From a7d059f87798075986f02dbdc15d3318b4438e3f Mon Sep 17 00:00:00 2001
From: neauoire <aliceffekt@gmail.com>
Date: Thu, 9 Nov 2023 20:45:33 -0800
Subject: [PATCH] Changing jump opcodes to signed bcb

---
 src/gyoemu.c | 118 +++++++++++++++++++++++++++++----------------------
 1 file changed, 67 insertions(+), 51 deletions(-)

diff --git a/src/gyoemu.c b/src/gyoemu.c
index f3341b2..6ca69c9 100644
--- a/src/gyoemu.c
+++ b/src/gyoemu.c
@@ -26,62 +26,78 @@ char *opcodes[] = {
 /* clang-format on */
 
 void
-disinstr(uc15 inst)
+dislit(uc15 inst)
+{
+	putchar('#'), phep(inst >> 2, 5);
+}
+
+void
+disjmp(uc15 inst)
 {
-	if((inst & 0x3) == BCP) {
-		putchar('#'), phep(inst >> 2, 5);
+	switch((inst >> 2) & 0x3) {
+	case 0: /* JCN */
+		putchar('?'), phep(inst >> 4, 5);
 		return;
-	} else if((inst & 0x3) == BCZ) {
-		if(((inst >> 2) & 0x3) == 1) {
-			putchar('?'), phep(inst >> 4, 5);
-			return;
-		} else if(((inst >> 2) & 0x3) == 0) {
-			putchar('>'), phep(inst >> 4, 5);
-			return;
-		}
-		printf("call:"), phep(inst >> 4, 5);
+	case 1: /* JMP */
+		putchar('>'), phep(inst >> 4, 5);
 		return;
-	} else if((inst & 0x3) == BCN) {
-		/* (RST->PC,NOP,T->N) */
-		switch((inst >> 2) & 0x3) {
-		case 0: putchar(';'); break;
-		case 2: putchar('%'); break;
-		}
-		/* (N,T,INS)->ACC */
-		switch((inst >> 4) & 0x3) {
-		case 0: putchar('n'); break;
-		case 2: putchar('i'); break;
-		}
-		/* ALU */
-		switch((inst >> 6) & 0xf) {
-		case 1: printf("CM"); break;
-		case 2: printf("UN"); break;
-		case 4: printf("BI"); break;
-		case 5: printf("AD"); break;
-		case 6: printf("LS"); break;
-		case 8: printf("RS"); break;
-		case 9: printf("ST"); break;
-		case 10: printf("ME"); break;
-		}
-		/* RST */
-		if(((inst >> 14) & 0x3) == 0) printf("[r");
-		switch((inst >> 12) & 0x3) {
-		case 0: printf("-"); break;
-		case 2: printf("+"); break;
-		}
-		/* DST */
-		if(((inst >> 14) & 0x3) == 2) printf("[d");
-		switch((inst >> 10) & 0x3) {
-		case 0: printf("-"); break;
-		case 2: printf("+"); break;
-		}
-		/* OUT */
-		switch((inst >> 16) & 0x3) {
-		case 0: printf("/"); break;
-		case 2: printf("!"); break;
-		}
+	case 2: /* JSR */
+		printf("call:"), phep(inst >> 4, 5);
 		return;
 	}
+}
+
+void
+disopc(uc15 inst)
+{
+	/* (RST->PC,NOP,T->N) */
+	switch((inst >> 2) & 0x3) {
+	case 0: putchar(';'); break;
+	case 2: putchar('%'); break;
+	}
+	/* (N,T,INS)->ACC */
+	switch((inst >> 4) & 0x3) {
+	case 0: putchar('n'); break;
+	case 2: putchar('i'); break;
+	}
+	/* ALU */
+	switch((inst >> 6) & 0xf) {
+	case 1: printf("CM"); break;
+	case 2: printf("UN"); break;
+	case 4: printf("BI"); break;
+	case 5: printf("AD"); break;
+	case 6: printf("LS"); break;
+	case 8: printf("RS"); break;
+	case 9: printf("ST"); break;
+	case 10: printf("ME"); break;
+	}
+	/* RST */
+	if(((inst >> 14) & 0x3) == 0) printf("[r");
+	switch((inst >> 12) & 0x3) {
+	case 0: printf("-"); break;
+	case 2: printf("+"); break;
+	}
+	/* DST */
+	if(((inst >> 14) & 0x3) == 2) printf("[d");
+	switch((inst >> 10) & 0x3) {
+	case 0: printf("-"); break;
+	case 2: printf("+"); break;
+	}
+	/* OUT */
+	switch((inst >> 16) & 0x3) {
+	case 0: printf("/"); break;
+	case 2: printf("!"); break;
+	}
+}
+
+void
+disinstr(uc15 inst)
+{
+	switch(inst & 0x3) {
+	case BCP: dislit(inst); return;
+	case BCZ: disjmp(inst); return;
+	case BCN: disopc(inst); return;
+	}
 	printf("Unknown instruciton\n");
 }
 
-- 
2.45.2