Implement variable-width shifts

calculator.asm

@@ -723,7 +723,7 @@ addByte:
 		; Calculate carries in r3
 		and r3, r0
 		or r2, r3 ; Accumulate carry into carryout
-		shl r3
+		shl r3, 1
 		; Calculate sums in r0
 		xor r0, r1
 		; Copy carries into second addend
@@ -735,13 +735,8 @@ addByte:
 		brneq r1, r3, addByteLoop
 
 	; Shift carryout, as we want carry from highest place = 1
-	shr r2
-	shr r2
-	shr r2
-	shr r2
-	shr r2
-	shr r2
-	shr r2
+	shr r2, 4
+	shr r2, 3
 
 	; Move carryout to r1
 	; (We know r1 is already 0 since it's the loop condition)
@@ -973,10 +968,7 @@ writehexByte:
 	or r2, r0
 
 	; High nybble
-	shr r0
-	shr r0
-	shr r0
-	shr r0
+	shr r0, 4
 	cleq r0, r0, nybble2hex
 	store ffff, r0
 

thingamajig_disasm.py

@@ -3,7 +3,7 @@ from collections import namedtuple
 import enum
 
 class rfield(enum.Enum):
-	none, reg, imm_flag = range(3)
+	none, reg, imm_flag, shift = range(4)
 
 Opcode = namedtuple('Opcode', ('mnemonic', 'rx', 'ry', 'addr'))
 
@@ -11,10 +11,10 @@ opcodes = [
 	Opcode('halt', rx=rfield.none, ry=rfield.none, addr=False),
 	Opcode('ret', rx=rfield.none, ry=rfield.none, addr=False),
 
-	Opcode('shl', rx=rfield.reg, ry=rfield.none, addr=False),
-	Opcode('shr', rx=rfield.reg, ry=rfield.none, addr=False),
-	Opcode('rol', rx=rfield.reg, ry=rfield.none, addr=False),
-	Opcode('ror', rx=rfield.reg, ry=rfield.none, addr=False),
+	Opcode('shl', rx=rfield.reg, ry=rfield.shift, addr=False),
+	Opcode('shr', rx=rfield.reg, ry=rfield.shift, addr=False),
+	Opcode('rol', rx=rfield.reg, ry=rfield.shift, addr=False),
+	Opcode('ror', rx=rfield.reg, ry=rfield.shift, addr=False),
 
 	Opcode('nand', rx=rfield.reg, ry=rfield.reg, addr=False),
 	Opcode('and', rx=rfield.reg, ry=rfield.reg, addr=False),
@@ -89,6 +89,9 @@ def disasm(binary, origin = 0):
 				fields.append(f'r{contents.rx}')
 			if opcodes[contents.opcode].ry == rfield.reg:
 				fields.append(f'r{contents.ry}')
+			elif opcodes[contents.opcode].ry == rfield.shift:
+				shift = contents.ry if contents.ry != 0 else 4
+				fields.append(f'{shift}')
 			if contents.immediate is not None:
 				fields.append(f'#{contents.immediate:02x}')
 			elif opcodes[contents.opcode].addr: