Index: include/llvm/Target/Target.td =================================================================== --- include/llvm/Target/Target.td +++ include/llvm/Target/Target.td @@ -815,7 +815,7 @@ let OutOperandList = (outs unknown:$dst); let InOperandList = (ins variable_ops); let AsmString = "PHINODE"; - let hasSideEffects = 1; + let hasSideEffects = 0; } def INLINEASM : Instruction { let OutOperandList = (outs); Index: lib/CodeGen/MachineInstr.cpp =================================================================== --- lib/CodeGen/MachineInstr.cpp +++ lib/CodeGen/MachineInstr.cpp @@ -1636,7 +1636,7 @@ // Treat volatile loads as stores. This is not strictly necessary for // volatiles, but it is required for atomic loads. It is not allowed to move // a load across an atomic load with Ordering > Monotonic. - if (mayStore() || isCall() || + if (mayStore() || isCall() || isPHI() || (mayLoad() && hasOrderedMemoryRef())) { SawStore = true; return false; Index: lib/Target/Hexagon/HexagonBitSimplify.cpp =================================================================== --- lib/Target/Hexagon/HexagonBitSimplify.cpp +++ lib/Target/Hexagon/HexagonBitSimplify.cpp @@ -1319,7 +1319,7 @@ if (MI->getOpcode() == TargetOpcode::COPY) continue; - if (MI->hasUnmodeledSideEffects() || MI->isInlineAsm()) + if (MI->isPHI() || MI->hasUnmodeledSideEffects() || MI->isInlineAsm()) continue; unsigned NumD = MI->getDesc().getNumDefs(); if (NumD != 1) @@ -1329,8 +1329,7 @@ if (!BT.has(RD.Reg)) continue; const BitTracker::RegisterCell &DC = BT.lookup(RD.Reg); - auto At = MI->isPHI() ? B.getFirstNonPHI() - : MachineBasicBlock::iterator(MI); + auto At = MachineBasicBlock::iterator(MI); // Find a source operand that is equal to the result. for (auto &Op : MI->uses()) {