Begin cutting over sqlite3FpDecode() into printf(). The code in this

check-in gets a lot right, but there are still some formatting
discrepencies.

FossilOrigin-Name: c134d423e79ba5d3343d7480229822a0c83210f67f12129e0237181f892f97a5

manifest

@@ -1,5 +1,5 @@
-C Add\sdecimal\srounding\sto\sthe\ssqlite3FpDecode()\sroutine.
+C Begin\scutting\sover\ssqlite3FpDecode()\sinto\sprintf().\s\sThe\scode\sin\sthis\ncheck-in\sgets\sa\slot\sright,\sbut\sthere\sare\sstill\ssome\sformatting\ndiscrepencies.
-D 2023-06-30T19:41:57.301
+D 2023-06-30T23:18:44.905
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -633,7 +633,7 @@ F src/pcache1.c 602acb23c471bb8d557a6f0083cc2be641d6cafcafa19e481eba7ef4c9ca0f00
 F src/pragma.c 37b8fb02d090262280c86e1e2654bf59d8dbfbfe8dc6733f2b968a11374c095a
 F src/pragma.h e690a356c18e98414d2e870ea791c1be1545a714ba623719deb63f7f226d8bb7
 F src/prepare.c d6c4354f8ea0dc06962fbabc4b68c4471a45276a2918c929be00f9f537f69eb1
-F src/printf.c a87473be34fa2acafa27692b8ae078275c7e23360956c93c07ff22f5d609cbd7
+F src/printf.c a3497bdf4e62b8bd56d4a9bb16f9da08ab86951612fcb252206f3f96a8f64557
 F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c
 F src/resolve.c 37953a5f36c60bea413c3c04efcd433b6177009f508ef2ace0494728912fe2e9
 F src/rowset.c 8432130e6c344b3401a8874c3cb49fefe6873fec593294de077afea2dce5ec97
@@ -705,7 +705,7 @@ F src/trigger.c ad6ab9452715fa9a8075442e15196022275b414b9141b566af8cdb7a1605f2b0
 F src/update.c 0aa36561167a7c40d01163238c297297962f31a15a8d742216b3c37cdf25f731
 F src/upsert.c 5303dc6c518fa7d4b280ec65170f465c7a70b7ac2b22491598f6d0b4875b3145
 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0
-F src/util.c 4a7343a01de122783d6d84c508af15674990578703d5bf55294066978c943f35
+F src/util.c f7efa26a9cae5efc0d01d008fe4bf0e5e1acc09c1a4a3f30d5097a8c67888d2f
 F src/vacuum.c 604fcdaebe76f3497c855afcbf91b8fa5046b32de3045bab89cc008d68e40104
 F src/vdbe.c 74282a947234513872a83b0bab1b8c644ece64b3e27b053ef17677c8ff9c81e0
 F src/vdbe.h 41485521f68e9437fdb7ec4a90f9d86ab294e9bb8281e33b235915e29122cfc0
@@ -2041,8 +2041,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P e923405e448385085224f9289991b303d86b02763535ea77d6fcee98ba6fc1f2
+P 27871140caa833f0bc0962e44356993938e93dcf81c1074382b1560a3e1aeb61
-R 49ab12ffcc52cccbb997811489070376
+R c28c8d21096bb9e27eacb6f123a9309b
 U drh
-Z 1293fc1c53a0c963d9c920ddba4be394
+Z 82b4e7c76d72d8b25d46a6dcbe6ae7dd
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-27871140caa833f0bc0962e44356993938e93dcf81c1074382b1560a3e1aeb61
+c134d423e79ba5d3343d7480229822a0c83210f67f12129e0237181f892f97a5

src/printf.c

@@ -105,57 +105,6 @@ static const et_info fmtinfo[] = {
 **    %!S   Like %S but prefer the zName over the zAlias
 */
 
-/* Floating point constants used for rounding */
-static const double arRound[] = {
-  5.0e-01, 5.0e-02, 5.0e-03, 5.0e-04, 5.0e-05,
-  5.0e-06, 5.0e-07, 5.0e-08, 5.0e-09, 5.0e-10,
-};
-
-/*
-** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point
-** conversions will work.
-*/
-#ifndef SQLITE_OMIT_FLOATING_POINT
-/*
-** "*val" is a double such that 0.1 <= *val < 10.0
-** Return the ascii code for the leading digit of *val, then
-** multiply "*val" by 10.0 to renormalize.
-**
-** Example:
-**     input:     *val = 3.14159
-**     output:    *val = 1.4159    function return = '3'
-**
-** The counter *cnt is incremented each time.  After counter exceeds
-** 16 (the number of significant digits in a 64-bit float) '0' is
-** always returned.
-*/
-static char et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
-  int digit;
-  LONGDOUBLE_TYPE d;
-  if( (*cnt)<=0 ) return '0';
-  (*cnt)--;
-  digit = (int)*val;
-  d = digit;
-  digit += '0';
-  *val = (*val - d)*10.0;
-  return (char)digit;
-}
-#endif /* SQLITE_OMIT_FLOATING_POINT */
-
-#ifndef SQLITE_OMIT_FLOATING_POINT
-/*
-** "*val" is a u64.  *msd is a divisor used to extract the
-** most significant digit of *val.  Extract that most significant
-** digit and return it.
-*/
-static char et_getdigit_int(u64 *val, u64 *msd){
-  u64 x = (*val)/(*msd);
-  *val -= x*(*msd);
-  if( *msd>=10 ) *msd /= 10;
-  return '0' + (char)(x & 15);
-}
-#endif /* SQLITE_OMIT_FLOATING_POINT */
-
 /*
 ** Set the StrAccum object to an error mode.
 */
@@ -247,20 +196,16 @@ void sqlite3_str_vappendf(
   u8 bArgList;               /* True for SQLITE_PRINTF_SQLFUNC */
   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
   sqlite_uint64 longvalue;   /* Value for integer types */
-  LONGDOUBLE_TYPE realvalue; /* Value for real types */
+  double realvalue;          /* Value for real types */
-  sqlite_uint64 msd;         /* Divisor to get most-significant-digit
-                             ** of longvalue */
   const et_info *infop;      /* Pointer to the appropriate info structure */
   char *zOut;                /* Rendering buffer */
   int nOut;                  /* Size of the rendering buffer */
   char *zExtra = 0;          /* Malloced memory used by some conversion */
-#ifndef SQLITE_OMIT_FLOATING_POINT
+  int exp, e2;               /* exponent of real numbers */
-  int  exp, e2;              /* exponent of real numbers */
+  int j;                     /* Number of significant digits returned */
-  int nsd;                   /* Number of significant digits returned */
-  double rounder;            /* Used for rounding floating point values */
   etByte flag_dp;            /* True if decimal point should be shown */
   etByte flag_rtz;           /* True if trailing zeros should be removed */
-#endif
+
   PrintfArguments *pArgList = 0; /* Arguments for SQLITE_PRINTF_SQLFUNC */
   char buf[etBUFSIZE];       /* Conversion buffer */
 
@@ -535,94 +480,51 @@ void sqlite3_str_vappendf(
         break;
       case etFLOAT:
       case etEXP:
-      case etGENERIC:
+      case etGENERIC: {
+        FpDecode s;
+
         if( bArgList ){
           realvalue = getDoubleArg(pArgList);
         }else{
           realvalue = va_arg(ap,double);
         }
-#ifdef SQLITE_OMIT_FLOATING_POINT
-        length = 0;
-#else
         if( precision<0 ) precision = 6;         /* Set default precision */
 #ifdef SQLITE_FP_PRECISION_LIMIT
         if( precision>SQLITE_FP_PRECISION_LIMIT ){
           precision = SQLITE_FP_PRECISION_LIMIT;
         }
 #endif
-        if( realvalue<0.0 ){
+        sqlite3FpDecode(&s, realvalue, xtype==etFLOAT ? -precision : precision);
-          realvalue = -realvalue;
+        if( s.isNan ){
+          if( flag_zeropad ){
+            bufpt = "null";
+            length = 4;
+          }else{
+            bufpt = "NaN";
+            length = 3;
+          }
+          break;
+        }
+        if( s.isInf ){
+          if( s.sign=='-' ){
+            bufpt = "-Inf";
+            length = 4;
+          }else{
+            bufpt = "Inf";
+            length = 3;
+          }
+          break;
+        }
+        if( flag_prefix ){
+          prefix = flag_prefix;
+        }else if( s.sign=='-' ){
           prefix = '-';
         }else{
-          prefix = flag_prefix;
+          prefix = 0;
         }
-        exp = 0;
-        if( xtype==etGENERIC && precision>0 ) precision--;
-        testcase( precision>0xfff );
-        if( realvalue<9.22e+18
-         && realvalue==(LONGDOUBLE_TYPE)(longvalue = (u64)realvalue)
-        ){
-          /* Number is a pure integer that can be represented as u64 */
-          for(msd=1; msd*10<=longvalue; msd *= 10, exp++){}
-          if( exp>precision && xtype!=etFLOAT ){
-            u64 rnd = msd/2;
-            int kk = precision;
-            while( kk-- > 0 ){  rnd /= 10; }
-            longvalue += rnd;
-          }
-        }else{
-          msd = 0;
-          longvalue = 0;  /* To prevent a compiler warning */
-          idx = precision & 0xfff;
-          rounder = arRound[idx%10];
-          while( idx>=10 ){ rounder *= 1.0e-10; idx -= 10; }
-          if( xtype==etFLOAT ){
-            double rx = (double)realvalue;
-            sqlite3_uint64 u;
-            int ex;
-            memcpy(&u, &rx, sizeof(u));
-            ex = -1023 + (int)((u>>52)&0x7ff);
-            if( precision+(ex/3) < 15 ) rounder += realvalue*3e-16;
-            realvalue += rounder;
-          }
-          if( sqlite3IsNaN((double)realvalue) ){
-            if( flag_zeropad ){
-              bufpt = "null";
-              length = 4;
-            }else{
-              bufpt = "NaN";
-              length = 3;
-            }
-            break;
-          }
 
-          /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
+        exp = s.iDP-1;
-          if( ALWAYS(realvalue>0.0) ){
+        if( xtype==etGENERIC && precision>0 ) precision--;
-            LONGDOUBLE_TYPE scale = 1.0L;
-            while( realvalue>=1e100*scale && exp<=350){ scale*=1e100L;exp+=100;}
-            while( realvalue>=1e10*scale && exp<=350 ){ scale*=1e10L; exp+=10; }
-            while( realvalue>=10.0*scale && exp<=350 ){ scale*=10.0L; exp++; }
-            realvalue /= scale;
-            while( realvalue<1e-8 ){ realvalue *= 1e8L; exp-=8; }
-            while( realvalue<1.0 ){ realvalue *= 10.0L; exp--; }
-            if( exp>350 ){
-              if( flag_zeropad ){
-                realvalue = 9.0;
-                exp = 999;
-              }else{
-                bufpt = buf;
-                buf[0] = prefix;
-                memcpy(buf+(prefix!=0),"Inf",4);
-                length = 3+(prefix!=0);
-                break;
-              }
-            }
-            if( xtype!=etFLOAT ){
-              realvalue += rounder;
-              if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
-            }
-          }
-        }
 
         /*
         ** If the field type is etGENERIC, then convert to either etEXP
@@ -642,9 +544,8 @@ void sqlite3_str_vappendf(
         if( xtype==etEXP ){
           e2 = 0;
         }else{
-          e2 = exp;
+          e2 = s.iDP - 1;
         }
-        nsd = 16 + flag_altform2*10;
         bufpt = buf;
         {
           i64 szBufNeeded;           /* Size of a temporary buffer needed */
@@ -662,16 +563,12 @@ void sqlite3_str_vappendf(
           *(bufpt++) = prefix;
         }
         /* Digits prior to the decimal point */
+        j = 0;
         if( e2<0 ){
           *(bufpt++) = '0';
-        }else if( msd>0 ){
-          for(; e2>=0; e2--){
-            *(bufpt++) = et_getdigit_int(&longvalue,&msd);
-            if( cThousand && (e2%3)==0 && e2>1 ) *(bufpt++) = ',';
-          }
         }else{
           for(; e2>=0; e2--){
-            *(bufpt++) = et_getdigit(&realvalue,&nsd);
+            *(bufpt++) = s.z[j++];
             if( cThousand && (e2%3)==0 && e2>1 ) *(bufpt++) = ',';
           }
         }
@@ -681,19 +578,12 @@ void sqlite3_str_vappendf(
         }
         /* "0" digits after the decimal point but before the first
         ** significant digit of the number */
-        for(e2++; e2<0; precision--, e2++){
+        for(e2++; e2<0 && precision>0; precision--, e2++){
-          assert( precision>0 );
           *(bufpt++) = '0';
         }
         /* Significant digits after the decimal point */
-        if( msd>0 ){
+        while( (precision--)>0 ){
-          while( (precision--)>0 ){
+          *(bufpt++) = j<s.n ? s.z[j++] : '0';
-            *(bufpt++) = et_getdigit_int(&longvalue,&msd);
-          }
-        }else{
-          while( (precision--)>0 ){
-            *(bufpt++) = et_getdigit(&realvalue,&nsd);
-          }
         }
         /* Remove trailing zeros and the "." if no digits follow the "." */
         if( flag_rtz && flag_dp ){
@@ -709,6 +599,7 @@ void sqlite3_str_vappendf(
         }
         /* Add the "eNNN" suffix */
         if( xtype==etEXP ){
+          exp = s.iDP - 1;
           *(bufpt++) = aDigits[infop->charset];
           if( exp<0 ){
             *(bufpt++) = '-'; exp = -exp;
@@ -742,8 +633,8 @@ void sqlite3_str_vappendf(
           while( nPad-- ) bufpt[i++] = '0';
           length = width;
         }
-#endif /* !defined(SQLITE_OMIT_FLOATING_POINT) */
         break;
+      }
       case etSIZE:
         if( !bArgList ){
           *(va_arg(ap,int*)) = pAccum->nChar;

src/util.c

@@ -949,6 +949,8 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound){
     p->n = 1;
     p->iDP = 1;
     p->z[0] = '0';
+    p->isNan = 0;
+    p->isInf = 0;
     return;
   }else{
     p->sign = '+';
@@ -973,6 +975,8 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound){
     p->iDP = 3;
     return;
   }
+  p->isNan = p->isInf = 0;
+
   /* At this point, r is positive (non-zero) and is not Inf or NaN.
   ** The strategy is to multiple or divide r by powers of 10 until
   ** it is in between 1.0e+17 and 1.0e+19.  Then convert r into