[PATCH] D100464: [DSE] Remove stores in the same loop iteration

[Chang Lin via Phabricator via llvm-commits]

clin1 added a comment.

@dmgreen, we found that DSE is removing a non dead store in a loop with multiple backedges. File "dse-double-loop.ll" attached. The 2nd store postdominates the 1st one, but it doesn't run on every iteration, so the 1st one is still needed. We worked around it by checking numBackEdges > 1 in addition to the irreducibility check. Would you mind taking a look? I hope bugpoint did not over-reduce the test case; it's derived from "real" code in spec2000 186.crafty. F17292378: dse-double-loop.ll <https://reviews.llvm.org/F17292378>


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https://reviews.llvm.org/D100464