How to find if native dll is compiled as x64 or x86?
You can use dumpbin too. Use the /headers or /all flag and it's the first file header listed.
dumpbin /headers cv210.dll
64-bit:
Microsoft (R) COFF/PE Dumper Version 10.00.30319.01
Copyright (C) Microsoft Corporation. All rights reserved.
Dump of file cv210.dll
PE signature found
File Type: DLL
FILE HEADER VALUES
8664 machine (x64)
6 number of sections
4BBAB813 time date stamp Tue Apr 06 12:26:59 2010
0 file pointer to symbol table
0 number of symbols
F0 size of optional header
2022 characteristics
Executable
Application can handle large (>2GB) addresses
DLL
32-bit:
Microsoft (R) COFF/PE Dumper Version 10.00.30319.01
Copyright (C) Microsoft Corporation. All rights reserved.
Dump of file acrdlg.dll
PE signature found
File Type: DLL
FILE HEADER VALUES
14C machine (x86)
5 number of sections
467AFDD2 time date stamp Fri Jun 22 06:38:10 2007
0 file pointer to symbol table
0 number of symbols
E0 size of optional header
2306 characteristics
Executable
Line numbers stripped
32 bit word machine
Debug information stripped
DLL
'find' can make life slightly easier:
dumpbin /headers cv210.dll |find "machine"
8664 machine (x64)