new version

move `o` out of g() to get rid of variable shift

diff --git a/foo.c b/foo.c
index 21b19fb0b7d185d7933bd4878407f4a3d50469df..fcb07cdaec9f6a310494b512f9880b749e08480e 100644 (file)
--- a/foo.c
+++ b/foo.c
@@ -49,7 +49,7 @@ void mod3(void) {
        #undef tmp
 }
 void g(void) {
-       // g(i, t, o) -> t
+       // g(i, t) -> t
        // tempvars: `x` and `_`
        #define tmp _
        ANDI    (t, 0x07)
@@ -67,8 +67,6 @@ void g(void) {
          ADC X_hi, zero
          LD  t, X         */
        t = (((i1&0x1f)<<8|i0)*t)>>8; //TODO
-       t >>= o; //NOTE: o == {1, 2, 4}
-       ANDI    (t, 3)
        RET //TODO: CALL/RET is expensive; store PC in register and RJMP, then JRMP back
 };
 
@@ -103,6 +101,8 @@ int main(void) {
                MOV     (t, n)
                LDI     (o, 4)
                RCALL   g();
+       t >>= o; //NOTE: o == {1, 2, 4}
+       ANDI    (t, 3)
                ANDI    (t, 1)
                MOV     (acc, t)
 
@@ -121,6 +121,8 @@ int main(void) {
                EOR     (t, n)
                LDI     (o, 2)
                RCALL   g();
+       t >>= o; //NOTE: o == {1, 2, 4}
+       ANDI    (t, 3)
                AND     (t, s)
                ADD     (acc, t)
 
@@ -151,6 +153,8 @@ int main(void) {
                ADD     (t, n)
                LDI     (o, 2)
                RCALL   g();
+       t >>= o; //NOTE: o == {1, 2, 4}
+       ANDI    (t, 3)
                MOV     (x, s)
                INC     (x)
                #define tmp o
@@ -200,6 +204,8 @@ int main(void) {
                SUBI    (t, -8)
                LDI     (o, 1)
                RCALL   g();
+       t >>= o; //NOTE: o == {1, 2, 4}
+       ANDI    (t, 3)
                MOV     (x, s)
                INC     (x)
                #define tmp o