uxn

commit f2029445665a21d113c054748cbd5c1c11814f26
parent 749066687851797930db68d83195d2aa36620b3d
Author: Andrew Alderwick <andrew@alderwick.co.uk>
Date:   Thu, 12 Jan 2023 13:22:21 +0000

Make JMI, JCI and JSI relative.

Diffstat:
M
src/uxn.c
 | 
6
+++---
M
src/uxnasm.c
 | 
12
++++++++++--

2 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/src/uxn.c b/src/uxn.c
@@ -50,9 +50,9 @@ uxn_eval(Uxn *u, Uint16 pc)
 		switch(opcode - (!opcode * (instr >> 5))) {
 		/* Literals/Calls */
 		case -0x0: /* BRK */ return 1;
-		case -0x1: /* JMI */ PEEK16(a, pc) pc = a; break;
-		case -0x2: /* JCI */ sp = &u->wst->ptr; src = u->wst; POP8(b) if(b) { PEEK16(a, pc) pc = a; } else pc += 2; break;
-		case -0x3: /* JSI */ PUSH16(u->rst, pc + 2) PEEK16(a, pc) pc = a; break;
+		case -0x1: /* JMI */ PEEK16(a, pc) pc += a + 2; break;
+		case -0x2: /* JCI */ sp = &u->wst->ptr; src = u->wst; POP8(b) if(b) { PEEK16(a, pc) pc += a + 2; } else pc += 2; break;
+		case -0x3: /* JSI */ PUSH16(u->rst, pc + 2) PEEK16(a, pc) pc += a + 2; break;
 		case -0x4: /* LIT */
 		case -0x6: /* LITr */ a = u->ram[pc++]; PUSH8(src, a) break;
 		case -0x5: /* LIT2 */
diff --git a/src/uxnasm.c b/src/uxnasm.c
@@ -360,6 +360,7 @@ resolve(void)
 {
 	Label *l;
 	int i;
+	Uint16 a;
 	for(i = 0; i < p.rlen; i++) {
 		Reference *r = &p.refs[i];
 		switch(r->rune) {
@@ -382,13 +383,20 @@ resolve(void)
 		case ':':
 		case '=':
 		case ';':
+			if(!(l = findlabel(r->name)))
+				return error("Unknown absolute reference", r->name);
+			p.data[r->addr] = l->addr >> 0x8;
+			p.data[r->addr + 1] = l->addr & 0xff;
+			l->refs++;
+			break;
 		case '?':
 		case '!':
 		default:
 			if(!(l = findlabel(r->name)))
 				return error("Unknown absolute reference", r->name);
-			p.data[r->addr] = l->addr >> 0x8;
-			p.data[r->addr + 1] = l->addr & 0xff;
+			a = l->addr - r->addr - 2;
+			p.data[r->addr] = a >> 0x8;
+			p.data[r->addr + 1] = a & 0xff;
 			l->refs++;
 			break;
 		}