[llvm] r242410 - AMDPGU/R600: Replace llvm_unreachable() call with LLVMContext::emitError()

[Tom Stellard]

Author: tstellar
Date: Thu Jul 16 10:38:29 2015
New Revision: 242410

URL: http://llvm.org/viewvc/llvm-project?rev=242410&view=rev
Log:
AMDPGU/R600: Replace llvm_unreachable() call with LLVMContext::emitError()

Summary:
This fixes an issue on MIPS where the infinite-loop-evergreen.ll test
was failing to terminate.

Fixes PR24147.

Reviewers: arsenm, dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11260

Modified:
    llvm/trunk/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp

Modified: llvm/trunk/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp?rev=242410&r1=242409&r2=242410&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp (original)
+++ llvm/trunk/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp Thu Jul 16 10:38:29 2015
@@ -1732,18 +1732,9 @@ AMDGPUCFGStructurizer::normalizeInfinite
   FuncRep->push_back(DummyExitBlk);  //insert to function
   SHOWNEWBLK(DummyExitBlk, "DummyExitBlock to normalize infiniteLoop: ");
   DEBUG(dbgs() << "Old branch instr: " << *BranchMI << "\n";);
-  MachineBasicBlock::iterator I = BranchMI;
-  unsigned ImmReg = FuncRep->getRegInfo().createVirtualRegister(I32RC);
-  llvm_unreachable("Extra register needed to handle CFG");
-  MachineInstr *NewMI = insertInstrBefore(I, AMDGPU::BRANCH_COND_i32);
-  MachineInstrBuilder MIB(*FuncRep, NewMI);
-  MIB.addMBB(LoopHeader);
-  MIB.addReg(ImmReg, false);
-  SHOWNEWINSTR(NewMI);
-  BranchMI->eraseFromParent();
-  LoopLatch->addSuccessor(DummyExitBlk);
-
-  return DummyExitBlk;
+  LLVMContext &Ctx = LoopHeader->getParent()->getFunction()->getContext();
+  Ctx.emitError("Extra register needed to handle CFG");
+  return nullptr;
 }
 
 void AMDGPUCFGStructurizer::removeUnconditionalBranch(MachineBasicBlock *MBB) {