database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-11-14 00:22:38 +03:00
Code Activity

Add compile-time option -DSQLITE_MIXED_ENDIAN_64BIT_FLOAT=1 that uses

Browse Source 
mixed-endian doubles.  This is needed on ARM7 to make database file
formats compatible with all other processors.  Tickets #2278 and #2335. (CVS 3913)

FossilOrigin-Name: 2a178d0c7950c9d403c0bc43c2043de945fb24e0
This commit is contained in:
drh
2007-05-04 11:59:31 +00:00
parent da10719890
commit 110daac9a1
4 changed files with 45 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
src/vdbeaux.c
View File

@@ -1767,6 +1767,32 @@ int sqlite3VdbeSerialTypeLen(u32 serial_type){
}
}
/*
** If we are on an architecture with mixed-endian floating
*** points (ex: ARM7) then swap the lower 4 bytes with the
** upper 4 bytes. Return the result.
**
** For most (sane) architectures, this is a no-op.
*/
#ifdef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
static double floatSwap(double in){
union {
double r;
u32 i[2];
} u;
u32 t;
u.r = in;
t = u.i[0];
u.i[0] = u.i[1];
u.i[1] = t;
return u.r;
}
# define swapMixedEndianFloat(X) X = floatSwap(X)
#else
# define swapMixedEndianFloat(X)
#endif
/*
** Write the serialized data blob for the value stored in pMem into
** buf. It is assumed that the caller has allocated sufficient space.
@@ -1795,6 +1821,7 @@ int sqlite3VdbeSerialPut(u8 *buf, int nBuf, Mem *pMem, int file_format){
int i;
if( serial_type==7 ){
assert( sizeof(v)==sizeof(pMem->r) );
swapMixedEndianFloat(pMem->r);
memcpy(&v, &pMem->r, sizeof(v));
}else{
v = pMem->u.i;
@@ -1879,11 +1906,15 @@ int sqlite3VdbeSerialGet(
u32 y;
#if !defined(NDEBUG) && !defined(SQLITE_OMIT_FLOATING_POINT)
/* Verify that integers and floating point values use the same
** byte order. The byte order differs on some (broken) architectures.
** byte order. Or, that if SQLITE_MIXED_ENDIAN_64BIT_FLOAT is
** defined that 64-bit floating point values really are mixed
** endian.
*/
static const u64 t1 = ((u64)0x3ff00000)<<32;
static const double r1 = 1.0;
assert( sizeof(r1)==sizeof(t1) && memcmp(&r1, &t1, sizeof(r1))==0 );
double r2 = r1;
swapMixedEndianFloat(r2);
assert( sizeof(r2)==sizeof(t1) && memcmp(&r2, &t1, sizeof(r1))==0 );
#endif
x = (buf[0]<<24) | (buf[1]<<16) | (buf[2]<<8) | buf[3];
@@ -1895,7 +1926,7 @@ int sqlite3VdbeSerialGet(
}else{
assert( sizeof(x)==8 && sizeof(pMem->r)==8 );
memcpy(&pMem->r, &x, sizeof(x));
/* pMem->r = *(double*)&x; */
swapMixedEndianFloat(pMem->r);
pMem->flags = MEM_Real;
}
return 8;