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8af8091ef5
Some benchmarks have shown that this could lead to a potential performance benefit, and so adding some flags to try to help measure the difference. A possible explanation. In diamond-shaped CFGs (A followed by either B or C both followed by D), putting B and C both in between A and D leads to the code being less dense than it could be. Always either B or C have to be skipped increasing the chance of cache misses etc. Moving either B or C to after D might be beneficial on average. In the long run, but we should probably do a better job of analyzing the basic block and branch probabilities to move the correct one of B or C to after D. But even if we don't use this in the long run, it is a good baseline for benchmarking. Original patch authored by Daniel Jasper with test tweaks and a second flag added by me. Differential Revision: http://reviews.llvm.org/D6969 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226034 91177308-0d34-0410-b5e6-96231b3b80d8