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Diffstat (limited to 'contrib/llvm/lib/CodeGen/ExpandISelPseudos.cpp')
-rw-r--r-- | contrib/llvm/lib/CodeGen/ExpandISelPseudos.cpp | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/ExpandISelPseudos.cpp b/contrib/llvm/lib/CodeGen/ExpandISelPseudos.cpp new file mode 100644 index 0000000..b2b6882 --- /dev/null +++ b/contrib/llvm/lib/CodeGen/ExpandISelPseudos.cpp @@ -0,0 +1,74 @@ +//===-- llvm/CodeGen/ExpandISelPseudos.cpp ----------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// Expand Pseudo-instructions produced by ISel. These are usually to allow +// the expansion to contain control flow, such as a conditional move +// implemented with a conditional branch and a phi, or an atomic operation +// implemented with a loop. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "expand-isel-pseudos" +#include "llvm/CodeGen/Passes.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/Support/Debug.h" +#include "llvm/Target/TargetLowering.h" +#include "llvm/Target/TargetMachine.h" +using namespace llvm; + +namespace { + class ExpandISelPseudos : public MachineFunctionPass { + public: + static char ID; // Pass identification, replacement for typeid + ExpandISelPseudos() : MachineFunctionPass(ID) {} + + private: + virtual bool runOnMachineFunction(MachineFunction &MF); + + virtual void getAnalysisUsage(AnalysisUsage &AU) const { + MachineFunctionPass::getAnalysisUsage(AU); + } + }; +} // end anonymous namespace + +char ExpandISelPseudos::ID = 0; +char &llvm::ExpandISelPseudosID = ExpandISelPseudos::ID; +INITIALIZE_PASS(ExpandISelPseudos, "expand-isel-pseudos", + "Expand ISel Pseudo-instructions", false, false) + +bool ExpandISelPseudos::runOnMachineFunction(MachineFunction &MF) { + bool Changed = false; + const TargetLowering *TLI = MF.getTarget().getTargetLowering(); + + // Iterate through each instruction in the function, looking for pseudos. + for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) { + MachineBasicBlock *MBB = I; + for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end(); + MBBI != MBBE; ) { + MachineInstr *MI = MBBI++; + + // If MI is a pseudo, expand it. + if (MI->usesCustomInsertionHook()) { + Changed = true; + MachineBasicBlock *NewMBB = + TLI->EmitInstrWithCustomInserter(MI, MBB); + // The expansion may involve new basic blocks. + if (NewMBB != MBB) { + MBB = NewMBB; + I = NewMBB; + MBBI = NewMBB->begin(); + MBBE = NewMBB->end(); + } + } + } + } + + return Changed; +} |