Hi, Support,
I've found the strange behavior in the rtree.c file.
I think that in the static int writeInt64(u8 *p, i64 i) function.
static int writeInt64(u8 *p, i64 i){
#if SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000
i = (i64)__builtin_bswap64((u64)i);
memcpy(p, &i, 8);
#elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300
i = (i64)_byteswap_uint64((u64)i);
memcpy(p, &i, 8);
#elif SQLITE_BYTEORDER==4321
memcpy(p, &i, 8);
#else
p[0] = (i>>56)&0xFF;
p[1] = (i>>48)&0xFF;
p[2] = (i>>40)&0xFF;
p[3] = (i>>32)&0xFF;
p[4] = (i>>24)&0xFF;
p[5] = (i>>16)&0xFF;
p[6] = (i>> 8)&0xFF;
p[7] = (i>> 0)&0xFF;
#endif
return 8;
}
If I build the SQLite with option 'Compile as C Code (/TC)' I've got the
warning warning C4013: '_byteswap_uint64' undefined; assuming extern returning
int
The highlighted line of function works incorrectly if #include <stdlib.h> is
missed. For example, it returns 0 value if i=1000 was passed into the function
_byteswap_uint64.
Steps to reproduce:
1. Create console application in Visual Studio. The source code is below.
#include "stdafx.h"
//#include <stdlib.h>
static __int64 writeInt64(char *p, __int64 i) {
i = (__int64)_byteswap_uint64((unsigned __int64)i);
memcpy(p, &i, 8);
return 8;
}
int main()
{
unsigned __int64 i = 1000;
char buff[8] = { 0, };
i = writeInt64(buff, i);
return 0;
}
1. Build it with the option 'Compile as C Code (/TC)'
2. Set breakpoint on the i = (__int64)_byteswap_uint64((unsigned __int64)i);
3. Run it and call 'Go to Disassembled'
w/o #include <stdlib.h>
i = (__int64)_byteswap_uint64((unsigned __int64)i);
008F17CE mov eax,dword ptr [ebp+10h]
008F17D1 push eax
008F17D2 mov ecx,dword ptr [i]
008F17D5 push ecx
008F17D6 call __byteswap_uint64 (08F1348h)
008F17DB add esp,8
008F17DE cdq
008F17DF mov dword ptr [i],eax
008F17E2 mov dword ptr [ebp+10h],edx
with #include <stdlib.h>
i = (__int64)_byteswap_uint64((unsigned __int64)i);
001217CE mov eax,dword ptr [ebp+10h]
001217D1 push eax
001217D2 mov ecx,dword ptr [i]
001217D5 push ecx
001217D6 call __byteswap_uint64 (0121348h)
001217DB add esp,8
001217DE mov dword ptr [i],eax
001217E1 mov dword ptr [ebp+10h],edx
Best Regards,
Alexander Ananin
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