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Diffstat (limited to 'TAO/tao/Align.h')
-rw-r--r-- | TAO/tao/Align.h | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/TAO/tao/Align.h b/TAO/tao/Align.h new file mode 100644 index 00000000000..14a670b7f7d --- /dev/null +++ b/TAO/tao/Align.h @@ -0,0 +1,82 @@ +// This may look like C, but it's really -*- C++ -*- +// @(#) $Id$ + +// ============================================================================ +// +// = LIBRARY +// TAO +// +// = FILENAME +// align.h +// +// = DESCRIPTION +// Pointer alignment utilities +// +// A "ptr_arith_t" type is defined for doing numerical operations +// on pointers, such as aligning them. Pointer sizes vary from 2 +// to 8 bytes in today's environments; a portable data type is much +// needed. +// +// = AUTHOR +// Copyright 1994-1995 by Sun Microsystems, Inc. +// +// ============================================================================ + +#if !defined (TAO_ALIGN_H) +#define TAO_ALIGN_H + +// Type for doing arithmetic on pointers ... as elsewhere, we assume +// that "unsigned" versions of a type are the same size as the +// "signed" version of the same type. + +#if ACE_SIZEOF_VOID_P == ACE_SIZEOF_INT +typedef u_int ptr_arith_t; + +#elif ACE_SIZEOF_VOID_P == ACE_SIZEOF_LONG +typedef u_long ptr_arith_t; + +#elif ACE_SIZEOF_VOID_P == ACE_SIZEOF_LONG_LONG +typedef u_long long ptr_arith_t; + +#else +# error "Can't find a suitable type for doing pointer arithmetic." +#endif /* error */ + +// Efficiently align "value" up to "alignment", knowing that all such +// boundaries are binary powers and that we're using two's complement +// arithmetic. + +#if 0 +static inline ptr_arith_t +align_binary (const ptr_arith_t value, + size_t alignment) +{ + ptr_arith_t temp = alignment - 1; + + return (value + temp) & ~temp; +} +#endif /* 0 */ +#define align_binary(ptr, alignment) \ + ((ptr + ((ptr_arith_t)((alignment)-1))) & (~((ptr_arith_t)((alignment)-1)))) + +// Efficiently round "ptr" up to an "alignment" boundary, knowing that +// all such boundaries are binary powers and that we're using two's +// complement arithmetic. +// +// XXX Returned as "byte pointer" -- CDR module would change to be +// seen as a "void *". May want to change this to add XDR cleanly. + +// @@ Andy, do we still need this function or is the macro sufficient? +// If the macro is sufficient can we remove the function? +#if 0 +static inline u_char * +ptr_align_binary (const u_char *ptr, + size_t alignment) +{ + return (u_char *) align_binary ((ptr_arith_t) ptr, alignment); +} +#endif /* 0 */ +#define ptr_align_binary(ptr, alignment) \ + ((u_char *) align_binary (((ptr_arith_t) (ptr)), (alignment))) + +#endif /* TAO_ALIGN_H */ |