[DebugInfo] Only handle DBG_VALUE in InlineSpiller

[HsiangKai]

Summary

The instructions using registers should be DBG_VALUE and normal
instructions. Use isDebugValue() to filter out DBG_VALUE and add
an assert to ensure there is no other kind of debug instructions
using the registers.

Related differential revision: https://reviews.llvm.org/D45342

[bjope]

Thanks! LGTM

llvm/trunk/lib/CodeGen/InlineSpiller.cpp

void InlineSpiller::reMaterializeAll() {
   for (unsigned Reg : RegsToSpill) {
     LiveInterval &LI = LIS.getInterval(Reg);
     for (MachineRegisterInfo::reg_bundle_iterator
            RegI = MRI.reg_bundle_begin(Reg), E = MRI.reg_bundle_end();
          RegI != E; ) {
       MachineInstr &MI = *RegI++;
 
       // Debug values are not allowed to affect codegen.
-      if (MI.isDebugInstr())
+      if (MI.isDebugValue())
         continue;
 
+      assert(!MI.isDebugInstr() && "Did not expect to find a use in debug "
+             "instruction that isn't a DBG_VALUE");
+
       anyRemat |= reMaterializeFor(LI, MI);
     }
   }
   if (!anyRemat)
     return;
 
   // Remove any values that were completely rematted.
   for (unsigned Reg : RegsToSpill) {
void InlineSpiller::spillAroundUses(unsigned Reg) {
 
   // Iterate over instructions using Reg.
   for (MachineRegisterInfo::reg_bundle_iterator
        RegI = MRI.reg_bundle_begin(Reg), E = MRI.reg_bundle_end();
        RegI != E; ) {
     MachineInstr *MI = &*(RegI++);
 
     // Debug values are not allowed to affect codegen.
-    if (MI->isDebugInstr()) {
+    if (MI->isDebugValue()) {
       // Modify DBG_VALUE now that the value is in a spill slot.
       MachineBasicBlock *MBB = MI->getParent();
       LLVM_DEBUG(dbgs() << "Modifying debug info due to spill:\t" << *MI);
       buildDbgValueForSpill(*MBB, MI, *MI, StackSlot);
       MBB->erase(MI);
       continue;
     }
 
+    assert(!MI->isDebugInstr() && "Did not expect to find a use in debug "
+           "instruction that isn't a DBG_VALUE");
+
     // Ignore copies to/from snippets. We'll delete them.
     if (SnippetCopies.count(MI))
       continue;
 
     // Stack slot accesses may coalesce away.
     if (coalesceStackAccess(MI, Reg))
       continue;