1 files changed, 20 insertions, 11 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCMIPeephole.cpp b/llvm/lib/Target/PowerPC/PPCMIPeephole.cpp
index 7eeff007b78..f42b4bcfc3c 100644
--- a/llvm/lib/Target/PowerPC/PPCMIPeephole.cpp
+++ b/llvm/lib/Target/PowerPC/PPCMIPeephole.cpp
@@ -382,13 +382,23 @@ bool PPCMIPeephole::simplifyCode(void) {
             // If this is a splat or a swap fed by another splat, we
             // can replace it with a copy.
             if (DefOpc == PPC::XXPERMDI) {
-              unsigned FeedImmed = DefMI->getOperand(3).getImm();
-              unsigned FeedReg1 =
-                TRI->lookThruCopyLike(DefMI->getOperand(1).getReg(), MRI);
-              unsigned FeedReg2 =
-                TRI->lookThruCopyLike(DefMI->getOperand(2).getReg(), MRI);
+              unsigned DefReg1 = DefMI->getOperand(1).getReg();
+              unsigned DefReg2 = DefMI->getOperand(2).getReg();
+              unsigned DefImmed = DefMI->getOperand(3).getImm();
+
+              // If the two inputs are not the same register, check to see if
+              // they originate from the same virtual register after only
+              // copy-like instructions.
+              if (DefReg1 != DefReg2) {
+                unsigned FeedReg1 = TRI->lookThruCopyLike(DefReg1, MRI);
+                unsigned FeedReg2 = TRI->lookThruCopyLike(DefReg2, MRI);
+
+                if (FeedReg1 != FeedReg2 ||
+                    Register::isPhysicalRegister(FeedReg1))
+                  break;
+              }
 
-              if ((FeedImmed == 0 || FeedImmed == 3) && FeedReg1 == FeedReg2) {
+              if (DefImmed == 0 || DefImmed == 3) {
                 LLVM_DEBUG(dbgs() << "Optimizing splat/swap or splat/splat "
                                      "to splat/copy: ");
                 LLVM_DEBUG(MI.dump());
@@ -402,19 +412,18 @@ bool PPCMIPeephole::simplifyCode(void) {
               // If this is a splat fed by a swap, we can simplify modify
               // the splat to splat the other value from the swap's input
               // parameter.
-              else if ((Immed == 0 || Immed == 3)
-                       && FeedImmed == 2 && FeedReg1 == FeedReg2) {
+              else if ((Immed == 0 || Immed == 3) && DefImmed == 2) {
                 LLVM_DEBUG(dbgs() << "Optimizing swap/splat => splat: ");
                 LLVM_DEBUG(MI.dump());
-                MI.getOperand(1).setReg(DefMI->getOperand(1).getReg());
-                MI.getOperand(2).setReg(DefMI->getOperand(2).getReg());
+                MI.getOperand(1).setReg(DefReg1);
+                MI.getOperand(2).setReg(DefReg2);
                 MI.getOperand(3).setImm(3 - Immed);
                 Simplified = true;
               }
 
               // If this is a swap fed by a swap, we can replace it
               // with a copy from the first swap's input.
-              else if (Immed == 2 && FeedImmed == 2 && FeedReg1 == FeedReg2) {
+              else if (Immed == 2 && DefImmed == 2) {
                 LLVM_DEBUG(dbgs() << "Optimizing swap/swap => copy: ");
                 LLVM_DEBUG(MI.dump());
                 BuildMI(MBB, &MI, MI.getDebugLoc(), TII->get(PPC::COPY),