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authorStephen Hines <srhines@google.com>2019-07-02 16:25:20 -0700
committerAli B <abittin@gmail.com>2019-07-05 19:33:16 +0300
commit9afee4e65dc5f9f5eb371683729ff67b8df81d03 (patch)
tree4cf241d6c9044f91ee8c06e6920174d06f8de0b6 /clang-r353983e/include/llvm/CodeGen/MachineSSAUpdater.h
parent2f19bd722c4c825320d1511c1ed83161b7f95d51 (diff)
Update prebuilt Clang to r353983e.HEADq10.0
clang 9.0.5 (based on r353983e) from build 5696680. Bug: http://b/135931688 Bug: http://b/136008926 Test: N/A Change-Id: I922d17410047d2e2df4625615352c588ee71b203
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+//===- MachineSSAUpdater.h - Unstructured SSA Update Tool -------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the MachineSSAUpdater class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_MACHINESSAUPDATER_H
+#define LLVM_CODEGEN_MACHINESSAUPDATER_H
+
+namespace llvm {
+
+class MachineBasicBlock;
+class MachineFunction;
+class MachineInstr;
+class MachineOperand;
+class MachineRegisterInfo;
+class TargetInstrInfo;
+class TargetRegisterClass;
+template<typename T> class SmallVectorImpl;
+template<typename T> class SSAUpdaterTraits;
+
+/// MachineSSAUpdater - This class updates SSA form for a set of virtual
+/// registers defined in multiple blocks. This is used when code duplication
+/// or another unstructured transformation wants to rewrite a set of uses of one
+/// vreg with uses of a set of vregs.
+class MachineSSAUpdater {
+ friend class SSAUpdaterTraits<MachineSSAUpdater>;
+
+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<MachineBasicBlock*, unsigned > AvailableValsTy;
+ void *AV = nullptr;
+
+ /// VR - Current virtual register whose uses are being updated.
+ unsigned VR;
+
+ /// VRC - Register class of the current virtual register.
+ const TargetRegisterClass *VRC;
+
+ /// InsertedPHIs - If this is non-null, the MachineSSAUpdater adds all PHI
+ /// nodes that it creates to the vector.
+ SmallVectorImpl<MachineInstr*> *InsertedPHIs;
+
+ const TargetInstrInfo *TII;
+ MachineRegisterInfo *MRI;
+
+public:
+ /// MachineSSAUpdater constructor. If InsertedPHIs is specified, it will be
+ /// filled in with all PHI Nodes created by rewriting.
+ explicit MachineSSAUpdater(MachineFunction &MF,
+ SmallVectorImpl<MachineInstr*> *NewPHI = nullptr);
+ MachineSSAUpdater(const MachineSSAUpdater &) = delete;
+ MachineSSAUpdater &operator=(const MachineSSAUpdater &) = delete;
+ ~MachineSSAUpdater();
+
+ /// Initialize - Reset this object to get ready for a new set of SSA
+ /// updates.
+ void Initialize(unsigned V);
+
+ /// AddAvailableValue - Indicate that a rewritten value is available at the
+ /// end of the specified block with the specified value.
+ void AddAvailableValue(MachineBasicBlock *BB, unsigned V);
+
+ /// HasValueForBlock - Return true if the MachineSSAUpdater already has a
+ /// value for the specified block.
+ bool HasValueForBlock(MachineBasicBlock *BB) const;
+
+ /// GetValueAtEndOfBlock - Construct SSA form, materializing a value that is
+ /// live at the end of the specified block.
+ unsigned GetValueAtEndOfBlock(MachineBasicBlock *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.
+ unsigned GetValueInMiddleOfBlock(MachineBasicBlock *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(MachineOperand &U);
+
+private:
+ unsigned GetValueAtEndOfBlockInternal(MachineBasicBlock *BB);
+};
+
+} // end namespace llvm
+
+#endif // LLVM_CODEGEN_MACHINESSAUPDATER_H