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Re: [tree-ssa] Copy prop into virtual operands

On Tue, 2003-07-29 at 11:14, Andrew MacLeod wrote:

> > Right.  But I don't see how we would get into this situation.  After
> > all, we only do constant propagation on real operands.
> > 
> How do you know what a real operand is now?  you don't have a flag any
> more...
> 
CCP only propagates from def_ops() into use_ops().  We only follow
use-def chains on real operands, not virtual.  And any definition coming
from anything but the LHS of a MODIFY_EXPR is considered VARYING.


Diego.
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