Adam Nemet 63ebf9bb19 Handle non-unique edges in edge-dominance ... This removes a quadratic behavior in assert-enabled builds. GVN propagates the equivalence from a condition into the blocks guarded by the condition. E.g. for 'if (a == 7) { ... }', 'a' will be replaced in the block with 7. It does this by replacing all the uses of 'a' that are dominated by the true edge. For a switch with N cases and U uses of the value, this will mean N * U calls to 'dominates'. Asserting isSingleEdge in 'dominates' make this N^2 * U because this function checks for the uniqueness of the edge. I.e. traverses each edge between the SwitchInst's block and the cases. The change removes the assert and makes 'dominates' works correctly in the presence of non-unique edges. This brings build time down by an order of magnitude for an input that has ~10k cases in a switch statement. Differential Revision: https://reviews.llvm.org/D33584 llvm-svn: 304721		2017-06-05 16:27:09 +00:00
..
llvm	Handle non-unique edges in edge-dominance	2017-06-05 16:27:09 +00:00
llvm-c	[LLVM-C] [OCaml] Expose Type::subtypes.	2017-06-05 11:49:52 +00:00