1) is infinity, st(0) not infinity */
- if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
-
- FPU_copy_to_reg1(&CONST_PI2, TAG_Valid);
- }
- setsign(st1_ptr, sign);
- }
- else if ( st1_tag == TAG_Zero )
- {
- /* st(0) must be valid or zero */
- u_char sign = getsign(st1_ptr);
-
- if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
-
- if ( signpositive(st0_ptr) )
- {
- /* An 80486 preserves the sign */
- FPU_pop();
- return;
- }
-
- FPU_copy_to_reg1(&CONST_PI, TAG_Valid);
- setsign(st1_ptr, sign);
- }
- else if ( st0_tag == TAG_Zero )
- {
- /* st(1) must be TAG_Valid here */
- u_char sign = getsign(st1_ptr);
-
- if ( (st1_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
-
- FPU_copy_to_reg1(&CONST_PI2, TAG_Valid);
- setsign(st1_ptr, sign);
- }
-#ifdef PARANOID
- else
- EXCEPTION(EX_INTERNAL | 0x125);
-#endif /* PARANOID */
-
- FPU_pop();
- set_precision_flag_up(); /* We do not really know if up or down */
-}
-
-
-static void fprem(FPU_REG *st0_ptr, u_char st0_tag)
-{
- do_fprem(st0_ptr, st0_tag, RC_CHOP);
-}
-
-
-static void fprem1(FPU_REG *st0_ptr, u_char st0_tag)
-{
- do_fprem(st0_ptr, st0_tag, RC_RND);
-}
-
-
-static void fyl2xp1(FPU_REG *st0_ptr, u_char st0_tag)
-{
- u_char sign, sign1;
- FPU_REG *st1_ptr = &st(1), a, b;
- u_char st1_tag = FPU_gettagi(1);
-
- clear_C1();
- if ( !((st0_tag ^ TAG_Valid) | (st1_tag ^ TAG_Valid)) )
- {
- valid_yl2xp1:
-
- sign = getsign(st0_ptr);
- sign1 = getsign(st1_ptr);
-
- FPU_to_exp16(st0_ptr, &a);
- FPU_to_exp16(st1_ptr, &b);
-
- if ( poly_l2p1(sign, sign1, &a, &b, st1_ptr) )
- return;
-
- FPU_pop();
- return;
- }
-
- if ( st0_tag == TAG_Special )
- st0_tag = FPU_Special(st0_ptr);
- if ( st1_tag == TAG_Special )
- st1_tag = FPU_Special(st1_ptr);
-
- if ( ((st0_tag == TAG_Valid) && (st1_tag == TW_Denormal))
- || ((st0_tag == TW_Denormal) && (st1_tag == TAG_Valid))
- || ((st0_tag == TW_Denormal) && (st1_tag == TW_Denormal)) )
- {
- if ( denormal_operand() < 0 )
- return;
-
- goto valid_yl2xp1;
- }
- else if ( (st0_tag == TAG_Empty) | (st1_tag == TAG_Empty) )
- {
- FPU_stack_underflow_pop(1);
- return;
- }
- else if ( st0_tag == TAG_Zero )
- {
- switch ( st1_tag )
- {
- case TW_Denormal:
- if ( denormal_operand() < 0 )
- return;
-
- case TAG_Zero:
- case TAG_Valid:
- setsign(st0_ptr, getsign(st0_ptr) ^ getsign(st1_ptr));
- FPU_copy_to_reg1(st0_ptr, st0_tag);
- break;
-
- case TW_Infinity:
- /* Infinity*log(1) */
- if ( arith_invalid(1) < 0 )
- return;
- break;
-
- case TW_NaN:
- if ( real_2op_NaN(st0_ptr, st0_tag, 1, st0_ptr) < 0 )
- return;
- break;
-
- default:
-#ifdef PARANOID
- EXCEPTION(EX_INTERNAL | 0x116);
- return;
-#endif /* PARANOID */
- break;
- }
- }
- else if ( (st0_tag == TAG_Valid) || (st0_tag == TW_Denormal) )
- {
- switch ( st1_tag )
- {
- case TAG_Zero:
- if ( signnegative(st0_ptr) )
- {
- if ( exponent(st0_ptr) >= 0 )
- {
- /* st(0) holds <= -1.0 */
-#ifdef PECULIAR_486 /* Stupid 80486 doesn't worry about log(negative). */
- changesign(st1_ptr);
-#else
- if ( arith_invalid(1) < 0 )
- return;
-#endif /* PECULIAR_486 */
- }
- else if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
- else
- changesign(st1_ptr);
- }
- else if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
- break;
-
- case TW_Infinity:
- if ( signnegative(st0_ptr) )
- {
- if ( (exponent(st0_ptr) >= 0) &&
- !((st0_ptr->sigh == 0x80000000) &&
- (st0_ptr->sigl == 0)) )
- {
- /* st(0) holds < -1.0 */
-#ifdef PECULIAR_486 /* Stupid 80486 doesn't worry about log(negative). */
- changesign(st1_ptr);
-#else
- if ( arith_invalid(1) < 0 ) return;
-#endif /* PECULIAR_486 */
- }
- else if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
- else
- changesign(st1_ptr);
- }
- else if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
- break;
-
- case TW_NaN:
- if ( real_2op_NaN(st0_ptr, st0_tag, 1, st0_ptr) < 0 )
- return;
- }
-
- }
- else if ( st0_tag == TW_NaN )
- {
- if ( real_2op_NaN(st0_ptr, st0_tag, 1, st0_ptr) < 0 )
- return;
- }
- else if ( st0_tag == TW_Infinity )
- {
- if ( st1_tag == TW_NaN )
- {
- if ( real_2op_NaN(st0_ptr, st0_tag, 1, st0_ptr) < 0 )
- return;
- }
- else if ( signnegative(st0_ptr) )
- {
-#ifndef PECULIAR_486
- /* This should have higher priority than denormals, but... */
- if ( arith_invalid(1) < 0 ) /* log(-infinity) */
- return;
-#endif /* PECULIAR_486 */
- if ( (st1_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
-#ifdef PECULIAR_486
- /* Denormal operands actually get higher priority */
- if ( arith_invalid(1) < 0 ) /* log(-infinity) */
- return;
-#endif /* PECULIAR_486 */
- }
- else if ( st1_tag == TAG_Zero )
- {
- /* log(infinity) */
- if ( arith_invalid(1) < 0 )
- return;
- }
-
- /* st(1) must be valid here. */
-
- else if ( (st1_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
-
- /* The Manual says that log(Infinity) is invalid, but a real
- 80486 sensibly says that it is o.k. */
- else
- {
- u_char sign = getsign(st1_ptr);
- FPU_copy_to_reg1(&CONST_INF, TAG_Special);
- setsign(st1_ptr, sign);
- }
- }
-#ifdef PARANOID
- else
- {
- EXCEPTION(EX_INTERNAL | 0x117);
- return;
- }
-#endif /* PARANOID */
-
- FPU_pop();
- return;
-
-}
-
-
-static void fscale(FPU_REG *st0_ptr, u_char st0_tag)
-{
- FPU_REG *st1_ptr = &st(1);
- u_char st1_tag = FPU_gettagi(1);
- int old_cw = control_word;
- u_char sign = getsign(st0_ptr);
-
- clear_C1();
- if ( !((st0_tag ^ TAG_Valid) | (st1_tag ^ TAG_Valid)) )
- {
- long scale;
- FPU_REG tmp;
-
- /* Convert register for internal use. */
- setexponent16(st0_ptr, exponent(st0_ptr));
-
- valid_scale:
-
- if ( exponent(st1_ptr) > 30 )
- {
- /* 2^31 is far too large, would require 2^(2^30) or 2^(-2^30) */
-
- if ( signpositive(st1_ptr) )
- {
- EXCEPTION(EX_Overflow);
- FPU_copy_to_reg0(&CONST_INF, TAG_Special);
- }
- else
- {
- EXCEPTION(EX_Underflow);
- FPU_copy_to_reg0(&CONST_Z, TAG_Zero);
- }
- setsign(st0_ptr, sign);
- return;
- }
-
- control_word &= ~CW_RC;
- control_word |= RC_CHOP;
- reg_copy(st1_ptr, &tmp);
- FPU_round_to_int(&tmp, st1_tag); /* This can never overflow here */
- control_word = old_cw;
- scale = signnegative(st1_ptr) ? -tmp.sigl : tmp.sigl;
- scale += exponent16(st0_ptr);
-
- setexponent16(st0_ptr, scale);
-
- /* Use FPU_round() to properly detect under/overflow etc */
- FPU_round(st0_ptr, 0, 0, control_word, sign);
-
- return;
- }
-
- if ( st0_tag == TAG_Special )
- st0_tag = FPU_Special(st0_ptr);
- if ( st1_tag == TAG_Special )
- st1_tag = FPU_Special(st1_ptr);
-
- if ( (st0_tag == TAG_Valid) || (st0_tag == TW_Denormal) )
- {
- switch ( st1_tag )
- {
- case TAG_Valid:
- /* st(0) must be a denormal */
- if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
-
- FPU_to_exp16(st0_ptr, st0_ptr); /* Will not be left on stack */
- goto valid_scale;
-
- case TAG_Zero:
- if ( st0_tag == TW_Denormal )
- denormal_operand();
- return;
-
- case TW_Denormal:
- denormal_operand();
- return;
-
- case TW_Infinity:
- if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
- return;
-
- if ( signpositive(st1_ptr) )
- FPU_copy_to_reg0(&CONST_INF, TAG_Special);
- else
- FPU_copy_to_reg0(&CONST_Z, TAG_Zero);
- setsign(st0_ptr, sign);
- return;
-
- case TW_NaN:
- real_2op_NaN(st1_ptr, st1_tag, 0, st0_ptr);
- return;
- }
- }
- else if ( st0_tag == TAG_Zero )
- {
- switch ( st1_tag )
- {
- case TAG_Valid:
- case TAG_Zero:
- return;
-
- case TW_Denormal:
- denormal_operand();
- return;
-
- case TW_Infinity:
- if ( signpositive(st1_ptr) )
- arith_invalid(0); /* Zero scaled by +Infinity */
- return;
-
- case TW_NaN:
- real_2op_NaN(st1_ptr, st1_tag, 0, st0_ptr);
- return;
- }
- }
- else if ( st0_tag == TW_Infinity )
- {
- switch ( st1_tag )
- {
- case TAG_Valid:
- case TAG_Zero:
- return;
-
- case TW_Denormal:
- denormal_operand();
- return;
-
- case TW_Infinity:
- if ( signnegative(st1_ptr) )
- arith_invalid(0); /* Infinity scaled by -Infinity */
- return;
-
- case TW_NaN:
- real_2op_NaN(st1_ptr, st1_tag, 0, st0_ptr);
- return;
- }
- }
- else if ( st0_tag == TW_NaN )
- {
- if ( st1_tag != TAG_Empty )
- { real_2op_NaN(st1_ptr, st1_tag, 0, st0_ptr); return; }
- }
-
-#ifdef PARANOID
- if ( !((st0_tag == TAG_Empty) || (st1_tag == TAG_Empty)) )
- {
- EXCEPTION(EX_INTERNAL | 0x115);
- return;
- }
-#endif
-
- /* At least one of st(0), st(1) must be empty */
- FPU_stack_underflow();
-
-}
-
-
-/*---------------------------------------------------------------------------*/
-
-static FUNC_ST0 const trig_table_a[] = {
- f2xm1, fyl2x, fptan, fpatan,
- fxtract, fprem1, (FUNC_ST0)fdecstp, (FUNC_ST0)fincstp
-};
-
-void FPU_triga(void)
-{
- (trig_table_a[FPU_rm])(&st(0), FPU_gettag0());
-}
-
-
-static FUNC_ST0 const trig_table_b[] =
- {
- fprem, fyl2xp1, fsqrt_, fsincos, frndint_, fscale, (FUNC_ST0)fsin, fcos
- };
-
-void FPU_trigb(void)
-{
- (trig_table_b[FPU_rm])(&st(0), FPU_gettag0());
-}