http://docs.sun.com/app/docs/doc/820-4155

Sun[tm] Studio 12: C++ 5.9 Compiler Readme

C. New and Changed Features

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A New Way To Specify 32-bit or 64-bit Address Model

You no longer need use the -xarch option to specify a 32-bit or 64-bit address model (LP64 versus ILP32). Two new options make it easier:

-m32 specifies the ILP32 model: 32-bit ints, longs, and pointer types.

-m64 specifies the LP64 model: 32-bit ints, 64-bit longs and pointers types. (Note that -m64 is the default on 64-bit Linux platforms.)

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Deprecated -xarch Flags and Their Replacements on SPARC Only

Use -xarch=sparc in place of -xarch=v8plus

Use -xarch=sparcvis in place of -xarch=v8plusa

Use -xarch=sparcvis2 in place of -xarch=v8plusb

Use -xarch=sparc -m64 in place of -xarch=v9

Use -xarch=sparcvis -m64 in place of -xarch=v9a

Use -xarch=sparcvis2 -m64 in place of -xarch=v9b