/*
      NetWinder Floating Point Emulator
      (c) Rebel.COM, 1998,1999
  
      Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
  
      This program is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published by
      the Free Software Foundation; either version 2 of the License, or
      (at your option) any later version.
  
      This program is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      GNU General Public License for more details.
  
      You should have received a copy of the GNU General Public License
      along with this program; if not, write to the Free Software
      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
  
  #include "fpa11.h"
  #include "softfloat.h"
  #include "fpopcode.h"
  
  union float64_components {
  	float64 f64;
  	unsigned int i[2];
  };
  
  float64 float64_exp(float64 Fm);
  float64 float64_ln(float64 Fm);
  float64 float64_sin(float64 rFm);
  float64 float64_cos(float64 rFm);
  float64 float64_arcsin(float64 rFm);
  float64 float64_arctan(float64 rFm);
  float64 float64_log(float64 rFm);
  float64 float64_tan(float64 rFm);
  float64 float64_arccos(float64 rFm);
  float64 float64_pow(float64 rFn, float64 rFm);
  float64 float64_pol(float64 rFn, float64 rFm);

  static float64 float64_rsf(struct roundingData *roundData, float64 rFn, float64 rFm)

  {

  	return float64_sub(roundData, rFm, rFn);

  }

  static float64 float64_rdv(struct roundingData *roundData, float64 rFn, float64 rFm)

  {

  	return float64_div(roundData, rFm, rFn);

  }

  static float64 (*const dyadic_double[16])(struct roundingData*, float64 rFn, float64 rFm) = {

  	[ADF_CODE >> 20] = float64_add,
  	[MUF_CODE >> 20] = float64_mul,
  	[SUF_CODE >> 20] = float64_sub,
  	[RSF_CODE >> 20] = float64_rsf,
  	[DVF_CODE >> 20] = float64_div,
  	[RDF_CODE >> 20] = float64_rdv,
  	[RMF_CODE >> 20] = float64_rem,
  
  	/* strictly, these opcodes should not be implemented */
  	[FML_CODE >> 20] = float64_mul,
  	[FDV_CODE >> 20] = float64_div,
  	[FRD_CODE >> 20] = float64_rdv,
  };

  static float64 float64_mvf(struct roundingData *roundData,float64 rFm)

  {
  	return rFm;
  }

  static float64 float64_mnf(struct roundingData *roundData,float64 rFm)

  {
  	union float64_components u;
  
  	u.f64 = rFm;
  #ifdef __ARMEB__
  	u.i[0] ^= 0x80000000;
  #else
  	u.i[1] ^= 0x80000000;
  #endif
  
  	return u.f64;
  }

  static float64 float64_abs(struct roundingData *roundData,float64 rFm)

  {
  	union float64_components u;
  
  	u.f64 = rFm;
  #ifdef __ARMEB__
  	u.i[0] &= 0x7fffffff;
  #else
  	u.i[1] &= 0x7fffffff;
  #endif
  
  	return u.f64;
  }

  static float64 (*const monadic_double[16])(struct roundingData *, float64 rFm) = {

  	[MVF_CODE >> 20] = float64_mvf,
  	[MNF_CODE >> 20] = float64_mnf,
  	[ABS_CODE >> 20] = float64_abs,
  	[RND_CODE >> 20] = float64_round_to_int,
  	[URD_CODE >> 20] = float64_round_to_int,
  	[SQT_CODE >> 20] = float64_sqrt,
  	[NRM_CODE >> 20] = float64_mvf,
  };

  unsigned int DoubleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd)

  {
  	FPA11 *fpa11 = GET_FPA11();
  	float64 rFm;
  	unsigned int Fm, opc_mask_shift;
  
  	Fm = getFm(opcode);
  	if (CONSTANT_FM(opcode)) {
  		rFm = getDoubleConstant(Fm);
  	} else {
  		switch (fpa11->fType[Fm]) {
  		case typeSingle:
  			rFm = float32_to_float64(fpa11->fpreg[Fm].fSingle);
  			break;
  
  		case typeDouble:
  			rFm = fpa11->fpreg[Fm].fDouble;
  			break;
  
  		default:
  			return 0;
  		}
  	}
  
  	opc_mask_shift = (opcode & MASK_ARITHMETIC_OPCODE) >> 20;
  	if (!MONADIC_INSTRUCTION(opcode)) {
  		unsigned int Fn = getFn(opcode);
  		float64 rFn;
  
  		switch (fpa11->fType[Fn]) {
  		case typeSingle:
  			rFn = float32_to_float64(fpa11->fpreg[Fn].fSingle);
  			break;
  
  		case typeDouble:
  			rFn = fpa11->fpreg[Fn].fDouble;
  			break;
  
  		default:
  			return 0;
  		}
  
  		if (dyadic_double[opc_mask_shift]) {

  			rFd->fDouble = dyadic_double[opc_mask_shift](roundData, rFn, rFm);

  		} else {
  			return 0;
  		}
  	} else {
  		if (monadic_double[opc_mask_shift]) {

  			rFd->fDouble = monadic_double[opc_mask_shift](roundData, rFm);

  		} else {
  			return 0;
  		}
  	}
  
  	return 1;
  }