+++ /dev/null
-Sketch of the new arrivals:
-
- MkZipCfg Constructor functions for control-flow graphs.
- Not understandable in its entirety without reference
- to ZipCfg, but nevertheless a worthy starting point,
- as it is a good deal simpler than full ZipCfg.
- MkZipCfg is polymorphic in the types of middle and last
- nodes.
-
- ZipCfg Describes a zipper-like representation for true basic-block
- control-flow graphs. A block has a single entry point,
- which is a always a label, followed by zero or mode 'middle
- nodes', each of which represents an uninterruptible
- single-entry, single-exit computation, then finally a 'last
- node', which may have zero or more successors. A special
- 'exit node' is used for splicing together graphs.
-
- In addition to three representations of flow graphs, the
- module provides a surfeit of functions for observing and
- modifying graphs and related data:
- - Block IDs, sets and environments thereof
- - supply of fresh block IDS (as String -> UniqSM BlockId)
- - myriad functions for splicing graphs
- - postorder_dfs layout of blocks
- - folding, mapping, and translation functions
-
- ZipCFG is polymorphic in the type of middle and last nodes.
-
- CmmExpr Code for C-- expressions, which is shared among old and new
- representations of flow graphs. Of primary interest is the
- type class UserOfLocalRegs and its method foldRegsUsed,
- which is sufficiently overloaded to be used against
- expressions, statements, formals, hinted formals, and so
- on. This overloading greatly clarifies the computation of
- liveness as well as some other analyses.
-
- ZipCfgCmm Types to instantiate ZipCfg for C--: middle and last nodes,
- and a bunch of abbreviations of types in ZipCfg and Cmm.
- Also provides suitable constructor functions for building
- graphs from Cmm statements.
-
- CmmLiveZ A good example of a very simple dataflow analysis. It
- computes the set of live local registers at each point.
-
- DFMonad Support for dataflow analysis and dataflow-based
- transformation. This module needs work. Includes
- DataflowLattice - for tracking dataflow facts (good)
- DFM - monad for iterative dataflow analysis and rewriting (OK)
- DFTx - monad to track Whalley/Davidson transactions (ugly)
- type class DataflowAnalysis - operations common to DFA, DFM
- Some dodgy bits are
- subAnalysis, which may not be right
-
- ZipDataflow Iteratively solve forward and backward dataflow problems over
- flow graphs. Polymorphic in the type of graph and in the
- lattice of dataflow facts. Supports the incremental
- rewriting technique described by Lerner, Grove, and Chambers
- in POPL 2002. The code is a mess and is still being
- sorted out.
-
-
- CmmTx A simple monad for tracking when a transformation has
- occurred (something has changed).
-
- CmmCvt Converts between Cmm and ZipCfgCmm representations.
-
- CmmProcPointZ One module that performs three analyses and
- transformations:
-
- 1. Using Michael Adams's iterative algorithm, computes a
- minimal set of proc points that enable code to be
- generated without copying any basic blocks.
-
- 2. Assigns a protocol to each proc point. The assigner
- is rigged to enable the 'Adams optimization' whereby
- we attempt to eliminate return continuations by
- making procedures return directly to join points.
- Arguably this could be done by a separate rewriting
- pass to perform earlier.
-
- 3. Insert CopyIn and CopyOut nodes where needed
- according to the protocols.
-
- CmmSpillReload Inserts spills and reloads to establish the invariant that
- at a safe call, there are no live variables in registers.
-
- CmmCPSZ The CPS transformation so far.
-
- CmmContFlowOpt Branch-chain elimination and elimination of unreachable code.
-
- CmmOpt Changed optimization to use 'foldRegsUsed'; eliminated
- significant duplication of code.
-
- PprCmmZ Prettyprinting functions related to ZipCfg and ZipCfgCmm
projects / ghc-hetmet.git / blobdiff