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-rw-r--r--src/util.c207
1 files changed, 86 insertions, 121 deletions
diff --git a/src/util.c b/src/util.c
index 0cebb474a..8e4fd516e 100644
--- a/src/util.c
+++ b/src/util.c
@@ -539,6 +539,8 @@ int sqlite3AtoF(const char *z, double *pResult, int length, u8 enc){
int eValid = 1; /* True exponent is either not used or is well-formed */
int nDigit = 0; /* Number of digits processed */
int eType = 1; /* 1: pure integer, 2+: fractional -1 or less: bad UTF16 */
+ u64 s2; /* round-tripped significand */
+ double rr[2];
assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
*pResult = 0.0; /* Default return value, in case of an error */
@@ -641,7 +643,7 @@ do_atof_calc:
e = (e*esign) + d;
/* Try to adjust the exponent to make it smaller */
- while( e>0 && s<(LARGEST_UINT64/10) ){
+ while( e>0 && s<((LARGEST_UINT64-0x7ff)/10) ){
s *= 10;
e--;
}
@@ -650,68 +652,52 @@ do_atof_calc:
e++;
}
- if( e==0 ){
- *pResult = s;
- }else if( sqlite3Config.bUseLongDouble ){
- LONGDOUBLE_TYPE r = (LONGDOUBLE_TYPE)s;
- if( e>0 ){
- while( e>=100 ){ e-=100; r *= 1.0e+100L; }
- while( e>=10 ){ e-=10; r *= 1.0e+10L; }
- while( e>=1 ){ e-=1; r *= 1.0e+01L; }
- }else{
- while( e<=-100 ){ e+=100; r *= 1.0e-100L; }
- while( e<=-10 ){ e+=10; r *= 1.0e-10L; }
- while( e<=-1 ){ e+=1; r *= 1.0e-01L; }
- }
- assert( r>=0.0 );
- if( r>+1.7976931348623157081452742373e+308L ){
-#ifdef INFINITY
- *pResult = +INFINITY;
-#else
- *pResult = 1.0e308*10.0;
+ rr[0] = (double)s;
+ assert( sizeof(s2)==sizeof(rr[0]) );
+#ifdef SQLITE_DEBUG
+ rr[1] = 18446744073709549568.0;
+ memcpy(&s2, &rr[1], sizeof(s2));
+ assert( s2==0x43efffffffffffffLL );
#endif
- }else{
- *pResult = (double)r;
- }
- }else{
- double rr[2];
- u64 s2;
- rr[0] = (double)s;
+ /* Largest double that can be safely converted to u64
+ ** vvvvvvvvvvvvvvvvvvvvvv */
+ if( rr[0]<=18446744073709549568.0 ){
s2 = (u64)rr[0];
-#if defined(_MSC_VER) && _MSC_VER<1700
- if( s2==0x8000000000000000LL ){ s2 = 2*(u64)(0.5*rr[0]); }
-#endif
rr[1] = s>=s2 ? (double)(s - s2) : -(double)(s2 - s);
- if( e>0 ){
- while( e>=100 ){
- e -= 100;
- dekkerMul2(rr, 1.0e+100, -1.5902891109759918046e+83);
- }
- while( e>=10 ){
- e -= 10;
- dekkerMul2(rr, 1.0e+10, 0.0);
- }
- while( e>=1 ){
- e -= 1;
- dekkerMul2(rr, 1.0e+01, 0.0);
- }
- }else{
- while( e<=-100 ){
- e += 100;
- dekkerMul2(rr, 1.0e-100, -1.99918998026028836196e-117);
- }
- while( e<=-10 ){
- e += 10;
- dekkerMul2(rr, 1.0e-10, -3.6432197315497741579e-27);
- }
- while( e<=-1 ){
- e += 1;
- dekkerMul2(rr, 1.0e-01, -5.5511151231257827021e-18);
- }
+ }else{
+ rr[1] = 0.0;
+ }
+ assert( rr[1]<=1.0e-10*rr[0] ); /* Equal only when rr[0]==0.0 */
+
+ if( e>0 ){
+ while( e>=100 ){
+ e -= 100;
+ dekkerMul2(rr, 1.0e+100, -1.5902891109759918046e+83);
+ }
+ while( e>=10 ){
+ e -= 10;
+ dekkerMul2(rr, 1.0e+10, 0.0);
+ }
+ while( e>=1 ){
+ e -= 1;
+ dekkerMul2(rr, 1.0e+01, 0.0);
+ }
+ }else{
+ while( e<=-100 ){
+ e += 100;
+ dekkerMul2(rr, 1.0e-100, -1.99918998026028836196e-117);
+ }
+ while( e<=-10 ){
+ e += 10;
+ dekkerMul2(rr, 1.0e-10, -3.6432197315497741579e-27);
+ }
+ while( e<=-1 ){
+ e += 1;
+ dekkerMul2(rr, 1.0e-01, -5.5511151231257827021e-18);
}
- *pResult = rr[0]+rr[1];
- if( sqlite3IsNaN(*pResult) ) *pResult = 1e300*1e300;
}
+ *pResult = rr[0]+rr[1];
+ if( sqlite3IsNaN(*pResult) ) *pResult = 1e300*1e300;
if( sign<0 ) *pResult = -*pResult;
assert( !sqlite3IsNaN(*pResult) );
@@ -1032,9 +1018,10 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){
int i;
u64 v;
int e, exp = 0;
+ double rr[2];
+
p->isSpecial = 0;
p->z = p->zBuf;
-
assert( mxRound>0 );
/* Convert negative numbers to positive. Deal with Infinity, 0.0, and
@@ -1062,62 +1049,45 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){
/* Multiply r by powers of ten until it lands somewhere in between
** 1.0e+19 and 1.0e+17.
+ **
+ ** Use Dekker-style double-double computation to increase the
+ ** precision.
+ **
+ ** The error terms on constants like 1.0e+100 computed using the
+ ** decimal extension, for example as follows:
+ **
+ ** SELECT decimal_exp(decimal_sub('1.0e+100',decimal(1.0e+100)));
*/
- if( sqlite3Config.bUseLongDouble ){
- LONGDOUBLE_TYPE rr = r;
- if( rr>=1.0e+19 ){
- while( rr>=1.0e+119L ){ exp+=100; rr *= 1.0e-100L; }
- while( rr>=1.0e+29L ){ exp+=10; rr *= 1.0e-10L; }
- while( rr>=1.0e+19L ){ exp++; rr *= 1.0e-1L; }
- }else{
- while( rr<1.0e-97L ){ exp-=100; rr *= 1.0e+100L; }
- while( rr<1.0e+07L ){ exp-=10; rr *= 1.0e+10L; }
- while( rr<1.0e+17L ){ exp--; rr *= 1.0e+1L; }
+ rr[0] = r;
+ rr[1] = 0.0;
+ if( rr[0]>9.223372036854774784e+18 ){
+ while( rr[0]>9.223372036854774784e+118 ){
+ exp += 100;
+ dekkerMul2(rr, 1.0e-100, -1.99918998026028836196e-117);
+ }
+ while( rr[0]>9.223372036854774784e+28 ){
+ exp += 10;
+ dekkerMul2(rr, 1.0e-10, -3.6432197315497741579e-27);
+ }
+ while( rr[0]>9.223372036854774784e+18 ){
+ exp += 1;
+ dekkerMul2(rr, 1.0e-01, -5.5511151231257827021e-18);
}
- v = (u64)rr;
}else{
- /* If high-precision floating point is not available using "long double",
- ** then use Dekker-style double-double computation to increase the
- ** precision.
- **
- ** The error terms on constants like 1.0e+100 computed using the
- ** decimal extension, for example as follows:
- **
- ** SELECT decimal_exp(decimal_sub('1.0e+100',decimal(1.0e+100)));
- */
- double rr[2];
- rr[0] = r;
- rr[1] = 0.0;
- if( rr[0]>9.223372036854774784e+18 ){
- while( rr[0]>9.223372036854774784e+118 ){
- exp += 100;
- dekkerMul2(rr, 1.0e-100, -1.99918998026028836196e-117);
- }
- while( rr[0]>9.223372036854774784e+28 ){
- exp += 10;
- dekkerMul2(rr, 1.0e-10, -3.6432197315497741579e-27);
- }
- while( rr[0]>9.223372036854774784e+18 ){
- exp += 1;
- dekkerMul2(rr, 1.0e-01, -5.5511151231257827021e-18);
- }
- }else{
- while( rr[0]<9.223372036854774784e-83 ){
- exp -= 100;
- dekkerMul2(rr, 1.0e+100, -1.5902891109759918046e+83);
- }
- while( rr[0]<9.223372036854774784e+07 ){
- exp -= 10;
- dekkerMul2(rr, 1.0e+10, 0.0);
- }
- while( rr[0]<9.22337203685477478e+17 ){
- exp -= 1;
- dekkerMul2(rr, 1.0e+01, 0.0);
- }
+ while( rr[0]<9.223372036854774784e-83 ){
+ exp -= 100;
+ dekkerMul2(rr, 1.0e+100, -1.5902891109759918046e+83);
+ }
+ while( rr[0]<9.223372036854774784e+07 ){
+ exp -= 10;
+ dekkerMul2(rr, 1.0e+10, 0.0);
+ }
+ while( rr[0]<9.22337203685477478e+17 ){
+ exp -= 1;
+ dekkerMul2(rr, 1.0e+01, 0.0);
}
- v = rr[1]<0.0 ? (u64)rr[0]-(u64)(-rr[1]) : (u64)rr[0]+(u64)rr[1];
}
-
+ v = rr[1]<0.0 ? (u64)rr[0]-(u64)(-rr[1]) : (u64)rr[0]+(u64)rr[1];
/* Extract significant digits. */
i = sizeof(p->zBuf)-1;
@@ -1160,7 +1130,11 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){
}
p->z = &p->zBuf[i+1];
assert( i+p->n < sizeof(p->zBuf) );
- while( ALWAYS(p->n>0) && p->z[p->n-1]=='0' ){ p->n--; }
+ assert( p->n>0 );
+ while( p->z[p->n-1]=='0' ){
+ p->n--;
+ assert( p->n>0 );
+ }
}
/*
@@ -1665,7 +1639,7 @@ int sqlite3MulInt64(i64 *pA, i64 iB){
}
/*
-** Compute the absolute value of a 32-bit signed integer, of possible. Or
+** Compute the absolute value of a 32-bit signed integer, if possible. Or
** if the integer has a value of -2147483648, return +2147483647
*/
int sqlite3AbsInt32(int x){
@@ -1887,12 +1861,3 @@ int sqlite3VListNameToNum(VList *pIn, const char *zName, int nName){
}while( i<mx );
return 0;
}
-
-/*
-** High-resolution hardware timer used for debugging and testing only.
-*/
-#if defined(VDBE_PROFILE) \
- || defined(SQLITE_PERFORMANCE_TRACE) \
- || defined(SQLITE_ENABLE_STMT_SCANSTATUS)
-# include "hwtime.h"
-#endif
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-18 22:39:38 +0000