Patch to allow Ada to work with tree-ssa

[Nathan Sidwell]

Richard Kenner wrote:
>     In particular, you've just added an extra entry to ARRAY_REF and
>     COMPONENT_REF, making these two common tree nodes bigger.
>     (COMPONENT_REF, in particular, is used extensively in C++; every
>     access to a class member variable is a COMPONENT_REF.)  These extra
>     entries are unnecessary in C and C++, meaning that for GCC's two
>     most-used languages you've just increased memory usage with no
>     benefit.  If you need some additional stuff for Ada, please find a way
>     that doesn't penalize C and C++.
> 
> Here's the specific test case for C.  I note that it isn't valid C++,
> but I don't know C++ well enough to make a similar case there.  Note
> that the proposal involving using an INDIRECT_REF won't work with this
> case because it's a bitfield.
> 
> int
> sub1 (int n)
> {
>   struct foo {int arr[n]; int filler : 3; int fld : 4;} x;
> 
>   return x.fld;
> }
This is not valid C89, C90, or documented as a GNU extension.

nathan

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