1 files changed, 76 insertions, 0 deletions
diff --git a/lib/CodeGen/FinalizeISel.cpp b/lib/CodeGen/FinalizeISel.cpp
new file mode 100644
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+++ b/lib/CodeGen/FinalizeISel.cpp
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+//===-- llvm/CodeGen/FinalizeISel.cpp ---------------------------*- 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 pass expands Pseudo-instructions produced by ISel, fixes register
+/// reservations and may do machine frame information adjustments.
+/// The pseudo instructions are used 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.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/TargetLowering.h"
+#include "llvm/CodeGen/TargetSubtargetInfo.h"
+#include "llvm/Support/Debug.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "finalize-isel"
+
+namespace {
+  class FinalizeISel : public MachineFunctionPass {
+  public:
+    static char ID; // Pass identification, replacement for typeid
+    FinalizeISel() : MachineFunctionPass(ID) {}
+
+  private:
+    bool runOnMachineFunction(MachineFunction &MF) override;
+
+    void getAnalysisUsage(AnalysisUsage &AU) const override {
+      MachineFunctionPass::getAnalysisUsage(AU);
+    }
+  };
+} // end anonymous namespace
+
+char FinalizeISel::ID = 0;
+char &llvm::FinalizeISelID = FinalizeISel::ID;
+INITIALIZE_PASS(FinalizeISel, DEBUG_TYPE,
+                "Finalize ISel and expand pseudo-instructions", false, false)
+
+bool FinalizeISel::runOnMachineFunction(MachineFunction &MF) {
+  bool Changed = false;
+  const TargetLowering *TLI = MF.getSubtarget().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->getIterator();
+          MBBI = NewMBB->begin();
+          MBBE = NewMBB->end();
+        }
+      }
+    }
+  }
+
+  TLI->finalizeLowering(MF);
+
+  return Changed;
+}