When we generate spill code, then decide we don't need

to spill after all, we weren't handling 2-instruction
spill sequences correctly (PPC Altivec).  We need to
remove the store in this case.  Removing the other
instruction(s) would be goodness but is not needed for
correctness, and isn't done here.  7331562.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85437 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/VirtRegRewriter.cpp b/lib/CodeGen/VirtRegRewriter.cpp
index 107c19ad01938e0018cf1334be83dcb1282d5184..a9ff1ad9aeddff0f4d19aed531b992d4876e5ace 100644 (file)
--- a/lib/CodeGen/VirtRegRewriter.cpp
+++ b/lib/CodeGen/VirtRegRewriter.cpp
@@ -1430,6 +1430,7 @@ private:
                            std::vector<MachineOperand*> &KillOps,
                            VirtRegMap &VRM) {
 
+    MachineBasicBlock::iterator oldNextMII = next(MII);
     TII->storeRegToStackSlot(MBB, next(MII), PhysReg, true, StackSlot, RC);
     MachineInstr *StoreMI = next(MII);
     VRM.addSpillSlotUse(StackSlot, StoreMI);
@@ -1466,7 +1467,9 @@ private:
       }
     }
 
-    LastStore = next(MII);
+    // Allow for multi-instruction spill sequences, as on PPC Altivec.  Presume
+    // the last of multiple instructions is the actual store.
+    LastStore = prior(oldNextMII);
 
     // If the stack slot value was previously available in some other
     // register, change it now.  Otherwise, make the register available,