set construction, rather than intersecting various std::sets. This reduces
the memory usage for the testcase in PR681 from 496 to 26MB of ram on my
darwin system, and reduces the runtime from 32.8 to 0.8 seconds on a
2.5GHz G5. This also enables future code sharing between Dom and PostDom
now that they share near-identical implementations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26707 91177308-0d34-0410-b5e6-96231b3b80d8
unify all exit nodes of a function to compute post-dominance information.
This does not work with functions that have both unwind and return nodes,
because we cannot unify these blocks. The new implementation is better
anyway. :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8459 91177308-0d34-0410-b5e6-96231b3b80d8
