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-rw-r--r--drivers/FPU-emu/poly_l2.c255
1 files changed, 0 insertions, 255 deletions
diff --git a/drivers/FPU-emu/poly_l2.c b/drivers/FPU-emu/poly_l2.c
deleted file mode 100644
index 1677f4aff..000000000
--- a/drivers/FPU-emu/poly_l2.c
+++ /dev/null
@@ -1,255 +0,0 @@
-/*---------------------------------------------------------------------------+
- | poly_l2.c |
- | |
- | Compute the base 2 log of a FPU_REG, using a polynomial approximation. |
- | |
- | Copyright (C) 1992,1993,1994 |
- | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
- | Australia. E-mail billm@vaxc.cc.monash.edu.au |
- | |
- | |
- +---------------------------------------------------------------------------*/
-
-
-#include "exception.h"
-#include "reg_constant.h"
-#include "fpu_emu.h"
-#include "control_w.h"
-#include "poly.h"
-
-
-
-static void log2_kernel(FPU_REG const *arg,
- Xsig *accum_result, long int *expon);
-
-
-/*--- poly_l2() -------------------------------------------------------------+
- | Base 2 logarithm by a polynomial approximation. |
- +---------------------------------------------------------------------------*/
-void poly_l2(FPU_REG const *arg, FPU_REG const *y, FPU_REG *result)
-{
- long int exponent, expon, expon_expon;
- Xsig accumulator, expon_accum, yaccum;
- char sign;
- FPU_REG x;
-
-
- exponent = arg->exp - EXP_BIAS;
-
- /* From arg, make a number > sqrt(2)/2 and < sqrt(2) */
- if ( arg->sigh > (unsigned)0xb504f334 )
- {
- /* Treat as sqrt(2)/2 < arg < 1 */
- significand(&x) = - significand(arg);
- x.sign = SIGN_NEG;
- x.tag = TW_Valid;
- x.exp = EXP_BIAS-1;
- exponent++;
- normalize(&x);
- }
- else
- {
- /* Treat as 1 <= arg < sqrt(2) */
- x.sigh = arg->sigh - 0x80000000;
- x.sigl = arg->sigl;
- x.sign = SIGN_POS;
- x.tag = TW_Valid;
- x.exp = EXP_BIAS;
- normalize(&x);
- }
-
- if ( x.tag == TW_Zero )
- {
- expon = 0;
- accumulator.msw = accumulator.midw = accumulator.lsw = 0;
- }
- else
- {
- log2_kernel(&x, &accumulator, &expon);
- }
-
- sign = exponent < 0;
- if ( sign ) exponent = -exponent;
- expon_accum.msw = exponent; expon_accum.midw = expon_accum.lsw = 0;
- if ( exponent )
- {
- expon_expon = 31 + norm_Xsig(&expon_accum);
- shr_Xsig(&accumulator, expon_expon - expon);
-
- if ( sign ^ (x.sign == SIGN_NEG) )
- negate_Xsig(&accumulator);
- add_Xsig_Xsig(&accumulator, &expon_accum);
- }
- else
- {
- expon_expon = expon;
- sign = x.sign;
- }
-
- yaccum.lsw = 0; XSIG_LL(yaccum) = significand(y);
- mul_Xsig_Xsig(&accumulator, &yaccum);
-
- expon_expon += round_Xsig(&accumulator);
-
- if ( accumulator.msw == 0 )
- {
- reg_move(&CONST_Z, y);
- }
- else
- {
- result->exp = expon_expon + y->exp + 1;
- significand(result) = XSIG_LL(accumulator);
- result->tag = TW_Valid; /* set the tags to Valid */
- result->sign = sign ^ y->sign;
- }
-
- return;
-}
-
-
-/*--- poly_l2p1() -----------------------------------------------------------+
- | Base 2 logarithm by a polynomial approximation. |
- | log2(x+1) |
- +---------------------------------------------------------------------------*/
-int poly_l2p1(FPU_REG const *arg, FPU_REG const *y, FPU_REG *result)
-{
- char sign;
- long int exponent;
- Xsig accumulator, yaccum;
-
-
- sign = arg->sign;
-
- if ( arg->exp < EXP_BIAS )
- {
- log2_kernel(arg, &accumulator, &exponent);
-
- yaccum.lsw = 0;
- XSIG_LL(yaccum) = significand(y);
- mul_Xsig_Xsig(&accumulator, &yaccum);
-
- exponent += round_Xsig(&accumulator);
-
- result->exp = exponent + y->exp + 1;
- significand(result) = XSIG_LL(accumulator);
- result->tag = TW_Valid; /* set the tags to Valid */
- result->sign = sign ^ y->sign;
-
- return 0;
- }
- else
- {
- /* The magnitude of arg is far too large. */
- reg_move(y, result);
- if ( sign != SIGN_POS )
- {
- /* Trying to get the log of a negative number. */
- return 1;
- }
- else
- {
- return 0;
- }
- }
-
-}
-
-
-
-
-#undef HIPOWER
-#define HIPOWER 10
-static const unsigned long long logterms[HIPOWER] =
-{
- 0x2a8eca5705fc2ef0LL,
- 0xf6384ee1d01febceLL,
- 0x093bb62877cdf642LL,
- 0x006985d8a9ec439bLL,
- 0x0005212c4f55a9c8LL,
- 0x00004326a16927f0LL,
- 0x0000038d1d80a0e7LL,
- 0x0000003141cc80c6LL,
- 0x00000002b1668c9fLL,
- 0x000000002c7a46aaLL
-};
-
-static const unsigned long leadterm = 0xb8000000;
-
-
-/*--- log2_kernel() ---------------------------------------------------------+
- | Base 2 logarithm by a polynomial approximation. |
- | log2(x+1) |
- +---------------------------------------------------------------------------*/
-static void log2_kernel(FPU_REG const *arg, Xsig *accum_result,
- long int *expon)
-{
- char sign;
- long int exponent, adj;
- unsigned long long Xsq;
- Xsig accumulator, Numer, Denom, argSignif, arg_signif;
-
- sign = arg->sign;
-
- exponent = arg->exp - EXP_BIAS;
- Numer.lsw = Denom.lsw = 0;
- XSIG_LL(Numer) = XSIG_LL(Denom) = significand(arg);
- if ( sign == SIGN_POS )
- {
- shr_Xsig(&Denom, 2 - (1 + exponent));
- Denom.msw |= 0x80000000;
- div_Xsig(&Numer, &Denom, &argSignif);
- }
- else
- {
- shr_Xsig(&Denom, 1 - (1 + exponent));
- negate_Xsig(&Denom);
- if ( Denom.msw & 0x80000000 )
- {
- div_Xsig(&Numer, &Denom, &argSignif);
- exponent ++;
- }
- else
- {
- /* Denom must be 1.0 */
- argSignif.lsw = Numer.lsw; argSignif.midw = Numer.midw;
- argSignif.msw = Numer.msw;
- }
- }
-
-#ifndef PECULIAR_486
- /* Should check here that |local_arg| is within the valid range */
- if ( exponent >= -2 )
- {
- if ( (exponent > -2) ||
- (argSignif.msw > (unsigned)0xafb0ccc0) )
- {
- /* The argument is too large */
- }
- }
-#endif PECULIAR_486
-
- arg_signif.lsw = argSignif.lsw; XSIG_LL(arg_signif) = XSIG_LL(argSignif);
- adj = norm_Xsig(&argSignif);
- accumulator.lsw = argSignif.lsw; XSIG_LL(accumulator) = XSIG_LL(argSignif);
- mul_Xsig_Xsig(&accumulator, &accumulator);
- shr_Xsig(&accumulator, 2*(-1 - (1 + exponent + adj)));
- Xsq = XSIG_LL(accumulator);
- if ( accumulator.lsw & 0x80000000 )
- Xsq++;
-
- accumulator.msw = accumulator.midw = accumulator.lsw = 0;
- /* Do the basic fixed point polynomial evaluation */
- polynomial_Xsig(&accumulator, &Xsq, logterms, HIPOWER-1);
-
- mul_Xsig_Xsig(&accumulator, &argSignif);
- shr_Xsig(&accumulator, 6 - adj);
-
- mul32_Xsig(&arg_signif, leadterm);
- add_two_Xsig(&accumulator, &arg_signif, &exponent);
-
- *expon = exponent + 1;
- accum_result->lsw = accumulator.lsw;
- accum_result->midw = accumulator.midw;
- accum_result->msw = accumulator.msw;
-
-}
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