struct

[Andrew Haley]

On 09/30/2018 06:44 PM, sundaresh wrote:
> Why do struct's take up a lot more memory than the sum of the sizes of its
> members ? This increases by even a lot more the larger the struct gets . If
> the compiler is doing padding or aligning I would like to disable and not
> have that at all since it is unnecessarily wasteful of memory ? I
> encountered a similar problem when declaring floating point variables
> independently outside a struct. The problem becomes worse if these floating
> point variables are struct members.

Alignment, usually. But it's worth noting that GCC follows the system
ABI specfication for laying out structures in memory. We usually don't
get to decide how it's done.

-- 
Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
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