mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-30 02:32:08 +00:00
4aad88d1fd
MachineSSAUpdater to avoid duplicating all the code. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103060 91177308-0d34-0410-b5e6-96231b3b80d8
107 lines
4.0 KiB
C++
107 lines
4.0 KiB
C++
//===-- SSAUpdater.h - Unstructured SSA Update Tool -------------*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file declares the SSAUpdater class.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_TRANSFORMS_UTILS_SSAUPDATER_H
|
|
#define LLVM_TRANSFORMS_UTILS_SSAUPDATER_H
|
|
|
|
namespace llvm {
|
|
class Value;
|
|
class BasicBlock;
|
|
class Use;
|
|
class PHINode;
|
|
template<typename T> class SmallVectorImpl;
|
|
template<typename T> class SSAUpdaterTraits;
|
|
class BumpPtrAllocator;
|
|
|
|
/// SSAUpdater - This class updates SSA form for a set of values defined in
|
|
/// multiple blocks. This is used when code duplication or another unstructured
|
|
/// transformation wants to rewrite a set of uses of one value with uses of a
|
|
/// set of values.
|
|
class SSAUpdater {
|
|
friend class SSAUpdaterTraits<SSAUpdater>;
|
|
|
|
private:
|
|
/// AvailableVals - This keeps track of which value to use on a per-block
|
|
/// basis. When we insert PHI nodes, we keep track of them here.
|
|
//typedef DenseMap<BasicBlock*, Value*> AvailableValsTy;
|
|
void *AV;
|
|
|
|
/// PrototypeValue is an arbitrary representative value, which we derive names
|
|
/// and a type for PHI nodes.
|
|
Value *PrototypeValue;
|
|
|
|
/// InsertedPHIs - If this is non-null, the SSAUpdater adds all PHI nodes that
|
|
/// it creates to the vector.
|
|
SmallVectorImpl<PHINode*> *InsertedPHIs;
|
|
|
|
public:
|
|
/// SSAUpdater constructor. If InsertedPHIs is specified, it will be filled
|
|
/// in with all PHI Nodes created by rewriting.
|
|
explicit SSAUpdater(SmallVectorImpl<PHINode*> *InsertedPHIs = 0);
|
|
~SSAUpdater();
|
|
|
|
/// Initialize - Reset this object to get ready for a new set of SSA
|
|
/// updates. ProtoValue is the value used to name PHI nodes.
|
|
void Initialize(Value *ProtoValue);
|
|
|
|
/// AddAvailableValue - Indicate that a rewritten value is available at the
|
|
/// end of the specified block with the specified value.
|
|
void AddAvailableValue(BasicBlock *BB, Value *V);
|
|
|
|
/// HasValueForBlock - Return true if the SSAUpdater already has a value for
|
|
/// the specified block.
|
|
bool HasValueForBlock(BasicBlock *BB) const;
|
|
|
|
/// GetValueAtEndOfBlock - Construct SSA form, materializing a value that is
|
|
/// live at the end of the specified block.
|
|
Value *GetValueAtEndOfBlock(BasicBlock *BB);
|
|
|
|
/// GetValueInMiddleOfBlock - Construct SSA form, materializing a value that
|
|
/// is live in the middle of the specified block.
|
|
///
|
|
/// GetValueInMiddleOfBlock is the same as GetValueAtEndOfBlock except in one
|
|
/// important case: if there is a definition of the rewritten value after the
|
|
/// 'use' in BB. Consider code like this:
|
|
///
|
|
/// X1 = ...
|
|
/// SomeBB:
|
|
/// use(X)
|
|
/// X2 = ...
|
|
/// br Cond, SomeBB, OutBB
|
|
///
|
|
/// In this case, there are two values (X1 and X2) added to the AvailableVals
|
|
/// set by the client of the rewriter, and those values are both live out of
|
|
/// their respective blocks. However, the use of X happens in the *middle* of
|
|
/// a block. Because of this, we need to insert a new PHI node in SomeBB to
|
|
/// merge the appropriate values, and this value isn't live out of the block.
|
|
///
|
|
Value *GetValueInMiddleOfBlock(BasicBlock *BB);
|
|
|
|
/// RewriteUse - Rewrite a use of the symbolic value. This handles PHI nodes,
|
|
/// which use their value in the corresponding predecessor. Note that this
|
|
/// will not work if the use is supposed to be rewritten to a value defined in
|
|
/// the same block as the use, but above it. Any 'AddAvailableValue's added
|
|
/// for the use's block will be considered to be below it.
|
|
void RewriteUse(Use &U);
|
|
|
|
private:
|
|
Value *GetValueAtEndOfBlockInternal(BasicBlock *BB);
|
|
|
|
void operator=(const SSAUpdater&); // DO NOT IMPLEMENT
|
|
SSAUpdater(const SSAUpdater&); // DO NOT IMPLEMENT
|
|
};
|
|
|
|
} // End llvm namespace
|
|
|
|
#endif
|