Re: your change to tree-sra.c

[kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)]

    Why isn't it a valid initializer?  It's not valid GIMPLE?

For automatic variables, we *always* clear DECL_INITIAL.

For static variables, the test is if initializer_constant_valid_p is
true for DECL_INITIAL.  If it is, then we can leave it set and the
assembler/linker will take care of it.

But if it *isn't* true, then we have to initialize it with code that's
placed somewhere.  There's no place to put such code in C, so it's
not allowed in the language.  But there is in Ada, the elaboration
procedure, so it is allowed.

The Ada code does the same thing that gimplify_decl_expr does: clears
DECL_INITIAL and arranges for it to be initialized some other way.

    I don't think we should give 3 meanings to a binary value.  DECL_INITIAL
    NULL -> it's not initialize.  DECL_INITIAL non-NULL -> it is
    initialized.  We use this in CCP.

I don't follow.   Are you talking about just the static case?  If the
automatic case, you can't derive *any* info from DECL_INITIAL since it's
always zero.

But do you care what the value is?  Should we define DECL_INITIAL for
statics being ERROR_MARK as saying that it's actually initialized?