iOS 64bit対応ではまったところ (書きかけ) ref: http://qiita.com/naotokui/items/38c9176ebece6aadf172

file0.m

#if defined(__LP64__) && __LP64__
# define CGFLOAT_TYPE double
# define CGFLOAT_IS_DOUBLE 1
# define CGFLOAT_MIN DBL_MIN
# define CGFLOAT_MAX DBL_MAX
#else
# define CGFLOAT_TYPE float
# define CGFLOAT_IS_DOUBLE 0
# define CGFLOAT_MIN FLT_MIN
# define CGFLOAT_MAX FLT_MAX
#endif

typedef CGFLOAT_TYPE CGFloat;

file1.m

 - (CGFloat) tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section

file2.m

 - (float) tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section

file3.m

#if __LP64__ || (TARGET_OS_EMBEDDED && !TARGET_OS_IPHONE) || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
typedef long NSInteger;
typedef unsigned long NSUInteger;
#else
typedef int NSInteger;
typedef unsigned int NSUInteger;
#endif

file4.m

int index = [someArray indexOfObject: someObj];
if ( index !=  NSNotFound) { ... }