Implement INC instructions and fix add/sub/mul behaviour

1 files changed, 24 insertions, 15 deletions

diff --git a/src/uxn-core.s b/src/uxn-core.s
index e35707f..95afc1a 100644
--- a/src/uxn-core.s
+++ b/src/uxn-core.s
@@ -79,9 +79,19 @@ lit2r:
     b       uxn_decode
 
 inc:
+    ldrb    r3, [r1, #-1]!
+    add     r3, #1
+    strb    r3, [r1], #1
     b       uxn_decode
 
 inc2:
+    ldrb    r3, [r1, #-1]!
+    ldrb    r5, [r1, #-1]!
+    orr     r3, r3, r5, lsl #8
+    add     r3, r3, #1
+    strb    r3, [r1, #1]
+    lsr     r3, #8
+    strb    r3, [r1], #2
     b       uxn_decode
 
 pop:
@@ -226,14 +236,14 @@ add:
 add2:
     ldrb    r3, [r1, #-1]!
     ldrb    r5, [r1, #-1]!
-    orr     r3, r5, r3, lsl #8
+    orr     r3, r3, r5, lsl #8
     ldrb    r4, [r1, #-1]!
     ldrb    r5, [r1, #-1]!
-    orr     r4, r5, r4, lsl #8
+    orr     r4, r4, r5, lsl #8
     add     r3, r3, r4
-    strb    r3, [r1], #1
+    strb    r3, [r1, #1]
     lsr     r3, #8
-    strb    r3, [r1], #1
+    strb    r3, [r1], #2
     b       uxn_decode
 
 sub:
@@ -246,14 +256,14 @@ sub:
 sub2:
     ldrb    r3, [r1, #-1]!
     ldrb    r5, [r1, #-1]!
-    orr     r3, r5, r3, lsl #8
+    orr     r3, r3, r5, lsl #8
     ldrb    r4, [r1, #-1]!
     ldrb    r5, [r1, #-1]!
-    orr     r4, r5, r4, lsl #8
+    orr     r4, r4, r5, lsl #8
     sub     r3, r4, r3
-    strb    r3, [r1], #1
+    strb    r3, [r1, #1]
     lsr     r3, #8
-    strb    r3, [r1], #1
+    strb    r3, [r1], #2
     b       uxn_decode
 
 mul:
@@ -266,15 +276,14 @@ mul:
 mul2:
     ldrb    r3, [r1, #-1]!
     ldrb    r5, [r1, #-1]!
-    orr     r3, r5, r3, lsl #8
+    orr     r3, r3, r5, lsl #8
     ldrb    r4, [r1, #-1]!
     ldrb    r5, [r1, #-1]!
-    orr     r4, r5, r4, lsl #8
-    mul     r5, r3, r4
-    lsr     r3, r5, #24
-    strb    r3, [r1], #1
-    lsr     r5, #16
-    strb    r5, [r1], #1
+    orr     r4, r4, r5, lsl #8
+    mul     r3, r3, r4
+    strb    r3, [r1, #1]
+    lsr     r3, #8
+    strb    r3, [r1], #2
     b       uxn_decode
 
 div: