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Overview
Comment:Remove still more unnecessary branches from sqlite3AtoF().
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SHA1: 3adfe9f3e6ce7cc09fcb570d9b65e830a96cac15
User & Date: drh 2016-04-27 02:35:03.572
Context
2016-04-27
15:24
More simplification of the sqlite3AtoF() routine. Add special comments to indicate branches that are for optimization purposes only and that give the correct answer even if always or never taken. (check-in: 0065fe97cb user: drh tags: trunk)
02:35
Remove still more unnecessary branches from sqlite3AtoF(). (check-in: 3adfe9f3e6 user: drh tags: trunk)
2016-04-26
23:14
Further simplifications to sqlite3AtoF() to remove unneeded branches. (check-in: dd69e53cb0 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/util.c.
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      e = e<10000 ? (e*10 + (*z - '0')) : 10000;
      z+=incr;
      eValid = 1;
    }
  }

  /* skip trailing spaces */
  if( nDigits && eValid ){
    while( z<zEnd && sqlite3Isspace(*z) ) z+=incr;
  }

do_atof_calc:
  /* adjust exponent by d, and update sign */
  e = (e*esign) + d;
  if( e<0 ) {
    esign = -1;
    e *= -1;
  } else {
    esign = 1;
  }

  /* if 0 significand */
  if( !s ) {
    /* In the IEEE 754 standard, zero is signed.
    ** Add the sign if we've seen at least one digit */
    result = (sign<0 && nDigits) ? -(double)0 : (double)0;
  } else {
    /* attempt to reduce exponent */
    if( esign>0 ){
      while( s<(LARGEST_INT64/10) && e>0 ) e--,s*=10;
    }else{
      while( !(s%10) && e>0 ) e--,s/=10;
    }








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      e = e<10000 ? (e*10 + (*z - '0')) : 10000;
      z+=incr;
      eValid = 1;
    }
  }

  /* skip trailing spaces */

  while( z<zEnd && sqlite3Isspace(*z) ) z+=incr;


do_atof_calc:
  /* adjust exponent by d, and update sign */
  e = (e*esign) + d;
  if( e<0 ) {
    esign = -1;
    e *= -1;
  } else {
    esign = 1;
  }

  /* if 0 significand */
  if( !s ) {
    /* In the IEEE 754 standard, zero is signed.
    ** Add the sign if we've seen at least one digit */
    result = sign<0 ? -(double)0 : (double)0;
  } else {
    /* attempt to reduce exponent */
    if( esign>0 ){
      while( s<(LARGEST_INT64/10) && e>0 ) e--,s*=10;
    }else{
      while( !(s%10) && e>0 ) e--,s/=10;
    }
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