apps/zasm/README.md

@@ -152,11 +152,4 @@ allowed. An included file cannot have an `.inc` directive.
           in the argument in the currently active filesystem and outputs its
           contents directly.
 
-## Undocumented instructions
-
-`zasm` doesn't support undocumented instructions such as the ones that involve
-using `IX` and `IY` as 8-bit registers. We used to support them, but because
-this makes our code incompatible with Z80-compatible CPUs such as the Z180, we
-prefer to avoid these in our code.
-
 [libz80]: https://github.com/ggambetta/libz80

apps/zasm/instr.asm

@@ -109,7 +109,7 @@ getInstID:
 	ret
 
 ; Parse the string at (HL) and check if it starts with IX+, IY+, IX- or IY-.
-; Sets Z if yes, unset if no. On success, A contains either '+' or '-'.
+; Sets Z if yes, unset if no.
 parseIXY:
 	push	hl
 	ld	a, (hl)
@@ -180,15 +180,13 @@ parseArg:
 	ld	a, 'N'
 	jr	.end
 .withParens:
-	ld	b, 0		; make sure it doesn't hold '-'
 	ld	c, 'M'		; C holds the argspec type until we reach
 				; .numberInParens
 	; We have parens. First, let's see if we have a (IX+d) type of arg.
 	call	parseIXY
 	jr	nz, .parseNumberInParens	; not I{X,Y}. just parse number.
 	; We have IX+/IY+/IX-/IY-.
-	; A contains either '+' or '-'. Save it for later, in B.
-	ld	b, a
+	; note: the "-" part isn't supported yet.
 	inc	hl	; (HL) now points to X or Y
 	ld	a, (hl)
 	call	upcase
@@ -204,22 +202,6 @@ parseArg:
 	call	.maybeParseExpr
 	jr	nz, .nomatch
 	; We have a proper number in parens. Number in IX
-	; is '-' in B? if yes, we need to negate the low part of IX
-	ld	a, b
-	cp	'-'
-	jr	nz, .dontNegateIX
-	; we need to negate the low part of IX
-	; TODO: when parsing routines properly support unary negative numbers,
-	; We could replace this complicated scheme below with a nice hack where
-	; we start parsing our displacement number at the '+' and '-' char.
-
-	; HL isn't needed anymore and can be destroyed.
-	push	ix \ pop hl
-	ld	a, l
-	neg
-	ld	l, a
-	push	hl \ pop ix
-.dontNegateIX:
 	ld	a, c	; M, x, or y
 	jr	.end
 .nomatch:

apps/zasm/symbol.asm

@@ -110,14 +110,12 @@ symRegister:
 	; Is our new name going to make us go out of bounds?
 	push	hl		; --> lvl 2
 	push	de		; --> lvl 3
-	ld 	d, 0
-	ld 	e, c
-	add 	hl, de		; if carry set here, sbc will carry too	
 	ld	e, (ix+2)	; DE --> pointer to record list, which is also
 	ld	d, (ix+3)	; the end of names pool
 	; DE --> names end
-	
-	sbc	hl, de		; compares hl and de destructively
+	ld	a, c
+	call	addHL
+	call	cpHLDE
 	pop	de		; <-- lvl 3
 	pop	hl		; <-- lvl 2
 	jr	nc, .outOfMemory	; HL >= DE
@@ -192,15 +190,9 @@ _symFind:
 	jr	z, .end		; match! Z already set, IY and HL placed.
 .skip:
 	; ok, next!
-	
-	push 	de		; --> lvl 1
-	ld 	de, 0x0003
-	add 	iy, de		; faster and shorter than three inc's
-	ld 	e, (iy-3)	; offset is also compulsory, so no extra bytes used	
-	; (iy-3) holds the name length of the string just processed
-	add 	hl, de	; advance HL by (iy-3) characters
-	pop	de		; <-- lvl 1
-
+	ld	a, (iy)		; name len again
+	call	addHL		; advance HL by A chars
+	inc	iy \ inc iy \ inc iy
 	djnz	.loop
 	; end of the chain, nothing found
 .nothing:

kernel/core.asm

@@ -53,25 +53,28 @@ intoIX:
 	ret
 
 ; add the value of A into HL
-; affects carry flag according to the 16-bit addition, Z, S and P untouched.
 addHL:
-	push	de
-	ld 	d, 0
-	ld	e, a
-	add	hl, de
-	pop	de
+	push	af
+	add	a, l
+	jr	nc, .end	; no carry? skip inc
+	inc	h
+.end:
+	ld	l, a
+	pop	af
 	ret
 
-
 ; subtract the value of A from HL
-; affects flags according to the 16-bit subtraction.
 subHL:
-	push	de
-	ld	d, 0
-	ld	e, a
-	or 	a		;reset carry flag
-	sbc	hl, de		;There is no 'sub hl, de', so we must use sbc
-	pop	de
+	push	af
+	; To avoid having to swap L and A, we sub "backwards", that is, we add
+	; a NEGated value. This means that the carry flag is inverted
+	neg
+	add	a, l
+	jr	c, .end		; if carry, no carry. :)
+	dec	h
+.end:
+	ld	l, a
+	pop	af
 	ret
 
 ; Compare HL with DE and sets Z and C in the same way as a regular cp X where

tools/tests/zasm/allinstrs.asm

@@ -48,22 +48,14 @@ ADD IY, IY
 ADD IY, SP
 ADD A, (IX)
 ADD A, (IX+1)
-ADD A, (IX-1)
 ADD A, (IX+10)
-ADD A, (IX-10)
 ADD A, (IX+100)
-ADD A, (IX-100)
 ADD A, (IX+127)
-ADD A, (IX-127)
 ADD A, (IY)
 ADD A, (IY+1)
-ADD A, (IY-1)
 ADD A, (IY+10)
-ADD A, (IY-10)
 ADD A, (IY+100)
-ADD A, (IY-100)
 ADD A, (IY+127)
-ADD A, (IY-127)
 AND (HL)
 AND B
 AND C
@@ -81,78 +73,46 @@ AND 32
 AND 64
 AND 128
 AND (IX+1)
-AND (IX-1)
 AND (IX+10)
-AND (IX-10)
 AND (IX+100)
-AND (IX-100)
 AND (IX+127)
-AND (IX-127)
 AND (IY+1)
-AND (IY-1)
 AND (IY+10)
-AND (IY-10)
 AND (IY+100)
-AND (IY-100)
 AND (IY+127)
-AND (IY-127)
 BIT 1, (HL)
 BIT 2, (HL)
 BIT 4, (HL)
 BIT 1, (IX)
 BIT 1, (IX+1)
-BIT 1, (IX-1)
 BIT 1, (IX+10)
-BIT 1, (IX-10)
 BIT 1, (IX+100)
-BIT 1, (IX-100)
 BIT 1, (IX+127)
-BIT 1, (IX-127)
 BIT 2, (IX)
 BIT 2, (IX+1)
-BIT 2, (IX-1)
 BIT 2, (IX+10)
-BIT 2, (IX-10)
 BIT 2, (IX+100)
-BIT 2, (IX-100)
 BIT 2, (IX+127)
-BIT 2, (IX-127)
 BIT 4, (IX)
 BIT 4, (IX+1)
-BIT 4, (IX-1)
 BIT 4, (IX+10)
-BIT 4, (IX-10)
 BIT 4, (IX+100)
-BIT 4, (IX-100)
 BIT 4, (IX+127)
-BIT 4, (IX-127)
 BIT 1, (IY)
 BIT 1, (IY+1)
-BIT 1, (IY-1)
 BIT 1, (IY+10)
-BIT 1, (IY-10)
 BIT 1, (IY+100)
-BIT 1, (IY-100)
 BIT 1, (IY+127)
-BIT 1, (IY-127)
 BIT 2, (IY)
 BIT 2, (IY+1)
-BIT 2, (IY-1)
 BIT 2, (IY+10)
-BIT 2, (IY-10)
 BIT 2, (IY+100)
-BIT 2, (IY-100)
 BIT 2, (IY+127)
-BIT 2, (IY-127)
 BIT 4, (IY)
 BIT 4, (IY+1)
-BIT 4, (IY-1)
 BIT 4, (IY+10)
-BIT 4, (IY-10)
 BIT 4, (IY+100)
-BIT 4, (IY-100)
 BIT 4, (IY+127)
-BIT 4, (IY-127)
 BIT 1, B
 BIT 1, C
 BIT 1, D
@@ -337,22 +297,14 @@ CP 64
 CP 128
 CP (IX)
 CP (IX+1)
-CP (IX-1)
 CP (IX+10)
-CP (IX-10)
 CP (IX+100)
-CP (IX-100)
 CP (IX+127)
-CP (IX-127)
 CP (IY)
 CP (IY+1)
-CP (IY-1)
 CP (IY+10)
-CP (IY-10)
 CP (IY+100)
-CP (IY-100)
 CP (IY+127)
-CP (IY-127)
 CPD
 CPDR
 CPI
@@ -363,23 +315,15 @@ DEC (HL)
 DEC IX
 DEC (IX)
 DEC (IX+1)
-DEC (IX-1)
 DEC (IX+10)
-DEC (IX-10)
 DEC (IX+100)
-DEC (IX-100)
 DEC (IX+127)
-DEC (IX-127)
 DEC IY
 DEC (IY)
 DEC (IY+1)
-DEC (IY-1)
 DEC (IY+10)
-DEC (IY-10)
 DEC (IY+100)
-DEC (IY-100)
 DEC (IY+127)
-DEC (IY-127)
 DEC B
 DEC C
 DEC D
@@ -436,23 +380,15 @@ INC (HL)
 INC IX
 INC (IX)
 INC (IX+1)
-INC (IX-1)
 INC (IX+10)
-INC (IX-10)
 INC (IX+100)
-INC (IX-100)
 INC (IX+127)
-INC (IX-127)
 INC IY
 INC (IY)
 INC (IY+1)
-INC (IY-1)
 INC (IY+10)
-INC (IY-10)
 INC (IY+100)
-INC (IY-100)
 INC (IY+127)
-INC (IY-127)
 INC B
 INC C
 INC D
@@ -1189,14 +1125,6 @@ LD (IX+1), 16
 LD (IX+1), 32
 LD (IX+1), 64
 LD (IX+1), 128
-LD (IX-1), 1
-LD (IX-1), 2
-LD (IX-1), 4
-LD (IX-1), 8
-LD (IX-1), 16
-LD (IX-1), 32
-LD (IX-1), 64
-LD (IX-1), 128
 LD (IX+10), 1
 LD (IX+10), 2
 LD (IX+10), 4
@@ -1205,14 +1133,6 @@ LD (IX+10), 16
 LD (IX+10), 32
 LD (IX+10), 64
 LD (IX+10), 128
-LD (IX-10), 1
-LD (IX-10), 2
-LD (IX-10), 4
-LD (IX-10), 8
-LD (IX-10), 16
-LD (IX-10), 32
-LD (IX-10), 64
-LD (IX-10), 128
 LD (IX+100), 1
 LD (IX+100), 2
 LD (IX+100), 4
@@ -1221,14 +1141,6 @@ LD (IX+100), 16
 LD (IX+100), 32
 LD (IX+100), 64
 LD (IX+100), 128
-LD (IX-100), 1
-LD (IX-100), 2
-LD (IX-100), 4
-LD (IX-100), 8
-LD (IX-100), 16
-LD (IX-100), 32
-LD (IX-100), 64
-LD (IX-100), 128
 LD (IX+127), 1
 LD (IX+127), 2
 LD (IX+127), 4
@@ -1237,14 +1149,6 @@ LD (IX+127), 16
 LD (IX+127), 32
 LD (IX+127), 64
 LD (IX+127), 128
-LD (IX-127), 1
-LD (IX-127), 2
-LD (IX-127), 4
-LD (IX-127), 8
-LD (IX-127), 16
-LD (IX-127), 32
-LD (IX-127), 64
-LD (IX-127), 128
 LD (IY), 1
 LD (IY), 2
 LD (IY), 4
@@ -1261,14 +1165,6 @@ LD (IY+1), 16
 LD (IY+1), 32
 LD (IY+1), 64
 LD (IY+1), 128
-LD (IY-1), 1
-LD (IY-1), 2
-LD (IY-1), 4
-LD (IY-1), 8
-LD (IY-1), 16
-LD (IY-1), 32
-LD (IY-1), 64
-LD (IY-1), 128
 LD (IY+10), 1
 LD (IY+10), 2
 LD (IY+10), 4
@@ -1277,14 +1173,6 @@ LD (IY+10), 16
 LD (IY+10), 32
 LD (IY+10), 64
 LD (IY+10), 128
-LD (IY-10), 1
-LD (IY-10), 2
-LD (IY-10), 4
-LD (IY-10), 8
-LD (IY-10), 16
-LD (IY-10), 32
-LD (IY-10), 64
-LD (IY-10), 128
 LD (IY+100), 1
 LD (IY+100), 2
 LD (IY+100), 4
@@ -1293,14 +1181,6 @@ LD (IY+100), 16
 LD (IY+100), 32
 LD (IY+100), 64
 LD (IY+100), 128
-LD (IY-100), 1
-LD (IY-100), 2
-LD (IY-100), 4
-LD (IY-100), 8
-LD (IY-100), 16
-LD (IY-100), 32
-LD (IY-100), 64
-LD (IY-100), 128
 LD (IY+127), 1
 LD (IY+127), 2
 LD (IY+127), 4
@@ -1309,14 +1189,6 @@ LD (IY+127), 16
 LD (IY+127), 32
 LD (IY+127), 64
 LD (IY+127), 128
-LD (IY-127), 1
-LD (IY-127), 2
-LD (IY-127), 4
-LD (IY-127), 8
-LD (IY-127), 16
-LD (IY-127), 32
-LD (IY-127), 64
-LD (IY-127), 128
 LD (IX), B
 LD (IX), C
 LD (IX), D
@@ -1331,13 +1203,6 @@ LD (IX+1), E
 LD (IX+1), H
 LD (IX+1), L
 LD (IX+1), A
-LD (IX-1), B
-LD (IX-1), C
-LD (IX-1), D
-LD (IX-1), E
-LD (IX-1), H
-LD (IX-1), L
-LD (IX-1), A
 LD (IX+10), B
 LD (IX+10), C
 LD (IX+10), D
@@ -1345,13 +1210,6 @@ LD (IX+10), E
 LD (IX+10), H
 LD (IX+10), L
 LD (IX+10), A
-LD (IX-10), B
-LD (IX-10), C
-LD (IX-10), D
-LD (IX-10), E
-LD (IX-10), H
-LD (IX-10), L
-LD (IX-10), A
 LD (IX+100), B
 LD (IX+100), C
 LD (IX+100), D
@@ -1359,13 +1217,6 @@ LD (IX+100), E
 LD (IX+100), H
 LD (IX+100), L
 LD (IX+100), A
-LD (IX-100), B
-LD (IX-100), C
-LD (IX-100), D
-LD (IX-100), E
-LD (IX-100), H
-LD (IX-100), L
-LD (IX-100), A
 LD (IX+127), B
 LD (IX+127), C
 LD (IX+127), D
@@ -1373,13 +1224,6 @@ LD (IX+127), E
 LD (IX+127), H
 LD (IX+127), L
 LD (IX+127), A
-LD (IX-127), B
-LD (IX-127), C
-LD (IX-127), D
-LD (IX-127), E
-LD (IX-127), H
-LD (IX-127), L
-LD (IX-127), A
 LD (IY), B
 LD (IY), C
 LD (IY), D
@@ -1394,13 +1238,6 @@ LD (IY+1), E
 LD (IY+1), H
 LD (IY+1), L
 LD (IY+1), A
-LD (IY-1), B
-LD (IY-1), C
-LD (IY-1), D
-LD (IY-1), E
-LD (IY-1), H
-LD (IY-1), L
-LD (IY-1), A
 LD (IY+10), B
 LD (IY+10), C
 LD (IY+10), D
@@ -1408,13 +1245,6 @@ LD (IY+10), E
 LD (IY+10), H
 LD (IY+10), L
 LD (IY+10), A
-LD (IY-10), B
-LD (IY-10), C
-LD (IY-10), D
-LD (IY-10), E
-LD (IY-10), H
-LD (IY-10), L
-LD (IY-10), A
 LD (IY+100), B
 LD (IY+100), C
 LD (IY+100), D
@@ -1422,13 +1252,6 @@ LD (IY+100), E
 LD (IY+100), H
 LD (IY+100), L
 LD (IY+100), A
-LD (IY-100), B
-LD (IY-100), C
-LD (IY-100), D
-LD (IY-100), E
-LD (IY-100), H
-LD (IY-100), L
-LD (IY-100), A
 LD (IY+127), B
 LD (IY+127), C
 LD (IY+127), D
@@ -1436,139 +1259,76 @@ LD (IY+127), E
 LD (IY+127), H
 LD (IY+127), L
 LD (IY+127), A
-LD (IY-127), B
-LD (IY-127), C
-LD (IY-127), D
-LD (IY-127), E
-LD (IY-127), H
-LD (IY-127), L
-LD (IY-127), A
 LD B, (IX)
 LD B, (IX+1)
-LD B, (IX-1)
 LD B, (IX+10)
-LD B, (IX-10)
 LD B, (IX+100)
-LD B, (IX-100)
 LD B, (IX+127)
-LD B, (IX-127)
 LD C, (IX)
 LD C, (IX+1)
-LD C, (IX-1)
 LD C, (IX+10)
-LD C, (IX-10)
 LD C, (IX+100)
-LD C, (IX-100)
 LD C, (IX+127)
-LD C, (IX-127)
 LD D, (IX)
 LD D, (IX+1)
-LD D, (IX-1)
 LD D, (IX+10)
-LD D, (IX-10)
 LD D, (IX+100)
-LD D, (IX-100)
 LD D, (IX+127)
-LD D, (IX-127)
 LD E, (IX)
 LD E, (IX+1)
-LD E, (IX-1)
 LD E, (IX+10)
-LD E, (IX-10)
 LD E, (IX+100)
-LD E, (IX-100)
 LD E, (IX+127)
-LD E, (IX-127)
 LD H, (IX)
 LD H, (IX+1)
-LD H, (IX-1)
 LD H, (IX+10)
-LD H, (IX-10)
 LD H, (IX+100)
-LD H, (IX-100)
 LD H, (IX+127)
-LD H, (IX-127)
 LD L, (IX)
 LD L, (IX+1)
-LD L, (IX-1)
 LD L, (IX+10)
-LD L, (IX-10)
 LD L, (IX+100)
-LD L, (IX-100)
 LD L, (IX+127)
-LD L, (IX-127)
 LD A, (IX)
 LD A, (IX+1)
-LD A, (IX-1)
 LD A, (IX+10)
-LD A, (IX-10)
 LD A, (IX+100)
-LD A, (IX-100)
 LD A, (IX+127)
-LD A, (IX-127)
 LD B, (IY)
 LD B, (IY+1)
-LD B, (IY-1)
 LD B, (IY+10)
-LD B, (IY-10)
 LD B, (IY+100)
-LD B, (IY-100)
 LD B, (IY+127)
-LD B, (IY-127)
 LD C, (IY)
 LD C, (IY+1)
-LD C, (IY-1)
 LD C, (IY+10)
-LD C, (IY-10)
 LD C, (IY+100)
-LD C, (IY-100)
 LD C, (IY+127)
-LD C, (IY-127)
 LD D, (IY)
 LD D, (IY+1)
-LD D, (IY-1)
 LD D, (IY+10)
-LD D, (IY-10)
 LD D, (IY+100)
-LD D, (IY-100)
 LD D, (IY+127)
-LD D, (IY-127)
 LD E, (IY)
 LD E, (IY+1)
-LD E, (IY-1)
 LD E, (IY+10)
-LD E, (IY-10)
 LD E, (IY+100)
-LD E, (IY-100)
 LD E, (IY+127)
-LD E, (IY-127)
 LD H, (IY)
 LD H, (IY+1)
-LD H, (IY-1)
 LD H, (IY+10)
-LD H, (IY-10)
 LD H, (IY+100)
-LD H, (IY-100)
 LD H, (IY+127)
-LD H, (IY-127)
 LD L, (IY)
 LD L, (IY+1)
-LD L, (IY-1)
 LD L, (IY+10)
-LD L, (IY-10)
 LD L, (IY+100)
-LD L, (IY-100)
 LD L, (IY+127)
-LD L, (IY-127)
 LD A, (IY)
 LD A, (IY+1)
-LD A, (IY-1)
 LD A, (IY+10)
-LD A, (IY-10)
 LD A, (IY+100)
-LD A, (IY-100)
 LD A, (IY+127)
-LD A, (IY-127)
 LDD
 LDDR
 LDI
@@ -1593,22 +1353,14 @@ OR 64
 OR 128
 OR (IX)
 OR (IX+1)
-OR (IX-1)
 OR (IX+10)
-OR (IX-10)
 OR (IX+100)
-OR (IX-100)
 OR (IX+127)
-OR (IX-127)
 OR (IY)
 OR (IY+1)
-OR (IY-1)
 OR (IY+10)
-OR (IY-10)
 OR (IY+100)
-OR (IY-100)
 OR (IY+127)
-OR (IY-127)
 OTDR
 OTIR
 OUT (1), A
@@ -1643,58 +1395,34 @@ RES 2, (HL)
 RES 4, (HL)
 RES 1, (IX)
 RES 1, (IX+1)
-RES 1, (IX-1)
 RES 1, (IX+10)
-RES 1, (IX-10)
 RES 1, (IX+100)
-RES 1, (IX-100)
 RES 1, (IX+127)
-RES 1, (IX-127)
 RES 2, (IX)
 RES 2, (IX+1)
-RES 2, (IX-1)
 RES 2, (IX+10)
-RES 2, (IX-10)
 RES 2, (IX+100)
-RES 2, (IX-100)
 RES 2, (IX+127)
-RES 2, (IX-127)
 RES 4, (IX)
 RES 4, (IX+1)
-RES 4, (IX-1)
 RES 4, (IX+10)
-RES 4, (IX-10)
 RES 4, (IX+100)
-RES 4, (IX-100)
 RES 4, (IX+127)
-RES 4, (IX-127)
 RES 1, (IY)
 RES 1, (IY+1)
-RES 1, (IY-1)
 RES 1, (IY+10)
-RES 1, (IY-10)
 RES 1, (IY+100)
-RES 1, (IY-100)
 RES 1, (IY+127)
-RES 1, (IY-127)
 RES 2, (IY)
 RES 2, (IY+1)
-RES 2, (IY-1)
 RES 2, (IY+10)
-RES 2, (IY-10)
 RES 2, (IY+100)
-RES 2, (IY-100)
 RES 2, (IY+127)
-RES 2, (IY-127)
 RES 4, (IY)
 RES 4, (IY+1)
-RES 4, (IY-1)
 RES 4, (IY+10)
-RES 4, (IY-10)
 RES 4, (IY+100)
-RES 4, (IY-100)
 RES 4, (IY+127)
-RES 4, (IY-127)
 RES 1, B
 RES 1, C
 RES 1, D
@@ -1777,58 +1505,34 @@ SET 2, (HL)
 SET 4, (HL)
 SET 1, (IX)
 SET 1, (IX+1)
-SET 1, (IX-1)
 SET 1, (IX+10)
-SET 1, (IX-10)
 SET 1, (IX+100)
-SET 1, (IX-100)
 SET 1, (IX+127)
-SET 1, (IX-127)
 SET 2, (IX)
 SET 2, (IX+1)
-SET 2, (IX-1)
 SET 2, (IX+10)
-SET 2, (IX-10)
 SET 2, (IX+100)
-SET 2, (IX-100)
 SET 2, (IX+127)
-SET 2, (IX-127)
 SET 4, (IX)
 SET 4, (IX+1)
-SET 4, (IX-1)
 SET 4, (IX+10)
-SET 4, (IX-10)
 SET 4, (IX+100)
-SET 4, (IX-100)
 SET 4, (IX+127)
-SET 4, (IX-127)
 SET 1, (IY)
 SET 1, (IY+1)
-SET 1, (IY-1)
 SET 1, (IY+10)
-SET 1, (IY-10)
 SET 1, (IY+100)
-SET 1, (IY-100)
 SET 1, (IY+127)
-SET 1, (IY-127)
 SET 2, (IY)
 SET 2, (IY+1)
-SET 2, (IY-1)
 SET 2, (IY+10)
-SET 2, (IY-10)
 SET 2, (IY+100)
-SET 2, (IY-100)
 SET 2, (IY+127)
-SET 2, (IY-127)
 SET 4, (IY)
 SET 4, (IY+1)
-SET 4, (IY-1)
 SET 4, (IY+10)
-SET 4, (IY-10)
 SET 4, (IY+100)
-SET 4, (IY-100)
 SET 4, (IY+127)
-SET 4, (IY-127)
 SET 1, B
 SET 1, C
 SET 1, D

tools/tests/zasm/geninstrs.py

@@ -103,7 +103,7 @@ def genargs(argspec):
         argspec = argspec.upper()
         for n in [1, 10, 100, 127]:
             result.append(f"(I{argspec}+{n})")
-            result.append(f"(I{argspec}-{n})")
+        # TODO: support minus
         return result
     if argspec in argspecTbl:
         return [argspecTbl[argspec]]

tools/tests/zasm/test1.asm

@@ -17,7 +17,7 @@ label2: .dw	0x42
 	ld	ix, 1234
 	ld	iy, 2345
 	ld	(ix+1), l
-	ld	l, (ix-1)
+	ld	l, (ix+1)
 	ld	hl, 0x100
 .equ	baz	0x20
 	; accept space before comma