diff options
Diffstat (limited to 'compiler/cmm/Hoopl/Dataflow.hs')
| -rw-r--r-- | compiler/cmm/Hoopl/Dataflow.hs | 29 |
1 files changed, 11 insertions, 18 deletions
diff --git a/compiler/cmm/Hoopl/Dataflow.hs b/compiler/cmm/Hoopl/Dataflow.hs index 0b0434bb36..2538b70ee3 100644 --- a/compiler/cmm/Hoopl/Dataflow.hs +++ b/compiler/cmm/Hoopl/Dataflow.hs @@ -111,8 +111,7 @@ analyzeCmm dir lattice transfer cmmGraph initFact = blockMap = case hooplGraph of GMany NothingO bm NothingO -> bm - entries = if mapNull initFact then [entry] else mapKeys initFact - in fixpointAnalysis dir lattice transfer entries blockMap initFact + in fixpointAnalysis dir lattice transfer entry blockMap initFact -- Fixpoint algorithm. fixpointAnalysis @@ -120,16 +119,16 @@ fixpointAnalysis Direction -> DataflowLattice f -> TransferFun f - -> [Label] + -> Label -> LabelMap CmmBlock -> FactBase f -> FactBase f -fixpointAnalysis direction lattice do_block entries blockmap = loop start +fixpointAnalysis direction lattice do_block entry blockmap = loop start where -- Sorting the blocks helps to minimize the number of times we need to -- process blocks. For instance, for forward analysis we want to look at -- blocks in reverse postorder. Also, see comments for sortBlocks. - blocks = sortBlocks direction entries blockmap + blocks = sortBlocks direction entry blockmap num_blocks = length blocks block_arr = {-# SCC "block_arr" #-} listArray (0, num_blocks - 1) blocks start = {-# SCC "start" #-} IntSet.fromDistinctAscList @@ -174,9 +173,8 @@ rewriteCmm dir lattice rwFun cmmGraph initFact = do blockMap1 = case hooplGraph of GMany NothingO bm NothingO -> bm - entries = if mapNull initFact then [entry] else mapKeys initFact (blockMap2, facts) <- - fixpointRewrite dir lattice rwFun entries blockMap1 initFact + fixpointRewrite dir lattice rwFun entry blockMap1 initFact return (cmmGraph {g_graph = GMany NothingO blockMap2 NothingO}, facts) fixpointRewrite @@ -184,16 +182,16 @@ fixpointRewrite Direction -> DataflowLattice f -> RewriteFun f - -> [Label] + -> Label -> LabelMap CmmBlock -> FactBase f -> UniqSM (LabelMap CmmBlock, FactBase f) -fixpointRewrite dir lattice do_block entries blockmap = loop start blockmap +fixpointRewrite dir lattice do_block entry blockmap = loop start blockmap where -- Sorting the blocks helps to minimize the number of times we need to -- process blocks. For instance, for forward analysis we want to look at -- blocks in reverse postorder. Also, see comments for sortBlocks. - blocks = sortBlocks dir entries blockmap + blocks = sortBlocks dir entry blockmap num_blocks = length blocks block_arr = {-# SCC "block_arr_rewrite" #-} listArray (0, num_blocks - 1) blocks @@ -268,20 +266,15 @@ we'll propagate (x=4) to L4, and nuke the otherwise-good rewriting of L4. -- | Sort the blocks into the right order for analysis. This means reverse -- postorder for a forward analysis. For the backward one, we simply reverse -- that (see Note [Backward vs forward analysis]). --- --- Note: We're using Hoopl's confusingly named `postorder_dfs_from` but AFAICS --- it returns the *reverse* postorder of the blocks (it visits blocks in the --- postorder and uses (:) to collect them, which gives the reverse of the --- visitation order). sortBlocks :: NonLocal n - => Direction -> [Label] -> LabelMap (Block n C C) -> [Block n C C] -sortBlocks direction entries blockmap = + => Direction -> Label -> LabelMap (Block n C C) -> [Block n C C] +sortBlocks direction entry blockmap = case direction of Fwd -> fwd Bwd -> reverse fwd where - fwd = postorder_dfs_from blockmap entries + fwd = revPostorderFrom blockmap entry -- Note [Backward vs forward analysis] -- |