X-Git-Url: http://shamusworld.gotdns.org/cgi-bin/gitweb.cgi?p=rmac;a=blobdiff_plain;f=expr.c;h=f31e9e59ddf67c1be317af23a1428c22da4ee534;hp=20f43cfcb3aace6feb23228e635f8a1cfd5d4dc1;hb=fbbe9b115f949735421485513154ce8abb8453eb;hpb=eace4e1b294ccec54a5c476619f616f5da0bf8a9

diff --git a/expr.c b/expr.c
index 20f43cf..f31e9e5 100644
--- a/expr.c
+++ b/expr.c
@@ -1,7 +1,7 @@
 //
 // RMAC - Reboot's Macro Assembler for all Atari computers
 // EXPR.C - Expression Analyzer
-// Copyright (C) 199x Landon Dyer, 2011-2017 Reboot and Friends
+// Copyright (C) 199x Landon Dyer, 2011-2020 Reboot and Friends
 // RMAC derived from MADMAC v1.07 Written by Landon Dyer, 1986
 // Source utilised with the kind permission of Landon Dyer
 //
@@ -35,8 +35,8 @@ char itokcl[] = {
 	CR_DEFINED, CR_REFERENCED,		// SUNARY (special unary)
 	CR_STREQ, CR_MACDEF,
 	CR_DATE, CR_TIME,
-	CR_ABSCOUNT, 0,
-	'!', '~', UNMINUS, 0,			// UNARY
+	CR_ABSCOUNT, CR_FILESIZE, 0,
+	'!', '~', UNMINUS, UNLT, UNGT, 0,	// UNARY
 	'*', '/', '%', 0,				// MULT
 	'+', '-', 0,					// ADD
 	SHL, SHR, 0,					// SHIFT
@@ -49,6 +49,7 @@ char itokcl[] = {
 
 const char missym_error[] = "missing symbol";
 const char str_error[] = "missing symbol or string";
+const char noflt_error[] = "operator not usable with float";
 
 // Convert expression to postfix
 static PTR evalTokenBuffer;		// Deposit tokens here (this is really a
@@ -125,23 +126,24 @@ int expr0(void)
 //
 int expr1(void)
 {
-	TOKEN t;
-	SYM * sy;
-	char * p, * p2;
+	char * p;
 	WORD w;
-	int j;
 
 	int class = tokenClass[*tok];
 
-	if (*tok == '-' || *tok == '+' || class == UNARY)
+	if (*tok == '-' || *tok == '+' || *tok == '<' || *tok == '>' || class == UNARY)
 	{
-		t = *tok++;
+		TOKEN t = *tok++;
 
 		if (expr2() != OK)
 			return ERROR;
 
 		if (t == '-')
 			t = UNMINUS;
+		else if (t == '<')
+			t = UNLT;
+		else if (t == '>')
+			t = UNGT;
 
 		// With leading + we don't have to deposit anything to the buffer
 		// because there's no unary '+' nor we have to do anything about it
@@ -153,8 +155,54 @@ int expr1(void)
 		switch (*tok++)
 		{
 		case CR_ABSCOUNT:
+			if (cursect != ABS)
+			{
+				*evalTokenBuffer.u32++ = CONST;
+				*evalTokenBuffer.u64++ = sect[ABS].sloc;
+			}
+			else
+			{
+				*evalTokenBuffer.u32++ = CONST;
+				*evalTokenBuffer.u64++ = sloc;
+			}
+			break;
+		case CR_FILESIZE:
+			if (*tok++ != STRING)
+				return error("^^FILESIZE expects filename inside string");
+
 			*evalTokenBuffer.u32++ = CONST;
-			*evalTokenBuffer.u64++ = (uint64_t)sect[ABS].sloc;
+			// @@copypasted from d_incbin, maybe factor this out somehow?
+			// Attempt to open the include file in the current directory, then (if that
+			// failed) try list of include files passed in the enviroment string or by
+			// the "-d" option.
+			int fd, i;
+			char buf1[256];
+
+			if ((fd = open(string[*tok], _OPEN_INC)) < 0)
+			{
+				for(i=0; nthpath("RMACPATH", i, buf1)!=0; i++)
+				{
+					fd = strlen(buf1);
+
+					// Append path char if necessary
+					if ((fd > 0) && (buf1[fd - 1] != SLASHCHAR))
+						strcat(buf1, SLASHSTRING);
+
+					strcat(buf1, string[*tok]);
+
+					if ((fd = open(buf1, _OPEN_INC)) >= 0)
+						goto allright;
+				}
+
+				return error("cannot open: \"%s\"", string[tok[1]]);
+			}
+
+allright:
+			*evalTokenBuffer.u64++ = (uint64_t)lseek(fd, 0L, SEEK_END);
+			close(fd);
+
+			// Advance tok because of consumed string token
+			tok++;
 			break;
 		case CR_TIME:
 			*evalTokenBuffer.u32++ = CONST;
@@ -183,8 +231,9 @@ getsym:
 				return error(missym_error);
 
 			p = string[*tok++];
-			j = (*p == '.' ? curenv : 0);
-			w = ((sy = lookup(p, LABEL, j)) != NULL && (sy->sattr & w) ? 1 : 0);
+			int j = (*p == '.' ? curenv : 0);
+			SYM * sy = lookup(p, LABEL, j);
+			w = ((sy != NULL) && (sy->sattr & w ? 1 : 0));
 			*evalTokenBuffer.u32++ = CONST;
 			*evalTokenBuffer.u64++ = (uint64_t)w;
 			break;
@@ -201,7 +250,7 @@ getsym:
 			if (*tok != SYMBOL && *tok != STRING)
 				return error(str_error);
 
-			p2 = string[tok[1]];
+			char * p2 = string[tok[1]];
 			tok += 2;
 
 			w = (WORD)(!strcmp(p, p2));
@@ -222,24 +271,27 @@ getsym:
 //
 int expr2(void)
 {
-	char * p;
-	SYM * sy;
-	int j;
 	PTR ptk;
 
 	switch (*tok++)
 	{
 	case CONST:
-	case FCONST:
 		ptk.u32 = tok;
 		*evalTokenBuffer.u32++ = CONST;
 		*evalTokenBuffer.u64++ = *ptk.u64++;
 		tok = ptk.u32;
 		break;
+	case FCONST:
+		ptk.u32 = tok;
+		*evalTokenBuffer.u32++ = FCONST;
+		*evalTokenBuffer.u64++ = *ptk.u64++;
+		tok = ptk.u32;
+		break;
 	case SYMBOL:
-		p = string[*tok++];
-		j = (*p == '.' ? curenv : 0);
-		sy = lookup(p, LABEL, j);
+	{
+		char * p = string[*tok++];
+		int j = (*p == '.' ? curenv : 0);
+		SYM * sy = lookup(p, LABEL, j);
 
 		if (sy == NULL)
 			sy = NewSymbol(p, LABEL, j);
@@ -259,6 +311,7 @@ int expr2(void)
 		symbolPtr[symbolNum] = sy;
 		symbolNum++;
 		break;
+ 	}
 	case STRING:
 		*evalTokenBuffer.u32++ = CONST;
 		*evalTokenBuffer.u64++ = str_value(string[*tok++]);
@@ -364,7 +417,7 @@ int expr(TOKEN * otk, uint64_t * a_value, WORD * a_attr, SYM ** a_esym)
 		{
 			*evalTokenBuffer.u32++ = CONST;
 			*evalTokenBuffer.u64++ = *a_value = (*tok - KW_R0);
-			*a_attr = ABS | DEFINED;
+			*a_attr = ABS | DEFINED | RISCREG;
 
 			if (a_esym != NULL)
 				*a_esym = NULL;
@@ -469,19 +522,19 @@ be converted from a linked list into an array).
 			symbolNum++;
 #endif
 
-			if (symbol->sattr & DEFINED)
-				*a_value = symbol->svalue;
-			else
-				*a_value = 0;
+			*a_value = (symbol->sattr & DEFINED ? symbol->svalue : 0);
+			*a_attr = (WORD)(symbol->sattr & ~GLOBAL);
 
 /*
 All that extra crap that was put into the svalue when doing the equr stuff is
 thrown away right here. What the hell is it for?
 */
 			if (symbol->sattre & EQUATEDREG)
+			{
 				*a_value &= 0x1F;
-
-			*a_attr = (WORD)(symbol->sattr & ~GLOBAL);
+				*a_attr |= RISCREG; // Mark it as a register, 'cause it is
+				*a_esym = symbol;
+			}
 
 			if ((symbol->sattr & (GLOBAL | DEFINED)) == GLOBAL
 				&& a_esym != NULL)
@@ -489,10 +542,15 @@ thrown away right here. What the hell is it for?
 
 			tok += 2;
 		}
+		// Holy hell... This is likely due to the fact that LSR is mistakenly set as a SUNARY type... Need to fix this... !!! FIX !!!
+		else if (m6502)
+		{
+			*evalTokenBuffer.u32++ = *tok++;
+		}
 		else
 		{
 			// Unknown type here... Alert the user!,
-			error("undefined RISC register in expression");
+			error("undefined RISC register in expression [token=$%X]", *tok);
 			// Prevent spurious error reporting...
 			tok++;
 			return ERROR;
@@ -518,7 +576,7 @@ thrown away right here. What the hell is it for?
 //
 int evexpr(TOKEN * _tk, uint64_t * a_value, WORD * a_attr, SYM ** a_esym)
 {
-	WORD attr, attr2;
+	WORD attr;
 	SYM * sy;
 	uint64_t * sval = evstk;				// (Empty) initial stack
 	WORD * sattr = evattr;
@@ -553,28 +611,28 @@ int evexpr(TOKEN * _tk, uint64_t * a_value, WORD * a_attr, SYM ** a_esym)
 			}
 
 			if (sy->sattr & DEFINED)
-			{
 				*++sval = sy->svalue;		// Push symbol's value
-			}
 			else
-			{
 				*++sval = 0;				// 0 for undefined symbols
-			}
 
 			*++sattr = (WORD)(sy->sattr & ~GLOBAL);	// Push attribs
 			sym_seg = (WORD)(sy->sattr & TDB);
 			break;
+
 		case CONST:
 			*++sval = *tk.u64++;
 //printf("evexpr(): CONST = %lX\n", *sval);
 			*++sattr = ABS | DEFINED;		// Push simple attribs
 			break;
+
 		case FCONST:
-//printf("evexpr(): FCONST = %i\n", *tk.u32);
-			*((double *)sval) = *((double *)tk.u32);
-			tk.u32 += 2;
+//printf("evexpr(): FCONST = %lf\n", *tk.dp);
+			// Even though it's a double, we can treat it like a uint64_t since
+			// we're just moving the bits around.
+			*++sval = *tk.u64++;
 			*++sattr = ABS | DEFINED | FLOAT; // Push simple attribs
 			break;
+
 		case ACONST:
 //printf("evexpr(): ACONST = %i\n", *tk.u32);
 			*++sval = *tk.u32++;				// Push value
@@ -592,36 +650,26 @@ int evexpr(TOKEN * _tk, uint64_t * a_value, WORD * a_attr, SYM ** a_esym)
 			//
 			//   [1] + : Error
 			//       - : ABS
+
 		case '+':
 //printf("evexpr(): +\n");
 			--sval;							// Pop value
 			--sattr;						// Pop attrib
 //printf("--> N+N: %i + %i = ", *sval, sval[1]);
-			// Extract float attributes from both terms and pack them
-			// into a single value
-			attr = sattr[0] & FLOAT | ((sattr[1] & FLOAT) >> 1);
-			attr2 = sattr[0] | sattr[1] & FLOAT; // Returns FLOAT if either of the two numbers are FLOAT
+			// Get FLOAT attribute, if any
+			attr = (sattr[0] | sattr[1]) & FLOAT;
 
-			if (attr == (FLOAT | (FLOAT >> 1)))
-			{
-				// Float + Float
-				double * dst = (double *)sval;
-				double * src = (double *)(sval + 1);
-				*dst += *src;
-			}
-			else if (attr == FLOAT)
-			{
-				// Float + Int
-				double * dst = (double *)sval;
-				uint64_t * src = (uint64_t *)(sval + 1);
-				*dst += *src;
-			}
-			else if (attr == FLOAT >> 1)
+			// Since adding an int to a fp value promotes it to a fp value, we
+			// don't care whether it's first or second; we cast to to a double
+			// regardless.
+			if (attr == FLOAT)
 			{
-				// Int + Float
-				uint64_t * dst = (uint64_t *)sval;
-				double * src = (double *)(sval + 1);
-				*(double *)dst = *src + *dst;
+				PTR p;
+				p.u64 = sval;
+				double fpval1 = (sattr[0] & FLOAT ? *p.dp : (double)*p.i64);
+				p.u64++;
+				double fpval2 = (sattr[1] & FLOAT ? *p.dp : (double)*p.i64);
+				*(double *)sval = fpval1 + fpval2;
 			}
 			else
 			{
@@ -630,54 +678,43 @@ int evexpr(TOKEN * _tk, uint64_t * a_value, WORD * a_attr, SYM ** a_esym)
 //printf("%i\n", *sval);
 
 			if (!(*sattr & TDB))
-				*sattr = sattr[1] | attr2;
+				*sattr = sattr[1] | attr;
 			else if (sattr[1] & TDB)
 				return error(seg_error);
 
 			break;
+
 		case '-':
 //printf("evexpr(): -\n");
 			--sval;							// Pop value
 			--sattr;						// Pop attrib
 //printf("--> N-N: %i - %i = ", *sval, sval[1]);
-			// Extract float attributes from both terms and pack them
-			// into a single value
-			attr = sattr[0] & FLOAT | ((sattr[1] & FLOAT) >> 1);
-			attr2 = sattr[0] | sattr[1] & FLOAT; // Returns FLOAT if either of the two numbers are FLOAT
+			// Get FLOAT attribute, if any
+			attr = (sattr[0] | sattr[1]) & FLOAT;
 
-			if (attr == (FLOAT | (FLOAT >> 1)))
+			// Since subtracting an int to a fp value promotes it to a fp
+			// value, we don't care whether it's first or second; we cast to to
+			// a double regardless.
+			if (attr == FLOAT)
 			{
-				// Float - Float
-				double * dst = (double *)sval;
-				double * src = (double *)(sval + 1);
-				*dst -= *src;
-			}
-			else if (attr == FLOAT)
-			{
-				// Float - Int
-				double * dst = (double *)sval;
-				uint64_t * src = (uint64_t *)(sval + 1);
-				*dst -= *src;
-			}
-			else if (attr == FLOAT >> 1)
-			{
-				// Int - Float
-				uint64_t * dst = (uint64_t *)sval;
-				double * src = (double *)(sval + 1);
-				*(double *)dst = *dst - *src;
+				PTR p;
+				p.u64 = sval;
+				double fpval1 = (sattr[0] & FLOAT ? *p.dp : (double)*p.i64);
+				p.u64++;
+				double fpval2 = (sattr[1] & FLOAT ? *p.dp : (double)*p.i64);
+				*(double *)sval = fpval1 - fpval2;
 			}
 			else
 			{
-				*sval -= sval[1];				// Compute value
+				*sval -= sval[1];
 			}
-
 //printf("%i\n", *sval);
 
+			*sattr |= attr;					// Inherit FLOAT attribute
 			attr = (WORD)(*sattr & TDB);
 #if 0
 printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 #endif
-			*sattr |= attr2;                // Inherit FLOAT attribute
 			// If symbol1 is ABS, take attributes from symbol2
 			if (!attr)
 				*sattr = sattr[1];
@@ -686,6 +723,7 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 				*sattr &= ~TDB;
 
 			break;
+
 		// Unary operators only work on ABS items
 		case UNMINUS:
 //printf("evexpr(): UNMINUS\n");
@@ -694,16 +732,42 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 
 			if (*sattr & FLOAT)
 			{
-				double *dst = (double *)sval;
+				double * dst = (double *)sval;
 				*dst = -*dst;
 				*sattr = ABS | DEFINED | FLOAT; // Expr becomes absolute
 			}
 			else
 			{
-				*sval = -(int)*sval;
+				*sval = -(int64_t)*sval;
 				*sattr = ABS | DEFINED;			// Expr becomes absolute
 			}
+
+			break;
+
+		case UNLT: // Unary < (get the low byte of a word)
+//printf("evexpr(): UNLT\n");
+			if (*sattr & TDB)
+				return error(seg_error);
+
+			if (*sattr & FLOAT)
+				return error(noflt_error);
+
+			*sval = (int64_t)((*sval) & 0x00FF);
+			*sattr = ABS | DEFINED;			// Expr becomes absolute
+			break;
+
+		case UNGT: // Unary > (get the high byte of a word)
+//printf("evexpr(): UNGT\n");
+			if (*sattr & TDB)
+				return error(seg_error);
+
+			if (*sattr & FLOAT)
+				return error(noflt_error);
+
+			*sval = (int64_t)(((*sval) >> 8) & 0x00FF);
+			*sattr = ABS | DEFINED;			// Expr becomes absolute
 			break;
+
 		case '!':
 //printf("evexpr(): !\n");
 			if (*sattr & TDB)
@@ -715,6 +779,7 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 			*sval = !*sval;
 			*sattr = ABS | DEFINED;			// Expr becomes absolute
 			break;
+
 		case '~':
 //printf("evexpr(): ~\n");
 			if (*sattr & TDB)
@@ -726,6 +791,7 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 			*sval = ~*sval;
 			*sattr = ABS | DEFINED;			// Expr becomes absolute
 			break;
+
 		// Comparison operators must have two values that
 		// are in the same segment, but that's the only requirement.
 		case LE:
@@ -736,38 +802,28 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 			if ((*sattr & TDB) != (sattr[1] & TDB))
 				return error(seg_error);
 
-			// Extract float attributes from both terms and pack them
-			// into a single value
-			attr = sattr[0] & FLOAT | ((sattr[1] & FLOAT) >> 1);
+			// Get FLOAT attribute, if any
+			attr = (sattr[0] | sattr[1]) & FLOAT;
 
-			if (attr == (FLOAT | (FLOAT >> 1)))
-			{
-				// Float <= Float
-				double * dst = (double *)sval;
-				double * src = (double *)(sval + 1);
-				*sval = *dst <= *src;
-			}
-			else if (attr == FLOAT)
-			{
-				// Float <= Int
-				double * dst = (double *)sval;
-				uint64_t * src = (uint64_t *)(sval + 1);
-				*sval = *dst <= *src;
-			}
-			else if (attr == FLOAT >> 1)
+			// Cast any ints in the comparison to double, if there's at least
+			// one double in the comparison.
+			if (attr == FLOAT)
 			{
-				// Int <= Float
-				uint64_t * dst = (uint64_t *)sval;
-				double * src = (double *)(sval + 1);
-				*sval = *dst <= *src;
+				PTR p;
+				p.u64 = sval;
+				double fpval1 = (sattr[0] & FLOAT ? *p.dp : (double)*p.i64);
+				p.u64++;
+				double fpval2 = (sattr[1] & FLOAT ? *p.dp : (double)*p.i64);
+				*sval = (fpval1 <= fpval2);
 			}
 			else
 			{
-				*sval = *sval <= sval[1];
+				*sval = (*sval <= sval[1]);
 			}
 
 			*sattr = ABS | DEFINED;
 			break;
+
 		case GE:
 //printf("evexpr(): GE\n");
 			sattr--;
@@ -776,39 +832,28 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 			if ((*sattr & TDB) != (sattr[1] & TDB))
 				return error(seg_error);
 
-			// Extract float attributes from both terms and pack them
-			// into a single value
-			attr = sattr[0] & FLOAT | ((sattr[1] & FLOAT) >> 1);
+			// Get FLOAT attribute, if any
+			attr = (sattr[0] | sattr[1]) & FLOAT;
 
-			if (attr == (FLOAT | (FLOAT >> 1)))
+			// Cast any ints in the comparison to double, if there's at least
+			// one double in the comparison.
+			if (attr == FLOAT)
 			{
-				// Float >= Float
-				double * dst = (double *)sval;
-				double * src = (double *)(sval + 1);
-				*sval = *dst >= *src;
-			}
-			else if (attr == FLOAT)
-			{
-				// Float >= Int
-				double * dst = (double *)sval;
-				uint64_t * src = (uint64_t *)(sval + 1);
-				*sval = *dst >= *src;
-			}
-			else if (attr == FLOAT >> 1)
-			{
-				// Int >= Float
-				uint64_t * dst = (uint64_t *)sval;
-				double * src = (double *)(sval + 1);
-				*sval = *dst >= *src;
+				PTR p;
+				p.u64 = sval;
+				double fpval1 = (sattr[0] & FLOAT ? *p.dp : (double)*p.i64);
+				p.u64++;
+				double fpval2 = (sattr[1] & FLOAT ? *p.dp : (double)*p.i64);
+				*sval = (fpval1 >= fpval2);
 			}
-			else if (attr == 0)
+			else
 			{
-				*sval = *sval >= sval[1];
+				*sval = (*sval >= sval[1]);
 			}
-			else
-				*sattr = ABS | DEFINED;
 
+			*sattr = ABS | DEFINED;
 			break;
+
 		case '>':
 //printf("evexpr(): >\n");
 			sattr--;
@@ -817,39 +862,28 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 			if ((*sattr & TDB) != (sattr[1] & TDB))
 				return error(seg_error);
 
-			// Extract float attributes from both terms and pack them
-			// into a single value
-			attr = sattr[0] & FLOAT | ((sattr[1] & FLOAT) >> 1);
+			// Get FLOAT attribute, if any
+			attr = (sattr[0] | sattr[1]) & FLOAT;
 
-			if (attr == (FLOAT | (FLOAT >> 1)))
-			{
-				// Float > Float
-				double * dst = (double *)sval;
-				double * src = (double *)(sval + 1);
-				*sval = *dst > *src;
-			}
-			else if (attr == FLOAT)
-			{
-				// Float > Int
-				double * dst = (double *)sval;
-				uint64_t * src = (uint64_t *)(sval + 1);
-				*sval = *dst > *src;
-			}
-			else if (attr == FLOAT >> 1)
+			// Cast any ints in the comparison to double, if there's at least
+			// one double in the comparison.
+			if (attr == FLOAT)
 			{
-				// Int > Float
-				uint64_t * dst = (uint64_t *)sval;
-				double * src = (double *)(sval + 1);
-				*sval = *dst > *src;
+				PTR p;
+				p.u64 = sval;
+				double fpval1 = (sattr[0] & FLOAT ? *p.dp : (double)*p.i64);
+				p.u64++;
+				double fpval2 = (sattr[1] & FLOAT ? *p.dp : (double)*p.i64);
+				*sval = (fpval1 > fpval2);
 			}
 			else
 			{
-				*sval = *sval > sval[1];
+				*sval = (*sval > sval[1]);
 			}
 
 			*sattr = ABS | DEFINED;
-
 			break;
+
 		case '<':
 //printf("evexpr(): <\n");
 			sattr--;
@@ -858,39 +892,28 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 			if ((*sattr & TDB) != (sattr[1] & TDB))
 				return error(seg_error);
 
-			// Extract float attributes from both terms and pack them
-			// into a single value
-			attr = sattr[0] & FLOAT | ((sattr[1] & FLOAT) >> 1);
+			// Get FLOAT attribute, if any
+			attr = (sattr[0] | sattr[1]) & FLOAT;
 
-			if (attr == (FLOAT | (FLOAT >> 1)))
-			{
-				// Float < Float
-				double * dst = (double *)sval;
-				double * src = (double *)(sval + 1);
-				*sval = *dst < *src;
-			}
-			else if (attr == FLOAT)
-			{
-				// Float < Int
-				double * dst = (double *)sval;
-				uint64_t * src = (uint64_t *)(sval + 1);
-				*sval = *dst < *src;
-			}
-			else if (attr == FLOAT >> 1)
+			// Cast any ints in the comparison to double, if there's at least
+			// one double in the comparison.
+			if (attr == FLOAT)
 			{
-				// Int < Float
-				uint64_t * dst = (uint64_t *)sval;
-				double * src = (double *)(sval + 1);
-				*sval = *dst < *src;
+				PTR p;
+				p.u64 = sval;
+				double fpval1 = (sattr[0] & FLOAT ? *p.dp : (double)*p.i64);
+				p.u64++;
+				double fpval2 = (sattr[1] & FLOAT ? *p.dp : (double)*p.i64);
+				*sval = (fpval1 < fpval2);
 			}
 			else
 			{
-				*sval = *sval < sval[1];
+				*sval = (*sval < sval[1]);
 			}
 
-			*sattr = ABS | DEFINED;
-
+			*sattr = ABS | DEFINED;		// Expr forced to ABS
 			break;
+
 		case NE:
 //printf("evexpr(): NE\n");
 			sattr--;
@@ -899,33 +922,28 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 			if ((*sattr & TDB) != (sattr[1] & TDB))
 				return error(seg_error);
 
-			// Extract float attributes from both terms and pack them
-			// into a single value
-			attr = sattr[0] & FLOAT | ((sattr[1] & FLOAT) >> 1);
+			// Get FLOAT attribute, if any
+			attr = (sattr[0] | sattr[1]) & FLOAT;
 
-			if (attr == (FLOAT | (FLOAT >> 1)))
-			{
-				// Float <> Float
-				return error("comparison for equality with float types not allowed.");
-			}
-			else if (attr == FLOAT)
-			{
-				// Float <> Int
-				return error("comparison for equality with float types not allowed.");
-			}
-			else if (attr == FLOAT >> 1)
+			// Cast any ints in the comparison to double, if there's at least
+			// one double in the comparison.
+			if (attr == FLOAT)
 			{
-				// Int != Float
-				return error("comparison for equality with float types not allowed.");
+				PTR p;
+				p.u64 = sval;
+				double fpval1 = (sattr[0] & FLOAT ? *p.dp : (double)*p.i64);
+				p.u64++;
+				double fpval2 = (sattr[1] & FLOAT ? *p.dp : (double)*p.i64);
+				*sval = (fpval1 != fpval2);
 			}
 			else
 			{
-				*sval = *sval != sval[1];
+				*sval = (*sval != sval[1]);
 			}
 
-			*sattr = ABS | DEFINED;
-
+			*sattr = ABS | DEFINED;		// Expr forced to ABS
 			break;
+
 		case '=':
 //printf("evexpr(): =\n");
 			sattr--;
@@ -934,76 +952,59 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 			if ((*sattr & TDB) != (sattr[1] & TDB))
 				return error(seg_error);
 
-			// Extract float attributes from both terms and pack them
-			// into a single value
-			attr = sattr[0] & FLOAT | ((sattr[1] & FLOAT) >> 1);
+			// Get FLOAT attribute, if any
+			attr = (sattr[0] | sattr[1]) & FLOAT;
 
-			if (attr == (FLOAT | (FLOAT >> 1)))
-			{
-				// Float = Float
-				double * dst = (double *)sval;
-				double * src = (double *)(sval + 1);
-				*sval = *src == *dst;
-			}
-			else if (attr == FLOAT)
-			{
-				// Float = Int
-				return error("equality with float ");
-			}
-			else if (attr == FLOAT >> 1)
+			// Cast any ints in the comparison to double, if there's at least
+			// one double in the comparison.
+			if (attr == FLOAT)
 			{
-				// Int == Float
-				uint64_t * dst = (uint64_t *)sval;
-				double * src = (double *)(sval + 1);
-				*sval = *src == *dst;
+				PTR p;
+				p.u64 = sval;
+				double fpval1 = (sattr[0] & FLOAT ? *p.dp : (double)*p.i64);
+				p.u64++;
+				double fpval2 = (sattr[1] & FLOAT ? *p.dp : (double)*p.i64);
+				*sval = (fpval1 == fpval2);
 			}
 			else
 			{
-				*sval = *sval == sval[1];
+				*sval = (*sval == sval[1]);
 			}
 
-			*sattr = ABS | DEFINED;
+			*sattr = ABS | DEFINED;		// Expr forced to ABS
 
 			break;
+
 		// All other binary operators must have two ABS items to work with.
 		// They all produce an ABS value.
+		// Shamus: Is this true? There's at least one counterexample of legit
+		//         code where this assumption fails to produce correct code.
 		default:
 //printf("evexpr(): default\n");
-			// GH - Removed for v1.0.15 as part of the fix for indexed loads.
-			//if ((*sattr & (TEXT|DATA|BSS)) || (*--sattr & (TEXT|DATA|BSS)))
-			//error(seg_error);
 
 			switch ((int)tk.u32[-1])
 			{
 			case '*':
 				sval--;
-				sattr--;					// Pop attrib
+				sattr--;
 //printf("--> NxN: %i x %i = ", *sval, sval[1]);
-				// Extract float attributes from both terms and pack them
-				// into a single value
-				attr = sattr[0] & FLOAT | ((sattr[1] & FLOAT) >> 1);
-				attr2 = sattr[0] | sattr[1] & FLOAT; // Returns FLOAT if either of the two numbers are FLOAT
+				// Get FLOAT attribute, if any
+				attr = (sattr[0] | sattr[1]) & FLOAT;
 
-				if (attr == (FLOAT | (FLOAT >> 1)))
-				{
-					// Float * Float
-					double * dst = (double *)sval;
-					double * src = (double *)(sval + 1);
-					*dst *= *src;
-				}
-				else if (attr == FLOAT)
-				{
-					// Float * Int
-					double * dst = (double *)sval;
-					uint64_t * src = (uint64_t *)(sval + 1);
-					*dst *= *src;
-				}
-				else if (attr == FLOAT >> 1)
+				// Since multiplying an int to a fp value promotes it to a fp
+				// value, we don't care whether it's first or second; it will
+				// be cast to a double regardless.
+/*
+An open question here is do we promote ints to floats as signed or unsigned? It makes a difference if, say, the int is put in as -1 but is promoted to a double as $FFFFFFFFFFFFFFFF--you get very different results that way! For now, we promote as signed until proven detrimental otherwise.
+*/
+				if (attr == FLOAT)
 				{
-					// Int * Float
-					uint64_t * dst = (uint64_t *)sval;
-					double * src = (double *)(sval + 1);
-					*(double *)dst = *src * *dst;
+					PTR p;
+					p.u64 = sval;
+					double fpval1 = (sattr[0] & FLOAT ? *p.dp : (double)*p.i64);
+					p.u64++;
+					double fpval2 = (sattr[1] & FLOAT ? *p.dp : (double)*p.i64);
+					*(double *)sval = fpval1 * fpval2;
 				}
 				else
 				{
@@ -1011,53 +1012,28 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 				}
 //printf("%i\n", *sval);
 
-				*sattr = ABS | DEFINED;			// Expr becomes absolute
-				*sattr |= attr2;
-
+//no				*sattr = ABS | DEFINED | attr;		// Expr becomes absolute
 				break;
+
 			case '/':
 				sval--;
-				sattr--;					// Pop attrib
-
-
+				sattr--;
 //printf("--> N/N: %i / %i = ", sval[0], sval[1]);
-				// Extract float attributes from both terms and pack them
-				// into a single value
-				attr = sattr[0] & FLOAT | ((sattr[1] & FLOAT) >> 1);
-				attr2 = sattr[0] | sattr[1] & FLOAT; // Returns FLOAT if either of the two numbers are FLOAT
-
-				if (attr == (FLOAT | (FLOAT >> 1)))
-				{
-					// Float / Float
-					double * dst = (double *)sval;
-					double * src = (double *)(sval + 1);
-
-					if (*src == 0)
-						return error("divide by zero");
-
-					*dst = *dst / *src;
-				}
-				else if (attr == FLOAT)
-				{
-					// Float / Int
-					double * dst = (double *)sval;
-					uint64_t * src = (uint64_t *)(sval + 1);
-
-					if (*src == 0)
-						return error("divide by zero");
+				// Get FLOAT attribute, if any
+				attr = (sattr[0] | sattr[1]) & FLOAT;
 
-					*dst = *dst / *src;
-				}
-				else if (attr == FLOAT >> 1)
+				if (attr == FLOAT)
 				{
-					// Int / Float
-					uint64_t * dst=(uint64_t *)sval;
-					double * src=(double *)(sval + 1);
+					PTR p;
+					p.u64 = sval;
+					double fpval1 = (sattr[0] & FLOAT ? *p.dp : (double)*p.i64);
+					p.u64++;
+					double fpval2 = (sattr[1] & FLOAT ? *p.dp : (double)*p.i64);
 
-					if (*src == 0)
+					if (fpval2 == 0)
 						return error("divide by zero");
 
-					*(double *)dst = *dst / *src;
+					*(double *)sval = fpval1 / fpval2;
 				}
 				else
 				{
@@ -1072,15 +1048,14 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 					// ints.
 					*sval = (int32_t)sval[0] / (int32_t)sval[1];
 				}
-
-				*sattr = ABS | DEFINED;			// Expr becomes absolute
-				*sattr |= attr2;
-
 //printf("%i\n", *sval);
+
+//no				*sattr = ABS | DEFINED | attr;		// Expr becomes absolute
 				break;
+
 			case '%':
 				sval--;
-				sattr--;					// Pop attrib
+				sattr--;
 
 				if ((*sattr | sattr[1]) & FLOAT)
 					return error("floating point numbers not allowed with operator '%'.");
@@ -1088,9 +1063,10 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 				if (sval[1] == 0)
 					return error("mod (%) by zero");
 
-				*sattr = ABS | DEFINED;			// Expr becomes absolute
 				*sval %= sval[1];
+//no				*sattr = ABS | DEFINED;			// Expr becomes absolute
 				break;
+
 			case SHL:
 				sval--;
 				sattr--;					// Pop attrib
@@ -1098,9 +1074,10 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 				if ((*sattr | sattr[1]) & FLOAT)
 					return error("floating point numbers not allowed with operator '<<'.");
 
-				*sattr = ABS | DEFINED;			// Expr becomes absolute
 				*sval <<= sval[1];
+//no				*sattr = ABS | DEFINED;			// Expr becomes absolute
 				break;
+
 			case SHR:
 				sval--;
 				sattr--;					// Pop attrib
@@ -1108,9 +1085,10 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 				if ((*sattr | sattr[1]) & FLOAT)
 					return error("floating point numbers not allowed with operator '>>'.");
 
-				*sattr = ABS | DEFINED;			// Expr becomes absolute
 				*sval >>= sval[1];
+//no				*sattr = ABS | DEFINED;			// Expr becomes absolute
 				break;
+
 			case '&':
 				sval--;
 				sattr--;					// Pop attrib
@@ -1118,9 +1096,10 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 				if ((*sattr | sattr[1]) & FLOAT)
 					return error("floating point numbers not allowed with operator '&'.");
 
-				*sattr = ABS | DEFINED;			// Expr becomes absolute
 				*sval &= sval[1];
+//no				*sattr = ABS | DEFINED;			// Expr becomes absolute
 				break;
+
 			case '^':
 				sval--;
 				sattr--;					// Pop attrib
@@ -1128,21 +1107,24 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 				if ((*sattr | sattr[1]) & FLOAT)
 					return error("floating point numbers not allowed with operator '^'.");
 
-				*sattr = ABS | DEFINED;			// Expr becomes absolute
 				*sval ^= sval[1];
+//no				*sattr = ABS | DEFINED;			// Expr becomes absolute
 				break;
+
 			case '|':
 				sval--;
-				sattr--;					// Pop attrib
+				sattr--;
 
 				if ((*sattr | sattr[1]) & FLOAT)
 					return error("floating point numbers not allowed with operator '|'.");
 
-				*sattr = ABS | DEFINED;			// Expr becomes absolute
 				*sval |= sval[1];
+//no				*sattr = ABS | DEFINED;			// Expr becomes absolute
 				break;
+
 			default:
-				interror(5);				// Bad operator in expression stream
+				// Bad operator in expression stream (this should never happen!)
+				interror(5);
 			}
 		}
 	}
@@ -1153,14 +1135,34 @@ printf("EVEXPR (-): sym1 = %X, sym2 = %X\n", attr, sattr[1]);
 	if (a_esym != NULL)
 		*a_esym = esym;
 
-	// sym_seg added in 1.0.16 to solve a problem with forward symbols in
-	// expressions where absolute values also existed. The absolutes were
-	// overiding the symbol segments and not being included :(
-	//*a_attr = *sattr | sym_seg;           // Copy value + attrib
-
-	*a_attr = *sattr;						// Copy value + attrib
+	// Copy value + attrib into return variables
 	*a_value = *sval;
+	*a_attr = *sattr;
 
 	return OK;
 }
 
+
+//
+// Count the # of tokens in the passed in expression
+// N.B.: 64-bit constants count as two tokens each
+//
+uint16_t ExpressionLength(TOKEN * tk)
+{
+	uint16_t length;
+
+	for(length=0; tk[length]!=ENDEXPR; length++)
+	{
+		// Add one to length for 2X tokens, two for 3X tokens
+		if (tk[length] == SYMBOL)
+			length++;
+		else if ((tk[length] == CONST) || (tk[length] == FCONST))
+			length += 2;
+	}
+
+	// Add 1 for ENDEXPR
+	length++;
+
+	return length;
+}
+