new version

div6 was prototyped with this program:

typedef unsigned char u8;
int main(void) {
	for (int i = 0; i <= 0x78; i++) {
		u8 real = i/6;
		u8 test = i;

		test >>= 1;
		test += i;

		test >>= 1;
		test += 0;

		test >>= 1;
		test += i;

		test >>= 1;
		test += 0;

		test >>= 1;
		test += i;

		test >>= 1;
		test += 0;

		test >>= 1;
		test >>= 1;

		if (test != real)
			printf ("%hhd/6 == %hhd != %hhd\n", i, real, test);
	}
	return 0;
}

diff --git a/bsv.c b/bsv.c
index 81095016fd2dfa1a950349d8d785ce53e4353b96..8ce4b42801dc782fc48ddc419dccbf1b34507e4e 100644 (file)
--- a/bsv.c
+++ b/bsv.c
@@ -70,31 +70,18 @@ void main(void){
                MOV     (tmp_1, acc) // acc saved in tmp_1; fresh acc
                MOV     (acc, i2)
                // shift-divide by six
                MOV     (tmp_1, acc) // acc saved in tmp_1; fresh acc
                MOV     (acc, i2)
                // shift-divide by six

-               // note: i2 is max 0x78; so acc will <= 20.
-
+               // note: i2 is max 0x78; so acc will <= 20. (breaks vor values >=128)

                 SR     (acc)
                ADD     (acc, i2)
                 SR     (acc)
                ADD     (acc, i2)

-

                SR      (acc)
                SR      (acc)

-                //ADD acc, 0
-

                 SR     (acc)
                ADD     (acc, i2)
                 SR     (acc)
                ADD     (acc, i2)

-

                SR      (acc)
                SR      (acc)

-                //ADD acc, 0
-

                 SR     (acc)
                ADD     (acc, i2)
                 SR     (acc)
                ADD     (acc, i2)

-

                SR      (acc)
                SR      (acc)

-                //ADD acc, 0
-

                SR      (acc)
                SR      (acc)

-                //ADD acc, 0

                SR      (acc)
                SR      (acc)

-                //ADD acc, 0
-

                // end divide by six
                AND     (acc, tmp_1) // acc restored from tmp_1
                AND     (acc, 3)
                // end divide by six
                AND     (acc, tmp_1) // acc restored from tmp_1
                AND     (acc, 3)