Various tommath/numeric related optimizations:

- Remove the DD_STEEL formatter: it isn't used anywhere in Tcl, and not recommended.
- Remove double limit-checks, which are already done inside mp_to_unsigned_bin_n()

1 files changed, 45 insertions, 93 deletions

diff --git a/generic/tclStrToD.c b/generic/tclStrToD.c
index 0770b88..ef1fcf4 100644
--- a/generic/tclStrToD.c
+++ b/generic/tclStrToD.c
@@ -320,36 +320,36 @@ static char *		StrictQuickFormat(double, int, int, double,
 static char *		QuickConversion(double, int, int, int, int, int, int,
 			    int *, char **);
 static void		CastOutPowersOf2(int *, int *, int *);
-static char *		ShorteningInt64Conversion(Double *, int, Tcl_WideUInt,
+static char *		ShorteningInt64Conversion(Double *, Tcl_WideUInt,
 			    int, int, int, int, int, int, int, int, int,
 			    int, int, int *, char **);
-static char *		StrictInt64Conversion(Double *, int, Tcl_WideUInt,
+static char *		StrictInt64Conversion(Double *, Tcl_WideUInt,
 			    int, int, int, int, int, int,
 			    int, int, int *, char **);
 static int		ShouldBankerRoundUpPowD(mp_int *, int, int);
 static int		ShouldBankerRoundUpToNextPowD(mp_int *, mp_int *,
-			    int, int, int, mp_int *);
+			    int, int, mp_int *);
 static char *		ShorteningBignumConversionPowD(Double *dPtr,
-			    int convType, Tcl_WideUInt bw, int b2, int b5,
+			    Tcl_WideUInt bw, int b2, int b5,
 			    int m2plus, int m2minus, int m5,
 			    int sd, int k, int len,
 			    int ilim, int ilim1, int *decpt,
 			    char **endPtr);
-static char *		StrictBignumConversionPowD(Double *dPtr, int convType,
+static char *		StrictBignumConversionPowD(Double *dPtr,
 			    Tcl_WideUInt bw, int b2, int b5,
 			    int sd, int k, int len,
 			    int ilim, int ilim1, int *decpt,
 			    char **endPtr);
 static int		ShouldBankerRoundUp(mp_int *, mp_int *, int);
 static int		ShouldBankerRoundUpToNext(mp_int *, mp_int *,
-			    mp_int *, int, int, mp_int *);
-static char *		ShorteningBignumConversion(Double *dPtr, int convType,
+			    mp_int *, int);
+static char *		ShorteningBignumConversion(Double *dPtr,
 			    Tcl_WideUInt bw, int b2,
 			    int m2plus, int m2minus,
 			    int s2, int s5, int k, int len,
 			    int ilim, int ilim1, int *decpt,
 			    char **endPtr);
-static char *		StrictBignumConversion(Double *dPtr, int convType,
+static char *		StrictBignumConversion(Double *dPtr,
 			    Tcl_WideUInt bw, int b2,
 			    int s2, int s5, int k, int len,
 			    int ilim, int ilim1, int *decpt,
@@ -2410,9 +2410,8 @@ ComputeScale(
 
 static inline void
 SetPrecisionLimits(
-    int convType,		/* Type of conversion: TCL_DD_SHORTEST,
-				 * TCL_DD_STEELE0, TCL_DD_E_FMT,
-				 * TCL_DD_F_FMT. */
+    int flags,		/* Type of conversion: TCL_DD_SHORTEST,
+				 * TCL_DD_E_FMT, TCL_DD_F_FMT. */
     int k,			/* Floor(log10(number to convert)) */
     int *ndigitsPtr,		/* IN/OUT: Number of digits requested (will be
 				 *         adjusted if needed). */
@@ -2422,13 +2421,7 @@ SetPrecisionLimits(
     int *iLim1Ptr)		/* OUT: Number of digits of significance if
 				 *      the quick method is used. */
 {
-    switch (convType) {
-    case TCL_DD_SHORTEST0:
-    case TCL_DD_STEELE0:
-	*iLimPtr = *iLim1Ptr = -1;
-	*iPtr = 18;
-	*ndigitsPtr = 0;
-	break;
+    switch (flags & TCL_DD_CONVERSION_TYPE_MASK) {
     case TCL_DD_E_FORMAT:
 	if (*ndigitsPtr <= 0) {
 	    *ndigitsPtr = 1;
@@ -2444,10 +2437,10 @@ SetPrecisionLimits(
 	}
 	break;
     default:
-	*iPtr = -1;
-	*iLimPtr = -1;
-	*iLim1Ptr = -1;
-	Tcl_Panic("impossible conversion type in TclDoubleDigits");
+	*iLimPtr = *iLim1Ptr = -1;
+	*iPtr = 18;
+	*ndigitsPtr = 0;
+	break;
     }
 }
 
@@ -2877,8 +2870,6 @@ CastOutPowersOf2(
 static inline char *
 ShorteningInt64Conversion(
     Double *dPtr,		/* Original number to convert. */
-    int convType,		/* Type of conversion (shortest, Steele,
-				 * E format, F format). */
     Tcl_WideUInt bw,		/* Integer significand. */
     int b2, int b5,		/* Scale factor for the significand in the
 				 * numerator. */
@@ -2945,7 +2936,7 @@ ShorteningInt64Conversion(
 	 */
 
 	if (b < mplus || (b == mplus
-		&& convType != TCL_DD_STEELE0 && (dPtr->w.word1 & 1) == 0)) {
+		&& (dPtr->w.word1 & 1) == 0)) {
 	    /*
 	     * Make sure we shouldn't be rounding *up* instead, in case the
 	     * next number above is closer.
@@ -2974,7 +2965,7 @@ ShorteningInt64Conversion(
 	 */
 
 	if (b > S - mminus || (b == S - mminus
-		&& convType != TCL_DD_STEELE0 && (dPtr->w.word1 & 1) == 0)) {
+		&& (dPtr->w.word1 & 1) == 0)) {
 	    if (digit == 9) {
 		*s++ = '9';
 		s = BumpUp(s, retval, &k);
@@ -3046,8 +3037,6 @@ ShorteningInt64Conversion(
 static inline char *
 StrictInt64Conversion(
     Double *dPtr,		/* Original number to convert. */
-    int convType,		/* Type of conversion (shortest, Steele,
-				 * E format, F format). */
     Tcl_WideUInt bw,		/* Integer significand. */
     int b2, int b5,		/* Scale factor for the significand in the
 				 * numerator. */
@@ -3156,7 +3145,7 @@ ShouldBankerRoundUpPowD(
     int isodd)			/* 1 if the digit is odd, 0 if even. */
 {
     int i;
-    static const mp_digit topbit = 1 << (DIGIT_BIT - 1);
+    static const mp_digit topbit = ((mp_digit)1) << (DIGIT_BIT - 1);
 
     if (b->used < sd || (b->dp[sd-1] & topbit) == 0) {
 	return 0;
@@ -3192,9 +3181,6 @@ ShouldBankerRoundUpToNextPowD(
     mp_int *b,			/* Numerator of the fraction. */
     mp_int *m,			/* Numerator of the rounding tolerance. */
     int sd,			/* Common denominator is 2**(sd*DIGIT_BIT). */
-    int convType,		/* Conversion type: STEELE defeats
-				 * round-to-even (not sure why one wants to do
-				 * this; I copied it from Gay). FIXME */
     int isodd,			/* 1 if the integer significand is odd. */
     mp_int *temp)		/* Work area for the calculation. */
 {
@@ -3220,10 +3206,6 @@ ShouldBankerRoundUpToNextPowD(
 	    return 1;
 	}
     }
-    if (convType == TCL_DD_STEELE0) {
-				/* Biased rounding. */
-	return 0;
-    }
     return isodd;
 }
 
@@ -3253,8 +3235,6 @@ ShouldBankerRoundUpToNextPowD(
 static inline char *
 ShorteningBignumConversionPowD(
     Double *dPtr,		/* Original number to convert. */
-    int convType,		/* Type of conversion (shortest, Steele,
-				 * E format, F format). */
     Tcl_WideUInt bw,		/* Integer significand. */
     int b2, int b5,		/* Scale factor for the significand in the
 				 * numerator. */
@@ -3340,7 +3320,7 @@ ShorteningBignumConversionPowD(
 
 	r1 = mp_cmp_mag(&b, (m2plus > m2minus)? &mplus : &mminus);
 	if (r1 == MP_LT || (r1 == MP_EQ
-		&& convType != TCL_DD_STEELE0 && (dPtr->w.word1 & 1) == 0)) {
+		&& (dPtr->w.word1 & 1) == 0)) {
 	    /*
 	     * Make sure we shouldn't be rounding *up* instead, in case the
 	     * next number above is closer.
@@ -3368,7 +3348,7 @@ ShorteningBignumConversionPowD(
 	 * number?
 	 */
 
-	if (ShouldBankerRoundUpToNextPowD(&b, &mminus, sd, convType,
+	if (ShouldBankerRoundUpToNextPowD(&b, &mminus, sd,
 		dPtr->w.word1 & 1, &temp)) {
 	    if (digit == 9) {
 		*s++ = '9';
@@ -3446,8 +3426,6 @@ ShorteningBignumConversionPowD(
 static inline char *
 StrictBignumConversionPowD(
     Double *dPtr,		/* Original number to convert. */
-    int convType,		/* Type of conversion (shortest, Steele,
-				 * E format, F format). */
     Tcl_WideUInt bw,		/* Integer significand. */
     int b2, int b5,		/* Scale factor for the significand in the
 				 * numerator. */
@@ -3468,7 +3446,6 @@ StrictBignumConversionPowD(
     mp_digit digit;		/* Current output digit. */
     char *s = retval;		/* Cursor in the output buffer. */
     int i;			/* Index in the output buffer. */
-    mp_int temp;
 
     /*
      * b = bw * 2**b2 * 5**b5
@@ -3487,7 +3464,6 @@ StrictBignumConversionPowD(
 	ilim = ilim1;
 	--k;
     }
-    mp_init(&temp);
 
     /*
      * Loop through the digits. Do division and mod by s == 2**(sd*DIGIT_BIT)
@@ -3536,7 +3512,7 @@ StrictBignumConversionPowD(
      * string.
      */
 
-    mp_clear_multi(&b, &temp, NULL);
+    mp_clear(&b);
     *s = '\0';
     *decpt = k;
     if (endPtr) {
@@ -3600,29 +3576,24 @@ ShouldBankerRoundUpToNext(
 				 * the last digit. */
     mp_int *m,			/* Numerator of the rounding tolerance. */
     mp_int *S,			/* Denominator. */
-    int convType,		/* Conversion type: STEELE0 defeats
-				 * round-to-even. (Not sure why one would want
-				 * this; I coped it from Gay). FIXME */
-    int isodd,			/* 1 if the integer significand is odd. */
-    mp_int *temp)		/* Work area needed for the calculation. */
+    int isodd)			/* 1 if the integer significand is odd. */
 {
     int r;
+    mp_int temp;
 
     /*
      * Compare b and S-m: this is the same as comparing B+m and S.
      */
 
-    mp_add(b, m, temp);
-    r = mp_cmp_mag(temp, S);
+    mp_init(&temp);
+    mp_add(b, m, &temp);
+    r = mp_cmp_mag(&temp, S);
+    mp_clear(&temp);
     switch(r) {
     case MP_LT:
 	return 0;
     case MP_EQ:
-	if (convType == TCL_DD_STEELE0) {
-	    return 0;
-	} else {
-	    return isodd;
-	}
+	return isodd;
     case MP_GT:
 	return 1;
     }
@@ -3651,7 +3622,6 @@ ShouldBankerRoundUpToNext(
 static inline char *
 ShorteningBignumConversion(
     Double *dPtr,		/* Original number being converted. */
-    int convType,		/* Conversion type. */
     Tcl_WideUInt bw,		/* Integer significand and exponent. */
     int b2,			/* Scale factor for the significand. */
     int m2plus, int m2minus,	/* Scale factors for 1/2 ulp in numerator. */
@@ -3672,7 +3642,6 @@ ShorteningBignumConversion(
     mp_int S;			/* Denominator of the result. */
     mp_int dig;			/* Current digit of the result. */
     int digit;			/* Current digit of the result. */
-    mp_int temp;		/* Work area. */
     int minit = 1;		/* Fudge factor for when we misguess k. */
     int i;
     int r1;
@@ -3708,7 +3677,6 @@ ShorteningBignumConversion(
 	mp_init_copy(&mplus, &mminus);
 	mp_mul_2d(&mplus, m2plus-m2minus, &mplus);
     }
-    mp_init(&temp);
 
     /*
      * Loop through the digits.
@@ -3729,8 +3697,7 @@ ShorteningBignumConversion(
 	 */
 
 	r1 = mp_cmp_mag(&b, (m2plus > m2minus)? &mplus : &mminus);
-	if (r1 == MP_LT || (r1 == MP_EQ
-		&& convType != TCL_DD_STEELE0 && (dPtr->w.word1 & 1) == 0)) {
+	if (r1 == MP_LT || (r1 == MP_EQ && (dPtr->w.word1 & 1) == 0)) {
 	    mp_mul_2d(&b, 1, &b);
 	    if (ShouldBankerRoundUp(&b, &S, digit&1)) {
 		++digit;
@@ -3749,8 +3716,8 @@ ShorteningBignumConversion(
 	 * commit to rounding up to the next higher digit?
 	 */
 
-	if (ShouldBankerRoundUpToNext(&b, &mminus, &S, convType,
-		dPtr->w.word1 & 1, &temp)) {
+	if (ShouldBankerRoundUpToNext(&b, &mminus, &S,
+		dPtr->w.word1 & 1)) {
 	    ++digit;
 	    if (digit == 10) {
 		*s++ = '9';
@@ -3837,7 +3804,7 @@ ShorteningBignumConversion(
     if (m2plus > m2minus) {
 	mp_clear(&mplus);
     }
-    mp_clear_multi(&b, &mminus, &temp, &dig, &S, NULL);
+    mp_clear_multi(&b, &mminus, &dig, &S, NULL);
     *s = '\0';
     *decpt = k;
     if (endPtr) {
@@ -3867,7 +3834,6 @@ ShorteningBignumConversion(
 static inline char *
 StrictBignumConversion(
     Double *dPtr,		/* Original number being converted. */
-    int convType,		/* Conversion type. */
     Tcl_WideUInt bw,		/* Integer significand and exponent. */
     int b2,			/* Scale factor for the significand. */
     int s2, int s5,		/* Scale factors for denominator. */
@@ -3885,7 +3851,6 @@ StrictBignumConversion(
     mp_int S;			/* Denominator of the result. */
     mp_int dig;			/* Current digit of the result. */
     int digit;			/* Current digit of the result. */
-    mp_int temp;		/* Work area. */
     int g;			/* Size of the current digit ground. */
     int i, j;
 
@@ -3894,7 +3859,7 @@ StrictBignumConversion(
      * S = 2**s2 * 5*s5
      */
 
-    mp_init_multi(&temp, &dig, NULL);
+    mp_init_multi(&dig, NULL);
     TclInitBignumFromWideUInt(&b, bw);
     mp_mul_2d(&b, b2, &b);
     mp_init_set_int(&S, 1);
@@ -4001,7 +3966,7 @@ StrictBignumConversion(
      * string.
      */
 
-    mp_clear_multi(&b, &S, &temp, &dig, NULL);
+    mp_clear_multi(&b, &S, &dig, NULL);
     *s = '\0';
     *decpt = k;
     if (endPtr) {
@@ -4037,15 +4002,6 @@ StrictBignumConversion(
  *		For floating point numbers that are exactly between two
  *		decimal numbers, it resolves using the 'round to even' rule.
  *		With this value, the 'ndigits' parameter is ignored.
- *	TCL_DD_STEELE - This value is not recommended and may be removed in
- *		the future. It follows the conversion algorithm outlined in
- *		"How to Print Floating-Point Numbers Accurately" by Guy
- *		L. Steele, Jr. and Jon L. White [Proc. ACM SIGPLAN '90,
- *		pp. 112-126]. This rule has the effect of rendering 1e23 as
- *		9.9999999999999999e22 - which is a 'better' approximation in
- *		the sense that it will reconvert correctly even if a
- *		subsequent input conversion is 'round up' or 'round down'
- *		rather than 'round to nearest', but is surprising otherwise.
  *	TCL_DD_E_FORMAT - This value is used to prepare numbers for %e format
  *		conversion (or for default floating->string if tcl_precision
  *		is not 0). It constructs a string of at most 'ndigits' digits,
@@ -4096,10 +4052,6 @@ TclDoubleDigits(
 				 *	   one character beyond the end of the
 				 *	   returned string. */
 {
-    int convType = (flags & TCL_DD_CONVERSION_TYPE_MASK);
-				/* Type of conversion being performed:
-				 * TCL_DD_SHORTEST0, TCL_DD_STEELE0,
-				 * TCL_DD_E_FORMAT, or TCL_DD_F_FORMAT. */
     Double d;			/* Union for deconstructing doubles. */
     Tcl_WideUInt bw;		/* Integer significand. */
     int be;			/* Power of 2 by which b must be multiplied */
@@ -4167,18 +4119,18 @@ TclDoubleDigits(
      * Correct an incorrect caller-supplied 'ndigits'.  Also determine:
      *	i = The maximum number of decimal digits that will be returned in the
      *      formatted string.  This is k + 1 + ndigits for F format, 18 for
-     *      shortest and Steele, and ndigits for E format.
+     *      shortest, and ndigits for E format.
      *  ilim = The number of significant digits to convert if k has been
-     *         guessed correctly. This is -1 for shortest and Steele (which
+     *         guessed correctly. This is -1 for shortest (which
      *         stop when all significance has been lost), 'ndigits' for E
      *         format, and 'k + 1 + ndigits' for F format.
      *  ilim1 = The minimum number of significant digits to convert if k has
-     *	        been guessed 1 too high. This, too, is -1 for shortest and
-     *	        Steele, and 'ndigits' for E format, but it's 'ndigits-1' for F
+     *	        been guessed 1 too high. This, too, is -1 for shortest,
+     *	        and 'ndigits' for E format, but it's 'ndigits-1' for F
      *	        format.
      */
 
-    SetPrecisionLimits(convType, k, &ndigits, &i, &ilim, &ilim1);
+    SetPrecisionLimits(flags, k, &ndigits, &i, &ilim, &ilim1);
 
     /*
      * Try to do low-precision conversion in floating point rather than
@@ -4251,7 +4203,7 @@ TclDoubleDigits(
 	     * [1.0e-3 .. 1.0e+24]).
 	     */
 
-	    return ShorteningInt64Conversion(&d, convType, bw, b2, b5, m2plus,
+	    return ShorteningInt64Conversion(&d, bw, b2, b5, m2plus,
 		    m2minus, m5, s2, s5, k, len, ilim, ilim1, decpt, endPtr);
 	} else if (s5 == 0) {
 	    /*
@@ -4270,7 +4222,7 @@ TclDoubleDigits(
 		m2minus += delta;
 		s2 += delta;
 	    }
-	    return ShorteningBignumConversionPowD(&d, convType, bw, b2, b5,
+	    return ShorteningBignumConversionPowD(&d, bw, b2, b5,
 		    m2plus, m2minus, m5, s2/DIGIT_BIT, k, len, ilim, ilim1,
 		    decpt, endPtr);
 	} else {
@@ -4279,7 +4231,7 @@ TclDoubleDigits(
 	     * arithmetic for the conversion.
 	     */
 
-	    return ShorteningBignumConversion(&d, convType, bw, b2, m2plus,
+	    return ShorteningBignumConversion(&d, bw, b2, m2plus,
 		    m2minus, s2, s5, k, len, ilim, ilim1, decpt, endPtr);
 	}
     } else {
@@ -4307,7 +4259,7 @@ TclDoubleDigits(
 	     * operations.
 	     */
 
-	    return StrictInt64Conversion(&d, convType, bw, b2, b5, s2, s5, k,
+	    return StrictInt64Conversion(&d, bw, b2, b5, s2, s5, k,
 		    len, ilim, ilim1, decpt, endPtr);
 	} else if (s5 == 0) {
 	    /*
@@ -4324,7 +4276,7 @@ TclDoubleDigits(
 		b2 += delta;
 		s2 += delta;
 	    }
-	    return StrictBignumConversionPowD(&d, convType, bw, b2, b5,
+	    return StrictBignumConversionPowD(&d, bw, b2, b5,
 		    s2/DIGIT_BIT, k, len, ilim, ilim1, decpt, endPtr);
 	} else {
 	    /*
@@ -4334,7 +4286,7 @@ TclDoubleDigits(
 	     * fewer mp_int divisions.
 	     */
 
-	    return StrictBignumConversion(&d, convType, bw, b2, s2, s5, k,
+	    return StrictBignumConversion(&d, bw, b2, s2, s5, k,
 		    len, ilim, ilim1, decpt, endPtr);
 	}
     }