Porting C code to the LP64 data model

The following list identifies some key points about porting C code to the LP64 data model:

• C long type grows to 64 bits
• C pointer types, e.g. char*, grow to 64 bits
• all other data types are unchanged from the 32-bit world
• C long and pointer types don't fit in a C int
• functions with no visible prototype are assumed to return int
• C long and pointer values are truncated to 32 bits when

- returned as an int type

- assigned to an int type

- cast to an int type

- printf %d or %x formats are used instead of %ld or %lx

• ints are zero- or sign-extended to 64 bits when

- returned as a long or pointer type

- assigned to a long or pointer type

- cast to a long or pointer type

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