1 files changed, 36 insertions, 13 deletions

diff --git a/lib/Target/PowerPC/PPCInstrInfo.cpp b/lib/Target/PowerPC/PPCInstrInfo.cpp
index 9bac91d..daf8790 100644
--- a/lib/Target/PowerPC/PPCInstrInfo.cpp
+++ b/lib/Target/PowerPC/PPCInstrInfo.cpp
@@ -75,7 +75,7 @@ PPCInstrInfo::CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
   if (Directive == PPC::DIR_440 || Directive == PPC::DIR_A2 ||
       Directive == PPC::DIR_E500mc || Directive == PPC::DIR_E5500) {
     const InstrItineraryData *II =
-        &static_cast<const PPCSubtarget *>(STI)->getInstrItineraryData();
+        static_cast<const PPCSubtarget *>(STI)->getInstrItineraryData();
     return new ScoreboardHazardRecognizer(II, DAG);
   }
 
@@ -331,6 +331,11 @@ void PPCInstrInfo::insertNoop(MachineBasicBlock &MBB,
   BuildMI(MBB, MI, DL, get(Opcode));
 }
 
+/// getNoopForMachoTarget - Return the noop instruction to use for a noop.
+void PPCInstrInfo::getNoopForMachoTarget(MCInst &NopInst) const {
+  NopInst.setOpcode(PPC::NOP);
+}
+
 // Branch analysis.
 // Note: If the condition register is set to CTR or CTR8 then this is a
 // BDNZ (imm == 1) or BDZ (imm == 0) branch.
@@ -1617,6 +1622,7 @@ protected:
       bool Changed = false;
 
       MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
+      const TargetRegisterInfo *TRI = &TII->getRegisterInfo();
       for (MachineBasicBlock::iterator I = MBB.begin(), IE = MBB.end();
            I != IE; ++I) {
         MachineInstr *MI = I;
@@ -1682,16 +1688,26 @@ protected:
         // In theory, there could be other uses of the addend copy before this
         // fma.  We could deal with this, but that would require additional
         // logic below and I suspect it will not occur in any relevant
-        // situations.
-        bool OtherUsers = false;
+        // situations.  Additionally, check whether the copy source is killed
+        // prior to the fma.  In order to replace the addend here with the
+        // source of the copy, it must still be live here.  We can't use
+        // interval testing for a physical register, so as long as we're
+        // walking the MIs we may as well test liveness here.
+        bool OtherUsers = false, KillsAddendSrc = false;
         for (auto J = std::prev(I), JE = MachineBasicBlock::iterator(AddendMI);
-             J != JE; --J)
+             J != JE; --J) {
           if (J->readsVirtualRegister(AddendMI->getOperand(0).getReg())) {
             OtherUsers = true;
             break;
           }
+          if (J->modifiesRegister(AddendSrcReg, TRI) ||
+              J->killsRegister(AddendSrcReg, TRI)) {
+            KillsAddendSrc = true;
+            break;
+          }
+        }
 
-        if (OtherUsers)
+        if (OtherUsers || KillsAddendSrc)
           continue;
 
         // Find one of the product operands that is killed by this instruction.
@@ -1712,10 +1728,11 @@ protected:
         if (!KilledProdOp)
           continue;
 
-        // In order to replace the addend here with the source of the copy,
-        // it must still be live here.
-        if (!LIS->getInterval(AddendMI->getOperand(1).getReg()).liveAt(FMAIdx))
-          continue;
+        // For virtual registers, verify that the addend source register
+        // is live here (as should have been assured above).
+        assert((!TargetRegisterInfo::isVirtualRegister(AddendSrcReg) ||
+                LIS->getInterval(AddendSrcReg).liveAt(FMAIdx)) &&
+               "Addend source register is not live!");
 
         // Transform: (O2 * O3) + O1 -> (O2 * O1) + O3.
 
@@ -1737,6 +1754,12 @@ protected:
 
         unsigned OldFMAReg = MI->getOperand(0).getReg();
 
+        // The transformation doesn't work well with things like:
+        //    %vreg5 = A-form-op %vreg5, %vreg11, %vreg5;
+        // so leave such things alone.
+        if (OldFMAReg == KilledProdReg)
+          continue;
+
         assert(OldFMAReg == AddendMI->getOperand(0).getReg() &&
                "Addend copy not tied to old FMA output!");
 
@@ -1827,7 +1850,7 @@ public:
 
       LIS = &getAnalysis<LiveIntervals>();
 
-      TII = TM->getInstrInfo();
+      TII = TM->getSubtargetImpl()->getInstrInfo();
 
       bool Changed = false;
 
@@ -1980,7 +2003,7 @@ public:
       // If we don't have VSX on the subtarget, don't do anything.
       if (!TM->getSubtargetImpl()->hasVSX())
         return false;
-      TII = TM->getInstrInfo();
+      TII = TM->getSubtargetImpl()->getInstrInfo();
 
       bool Changed = false;
 
@@ -2057,7 +2080,7 @@ public:
       // If we don't have VSX don't bother doing anything here.
       if (!TM->getSubtargetImpl()->hasVSX())
         return false;
-      TII = TM->getInstrInfo();
+      TII = TM->getSubtargetImpl()->getInstrInfo();
 
       bool Changed = false;
 
@@ -2214,7 +2237,7 @@ protected:
 public:
     bool runOnMachineFunction(MachineFunction &MF) override {
       TM = static_cast<const PPCTargetMachine *>(&MF.getTarget());
-      TII = TM->getInstrInfo();
+      TII = TM->getSubtargetImpl()->getInstrInfo();
 
       bool Changed = false;