 | Flat Address with 64-bit pointers
 | Allows access to 512GB virtual memory |
|
| Small Address Space
| Pointers are 32-bits |
| Restricts access to 2GB virtual memory |
| Provides instruction reordering and other optimizations for IA-64 |
| 64-bit pointers are allowed, but upper 32 bits are zeroes |
|
| IA-32 Compatability
| Pointers are 32-bits |
| 2GB Virtual Memory Limitation |
| No IA-64 Optimizations |
|
| Mixed Mode
| Flat address with both 64-bit and 32-bit pointers |
| 32-bit pointers are offset pointers relative to an originating 64-bit
pointer |
| Access to 512GB virtual memory through 64-bit pointers |
|
| Small Address Space with 64-bit pointers
| Pointers are 64-bits |
| Restricts access to 2GB virtual memory |
| All 64-bit pointers are cast to 32-bit ints or longs |
|
