Increased precision of floating-point to decimal conversions when the
floating point value has no fractional part. [forum:/forumpost/d1387c3979c7f557|Forum post d1387c3979c7f557] FossilOrigin-Name: 18de3a8e6b431a075143631eafdcf0e1b1a21868b417394c365d46d2feca10b5
This commit is contained in:
drh
parent
648de49c03
commit
4df23a3248
14
manifest
14
manifest
@ -1,5 +1,5 @@
|
||||
C Fix\sharmless\scompiler\swarnings\sand\sa\scode\sindentation\serror.
|
||||
D 2023-02-23T14:43:15.500
|
||||
C Increased\sprecision\sof\sfloating-point\sto\sdecimal\sconversions\swhen\sthe\nfloating\spoint\svalue\shas\sno\sfractional\spart.\n[forum:/forumpost/d1387c3979c7f557|Forum\spost\sd1387c3979c7f557]
|
||||
D 2023-02-23T21:18:47.560
|
||||
F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
|
||||
F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
|
||||
F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
|
||||
@ -617,7 +617,7 @@ F src/pcache1.c dee95e3cd2b61e6512dc814c5ab76d5eb36f0bfc9441dbb4260fccc0d12bbddc
|
||||
F src/pragma.c 82d5090a35eac75876d3b41f48d06b2370553c9576bf2942233c462e03eb94c9
|
||||
F src/pragma.h e690a356c18e98414d2e870ea791c1be1545a714ba623719deb63f7f226d8bb7
|
||||
F src/prepare.c ce87a08cfddd45a147150db34190b1986f2d4a0e0828858cb6bd908c78fb02e3
|
||||
F src/printf.c ff4b05e38bf928ff1b80d3dda4f977b10fe39ecbfe69c018224c7e5594fb2455
|
||||
F src/printf.c d7b8c87d3525ee3eea3c4d291023540c88788e47a65c5b1dcff1b432ec9dbda5
|
||||
F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c
|
||||
F src/resolve.c d62c5665279cc7485f9d45b5e20911cc7b19c203f268321a90d05d74f4725750
|
||||
F src/rowset.c ba9515a922af32abe1f7d39406b9d35730ed65efab9443dc5702693b60854c92
|
||||
@ -1381,7 +1381,7 @@ F test/pragma4.test ca5e4dfc46adfe490f75d73734f70349d95a199e6510973899e502eef2c8
|
||||
F test/pragma5.test 7b33fc43e2e41abf17f35fb73f71b49671a380ea92a6c94b6ce530a25f8d9102
|
||||
F test/pragmafault.test 275edaf3161771d37de60e5c2b412627ac94cef11739236bec12ed1258b240f8
|
||||
F test/prefixes.test b524a1c44bffec225b9aec98bd728480352aa8532ac4c15771fb85e8beef65d9
|
||||
F test/printf.test 390d0d7fcffc3c4ea3c1bb4cbb267444e32b33b048ae21895f23a291844fe1da
|
||||
F test/printf.test 22449e13983e9d94fe9a671db68a086c4c55dea51daad825ef7ebb3d192ee997
|
||||
F test/printf2.test 3f55c1871a5a65507416076f6eb97e738d5210aeda7595a74ee895f2224cce60
|
||||
F test/progress.test ebab27f670bd0d4eb9d20d49cef96e68141d92fb
|
||||
F test/ptrchng.test ef1aa72d6cf35a2bbd0869a649b744e9d84977fc
|
||||
@ -2046,8 +2046,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
|
||||
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
|
||||
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
|
||||
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
|
||||
P 7ee22f95e7a7d8650f961f20e304e56c7813e624f05655d7392ca9347748270f
|
||||
R 6f3dc9114a2c05702b3aef7d84d0887b
|
||||
P de6c5c6bb49a0beca793cdc0462da2c17bb05f3292e08dd815be29b45b59a8fb
|
||||
R 4769ae3a046ae725cd776ab02bbf2890
|
||||
U drh
|
||||
Z ad82adef5ba3f74b5f1d1691fda9e306
|
||||
Z bc3a2ae65a6e7b1f83be3e57f2f8ed26
|
||||
# Remove this line to create a well-formed Fossil manifest.
|
||||
|
||||
@ -1 +1 @@
|
||||
de6c5c6bb49a0beca793cdc0462da2c17bb05f3292e08dd815be29b45b59a8fb
|
||||
18de3a8e6b431a075143631eafdcf0e1b1a21868b417394c365d46d2feca10b5
|
||||
65
src/printf.c
65
src/printf.c
@ -142,6 +142,20 @@ static char et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
|
||||
}
|
||||
#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.
|
||||
*/
|
||||
@ -234,6 +248,8 @@ void sqlite3_str_vappendf(
|
||||
char prefix; /* Prefix character. "+" or "-" or " " or '\0'. */
|
||||
sqlite_uint64 longvalue; /* Value for integer types */
|
||||
LONGDOUBLE_TYPE 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 */
|
||||
@ -540,9 +556,27 @@ void sqlite3_str_vappendf(
|
||||
}else{
|
||||
prefix = flag_prefix;
|
||||
}
|
||||
exp = 0;
|
||||
if( xtype==etGENERIC && precision>0 ) precision--;
|
||||
testcase( precision>0xfff );
|
||||
if( realvalue<1.0e+16
|
||||
&& 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 ){ rnd /= 10; }
|
||||
longvalue += rnd;
|
||||
}
|
||||
}else{
|
||||
msd = 0;
|
||||
longvalue = 0; /* To prevent a compiler warning */
|
||||
idx = precision & 0xfff;
|
||||
if( idx>20 ){
|
||||
rounder = 0.0;
|
||||
}else{
|
||||
rounder = arRound[idx%10];
|
||||
while( idx>=10 ){ rounder *= 1.0e-10; idx -= 10; }
|
||||
if( xtype==etFLOAT ){
|
||||
@ -554,13 +588,14 @@ void sqlite3_str_vappendf(
|
||||
if( precision+(ex/3) < 15 ) rounder += realvalue*3e-16;
|
||||
realvalue += rounder;
|
||||
}
|
||||
/* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
|
||||
exp = 0;
|
||||
}
|
||||
if( sqlite3IsNaN((double)realvalue) ){
|
||||
bufpt = "NaN";
|
||||
length = 3;
|
||||
break;
|
||||
}
|
||||
|
||||
/* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
|
||||
if( realvalue>0.0 ){
|
||||
LONGDOUBLE_TYPE scale = 1.0;
|
||||
while( realvalue>=1e100*scale && exp<=350){ scale*=1e100;exp+=100;}
|
||||
@ -576,16 +611,17 @@ void sqlite3_str_vappendf(
|
||||
length = 3+(prefix!=0);
|
||||
break;
|
||||
}
|
||||
}
|
||||
bufpt = buf;
|
||||
/*
|
||||
** If the field type is etGENERIC, then convert to either etEXP
|
||||
** or etFLOAT, as appropriate.
|
||||
*/
|
||||
if( xtype!=etFLOAT ){
|
||||
realvalue += rounder;
|
||||
if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
** If the field type is etGENERIC, then convert to either etEXP
|
||||
** or etFLOAT, as appropriate.
|
||||
*/
|
||||
if( xtype==etGENERIC ){
|
||||
flag_rtz = !flag_alternateform;
|
||||
if( exp<-4 || exp>precision ){
|
||||
@ -602,6 +638,8 @@ void sqlite3_str_vappendf(
|
||||
}else{
|
||||
e2 = exp;
|
||||
}
|
||||
nsd = 16 + flag_altform2*10;
|
||||
bufpt = buf;
|
||||
{
|
||||
i64 szBufNeeded; /* Size of a temporary buffer needed */
|
||||
szBufNeeded = MAX(e2,0)+(i64)precision+(i64)width+15;
|
||||
@ -611,7 +649,6 @@ void sqlite3_str_vappendf(
|
||||
}
|
||||
}
|
||||
zOut = bufpt;
|
||||
nsd = 16 + flag_altform2*10;
|
||||
flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
|
||||
/* The sign in front of the number */
|
||||
if( prefix ){
|
||||
@ -620,6 +657,10 @@ void sqlite3_str_vappendf(
|
||||
/* Digits prior to the decimal point */
|
||||
if( e2<0 ){
|
||||
*(bufpt++) = '0';
|
||||
}else if( msd>0 ){
|
||||
for(; e2>=0; e2--){
|
||||
*(bufpt++) = et_getdigit_int(&longvalue,&msd);
|
||||
}
|
||||
}else{
|
||||
for(; e2>=0; e2--){
|
||||
*(bufpt++) = et_getdigit(&realvalue,&nsd);
|
||||
@ -636,9 +677,15 @@ void sqlite3_str_vappendf(
|
||||
*(bufpt++) = '0';
|
||||
}
|
||||
/* Significant digits after the decimal point */
|
||||
if( msd>0 ){
|
||||
while( (precision--)>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 ){
|
||||
while( bufpt[-1]=='0' ) *(--bufpt) = 0;
|
||||
|
||||
@ -3786,4 +3786,39 @@ do_execsql_test printf-16.1 {
|
||||
SELECT printf('%.*g',2147483647,0.01);
|
||||
} {0.01}
|
||||
|
||||
# 2023-02-23 https://sqlite.org/forum/forumpost/d1387c3979c7f557
|
||||
# Loss of precision when doing floating-point to decimal
|
||||
# conversions on values that have no factional part.
|
||||
#
|
||||
do_execsql_test printf-17.1 {
|
||||
SELECT format('%!.20g', 13.0);
|
||||
} 13.0
|
||||
do_execsql_test printf-17.2 {
|
||||
SELECT format('%.3e', 199990000.0);
|
||||
} 2.000e+08
|
||||
do_execsql_test printf-17.3 {
|
||||
SELECT format('%.3f', 199990000.0);
|
||||
} 199990000.000
|
||||
do_execsql_test printf-17.4 {
|
||||
SELECT format('%.3g', 199990000.0);
|
||||
} 2e+08
|
||||
do_execsql_test printf-17.5 {
|
||||
SELECT format('%.4e', 199990000.0);
|
||||
} 1.9999e+08
|
||||
do_execsql_test printf-17.6 {
|
||||
SELECT format('%.4f', 199990000.0);
|
||||
} 199990000.0000
|
||||
do_execsql_test printf-17.7 {
|
||||
SELECT format('%.4g', 199990000.0);
|
||||
} 2e+08
|
||||
do_execsql_test printf-17.8 {
|
||||
SELECT format('%.5e', 199990000.0);
|
||||
} 1.99990e+08
|
||||
do_execsql_test printf-17.9 {
|
||||
SELECT format('%.5f', 199990000.0);
|
||||
} 199990000.00000
|
||||
do_execsql_test printf-17.10 {
|
||||
SELECT format('%.5g', 199990000.0);
|
||||
} 1.9999e+08
|
||||
|
||||
finish_test
|
||||
|
||||
Loading…
Reference in New Issue
Block a user