[cfe-commits] r133261 - in /cfe/trunk: lib/CodeGen/CGExprAgg.cpp test/CodeGen/compound-literal.c

Chris Lattner clattner at apple.com
Fri Jun 17 09:46:49 PDT 2011

On Jun 17, 2011, at 9:37 AM, Douglas Gregor wrote:

> I'm deeply suspicious of AggExprEmitter::VisitBinAssign()'s
> optimization where it emits the RHS of an aggregate assignment
> directly into the LHS lvalue without checking whether there is any
> aliasing between the LHS/RHS. However, I'm not in a position to
> revisit this now.

FWIW, it is making the assumption that the LHS/RHS either don't alias, or that they *exactly* alias.  The LLVM optimizer (and gcc fwiw) make the assumption that memcpy(X,X, ...) is safe.


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