forked from OSchip/llvm-project
74 lines
2.5 KiB
C++
74 lines
2.5 KiB
C++
//===-- llvm/CodeGen/ExpandISelPseudos.cpp ----------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// Expand Pseudo-instructions produced by ISel. These are usually to allow
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// the expansion to contain control flow, such as a conditional move
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// implemented with a conditional branch and a phi, or an atomic operation
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// implemented with a loop.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/MachineFunction.h"
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#include "llvm/CodeGen/MachineFunctionPass.h"
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#include "llvm/CodeGen/Passes.h"
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#include "llvm/CodeGen/TargetLowering.h"
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#include "llvm/CodeGen/TargetSubtargetInfo.h"
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#include "llvm/Support/Debug.h"
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using namespace llvm;
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#define DEBUG_TYPE "expand-isel-pseudos"
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namespace {
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class ExpandISelPseudos : public MachineFunctionPass {
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public:
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static char ID; // Pass identification, replacement for typeid
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ExpandISelPseudos() : MachineFunctionPass(ID) {}
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private:
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bool runOnMachineFunction(MachineFunction &MF) override;
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void getAnalysisUsage(AnalysisUsage &AU) const override {
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MachineFunctionPass::getAnalysisUsage(AU);
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}
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};
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} // end anonymous namespace
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char ExpandISelPseudos::ID = 0;
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char &llvm::ExpandISelPseudosID = ExpandISelPseudos::ID;
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INITIALIZE_PASS(ExpandISelPseudos, DEBUG_TYPE,
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"Expand ISel Pseudo-instructions", false, false)
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bool ExpandISelPseudos::runOnMachineFunction(MachineFunction &MF) {
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bool Changed = false;
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const TargetLowering *TLI = MF.getSubtarget().getTargetLowering();
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// Iterate through each instruction in the function, looking for pseudos.
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for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) {
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MachineBasicBlock *MBB = &*I;
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for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end();
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MBBI != MBBE; ) {
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MachineInstr &MI = *MBBI++;
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// If MI is a pseudo, expand it.
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if (MI.usesCustomInsertionHook()) {
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Changed = true;
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MachineBasicBlock *NewMBB = TLI->EmitInstrWithCustomInserter(MI, MBB);
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// The expansion may involve new basic blocks.
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if (NewMBB != MBB) {
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MBB = NewMBB;
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I = NewMBB->getIterator();
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MBBI = NewMBB->begin();
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MBBE = NewMBB->end();
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}
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}
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}
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}
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return Changed;
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}
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