Support for 64-bit architectures: generic support

- Introduce Archi.ptr64 parameter.
- Define module Ptrofs of integers as wide as a pointer (64 if Archi.ptr64, 32 otherwise).
- Use Ptrofs.int as the offset type for Vptr values and anywhere pointer offsets are manipulated.
- Modify Val operations that handle pointers (e.g. Val.add, Val.sub, Val.cmpu) so that in 64-bit pointer mode it is the "long" operation (e.g. Val.addl, Val.subl, Val.cmplu) that handles pointers.
- Update the memory model accordingly.
- Modify C operations that handle pointers (e.g. addition, subtraction, comparisons) accordingly.
- Make it possible to turn off the splitting of 64-bit integers into pairs of 32-bit integers.
- Update the compiler front-end and back-end accordingly.

1 files changed, 5 insertions, 5 deletions

diff --git a/test/regression/alias.c b/test/regression/alias.c
index 9887ae2b..925979cb 100644
--- a/test/regression/alias.c
+++ b/test/regression/alias.c
@@ -69,14 +69,14 @@ int get4(void)
   return x;
 }
 
-/* Byte-swapping a pointer */
+/* Byte-swapping a pointer.  For 32/64 bit compatibility, we just swap
+   the two low bytes, but that's in the spirit. */
 
 inline uintptr_t bswap(uintptr_t x)
 {
-  return (x >> 24)
-    | (((x >> 16) & 0xFF) << 8)
-    | (((x >> 8) & 0xFF) << 16)
-    | ((x & 0xFF) << 24);
+  return (x & ~((uintptr_t) 0xFFFF))
+    | ((x >> 8) & 0xFF)
+    | ((x << 8) & 0xFF00);
 }
 
 void NOINLINE set5(uintptr_t x)