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Diffstat (limited to 'compiler/cmm/CmmCommonBlockElim.hs')
| -rw-r--r-- | compiler/cmm/CmmCommonBlockElim.hs | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/compiler/cmm/CmmCommonBlockElim.hs b/compiler/cmm/CmmCommonBlockElim.hs index fce8f7dae8..c91d553c47 100644 --- a/compiler/cmm/CmmCommonBlockElim.hs +++ b/compiler/cmm/CmmCommonBlockElim.hs @@ -64,7 +64,9 @@ elimCommonBlocks :: CmmGraph -> CmmGraph elimCommonBlocks g = replaceLabels env $ copyTicks env g where env = iterate mapEmpty blocks_with_key - groups = groupByInt hash_block (postorderDfs g) + -- The order of blocks doesn't matter here, but revPostorder also drops any + -- unreachable blocks, which is useful. + groups = groupByInt hash_block (revPostorder g) blocks_with_key = [ [ (successors b, [b]) | b <- bs] | bs <- groups] -- Invariant: The blocks in the list are pairwise distinct |