| Index: third_party/sqlite/src/ext/misc/ieee754.c
|
| diff --git a/third_party/sqlite/src/ext/misc/ieee754.c b/third_party/sqlite/src/ext/misc/ieee754.c
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..f1438938857723b53d32b2ce14ce31c62310efd9
|
| --- /dev/null
|
| +++ b/third_party/sqlite/src/ext/misc/ieee754.c
|
| @@ -0,0 +1,131 @@
|
| +/*
|
| +** 2013-04-17
|
| +**
|
| +** The author disclaims copyright to this source code. In place of
|
| +** a legal notice, here is a blessing:
|
| +**
|
| +** May you do good and not evil.
|
| +** May you find forgiveness for yourself and forgive others.
|
| +** May you share freely, never taking more than you give.
|
| +**
|
| +******************************************************************************
|
| +**
|
| +** This SQLite extension implements functions for the exact display
|
| +** and input of IEEE754 Binary64 floating-point numbers.
|
| +**
|
| +** ieee754(X)
|
| +** ieee754(Y,Z)
|
| +**
|
| +** In the first form, the value X should be a floating-point number.
|
| +** The function will return a string of the form 'ieee754(Y,Z)' where
|
| +** Y and Z are integers such that X==Y*pow(2,Z).
|
| +**
|
| +** In the second form, Y and Z are integers which are the mantissa and
|
| +** base-2 exponent of a new floating point number. The function returns
|
| +** a floating-point value equal to Y*pow(2,Z).
|
| +**
|
| +** Examples:
|
| +**
|
| +** ieee754(2.0) -> 'ieee754(2,0)'
|
| +** ieee754(45.25) -> 'ieee754(181,-2)'
|
| +** ieee754(2, 0) -> 2.0
|
| +** ieee754(181, -2) -> 45.25
|
| +*/
|
| +#include "sqlite3ext.h"
|
| +SQLITE_EXTENSION_INIT1
|
| +#include <assert.h>
|
| +#include <string.h>
|
| +
|
| +/*
|
| +** Implementation of the ieee754() function
|
| +*/
|
| +static void ieee754func(
|
| + sqlite3_context *context,
|
| + int argc,
|
| + sqlite3_value **argv
|
| +){
|
| + if( argc==1 ){
|
| + sqlite3_int64 m, a;
|
| + double r;
|
| + int e;
|
| + int isNeg;
|
| + char zResult[100];
|
| + assert( sizeof(m)==sizeof(r) );
|
| + if( sqlite3_value_type(argv[0])!=SQLITE_FLOAT ) return;
|
| + r = sqlite3_value_double(argv[0]);
|
| + if( r<0.0 ){
|
| + isNeg = 1;
|
| + r = -r;
|
| + }else{
|
| + isNeg = 0;
|
| + }
|
| + memcpy(&a,&r,sizeof(a));
|
| + if( a==0 ){
|
| + e = 0;
|
| + m = 0;
|
| + }else{
|
| + e = a>>52;
|
| + m = a & ((((sqlite3_int64)1)<<52)-1);
|
| + m |= ((sqlite3_int64)1)<<52;
|
| + while( e<1075 && m>0 && (m&1)==0 ){
|
| + m >>= 1;
|
| + e++;
|
| + }
|
| + if( isNeg ) m = -m;
|
| + }
|
| + sqlite3_snprintf(sizeof(zResult), zResult, "ieee754(%lld,%d)",
|
| + m, e-1075);
|
| + sqlite3_result_text(context, zResult, -1, SQLITE_TRANSIENT);
|
| + }else if( argc==2 ){
|
| + sqlite3_int64 m, e, a;
|
| + double r;
|
| + int isNeg = 0;
|
| + m = sqlite3_value_int64(argv[0]);
|
| + e = sqlite3_value_int64(argv[1]);
|
| + if( m<0 ){
|
| + isNeg = 1;
|
| + m = -m;
|
| + if( m<0 ) return;
|
| + }else if( m==0 && e>1000 && e<1000 ){
|
| + sqlite3_result_double(context, 0.0);
|
| + return;
|
| + }
|
| + while( (m>>32)&0xffe00000 ){
|
| + m >>= 1;
|
| + e++;
|
| + }
|
| + while( ((m>>32)&0xfff00000)==0 ){
|
| + m <<= 1;
|
| + e--;
|
| + }
|
| + e += 1075;
|
| + if( e<0 ) e = m = 0;
|
| + if( e>0x7ff ) m = 0;
|
| + a = m & ((((sqlite3_int64)1)<<52)-1);
|
| + a |= e<<52;
|
| + if( isNeg ) a |= ((sqlite3_int64)1)<<63;
|
| + memcpy(&r, &a, sizeof(r));
|
| + sqlite3_result_double(context, r);
|
| + }
|
| +}
|
| +
|
| +
|
| +#ifdef _WIN32
|
| +__declspec(dllexport)
|
| +#endif
|
| +int sqlite3_ieee_init(
|
| + sqlite3 *db,
|
| + char **pzErrMsg,
|
| + const sqlite3_api_routines *pApi
|
| +){
|
| + int rc = SQLITE_OK;
|
| + SQLITE_EXTENSION_INIT2(pApi);
|
| + (void)pzErrMsg; /* Unused parameter */
|
| + rc = sqlite3_create_function(db, "ieee754", 1, SQLITE_UTF8, 0,
|
| + ieee754func, 0, 0);
|
| + if( rc==SQLITE_OK ){
|
| + rc = sqlite3_create_function(db, "ieee754", 2, SQLITE_UTF8, 0,
|
| + ieee754func, 0, 0);
|
| + }
|
| + return rc;
|
| +}
|
|
|