Support ! operator for condition codes (#720)

Fixes #719

src/asm/parser.y

@@ -653,6 +653,7 @@ enum {
 %type	<constValue>	reg_ss
 %type	<constValue>	reg_rr
 %type	<constValue>	reg_tt
+%type	<constValue>	ccode_expr
 %type	<constValue>	ccode
 %type	<expr>		op_a_n
 %type	<constValue>	op_a_r
@@ -1775,7 +1776,7 @@ z80_call	: T_Z80_CALL reloc_16bit {
 			sect_AbsByte(0xCD);
 			sect_RelWord(&$2, 1);
 		}
-		| T_Z80_CALL ccode T_COMMA reloc_16bit {
+		| T_Z80_CALL ccode_expr T_COMMA reloc_16bit {
 			sect_AbsByte(0xC4 | ($2 << 3));
 			sect_RelWord(&$4, 1);
 		}
@@ -1822,7 +1823,7 @@ z80_jp		: T_Z80_JP reloc_16bit {
 			sect_AbsByte(0xC3);
 			sect_RelWord(&$2, 1);
 		}
-		| T_Z80_JP ccode T_COMMA reloc_16bit {
+		| T_Z80_JP ccode_expr T_COMMA reloc_16bit {
 			sect_AbsByte(0xC2 | ($2 << 3));
 			sect_RelWord(&$4, 1);
 		}
@@ -1835,7 +1836,7 @@ z80_jr		: T_Z80_JR reloc_16bit {
 			sect_AbsByte(0x18);
 			sect_PCRelByte(&$2, 1);
 		}
-		| T_Z80_JR ccode T_COMMA reloc_16bit {
+		| T_Z80_JR ccode_expr T_COMMA reloc_16bit {
 			sect_AbsByte(0x20 | ($2 << 3));
 			sect_PCRelByte(&$4, 1);
 		}
@@ -2017,7 +2018,7 @@ z80_res		: T_Z80_RES const_3bit T_COMMA reg_r {
 ;
 
 z80_ret		: T_Z80_RET { sect_AbsByte(0xC9); }
-		| T_Z80_RET ccode { sect_AbsByte(0xC0 | ($2 << 3)); }
+		| T_Z80_RET ccode_expr { sect_AbsByte(0xC0 | ($2 << 3)); }
 ;
 
 z80_reti	: T_Z80_RETI { sect_AbsByte(0xD9); }
@@ -2172,6 +2173,12 @@ T_MODE_L	: T_TOKEN_L
 		| T_OP_LOW T_LPAREN T_MODE_HL T_RPAREN
 ;
 
+ccode_expr	: ccode
+		| T_OP_LOGICNOT ccode_expr {
+			$$ = $2 ^ 1;
+		}
+;
+
 ccode		: T_CC_NZ { $$ = CC_NZ; }
 		| T_CC_Z { $$ = CC_Z; }
 		| T_CC_NC { $$ = CC_NC; }

src/gbz80.7

@@ -62,6 +62,8 @@ Execute if Z is not set.
 Execute if C is set.
 .It Sy NC
 Execute if C is not set.
+.It Sy ! cc
+Negates a condition code.
 .El
 .It Ar vec
 One of the

test/asm/ccode.asm

@@ -0,0 +1,21 @@
+SECTION "ccode test", ROM0[0]
+
+Label:
+
+.local1
+	jp z, Label
+	jr nz, .local1
+	call c, Label
+	call nc, Label
+
+.local2
+	jp !nz, Label
+	jr !z, .local2
+	call !nc, Label
+	call !c, Label
+
+.local3
+	jp !!z, Label
+	jr !!nz, .local3
+	call !!c, Label
+	call !!nc, Label