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Compactify

CFGCompactify dataclass 

CFGCompactify()

Bases: RewriteRule


              flowchart TD
              kirin.rewrite.compactify.CFGCompactify[CFGCompactify]
              kirin.rewrite.abc.RewriteRule[RewriteRule]

                              kirin.rewrite.abc.RewriteRule --> kirin.rewrite.compactify.CFGCompactify
                


              click kirin.rewrite.compactify.CFGCompactify href "" "kirin.rewrite.compactify.CFGCompactify"
              click kirin.rewrite.abc.RewriteRule href "" "kirin.rewrite.abc.RewriteRule"

Compactify the CFG by removing dead blocks and merging blocks if the statement uses the SSACFG convention. Do nothing if given ir.Region or ir.Block due to no context of the region.

To compactify hierarchical CFG, combine this rule with kirin.rewrite.Walk to recursively apply this rule to all statements.

CFGEdge dataclass 

CFGEdge(cfg: CFG)

Bases: RewriteRule


              flowchart TD
              kirin.rewrite.compactify.CFGEdge[CFGEdge]
              kirin.rewrite.abc.RewriteRule[RewriteRule]

                              kirin.rewrite.abc.RewriteRule --> kirin.rewrite.compactify.CFGEdge
                


              click kirin.rewrite.compactify.CFGEdge href "" "kirin.rewrite.compactify.CFGEdge"
              click kirin.rewrite.abc.RewriteRule href "" "kirin.rewrite.abc.RewriteRule"

Merge non-branching blocks on the edge of the CFG.

Example:

/---> [B] --> [D] --> [E]

[A]-----> [C] -------------^

[B] and [D] are non-branching blocks on the same edge. They can be merged into one block.

/---> [B,D] --> [E]

[A]-----> [C] -------^

CompactifyRegion dataclass 

CompactifyRegion(cfg: CFG)

Bases: RewriteRule


              flowchart TD
              kirin.rewrite.compactify.CompactifyRegion[CompactifyRegion]
              kirin.rewrite.abc.RewriteRule[RewriteRule]

                              kirin.rewrite.abc.RewriteRule --> kirin.rewrite.compactify.CompactifyRegion
                


              click kirin.rewrite.compactify.CompactifyRegion href "" "kirin.rewrite.compactify.CompactifyRegion"
              click kirin.rewrite.abc.RewriteRule href "" "kirin.rewrite.abc.RewriteRule"

Wrapper to share the CFG object with same CFG region.

Source code in src/kirin/rewrite/compactify.py 
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def __init__(self, cfg: CFG):
    self.cfg = cfg
    self.rule = Fixpoint(
        Chain(
            DeadBlock(cfg), Walk(DuplicatedBranch()), SkipBlock(cfg), CFGEdge(cfg)
        )
    )

DeadBlock dataclass 

DeadBlock(cfg: CFG)

Bases: RewriteRule


              flowchart TD
              kirin.rewrite.compactify.DeadBlock[DeadBlock]
              kirin.rewrite.abc.RewriteRule[RewriteRule]

                              kirin.rewrite.abc.RewriteRule --> kirin.rewrite.compactify.DeadBlock
                


              click kirin.rewrite.compactify.DeadBlock href "" "kirin.rewrite.compactify.DeadBlock"
              click kirin.rewrite.abc.RewriteRule href "" "kirin.rewrite.abc.RewriteRule"

Compactify the CFG by removing dead blocks.

DuplicatedBranch dataclass 

DuplicatedBranch()

Bases: RewriteRule


              flowchart TD
              kirin.rewrite.compactify.DuplicatedBranch[DuplicatedBranch]
              kirin.rewrite.abc.RewriteRule[RewriteRule]

                              kirin.rewrite.abc.RewriteRule --> kirin.rewrite.compactify.DuplicatedBranch
                


              click kirin.rewrite.compactify.DuplicatedBranch href "" "kirin.rewrite.compactify.DuplicatedBranch"
              click kirin.rewrite.abc.RewriteRule href "" "kirin.rewrite.abc.RewriteRule"

Merge duplicated branches into a single branch.

Example:

[A]-->[B]
  -----^

Merge the two branches into one without changing the CFG:

[A]-->[B]

SkipBlock dataclass 

SkipBlock(cfg: CFG)

Bases: RewriteRule


              flowchart TD
              kirin.rewrite.compactify.SkipBlock[SkipBlock]
              kirin.rewrite.abc.RewriteRule[RewriteRule]

                              kirin.rewrite.abc.RewriteRule --> kirin.rewrite.compactify.SkipBlock
                


              click kirin.rewrite.compactify.SkipBlock href "" "kirin.rewrite.compactify.SkipBlock"
              click kirin.rewrite.abc.RewriteRule href "" "kirin.rewrite.abc.RewriteRule"

Simplify a block that only contains a branch statement.