#ifndef LLVM_TRANSFORMS_UTILS_LOOPUTILS_H
#define LLVM_TRANSFORMS_UTILS_LOOPUTILS_H
-namespace llvm {
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/IR/Dominators.h"
+namespace llvm {
+class AliasAnalysis;
+class AliasSet;
+class AliasSetTracker;
+class AssumptionCache;
+class BasicBlock;
+class DataLayout;
+class DominatorTree;
class Loop;
+class LoopInfo;
class Pass;
+class PredIteratorCache;
+class ScalarEvolution;
+class TargetLibraryInfo;
+
+/// \brief Captures loop safety information.
+/// It keep information for loop & its header may throw exception.
+struct LICMSafetyInfo {
+ bool MayThrow; // The current loop contains an instruction which
+ // may throw.
+ bool HeaderMayThrow; // Same as previous, but specific to loop header
+ LICMSafetyInfo() : MayThrow(false), HeaderMayThrow(false)
+ {}
+};
BasicBlock *InsertPreheaderForLoop(Loop *L, Pass *P);
+/// \brief Simplify each loop in a loop nest recursively.
+///
+/// This takes a potentially un-simplified loop L (and its children) and turns
+/// it into a simplified loop nest with preheaders and single backedges. It
+/// will optionally update \c AliasAnalysis and \c ScalarEvolution analyses if
+/// passed into it.
+bool simplifyLoop(Loop *L, DominatorTree *DT, LoopInfo *LI, Pass *PP,
+ AliasAnalysis *AA = nullptr, ScalarEvolution *SE = nullptr,
+ const DataLayout *DL = nullptr,
+ AssumptionCache *AC = nullptr);
+
+/// \brief Put loop into LCSSA form.
+///
+/// Looks at all instructions in the loop which have uses outside of the
+/// current loop. For each, an LCSSA PHI node is inserted and the uses outside
+/// the loop are rewritten to use this node.
+///
+/// LoopInfo and DominatorTree are required and preserved.
+///
+/// If ScalarEvolution is passed in, it will be preserved.
+///
+/// Returns true if any modifications are made to the loop.
+bool formLCSSA(Loop &L, DominatorTree &DT, LoopInfo *LI,
+ ScalarEvolution *SE = nullptr);
+
+/// \brief Put a loop nest into LCSSA form.
+///
+/// This recursively forms LCSSA for a loop nest.
+///
+/// LoopInfo and DominatorTree are required and preserved.
+///
+/// If ScalarEvolution is passed in, it will be preserved.
+///
+/// Returns true if any modifications are made to the loop.
+bool formLCSSARecursively(Loop &L, DominatorTree &DT, LoopInfo *LI,
+ ScalarEvolution *SE = nullptr);
+
+/// \brief Walk the specified region of the CFG (defined by all blocks
+/// dominated by the specified block, and that are in the current loop) in
+/// reverse depth first order w.r.t the DominatorTree. This allows us to visit
+/// uses before definitions, allowing us to sink a loop body in one pass without
+/// iteration. Takes DomTreeNode, AliasAnalysis, LoopInfo, DominatorTree,
+/// DataLayout, TargetLibraryInfo, Loop, AliasSet information for all
+/// instructions of the loop and loop safety information as arguments.
+/// It returns changed status.
+bool sinkRegion(DomTreeNode *, AliasAnalysis *, LoopInfo *, DominatorTree *,
+ const DataLayout *, TargetLibraryInfo *, Loop *,
+ AliasSetTracker *, LICMSafetyInfo *);
+
+/// \brief Walk the specified region of the CFG (defined by all blocks
+/// dominated by the specified block, and that are in the current loop) in depth
+/// first order w.r.t the DominatorTree. This allows us to visit definitions
+/// before uses, allowing us to hoist a loop body in one pass without iteration.
+/// Takes DomTreeNode, AliasAnalysis, LoopInfo, DominatorTree, DataLayout,
+/// TargetLibraryInfo, Loop, AliasSet information for all instructions of the
+/// loop and loop safety information as arguments. It returns changed status.
+bool hoistRegion(DomTreeNode *, AliasAnalysis *, LoopInfo *, DominatorTree *,
+ const DataLayout *, TargetLibraryInfo *, Loop *,
+ AliasSetTracker *, LICMSafetyInfo *);
+
+/// \brief Try to promote memory values to scalars by sinking stores out of
+/// the loop and moving loads to before the loop. We do this by looping over
+/// the stores in the loop, looking for stores to Must pointers which are
+/// loop invariant. It takes AliasSet, Loop exit blocks vector, loop exit blocks
+/// insertion point vector, PredIteratorCache, LoopInfo, DominatorTree, Loop,
+/// AliasSet information for all instructions of the loop and loop safety
+/// information as arguments. It returns changed status.
+bool promoteLoopAccessesToScalars(AliasSet &, SmallVectorImpl<BasicBlock*> &,
+ SmallVectorImpl<Instruction*> &,
+ PredIteratorCache &, LoopInfo *,
+ DominatorTree *, Loop *, AliasSetTracker *,
+ LICMSafetyInfo *);
+
+/// \brief Computes safety information for a loop
+/// checks loop body & header for the possiblity of may throw
+/// exception, it takes LICMSafetyInfo and loop as argument.
+/// Updates safety information in LICMSafetyInfo argument.
+void computeLICMSafetyInfo(LICMSafetyInfo *, Loop *);
+
}
#endif
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