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Diffstat (limited to 'lib/libsqlite3/ext/misc/ieee754.c')
-rw-r--r-- | lib/libsqlite3/ext/misc/ieee754.c | 131 |
1 files changed, 0 insertions, 131 deletions
diff --git a/lib/libsqlite3/ext/misc/ieee754.c b/lib/libsqlite3/ext/misc/ieee754.c deleted file mode 100644 index f1438938857..00000000000 --- a/lib/libsqlite3/ext/misc/ieee754.c +++ /dev/null @@ -1,131 +0,0 @@ -/* -** 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; -} |