some FP wrappers and test code, not very good yet

1 files changed, 49 insertions, 0 deletions

diff --git a/bignum.h b/bignum.h
new file mode 100644
index 0000000..a6306f4
--- /dev/null
+++ b/bignum.h
@@ -0,0 +1,49 @@
+/* big number functions needed by taipan.c.
+
+	The implementation will actually use the Atari ROM floating point
+	routines. To port Taipan to a new cc65 platform, the functions listed
+	here will have to be rewritten, but taipan.c itself shouldn't need
+	changing (at least, not in relation to bignums!) */
+
+#define bignum(x) char x[6]
+#define bignump char *
+
+
+/* zero */
+#define BIG_0 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
+
+/* constant initializer for 1.05 goes here */
+#define BIG_1_05 { 0x40, 0x01, 0x05, 0x00, 0x00, 0x00 }
+
+/* bignum 100, used for score calculations in final_stats() */
+#define BIG_10 { 0x41, 0x01, 0x00, 0x00, 0x00, 0x00 }
+
+// void int_to_big(int i, bignum *b);
+// void uint_to_big(unsigned int i, bignum *b);
+
+extern void __fastcall__ ulong_to_big(const unsigned long l, bignump b);
+
+/* returns 0 for success, nonzero for fail (overflow or negative) */
+extern char __fastcall__ big_to_ulong(bignump b, unsigned long *l);
+
+/* this should work like cprintfancy(), but doesn't need centering. */
+// void cprint_big(const bignum *b);
+
+/* basic math functions. conceptually they return a boolean for
+	success, but only division has error checking.
+	all can be read as: dest = arg2 OP arg3;
+	modulus isn't implemented as taipan doesn't use it for the bank.
+ */
+// char big_add(bignum *dest, bignum *addend1, bignum *addend2);
+// char big_sub(bignum *dest, bignum *minuend, bignum *subtrahend);
+// char big_mul(bignum *dest, bignum *multiplicand, bignum *multiplier);
+// char big_div(bignum *dest, bignum *dividend, bignum *divisor);
+
+/* comparison. Perl spaceship operator, <=>
+	returns  | if
+	---------+----------------
+	    0    | a == b
+	    1    | a > b
+	   -1    | a < b
+ */
+// signed char big_cmp(const bignum *a, const bignum *b)