When compiling pixman for 64-bit Windows (where int and long are 32 still bits, pointers  and "long long" 64 bits) at least gcc 4.4 emits quite a lot of warnings because the code casts pointers to unsigned long. It's better to cast to uintptr_t instead. Unfortunately, not all platforms have <stdint.h>, for instance not even the latest MS Visial Studio. So some boring ifdefs are presumably required.

I will attach a patch, but it needs work at least because it has no ifdef logic to typedef uintptr_t for platforms that don't have it.