How to align a global array in C.

[rajivatbytes]

I need a global array in C to be aligned (say 64 Bytes) to store a data of oder of KBs.

I don't want to do dynamic allocation as this would be copy of huge data.


any suggestion will be appreciated.

Thanks in advance.

[weaknessforcats]

Memory for global data may be limited.

I suggest you use the heap.

Why 64-byte alognment?

[donbock]

What is the array type (array of shorts, ints, longs, structures)?

Is your alignment criteria any more stringent than that imposed by your processor on a single element of the array?

[rajivatbytes]

Memory for global data may be limited.

I suggest you use the heap.

[rajivatbytes]: its so required as data is some DSP codec which would be copied on DSP RAM on need basis.

Why 64-byte alognment?

[rajivatbytes]: its some hardware requirement.

[rajivatbytes]

What is the array type (array of shorts, ints, longs, structures)?
[rajivatbytes]: its an array of integer(i guess data type should not effect).

Is your alignment criteria any more stringent than that imposed by your processor on a single element of the array?
[rajivatbytes]: all data should be contagious(very nature of array) and first member of the array should be at the address which is aligned at 64K boundary.

please find my comment inline.

Thanks,

[donbock]

There is no portable way in C to insure some arbitrary alignment for a static variable. (By "arbitrary" I mean that the alignment requirement is unrelated to the data type of the static variable; not that you don't have a good reason for it.)

That said; there are nonportable ways to achieve a desired alignment. Some compilers provide special keywords for setting the alignment (#pragma, __attribute__, etc.). Some linkers provide syntax for aligning particular memory segments. It all depends on which compiler and linker you're using.