Transfer implicit operands in NEONMoveFixPass.

Later passes /are/ using this information when running the register
scavenger.

This fixes the second problem in PR10520.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136440 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 20 insertions, 10 deletions

diff --git a/lib/Target/ARM/NEONMoveFix.cpp b/lib/Target/ARM/NEONMoveFix.cpp
index c85d1e9..bd8c882 100644
--- a/lib/Target/ARM/NEONMoveFix.cpp
+++ b/lib/Target/ARM/NEONMoveFix.cpp
@@ -40,6 +40,8 @@ namespace {
     typedef DenseMap<unsigned, const MachineInstr*> RegMap;
 
     bool InsertMoves(MachineBasicBlock &MBB);
+
+    void TransferImpOps(MachineInstr &Old, MachineInstr &New);
   };
   char NEONMoveFixPass::ID = 0;
 }
@@ -49,6 +51,16 @@ static bool inNEONDomain(unsigned Domain, bool isA8) {
     (isA8 && (Domain & ARMII::DomainNEONA8));
 }
 
+/// Transfer implicit kill and def operands from Old to New.
+void NEONMoveFixPass::TransferImpOps(MachineInstr &Old, MachineInstr &New) {
+  for (unsigned i = 0, e = Old.getNumOperands(); i != e; ++i) {
+    MachineOperand &MO = Old.getOperand(i);
+    if (!MO.isReg() || !MO.isImplicit())
+      continue;
+    New.addOperand(MO);
+  }
+}
+
 bool NEONMoveFixPass::InsertMoves(MachineBasicBlock &MBB) {
   RegMap Defs;
   bool Modified = false;
@@ -82,17 +94,15 @@ bool NEONMoveFixPass::InsertMoves(MachineBasicBlock &MBB) {
 
         DEBUG({errs() << "vmov convert: "; MI->dump();});
 
-        // It's safe to ignore imp-defs / imp-uses here, since:
-        //  - We're running late, no intelligent condegen passes should be run
-        //    afterwards
-        //  - The imp-defs / imp-uses are superregs only, we don't care about
-        //    them.
-        AddDefaultPred(BuildMI(MBB, *MI, MI->getDebugLoc(),
-                             TII->get(ARM::VORRd), DestReg)
-          .addReg(SrcReg).addReg(SrcReg));
+        // We need to preserve imp-defs / imp-uses here. Following passes may
+        // use the register scavenger to update liveness.
+        MachineInstr *NewMI =
+          AddDefaultPred(BuildMI(MBB, *MI, MI->getDebugLoc(),
+                                 TII->get(ARM::VORRd), DestReg)
+                         .addReg(SrcReg).addReg(SrcReg));
+        TransferImpOps(*MI, *NewMI);
         MBB.erase(MI);
-        MachineBasicBlock::iterator I = prior(NextMII);
-        MI = &*I;
+        MI = NewMI;
 
         DEBUG({errs() << "        into: "; MI->dump();});