transcribe fakeasm into realasm (I)

diff --git a/foo.S b/foo.S
index ac7d6ad..0a2d6bf 100644 (file)
--- a/foo.S
+++ b/foo.S
@@ -1,37 +1,47 @@
-#include <stdio.h>
-#include "fakeasm.h"
-typedef unsigned char u8;
+/* REGISTER NAMES */
+#define zero r16
+#define acc  r17
+#define i0   r18
+#define i1   r19
+#define i2   r20
+#define i3   r21
+#define n    r22
+#define s    r23
+#define _    r24
+;            r25
+#define x    r26 //==Xlo==Mh
+#define t    r27 //==Xhi==Ml
+;            r28
+;            r29
+;            r30 Zlo
+;            r31 Zhi
+; aliases:
+#define Xlo  r26
+#define Xhi  r27
+#define Mh   r26 //mod3 vars
+#define Ml   r27 // -"-
 
-u8 zero;       //r16
-u8 acc;                //r17
-u8 i0;         //r18
-u8 i1;         //r19
-u8 i2;         //r20
-u8 i3;         //r21
-u8 n;          //r22
-u8 s;          //r23
-u8 _;          //r24
-               //r25
-u8 x;/*==Ml*/  //r26 (Xlo)
-u8 t;/*==Mh*/  //r27 (Xhi)
-               //r28
-               //r29
-void *Z;       //r30 (Zlo)
-/*...*/                //r31 (Zhi)
-#define Mh x //mod3 vars
-#define Ml t // -"-
+/* I/O REGISTERS */
+OCR0AL = 0x26
+DDRB   = 0x01
+PUEB   = 0x03
+SPL    = 0x3D
+SPH    = 0x3E
+CCP    = 0x3C
+CLKPSR = 0x36
+SMCR   = 0x3A
+TCCR0A = 0x2E
+TCCR0B = 0x2D
+TIMSK0 = 0x2B
+TIFR0  = 0x2A
 
-// .section .data
-u8 data[] = {
-       /*.byte*/ 0x84, 0x9d, 0xb0, 0x69, 0x9d, 0x84, 0x69, 0x58,
-       /*.byte*/ 0x75, 0x8c, 0xb0, 0x69, 0x8c, 0x75, 0x69, 0x58
-};
+.section .data
+       .byte 0x84, 0x9d, 0xb0, 0x69, 0x9d, 0x84, 0x69, 0x58
+       .byte 0x75, 0x8c, 0xb0, 0x69, 0x8c, 0x75, 0x69, 0x58
 
-// .section .text
+.section .text
 
-//http://homepage.divms.uiowa.edu/~jones/bcd/mod.shtml
-void mod3(void) {
-       // mod3(Mh.Ml) -> t
+mod3: ; mod3(Mh.Ml) -> t
        #define tmp _
        ADD     (Ml, Mh)
        CLR     (Mh)
@@ -59,31 +69,39 @@ void mod3(void) {
        skip:;
        RET
        #undef tmp
-}
-//.macro definitions for mul-tree:
-#define always(_bit) //nop; for when a test() is not necessary (see tree)
-#define never(_bit)  //nop; for when a test() is not necessary (see tree)
-#define test(_bit,_jmpto) \
-       SBRC    (t, _bit) \
-       RJMP    (_jmpto)
-#define shift16 \
-       LSR     (a2) \
-       ROR     (a1)
-#define shift8 /*top three bits don't need to be corrrect, so save cycles by not carrying*/ \
-       LSR     (a1)
-#define shift0 //nop; last shift is common
-#define add_shift16 \
-       ADD     (a1, i0) \
-       ADC     (a2, i1, carry) \
+
+; definitions to mul-tree readable:
+.macro always _bit ; nop; for when a test() is not necessary (see tree)
+.endm
+.macro never _bit  ; nop; for when a test() is not necessary (see tree)
+.endm
+.macro test _bit,_jmpto
+       SBRC    t, _bit
+       RJMP    _jmpto
+.endm
+.macro shift16
+       LSR     a2
+       ROR     a1
+.endm
+.macro shift8 ; top three bits don't need to be corrrect, so save cycles by not carrying
+       LSR     a1
+.endm
+.macro shift0 ; nop; last shift is common
+.endm
+.macro add_shift16
+       ADD     a1, i0
+       ADC     a2, i1
        shift16
-#define add_shift8 /*ditto with carrying*/ \
-       ADD     (a1, i0) \
+.endm
+.macro add_shift8 ; ditto with carrying
+       ADD     a1, i0
        shift8
-#define add_shift0 /*last shift is common*/ \
-       ADD     (a1, i0)
-void g(void) {
-       // g(i, t) -> t
-       // tempvars: `x` and `_`
+.endm
+.macro add_shift0 ; last shift is common
+       ADD     a1, i0
+.endm
+
+g: ; g(i, t) -> t
        #define tmp _
        ANDI    (t, 0x07)
        MOV     (tmp, i2)
@@ -219,15 +237,16 @@ void g(void) {
        #undef a1
        #undef a2
        RET //TODO: replace CALL/RET with IJMP? (requires undoing goto-mul-hack)
-};
 
-int main(void) {
+main:
        CLR     (zero)
        CLR     (i0)
        CLR     (i1)
        CLR     (i2)
        CLR     (i3)
-       for (;;) {
+       //TODO: setup stack pointer, portb, clock, sleep mode, timer0
+       RJMP    sample
+sample: //TODO: this will probably become the timer0 overflow interrupt handler
                MOV     (n, i2)
                LSL     (n)
                LSL     (n)
@@ -377,5 +396,3 @@ int main(void) {
                ADC     (i1, zero, !i0) //XXX: must use "sbci i1,-1" in the assembly version
                ADC     (i2, zero, !i0&&!i1) //          sbci i2,-1
                ADC     (i3, zero, !i0&&!i1&&!i2) //     sbci i3,-1
-       }
-}