blob: a9df9a108b4eea3a3cc905bb4cc3306c58b440e8 [file] [log] [blame] [raw]
/* hp3000_cpu_fp.h: HP 3000 floating-point interface declarations
Copyright (c) 2016, J. David Bryan
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Except as contained in this notice, the name of the author shall not be used
in advertising or otherwise to promote the sale, use or other dealings in
this Software without prior written authorization from the author.
21-Jan-16 JDB First release version
29-Mar-15 JDB Created
This file contains declarations used by the CPU to interface with the
floating-point operations executor.
*/
/* Program constants */
#define SIGN_BIT 0100000
#define EXPONENT_BITS 0077700
#define ASSUMED_BIT 0000100
#define FRACTION_BITS 0000077
/* Operand precisions:
- S = 1-word integer
- D = 2-word integer
- F = 2-word single-precision floating-point
- X = 3-word extended-precision floating-point
- E = 4-word double-precision floating-point
Implementation notes:
1. The ordering of the enumeration constants is important, as we depend on
the "fp" type codes to reflect the number of words used by the packed
representation.
*/
typedef enum {
in_s = 0, /* 1-word integer */
in_d = 1, /* 2-word integer */
fp_f = 2, /* 2-word single-precision floating-point */
fp_x = 3, /* 3-word extended-precision floating-point */
fp_e = 4 /* 4-word double-precision floating-point */
} FP_OPSIZE;
/* Conversion from operand size to word count */
#define TO_COUNT(s) ((uint32) (s + (s < fp_f)))
/* Floating point operations */
typedef enum {
fp_add,
fp_sub,
fp_mpy,
fp_div,
fp_flt,
fp_fixr,
fp_fixt
} FP_OPR;
/* General operand.
An in-memory representation of an integer or packed floating-point number.
An actual value will use one, two, three, or four words, as indicated by the
"precision" specified.
"trap" is significant only for result values; it is ignored for operand
values. A good result will have trap_None.
*/
typedef struct {
HP_WORD words [4]; /* integer or floating-point value */
FP_OPSIZE precision; /* operand size descriptor */
uint32 trap; /* validity of the result */
} FP_OPND;
/* Special operands */
static const FP_OPND FP_NOP = { { 0, 0, 0, 0 }, in_s, trap_None }; /* an unneeded operand */
/* Floating-point global routines */
extern FP_OPND fp_exec (FP_OPR operator, FP_OPND left, FP_OPND right);