]> Shamusworld >> Repos - rmac/blobdiff - expr.c
Added in DSP fixups to sect.c, misc. fixes for 6502 assembler.
[rmac] / expr.c
diff --git a/expr.c b/expr.c
index 20f43cfcb3aace6feb23228e635f8a1cfd5d4dc1..d1ee1f55a1ffc824ecfaa540a91aa8b422baa17d 100644 (file)
--- 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, 2011-2019 Reboot and Friends
 // RMAC derived from MADMAC v1.07 Written by Landon Dyer, 1986
 // Source utilised with the kind permission of Landon Dyer
 //
@@ -36,7 +36,7 @@ char itokcl[] = {
        CR_STREQ, CR_MACDEF,
        CR_DATE, CR_TIME,
        CR_ABSCOUNT, 0,
-       '!', '~', UNMINUS, 0,                   // UNARY
+       '!', '~', 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
@@ -183,8 +185,9 @@ 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 +204,7 @@ 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 +225,27 @@ 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 +265,7 @@ int expr2(void)
                symbolPtr[symbolNum] = sy;
                symbolNum++;
                break;
+       }
        case STRING:
                *evalTokenBuffer.u32++ = CONST;
                *evalTokenBuffer.u64++ = str_value(string[*tok++]);
@@ -489,10 +496,15 @@ 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 +530,7 @@ 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 +565,28 @@ 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 +604,26 @@ 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)))
+                       // 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)
                        {
-                               // 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 = *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 +632,43 @@ 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)))
-                       {
-                               // Float - Float
-                               double * dst = (double *)sval;
-                               double * src = (double *)(sval + 1);
-                               *dst -= *src;
-                       }
-                       else if (attr == FLOAT)
+                       // 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 - 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 +677,7 @@ 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 +686,42 @@ 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 +733,7 @@ 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 +745,7 @@ 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 +756,28 @@ 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
                        {
-                               *sval = *sval <= sval[1];
+                               *sval = (*sval <= sval[1]);
                        }
 
                        *sattr = ABS | DEFINED;
                        break;
+
                case GE:
 //printf("evexpr(): GE\n");
                        sattr--;
@@ -776,39 +786,28 @@ 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)
+                       // Cast any ints in the comparison to double, if there's at least
+                       // one double in the comparison.
+                       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 +816,28 @@ 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
                        {
-                               *sval = *sval > sval[1];
+                               *sval = (*sval > sval[1]);
                        }
 
                        *sattr = ABS | DEFINED;
-
                        break;
+
                case '<':
 //printf("evexpr(): <\n");
                        sattr--;
@@ -858,39 +846,28 @@ 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 +876,28 @@ 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)
+                       // Cast any ints in the comparison to double, if there's at least
+                       // one double in the comparison.
+                       if (attr == FLOAT)
                        {
-                               // Float <> Int
-                               return error("comparison for equality with float types not allowed.");
-                       }
-                       else if (attr == FLOAT >> 1)
-                       {
-                               // 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 +906,59 @@ 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)))
+                       // 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 = *src == *dst;
-                       }
-                       else if (attr == FLOAT)
-                       {
-                               // Float = Int
-                               return error("equality with float ");
-                       }
-                       else if (attr == FLOAT >> 1)
-                       {
-                               // 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 +966,28 @@ 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
+                               // Get FLOAT attribute, if any
+                               attr = (sattr[0] | sattr[1]) & FLOAT;
 
-                               if (attr == (FLOAT | (FLOAT >> 1)))
+                               if (attr == FLOAT)
                                {
-                                       // Float / Float
-                                       double * dst = (double *)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");
 
-                                       *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");
-
-                                       *dst = *dst / *src;
-                               }
-                               else if (attr == FLOAT >> 1)
-                               {
-                                       // Int / Float
-                                       uint64_t * dst=(uint64_t *)sval;
-                                       double * src=(double *)(sval + 1);
-
-                                       if (*src == 0)
-                                               return error("divide by zero");
-
-                                       *(double *)dst = *dst / *src;
+                                       *(double *)sval = fpval1 / fpval2;
                                }
                                else
                                {
@@ -1072,15 +1002,14 @@ 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 +1017,10 @@ 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 +1028,10 @@ 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 +1039,10 @@ 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 +1050,10 @@ 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 +1061,24 @@ 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 +1089,34 @@ 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;
+}
+