diff options
Diffstat (limited to 'drivers/FPU-emu/poly_atan.c')
| -rw-r--r-- | drivers/FPU-emu/poly_atan.c | 197 |
1 files changed, 0 insertions, 197 deletions
diff --git a/drivers/FPU-emu/poly_atan.c b/drivers/FPU-emu/poly_atan.c deleted file mode 100644 index 6edca625f..000000000 --- a/drivers/FPU-emu/poly_atan.c +++ /dev/null @@ -1,197 +0,0 @@ -/*---------------------------------------------------------------------------+ - | poly_atan.c | - | | - | Compute the arctan 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 "status_w.h" -#include "control_w.h" -#include "poly.h" - - -#define HIPOWERon 6 /* odd poly, negative terms */ -static const unsigned long long oddnegterms[HIPOWERon] = -{ - 0x0000000000000000LL, /* Dummy (not for - 1.0) */ - 0x015328437f756467LL, - 0x0005dda27b73dec6LL, - 0x0000226bf2bfb91aLL, - 0x000000ccc439c5f7LL, - 0x0000000355438407LL -} ; - -#define HIPOWERop 6 /* odd poly, positive terms */ -static const unsigned long long oddplterms[HIPOWERop] = -{ -/* 0xaaaaaaaaaaaaaaabLL, transferred to fixedpterm[] */ - 0x0db55a71875c9ac2LL, - 0x0029fce2d67880b0LL, - 0x0000dfd3908b4596LL, - 0x00000550fd61dab4LL, - 0x0000001c9422b3f9LL, - 0x000000003e3301e1LL -}; - -static const unsigned long long denomterm = 0xebd9b842c5c53a0eLL; - -static const Xsig fixedpterm = MK_XSIG(0xaaaaaaaa, 0xaaaaaaaa, 0xaaaaaaaa); - -static const Xsig pi_signif = MK_XSIG(0xc90fdaa2, 0x2168c234, 0xc4c6628b); - - -/*--- poly_atan() -----------------------------------------------------------+ - | | - +---------------------------------------------------------------------------*/ -void poly_atan(FPU_REG *arg1, FPU_REG *arg2, FPU_REG *result) -{ - char transformed, inverted, - sign1 = arg1->sign, sign2 = arg2->sign; - long int exponent, dummy_exp; - Xsig accumulator, Numer, Denom, accumulatore, argSignif, - argSq, argSqSq; - - - arg1->sign = arg2->sign = SIGN_POS; - if ( (compare(arg2) & ~COMP_Denormal) == COMP_A_lt_B ) - { - inverted = 1; - exponent = arg1->exp - arg2->exp; - Numer.lsw = Denom.lsw = 0; - XSIG_LL(Numer) = significand(arg1); - XSIG_LL(Denom) = significand(arg2); - } - else - { - inverted = 0; - exponent = arg2->exp - arg1->exp; - Numer.lsw = Denom.lsw = 0; - XSIG_LL(Numer) = significand(arg2); - XSIG_LL(Denom) = significand(arg1); - } - div_Xsig(&Numer, &Denom, &argSignif); - exponent += norm_Xsig(&argSignif); - - if ( (exponent >= -1) - || ((exponent == -2) && (argSignif.msw > 0xd413ccd0)) ) - { - /* The argument is greater than sqrt(2)-1 (=0.414213562...) */ - /* Convert the argument by an identity for atan */ - transformed = 1; - - if ( exponent >= 0 ) - { -#ifdef PARANOID - if ( !( (exponent == 0) && - (argSignif.lsw == 0) && (argSignif.midw == 0) && - (argSignif.msw == 0x80000000) ) ) - { - EXCEPTION(EX_INTERNAL|0x104); /* There must be a logic error */ - return; - } -#endif PARANOID - argSignif.msw = 0; /* Make the transformed arg -> 0.0 */ - } - else - { - Numer.lsw = Denom.lsw = argSignif.lsw; - XSIG_LL(Numer) = XSIG_LL(Denom) = XSIG_LL(argSignif); - - if ( exponent < -1 ) - shr_Xsig(&Numer, -1-exponent); - negate_Xsig(&Numer); - - shr_Xsig(&Denom, -exponent); - Denom.msw |= 0x80000000; - - div_Xsig(&Numer, &Denom, &argSignif); - - exponent = -1 + norm_Xsig(&argSignif); - } - } - else - { - transformed = 0; - } - - argSq.lsw = argSignif.lsw; argSq.midw = argSignif.midw; - argSq.msw = argSignif.msw; - mul_Xsig_Xsig(&argSq, &argSq); - - argSqSq.lsw = argSq.lsw; argSqSq.midw = argSq.midw; argSqSq.msw = argSq.msw; - mul_Xsig_Xsig(&argSqSq, &argSqSq); - - accumulatore.lsw = argSq.lsw; - XSIG_LL(accumulatore) = XSIG_LL(argSq); - - shr_Xsig(&argSq, 2*(-1-exponent-1)); - shr_Xsig(&argSqSq, 4*(-1-exponent-1)); - - /* Now have argSq etc with binary point at the left - .1xxxxxxxx */ - - /* Do the basic fixed point polynomial evaluation */ - accumulator.msw = accumulator.midw = accumulator.lsw = 0; - polynomial_Xsig(&accumulator, &XSIG_LL(argSqSq), - oddplterms, HIPOWERop-1); - mul64_Xsig(&accumulator, &XSIG_LL(argSq)); - negate_Xsig(&accumulator); - polynomial_Xsig(&accumulator, &XSIG_LL(argSqSq), oddnegterms, HIPOWERon-1); - negate_Xsig(&accumulator); - add_two_Xsig(&accumulator, &fixedpterm, &dummy_exp); - - mul64_Xsig(&accumulatore, &denomterm); - shr_Xsig(&accumulatore, 1 + 2*(-1-exponent)); - accumulatore.msw |= 0x80000000; - - div_Xsig(&accumulator, &accumulatore, &accumulator); - - mul_Xsig_Xsig(&accumulator, &argSignif); - mul_Xsig_Xsig(&accumulator, &argSq); - - shr_Xsig(&accumulator, 3); - negate_Xsig(&accumulator); - add_Xsig_Xsig(&accumulator, &argSignif); - - if ( transformed ) - { - /* compute pi/4 - accumulator */ - shr_Xsig(&accumulator, -1-exponent); - negate_Xsig(&accumulator); - add_Xsig_Xsig(&accumulator, &pi_signif); - exponent = -1; - } - - if ( inverted ) - { - /* compute pi/2 - accumulator */ - shr_Xsig(&accumulator, -exponent); - negate_Xsig(&accumulator); - add_Xsig_Xsig(&accumulator, &pi_signif); - exponent = 0; - } - - if ( sign1 ) - { - /* compute pi - accumulator */ - shr_Xsig(&accumulator, 1 - exponent); - negate_Xsig(&accumulator); - add_Xsig_Xsig(&accumulator, &pi_signif); - exponent = 1; - } - - exponent += round_Xsig(&accumulator); - significand(result) = XSIG_LL(accumulator); - result->exp = exponent + EXP_BIAS; - result->tag = TW_Valid; - result->sign = sign2; - -} |