* expr.h (STACK_SIZE_MODE): New macro.
        * explow.c (allocate_dynamic_stack_space): Use it for
        mode of allocate_stack pattern increment operand.
        * tm.texi (STACK_SAVEAREA_MODE, STACK_SIZE_MODE): Document.
        * md.texi (stack_save_block, ...): Reflect use of macro.
        * rs6000.h (PROMOTE_MODE): Always promote to word_mode.
        (PROMOTE_FUNCTION_ARGS): Define.
        (PROMOTE_FUNCTION_RETURN): Define.
        (FUNCTION_VALUE): Promote to word_mode if smaller.
        Convert to gen_rtx_FOO.
        * rs6000.md (call_indirect): Store doubleword in 64-bit mode.
        Convert to gen_rtx_FOO.

From-SVN: r20893