Handle more cases in LiveRangeEdit::eliminateDeadDefs.

Live intervals for dead physregs may be created during coalescing. We
need to update these in the event that their instruction goes away.

crash.ll is the unit test that catches it when MI sched is enabled on
X86.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184572 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/CodeGen/LiveRangeEdit.cpp b/lib/CodeGen/LiveRangeEdit.cpp
index 0c1d45902f..d215d0c28a 100644
--- a/lib/CodeGen/LiveRangeEdit.cpp
+++ b/lib/CodeGen/LiveRangeEdit.cpp
@@ -249,6 +249,15 @@ void LiveRangeEdit::eliminateDeadDef(MachineInstr *MI, ToShrinkSet &ToShrink) {
       // Check if MI reads any unreserved physregs.
       if (Reg && MOI->readsReg() && !MRI.isReserved(Reg))
         ReadsPhysRegs = true;
+      else if (MOI->isDef()) {
+        for (MCRegUnitIterator Units(Reg, MRI.getTargetRegisterInfo());
+             Units.isValid(); ++Units) {
+          if (LiveInterval *LI = LIS.getCachedRegUnit(*Units)) {
+            if (VNInfo *VNI = LI->getVNInfoAt(Idx))
+              LI->removeValNo(VNI);
+          }
+        }
+      }
       continue;
     }
     LiveInterval &LI = LIS.getInterval(Reg);