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/* fake 6502. a perl script converts this:
ldy #10
loop:
lda blah,y
sta (p1),y
dey
bpl loop
to something like:
ldy_i(10)
loop:
lda_absy(blah)
sta_zpy(p1)
dey();
bpl(loop);
where e.g.
#define ldy_i(x) Y=x; ZF=!Y; NF=Y&0x80;
#define lda_absy(x) A=mem[x+y]; ZF=!A; NF=A&0x80;
#define sta_zpy(x) mem[(mem[x] | mem[x+1] << 8) + y] = A;
#define dey() Y--; ZF=!Y; NF=Y&0x80;
#define bpl(x) if(!NF) goto x
...and the 'loop:' is a real C line label.
we don't worry about the V flag since unalf doesn't use it.
This isn't emulation exactly, and it isn't dynamic recompilation because
it's static. "Static recompilation" maybe?
*/
#include "f65.h"
u8 A, X, Y, S = 0xff, tmp; /* tmp is result for cmp/cpx/cpy */
u8 mem[1 << 16]; /* 64K */
u8 *stack = mem + 0x100; /* page 1 */
u8 CF, ZF, NF; /* flags should really be a bitfield, *shrug* */
unsigned int wtmp;
void dump_state(void) {
fprintf(stderr,
"A = $%02x X = $%02x Y = $%02x S = $%02x | "
"CF = %d ZF=%d NF=%d\n",
A, X, Y, S, (CF ? 1 : 0), (ZF ? 1 : 0), (NF ? 1 : 0));
}
void dump_mem(int start, int end) {
int count = 0;
while(start <= end) {
if(count % 16 == 0) {
if(count) fputc('\n', stderr);
fprintf(stderr, "%04x:", start);
}
fprintf(stderr, " %02x", mem[start]);
count++;
start++;
}
fputc('\n', stderr);
}
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