From: Dale Johannesen <dalej@apple.com>
Date: Wed, 28 Oct 2009 21:56:18 +0000 (+0000)
Subject: When we generate spill code, then decide we don't need
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e841d2f8679f603ec453fe56a3bf9bea97aef303;p=oota-llvm.git

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 107c19ad019..a9ff1ad9aed 100644
--- 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,