Also update sub-register intervals after a trivial computation is rematt'ed for a copy instruction. PR2775.

llvm-svn: 57458

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp b/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp
index bb860d293e55..2f2d549a1952 100644
--- a/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -460,6 +460,16 @@ bool SimpleRegisterCoalescing::ReMaterializeTrivialDef(LiveInterval &SrcInt,
   unsigned DefIdx = li_->getDefIndex(CopyIdx);
   const LiveRange *DLR= li_->getInterval(DstReg).getLiveRangeContaining(DefIdx);
   DLR->valno->copy = NULL;
+  // Don't forget to update sub-register intervals.
+  if (TargetRegisterInfo::isPhysicalRegister(DstReg)) {
+    for (const unsigned* SR = tri_->getSubRegisters(DstReg); *SR; ++SR) {
+      if (!li_->hasInterval(*SR))
+        continue;
+      DLR = li_->getInterval(*SR).getLiveRangeContaining(DefIdx);
+      if (DLR && DLR->valno->copy == CopyMI)
+        DLR->valno->copy = NULL;
+    }
+  }
 
   MachineBasicBlock::iterator MII = CopyMI;
   MachineBasicBlock *MBB = CopyMI->getParent();