Implement WORD() function

include/asm/rpn.h

@@ -56,6 +56,7 @@ void rpn_BinaryOp(enum RPNCommand op, struct Expression *expr,
 		  const struct Expression *src2);
 void rpn_HIGH(struct Expression *expr, const struct Expression *src);
 void rpn_LOW(struct Expression *expr, const struct Expression *src);
+void rpn_WORD(struct Expression *expr, const struct Expression *src);
 void rpn_ISCONST(struct Expression *expr, const struct Expression *src);
 void rpn_UNNEG(struct Expression *expr, const struct Expression *src);
 void rpn_UNNOT(struct Expression *expr, const struct Expression *src);

src/asm/asmy.y

@@ -544,6 +544,7 @@ static void strsubUTF8(char *dest, const char *src, uint32_t pos, uint32_t len)
 %left	T_OP_FLOOR
 
 %token	T_OP_HIGH T_OP_LOW
+%token	T_OP_WORD
 %token	T_OP_ISCONST
 
 %left	T_OP_STRCMP
@@ -1331,6 +1332,7 @@ relocexpr_no_str : scoped_id	{ rpn_Symbol(&$$, $1); }
 		| T_OP_NOT relocexpr %prec NEG	{ rpn_UNNOT(&$$, &$2); }
 		| T_OP_HIGH '(' relocexpr ')'	{ rpn_HIGH(&$$, &$3); }
 		| T_OP_LOW '(' relocexpr ')'	{ rpn_LOW(&$$, &$3); }
+		| T_OP_WORD '(' relocexpr ')'	{ rpn_WORD(&$$, &$3); }
 		| T_OP_ISCONST '(' relocexpr ')'{ rpn_ISCONST(&$$, &$3); }
 		| T_OP_BANK '(' scoped_id ')' {
 			/* '@' is also a T_ID, it is handled here. */

src/asm/globlex.c

@@ -455,6 +455,7 @@ const struct sLexInitString lexer_strings[] = {
 
 	{"high", T_OP_HIGH},
 	{"low", T_OP_LOW},
+	{"word", T_OP_WORD},
 	{"isconst", T_OP_ISCONST},
 
 	{"strcmp", T_OP_STRCMP},

src/asm/rgbasm.5

@@ -351,6 +351,7 @@ has been defined, FALSE (0) otherwise.
 String symbols are not expanded within the parentheses.
 .It Fn HIGH arg Ta Returns the top 8 bits of the operand if Ar arg No is a label or constant, or the top 8-bit register if it is a 16-bit register.
 .It Fn LOW arg Ta Returns the bottom 8 bits of the operand if Ar arg No is a label or constant, or the bottom 8-bit register if it is a 16-bit register Pq Cm AF No isn't a valid register for this function .
+.It Fn WORD arg Ta Returns the bottom 16 bits of the operand if Ar arg No is a label or constant.
 .It Fn ISCONST arg Ta Returns 1 if Ar arg Ap s value is known by RGBASM (e.g. if it can be an argument to
 .Ic IF ) ,
 or 0 if only RGBLINK can compute its value.

src/asm/rpn.c

@@ -497,7 +497,7 @@ void rpn_HIGH(struct Expression *expr, const struct Expression *src)
 	if (rpn_isKnown(expr)) {
 		expr->nVal = (uint32_t)expr->nVal >> 8 & 0xFF;
 	} else {
-		uint8_t bytes[] = {RPN_CONST,    8, 0, 0, 0, RPN_SHR,
+		static const uint8_t bytes[] = {RPN_CONST,    8, 0, 0, 0, RPN_SHR,
 				   RPN_CONST, 0xFF, 0, 0, 0, RPN_AND};
 		expr->nRPNPatchSize += sizeof(bytes);
 		memcpy(reserveSpace(expr, sizeof(bytes)), bytes, sizeof(bytes));
@@ -512,7 +512,22 @@ void rpn_LOW(struct Expression *expr, const struct Expression *src)
 	if (rpn_isKnown(expr)) {
 		expr->nVal = expr->nVal & 0xFF;
 	} else {
-		uint8_t bytes[] = {RPN_CONST, 0xFF, 0, 0, 0, RPN_AND};
+		static const uint8_t bytes[] = {RPN_CONST, 0xFF, 0, 0, 0, RPN_AND};
+
+		expr->nRPNPatchSize += sizeof(bytes);
+		memcpy(reserveSpace(expr, sizeof(bytes)), bytes, sizeof(bytes));
+	}
+}
+
+void rpn_WORD(struct Expression *expr, const struct Expression *src)
+{
+	*expr = *src;
+	expr->isSymbol = false;
+
+	if (rpn_isKnown(expr)) {
+		expr->nVal = expr->nVal & 0xFFFF;
+	} else {
+		static const uint8_t bytes[] = {RPN_CONST, 0xFF, 0xFF, 0, 0, RPN_AND};
 
 		expr->nRPNPatchSize += sizeof(bytes);
 		memcpy(reserveSpace(expr, sizeof(bytes)), bytes, sizeof(bytes));

test/asm/dw-word.asm

@@ -0,0 +1,17 @@
+SECTION "test", ROM0[0]
+
+	dw WORD($12)
+	dw WORD($1234)
+	dw WORD($123456)
+	dw WORD(-Label)
+
+
+SECTION "ram", WRAM0[$c123]
+
+Label:
+
+
+SECTION "test2", ROM0[8]
+
+	dw -Label
+	dw WORD(-Label)

test/asm/dw-word.err

@@ -0,0 +1,2 @@
+warning: dw-word.asm(16): [-Wtruncation]
+    Expression must be 16-bit

test/asm/ram-code.asm

@@ -13,7 +13,7 @@ Target:	dl DEAD << 16 | BEEF
 	ENDL
 After:
 	jp Target
-	ld hl, Word
+	ld hl, Word_
 	dw Byte, Target.end, After
 
 SECTION "dead", WRAMX[$DEAD],BANK[2]
@@ -22,7 +22,7 @@ SECTION "beef", SRAM[$BEEF]
 BEEF:
 
 SECTION "ram test", WRAMX,BANK[1] ; Should end up at $D005
-Word:
+Word_:
 	dw
 
 SECTION "small ram test", WRAMX,BANK[1] ; Should end up at $D000