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// ============================================================================

//        __

//   \\__/ o\    (C) 2020-2021  Robert Finch, Waterloo

//    \  __ /    All rights reserved.

//     \/_//     robfinch@finitron.ca

//       ||

//

//      DFPPkg.sv

//    - decimal floating point package

//

//

// This source file is free software: you can redistribute it and/or modify

// it under the terms of the GNU Lesser General Public License as published

// by the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// This source file 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, see .

//

//      This unit takes a floating point number in an intermediate

// format and normalizes it. No normalization occurs

// for NaN's or infinities. The unit has a two cycle latency.

//

// The mantissa is assumed to start with two whole bits on

// the left. The remaining bits are fractional.

//

// The width of the incoming format is reduced via a generation

// of sticky bit in place of the low order fractional bits.

//

// On an underflowed input, the incoming exponent is assumed

// to be negative. A right shift is needed.

// ============================================================================

package DFPPkg;

`define SUPPORT_DENORMALS       1'b1

typedef struct packed

{

        logic sign;

        logic [4:0] combo;

        logic [14:0] expc;      // exponent continuation field

        logic [139:0] sigc;     // significand continuation field

} DFP160;

// Packed 128 bit (storage) format

typedef struct packed

{

        logic sign;

        logic [4:0] combo;

        logic [11:0] expc;      // exponent continuation field

        logic [109:0] sigc;     // significand continuation field

} DFP128;

typedef logic [13:0] DFP128EXP;

typedef logic [135:0] DFP128SIG;

// Unpacked 128 bit format

typedef struct packed

{

        logic nan;

        logic qnan;

        logic snan;

        logic infinity;

        logic sign;

        logic [13:0] exp;

        logic [135:0] sig;      // significand 34 digits

} DFP128U;

// Normalizer output to rounding, one extra digit

typedef struct packed

{

        logic nan;

        logic qnan;

        logic snan;

        logic infinity;

        logic sign;

        logic [13:0] exp;

        logic [139:0] sig;      // significand 35 digits

} DFP128UN;

// 128-bit Double width significand, normalizer input

typedef struct packed

{

        logic nan;

        logic qnan;

        logic snan;

        logic infinity;

        logic sign;

        logic [13:0] exp;

        logic [279:0] sig;      // significand 68+ 1 lead, 1-trail digit

} DFP128UD;

typedef logic [9:0] DFP64EXP;

typedef logic [63:0] DFP64SIG;

typedef struct packed

{

        logic sign;

        logic [4:0] combo;

        logic [7:0] expc;               // exponent continuation field

        logic [49:0] sigc;      // significand continuation field

} DFP64;

typedef struct packed

{

        logic nan;

        logic qnan;

        logic snan;

        logic infinity;

        logic sign;

        logic [9:0] exp;

        logic [63:0] sig;               // significand 16 digits

} DFP64U;

typedef struct packed

{

        logic nan;

        logic qnan;

        logic snan;

        logic infinity;

        logic sign;

        logic [9:0] exp;

        logic [67:0] sig;               // significand 17 digits

} DFP64UN;

typedef struct packed

{

        logic nan;

        logic qnan;

        logic snan;

        logic infinity;

        logic sign;

        logic [9:0] exp;

        logic [127:0] sig;              // significand 32 digits

} DFP64UD;

endpackage