live vars

anoma · Jun 18, 2024 · 69c10ca · 69c10ca
1 parent 320e2cd
commit 69c10ca
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Showing 4 changed files with 15 additions and 10 deletions.
diff --git a/src/Juvix/Compiler/Reg/Data/TransformationId.hs b/src/Juvix/Compiler/Reg/Data/TransformationId.hs
@@ -20,6 +20,8 @@ data PipelineId
 
 type TransformationLikeId = TransformationLikeId' TransformationId PipelineId
 
+-- Note: this works only because for now we mark all variables as live. Liveness
+-- information needs to be re-computed after copy propagation.
 toCTransformations :: [TransformationId]
 toCTransformations = [Cleanup, CopyPropagation]
 

diff --git a/src/Juvix/Compiler/Reg/Extra/Base.hs b/src/Juvix/Compiler/Reg/Extra/Base.hs
@@ -148,3 +148,13 @@ overValueRefs f = \case
 
     goBlock :: InstrBlock -> InstrBlock
     goBlock x = x
+
+updateLiveVars' :: (VarRef -> Maybe VarRef) -> Instruction -> Instruction
+updateLiveVars' f = \case
+  Prealloc x -> Prealloc $ over instrPreallocLiveVars (mapMaybe f) x
+  Call x -> Call $ over instrCallLiveVars (mapMaybe f) x
+  CallClosures x -> CallClosures $ over instrCallClosuresLiveVars (mapMaybe f) x
+  instr -> instr
+
+updateLiveVars :: (VarRef -> VarRef) -> Instruction -> Instruction
+updateLiveVars f = updateLiveVars' (Just . f)
diff --git a/src/Juvix/Compiler/Reg/Transformation/CopyPropagation.hs b/src/Juvix/Compiler/Reg/Transformation/CopyPropagation.hs
@@ -27,7 +27,7 @@ copyPropagateFunction =
         (mpv', instr')
       where
         instr' = overValueRefs (adjustVarRef mpv) instr
-        mpv' = maybe mpv (filterOutVars mpv) (getResultVar instr')
+        mpv' = maybe mpv (filterOutVars mpv) (getResultVar instr)
 
     filterOutVars :: VarMap -> VarRef -> VarMap
     filterOutVars mpv v = HashMap.delete v $ HashMap.filter (/= v) mpv

diff --git a/src/Juvix/Compiler/Reg/Transformation/SSA.hs b/src/Juvix/Compiler/Reg/Transformation/SSA.hs
@@ -22,20 +22,13 @@ computeFunctionSSA =
   where
     go :: Instruction -> IndexMap VarRef -> (IndexMap VarRef, Instruction)
     go instr mp = case getResultVar instr' of
-      Just vref -> (mp', updateLiveVars mp' (setResultVar instr' (mkVarRef VarGroupLocal idx)))
+      Just vref -> (mp', updateLiveVars' (adjustVarRef' mp') (setResultVar instr' (mkVarRef VarGroupLocal idx)))
         where
           (idx, mp') = IndexMap.assign mp vref
-      Nothing -> (mp, updateLiveVars mp instr')
+      Nothing -> (mp, updateLiveVars' (adjustVarRef' mp) instr')
       where
         instr' = overValueRefs (adjustVarRef mp) instr
 
-    updateLiveVars :: IndexMap VarRef -> Instruction -> Instruction
-    updateLiveVars mp = \case
-      Prealloc x -> Prealloc $ over instrPreallocLiveVars (mapMaybe (adjustVarRef' mp)) x
-      Call x -> Call $ over instrCallLiveVars (mapMaybe (adjustVarRef' mp)) x
-      CallClosures x -> CallClosures $ over instrCallClosuresLiveVars (mapMaybe (adjustVarRef' mp)) x
-      instr -> instr
-
     -- For branches, when necessary we insert assignments unifying the renamed
     -- output variables into a single output variable for both branches.
     combine :: Instruction -> NonEmpty (IndexMap VarRef) -> (IndexMap VarRef, Instruction)