new version

[Chiptunes.git] / foo.c

diff --git a/foo.c b/foo.c
index 5d719d875674b3484d0535b434c3455726f5b027..6c1e73834f4ecc6d6923cf94f8b6c5412513405f 100644 (file)
--- a/foo.c
+++ b/foo.c
@@ -6,60 +6,103 @@ u8 data[] = {
        0x84, 0x9d, 0xb0, 0x69, 0x9d, 0x84, 0x69, 0x58,
        0x75, 0x8c, 0xb0, 0x69, 0x8c, 0x75, 0x69, 0x58
 };
+u8 i0;
+u8 i1;
+u8 i2;
+u8 i3;
 u8 x;
 u8 t;
 u8 o;
-u8 g(int i) {
+void g(void) {
+       // g(i, x, t, o) -> t
        u8 tmp;
        ANDI    (t, 0x07)
-       tmp = i >> 16;
+       MOV     (tmp, i2)
        ANDI    (tmp, 3)
        TST     (tmp)
        BREQ    (skip)
        SUBI    (t, -8)
        skip:
        t = data[t];
-       t = (i*t) >> o;
+       t = ((i3<<24|i2<<16|i1<<8|i0)*t) >> o;
        AND     (t, x)
        ANDI    (t, 3)
-       return t;
+       RET
 };
 
 int main(void) {
-       int i = 0;
-       unsigned short n;
-       unsigned short s;
+       u8 n;
+       u8 s;
        u8 acc;
+       //TODO: clear all vars/registers
        for (;;) {
-               acc = 0;
-               n = i >> 14;
-               s = i >> 17;
+               MOV     (n, i2)
+               LSL     (n)
+               LSL     (n)
+               #define tmp acc
+               MOV     (tmp, i1)
+               SWAP    (tmp)
+               ANDI    (tmp, 0x0f)
+               LSR     (tmp)
+               LSR     (tmp)
+               OR      (n, tmp)
+               #undef tmp
+               MOV     (s, i3)
+               ROR     (s)
+               ROR     (s)
+               ANDI    (s, 0x80)
+               #define tmp acc
+               MOV     (tmp, i2)
+               LSR     (tmp)
+               OR      (s, tmp)
+               #undef tmp
 
                //voice 1:
                LDI     (x, 1)
                MOV     (t, n)
                LDI     (o, 12)
-               acc += g(i);
+               RCALL   g();
+               MOV     (acc, t)
 
                //voice 2:
                MOV     (x, s)
-               t = n ^ i >> 13;
+               #define tmp o
+               MOV     (tmp, i2)
+               LSL     (tmp)
+               LSL     (tmp)
+               LSL     (tmp)
+               MOV     (t, i1)
+               SWAP    (t)
+               ANDI    (t, 0xf)
+               LSR     (t)
+               OR      (t, tmp)
+               #undef tmp
+               EOR     (t, n)
                LDI     (o, 10)
-               acc += g(i);
+               RCALL   g();
+               ADD     (acc, t)
 
                //voice 3:
                x = s / 3;
-               t = n + ((i >> 11) % 3);
+               t = n + ((i3<<13 | i2<<5 | i1>>3) % 3);
                LDI     (o, 10)
-               acc += g(i);
+               RCALL   g();
+               ADD     (acc, t)
 
                //voice 4:
                x = s / 5;
-               t = 8 + n - ((i >> 10) % 3);
+               t = 8 + n - ((i3<<14 | i2<<6 | i1>>2) % 3);
                LDI     (o, 9)
-               acc += g(i);
+               RCALL   g();
+               ADD     (acc, t)
 
-               i++;
                putchar(acc<<4);
+               #define tmp acc
+               LDI     (tmp, 0)
+               SUBI    (i0, -1)
+               ADC     (i1, tmp, !i0)
+               ADC     (i2, tmp, !i0&&!i1)
+               ADC     (i3, tmp, !i0&&!i1&&!i2)
+               #undef tmp
        }
 }