[patch] bsi_for_stmt

Jeffrey A Law law@redhat.com
Mon Aug 30 21:25:00 GMT 2004


On Mon, 2004-08-30 at 13:58, Andrew Pinski wrote:
> On Aug 30, 2004, at 12:42 PM, Diego Novillo wrote:
> 
> > On Mon, 2004-08-30 at 15:27, Zdenek Dvorak wrote:
> >
> >> suppose you want to replace a statement defining a SSA name by some
> >> other computation.
> >>
> > You just modify the statement's RHS.  Or do you mean replacing a
> > CALL_EXPR or an ASM_EXPR?  Again, I need a specific example with more
> > context.
> 
> 
> For an example (for me):
> 
> I have the following stmt:
> 
> *a_1 = 0;
> 
> I want to remove it, replacing the RHS will not work but replacing the 
> LHS
> with a temporary variable will work but it seems like more work as you 
> have
> to do SSA_rename on that new variable.
Well, you could easily replace the toplevel MODIFY_EXPR node with
a NOP conversion node.

But we're starting to build into the tree-ssa code stuff that looks
a whole lot like NOTE_INSN_DELETED from the RTL world, a mistake I'm
not too inclined to want to repeat again.

I'm starting to lean towards providing a means to get to the container
for each statement....

jeff




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