SSA operand interface change proposal

[Andrew MacLeod]

On Tue, 2004-06-15 at 14:38, Zdenek Dvorak wrote:
> Hello,
> 
> > As best I can tell, the 'ivuse' structure used thorughout
> > tree-ssa-loop-ivopts.c contains a pointer to a tree which can be either
> > a use, a def, or an expression of some sort.  If we proceed with an
> > interface like this (which I think we ought to), this hunk of code will
> > need to be reworked. I dont want to make this unbearably difficult
> > however.  I guess the ivuse structure could have all three pointers
> > (use_operand_p, def_operand_p, and tree *) , and a flag indicating which
> > field it uses, but maybe there is a better solution.
> 
> in fact what *op_p refers to is determined by the enum use_type type
> field.  So you can just make it an union and updating the code to
> reflect this should be trivial.

Then in fact there may have no issue at all :-)  I'll provide an LNO
patch along with the mainline patch which does everything except for
those bits then.

Andrew