diff options
| -rw-r--r-- | llvm/lib/CodeGen/MachineLICM.cpp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/MachineLICM.cpp b/llvm/lib/CodeGen/MachineLICM.cpp index 61206173e64..d9623ab45c9 100644 --- a/llvm/lib/CodeGen/MachineLICM.cpp +++ b/llvm/lib/CodeGen/MachineLICM.cpp @@ -62,6 +62,7 @@ namespace { // State that is updated as we process loops bool Changed; // True if a loop is changed. + bool FirstInLoop; // True if it's the first LICM in the loop. MachineLoop *CurLoop; // The current loop we are working on. MachineBasicBlock *CurPreheader; // The preheader for CurLoop. @@ -207,7 +208,7 @@ bool MachineLICM::runOnMachineFunction(MachineFunction &MF) { else DEBUG(dbgs() << "******** Post-regalloc Machine LICM ********\n"); - Changed = false; + Changed = FirstInLoop = false; TM = &MF.getTarget(); TII = TM->getInstrInfo(); TRI = TM->getRegisterInfo(); @@ -244,6 +245,7 @@ bool MachineLICM::runOnMachineFunction(MachineFunction &MF) { // CSEMap is initialized for loop header when the first instruction is // being hoisted. MachineDomTreeNode *N = DT->getNode(CurLoop->getHeader()); + FirstInLoop = true; HoistRegion(N); CSEMap.clear(); } @@ -776,7 +778,10 @@ void MachineLICM::Hoist(MachineInstr *MI) { // If this is the first instruction being hoisted to the preheader, // initialize the CSE map with potential common expressions. - InitCSEMap(CurPreheader); + if (FirstInLoop) { + InitCSEMap(CurPreheader); + FirstInLoop = false; + } // Look for opportunity to CSE the hoisted instruction. unsigned Opcode = MI->getOpcode(); |
