[CodeGen] Rename AtomicRMWExpansionKind to AtomicExpansionKind.

[oota-llvm.git] / lib / Target / ARM / Thumb2ITBlockPass.cpp

diff --git a/lib/Target/ARM/Thumb2ITBlockPass.cpp b/lib/Target/ARM/Thumb2ITBlockPass.cpp
index 8f1ae2eaf8fe7111bffd478246814772e0dc86b6..68736bc1decd3cfc1e51f69a793eba2f87c8f5ec 100644 (file)
--- a/lib/Target/ARM/Thumb2ITBlockPass.cpp
+++ b/lib/Target/ARM/Thumb2ITBlockPass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "thumb2-it"
 #include "ARM.h"
 #include "ARMMachineFunctionInfo.h"
 #include "Thumb2InstrInfo.h"
@@ -19,6 +18,8 @@
 #include "llvm/CodeGen/MachineInstrBundle.h"
 using namespace llvm;
 
+#define DEBUG_TYPE "thumb2-it"
+
 STATISTIC(NumITs,        "Number of IT blocks inserted");
 STATISTIC(NumMovedInsts, "Number of predicated instructions moved");
 
@@ -28,14 +29,14 @@ namespace {
     static char ID;
     Thumb2ITBlockPass() : MachineFunctionPass(ID) {}
 
-    bool hasV8Ops;
+    bool restrictIT;
     const Thumb2InstrInfo *TII;
     const TargetRegisterInfo *TRI;
     ARMFunctionInfo *AFI;
 
-    virtual bool runOnMachineFunction(MachineFunction &Fn);
+    bool runOnMachineFunction(MachineFunction &Fn) override;
 
-    virtual const char *getPassName() const {
+    const char *getPassName() const override {
       return "Thumb IT blocks insertion pass";
     }
 
@@ -89,6 +90,19 @@ static void TrackDefUses(MachineInstr *MI,
   }
 }
 
+/// Clear kill flags for any uses in the given set.  This will likely
+/// conservatively remove more kill flags than are necessary, but removing them
+/// is safer than incorrect kill flags remaining on instructions.
+static void ClearKillFlags(MachineInstr *MI, SmallSet<unsigned, 4> &Uses) {
+  for (MachineOperand &MO : MI->operands()) {
+    if (!MO.isReg() || MO.isDef() || !MO.isKill())
+      continue;
+    if (!Uses.count(MO.getReg()))
+      continue;
+    MO.setIsKill(false);
+  }
+}
+
 static bool isCopy(MachineInstr *MI) {
   switch (MI->getOpcode()) {
   default:
@@ -187,15 +201,16 @@ bool Thumb2ITBlockPass::InsertITInstructions(MachineBasicBlock &MBB) {
                                              true/*isImp*/, false/*isKill*/));
 
     MachineInstr *LastITMI = MI;
-    MachineBasicBlock::iterator InsertPos = MIB;
+    MachineBasicBlock::iterator InsertPos = MIB.getInstr();
     ++MBBI;
 
     // Form IT block.
     ARMCC::CondCodes OCC = ARMCC::getOppositeCondition(CC);
     unsigned Mask = 0, Pos = 3;
 
-    // v8 IT blocks are limited to one conditional op: skip the loop
-    if (!hasV8Ops) {
+    // v8 IT blocks are limited to one conditional op unless -arm-no-restrict-it
+    // is set: skip the loop
+    if (!restrictIT) {
       // Branches, including tricky ones like LDM_RET, need to end an IT
       // block so check the instruction we just put in the block.
       for (; MBBI != E && Pos &&
@@ -220,6 +235,7 @@ bool Thumb2ITBlockPass::InsertITInstructions(MachineBasicBlock &MBB) {
             --MBBI;
             MBB.remove(NMI);
             MBB.insert(InsertPos, NMI);
+            ClearKillFlags(MI, Uses);
             ++NumMovedInsts;
             continue;
           }
@@ -241,7 +257,7 @@ bool Thumb2ITBlockPass::InsertITInstructions(MachineBasicBlock &MBB) {
 
     // Finalize the bundle.
     MachineBasicBlock::instr_iterator LI = LastITMI;
-    finalizeBundle(MBB, InsertPos.getInstrIterator(), llvm::next(LI));
+    finalizeBundle(MBB, InsertPos.getInstrIterator(), std::next(LI));
 
     Modified = true;
     ++NumITs;
@@ -251,11 +267,14 @@ bool Thumb2ITBlockPass::InsertITInstructions(MachineBasicBlock &MBB) {
 }
 
 bool Thumb2ITBlockPass::runOnMachineFunction(MachineFunction &Fn) {
-  const TargetMachine &TM = Fn.getTarget();
+  const ARMSubtarget &STI =
+      static_cast<const ARMSubtarget &>(Fn.getSubtarget());
+  if (!STI.isThumb2())
+    return false;
   AFI = Fn.getInfo<ARMFunctionInfo>();
-  TII = static_cast<const Thumb2InstrInfo*>(TM.getInstrInfo());
-  TRI = TM.getRegisterInfo();
-  hasV8Ops = TM.getSubtarget<ARMSubtarget>().hasV8Ops();
+  TII = static_cast<const Thumb2InstrInfo *>(STI.getInstrInfo());
+  TRI = STI.getRegisterInfo();
+  restrictIT = STI.restrictIT();
 
   if (!AFI->isThumbFunction())
     return false;