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Re: Short Displacement Problems.
- From: Joe Buck <Joe dot Buck at synopsys dot com>
- To: jh at suse dot cz (Jan Hubicka)
- Cc: zack at codesourcery dot com (Zack Weinberg),naveens at noida dot hcltech dot com (Naveen Sharma Noida),joern dot rennecke at superh dot com (Joern Rennecke), law at redhat dot com,aoliva at redhat dot com (Alexandre Oliva), bernds at redhat dot com,gniibe at m17n dot org, rth at redhat dot com (Richard Henderson), gcc at gcc dot gnu dot org
- Date: Thu, 30 May 2002 10:29:28 -0700 (PDT)
- Subject: Re: Short Displacement Problems.
> In my experiments I've been simply using ADRESSOF as kind of "ticket for
> stack slot" and it appears to work pretty well up to the reload. Major
> problem is that lowering the code may result in CSEable expressions.
Right, but the problem is that ADDRESSOF doesn't work in general for
structs. The result is a huge penalty in C++ for temporary objects
with more than one data member, compared to with one.
Stack slot assignment probably isn't worth the bother unless it works
for structs, not just objects that have a mode that GCC knows about.