Corrected BCD management

include/libg1m/bcd.h

@@ -36,19 +36,25 @@ extern "C" {
  * This is the "unzipped" BCD format. There are several, this is the one libg1m
  * will always convert to.
  *
- * `neg` is whether the number is negative or not.
+ * `flags` is the flags (negative, special, precision) of the BCD.
  * `exp` is the 10-exponent, between -99 and 99.
- * `digits` is the number of significant digits in the mantissa.
- * `spe` is the special bit.
  * `mant` is the mantissa: unpacked BCD digits (one digit per byte).
  *
- * It is advised to use the macros, as some of these could change. */
+ * To interact the flags, it is advised to use the g1m_bcd_* macros, as some
+ * of them could change. */
+
+# define g1m_bcdflag_neg 0x80
+# define g1m_bcdflag_spe 0x40
+# define g1m_bcdmask_pre 0x3F
+
+# define g1m_bcd_has_special(B) ((B)->flags & g1m_bcdflag_spe)
+# define g1m_bcd_is_negative(B) ((B)->flags & g1m_bcdflag_neg)
+# define g1m_bcd_precision(B)   ((B)->flags & g1m_bcdmask_pre)
+# define g1m_make_bcdflags(SPE, NEG, PREC) \
+	(((SPE) << 7) | ((NEG) << 6) | (PREC))
 
-# define g1m_bcd_has_special(B) ((B)->spe)
-# define g1m_bcd_is_negative(B) ((B)->neg)
 typedef struct g1m_bcd_s {
-	int exp, digits;
-	int neg, spe; /* use the macros for these! */
+	unsigned char flags; char exp;
 	char mant[G1M_BCD_MANTISSA_SIZE];
 } g1m_bcd_t;
 

src/bcd/cas.c

@@ -34,7 +34,6 @@ int g1m_bcd_fromcas(const cas_bcd_t *raw, g1m_bcd_t *bcd)
 	const unsigned char *bytes = raw->mantissa;
 
 	/* get the exponent and sign */
-	bcd->digits = 15;
 	bcd->exp = (raw->exponent >> 4) * 10 + (raw->exponent & 0x0F);
 	if (raw->signinfo & g1m_casbcd_pow_neg)
 		bcd->exp = -bcd->exp;
@@ -57,9 +56,9 @@ int g1m_bcd_fromcas(const cas_bcd_t *raw, g1m_bcd_t *bcd)
 	bcd->mant[14] = lwr(7);
 
 	/* set the special things and return */
-	bcd->neg = raw->signinfo & g1m_casbcd_negative;
-	bcd->spe = raw->signinfo & g1m_casbcd_special;
-	return (bcd->spe);
+	bcd->flags = g1m_make_bcdflags(!!(raw->signinfo & g1m_casbcd_special),
+		(raw->signinfo & g1m_casbcd_negative) == g1m_casbcd_negative, 15);
+	return (g1m_bcd_has_special(bcd));
 }
 
 /**
@@ -88,7 +87,10 @@ void g1m_bcd_tocas(const g1m_bcd_t *bcd, cas_bcd_t *raw)
 
 	/* put the flags */
 	raw->signinfo = 0;
-	if (bcd->exp < 0) raw->signinfo |= g1m_casbcd_pow_neg;
-	if (bcd->neg)     raw->signinfo |= g1m_casbcd_negative;
-	if (bcd->spe)     raw->signinfo |= g1m_casbcd_special;
+	if (bcd->exp < 0)
+		raw->signinfo |= g1m_casbcd_pow_neg;
+	if (g1m_bcd_is_negative(bcd))
+		raw->signinfo |= g1m_casbcd_negative;
+	if (g1m_bcd_has_special(bcd))
+		raw->signinfo |= g1m_casbcd_special;
 }

src/bcd/mcs.c

@@ -33,15 +33,13 @@ int g1m_bcd_frommcs(const mcs_bcd_t *raw, g1m_bcd_t *bcd)
 {
 	const unsigned char *bytes = raw->BCDval;
 
-	/* get the 10-exponent */
-	bcd->digits = 15;
-	bcd->spe = upr(0) & 0x8;
-	bcd->exp = (upr(0) & 7) * 100 + lwr(0) * 10 + upr(1);
+	/* get the exponent and correct it */
+	int exp = (upr(0) & 7) * 100 + lwr(0) * 10 + upr(1), neg = 0;
+	if (exp >= 500) exp -= 500, neg = 1;
+	bcd->exp = (char)(exp - 99);
 
-	/* check the negative number, correct the exponent */
-	bcd->neg = 0;
-	if (bcd->exp >= 500) bcd->exp -= 500, bcd->neg = 1;
-	bcd->exp -= 99;
+	/* set the flags */
+	bcd->flags = g1m_make_bcdflags(bytes[0] & 0x80 >> 7, neg, 15);
 
 	/* get the mantissa */
 	bcd->mant[0]  = lwr(1);
@@ -61,7 +59,7 @@ int g1m_bcd_frommcs(const mcs_bcd_t *raw, g1m_bcd_t *bcd)
 	bcd->mant[14] = lwr(8);
 
 	/* return the special bit */
-	return (bcd->spe);
+	return (g1m_bcd_has_special(bcd));
 }
 
 /**
@@ -75,12 +73,12 @@ int g1m_bcd_frommcs(const mcs_bcd_t *raw, g1m_bcd_t *bcd)
 void g1m_bcd_tomcs(const g1m_bcd_t *bcd, mcs_bcd_t *raw)
 {
 	int exp = bcd->exp + 99;
-	if (bcd->neg) exp += 500;
+	if (g1m_bcd_is_negative(bcd)) exp += 500;
 
 	/* put the exponent (and first digit of the mantissa) */
 	div_t c = div(exp, 100);
 	div_t d = div(c.rem, 10);
-	raw->BCDval[0] = (c.quot << 4) | d.quot | (!!bcd->spe << 7);
+	raw->BCDval[0] = (c.quot << 4) | d.quot | (!!g1m_bcd_has_special(bcd) << 7);
 	raw->BCDval[1] = (d.rem << 4) | bcd->mant[0];
 
 	/* put the mantissa */

src/decode/mcs/matrix.c

@@ -84,7 +84,7 @@ int g1m_decode_mcs_matrix(g1m_mcsfile_t *handle, g1m_buffer_t *buffer,
 			for (uint_fast32_t y = 0; y < h; y++)
 			  for (uint_fast32_t x = 0; x < w; x++) {
 				GDREAD(rawbcd, bcd)
-				if (tab[y][x].real.spe) {
+				if (g1m_bcd_has_special(&tab[y][x].real)) {
 					g1m_bcd_frommcs(&rawbcd, &bcd);
 					tab[y][x].imgn = bcd;
 				}

src/type/mcs.c

@@ -55,7 +55,7 @@ struct group_corresp {
 /*  Correspondances                                                           */
 /* ************************************************************************** */
 /*	All correspondances. Some remarks:
- *	- I think files with "PROGRAM" group are splitted because it was originally
+ *	- I think files with "PROGRAM" group are split because it was originally
  *	  planned they would be in groups like 'PROGRAM <name>', like for captures
  *	  or lists, but they abandoned that. Why they made such groups, I have no
  *	  idea yet.