1 files changed, 6 insertions, 44 deletions

diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp
index 1cb0a23..3b3e7a4 100644
--- a/llvm/lib/CodeGen/BranchFolding.cpp
+++ b/llvm/lib/CodeGen/BranchFolding.cpp
@@ -2083,59 +2083,22 @@ bool BranchFolder::HoistCommonCodeInSuccs(MachineBasicBlock *MBB) {
   if (TBB == FBB) {
     MBB->splice(Loc, TBB, TBB->begin(), TIB);
   } else {
-    // Merge the debug locations, and hoist and kill the debug instructions from
-    // both branches. FIXME: We could probably try harder to preserve some debug
-    // instructions (but at least this isn't producing wrong locations).
-    MachineInstrBuilder MIRBuilder(*MBB->getParent(), Loc);
-    auto HoistAndKillDbgInstr = [MBB, Loc](MachineBasicBlock::iterator DI) {
-      assert(DI->isDebugInstr() && "Expected a debug instruction");
-      if (DI->isDebugRef()) {
-        const TargetInstrInfo *TII =
-            MBB->getParent()->getSubtarget().getInstrInfo();
-        const MCInstrDesc &DBGV = TII->get(TargetOpcode::DBG_VALUE);
-        DI = BuildMI(*MBB->getParent(), DI->getDebugLoc(), DBGV, false, 0,
-                     DI->getDebugVariable(), DI->getDebugExpression());
-        MBB->insert(Loc, &*DI);
-        return;
-      }
-      // Deleting a DBG_PHI results in an undef at the referenced DBG_INSTR_REF.
-      if (DI->isDebugPHI()) {
-        DI->eraseFromParent();
-        return;
-      }
-
-      DI->setDebugValueUndef();
-      DI->moveBefore(&*Loc);
-    };
-
     // TIB and FIB point to the end of the regions to hoist/merge in TBB and
     // FBB.
     MachineBasicBlock::iterator FE = FIB;
     MachineBasicBlock::iterator FI = FBB->begin();
     for (MachineBasicBlock::iterator TI :
          make_early_inc_range(make_range(TBB->begin(), TIB))) {
-      // Hoist and kill debug instructions from FBB. After this loop FI points
-      // to the next non-debug instruction to hoist (checked in assert after the
-      // TBB debug instruction handling code).
-      while (FI->isDebugInstr()) {
-        assert(FI != FE && "Unexpected end of FBB range");
-        MachineBasicBlock::iterator FINext = std::next(FI);
-        HoistAndKillDbgInstr(FI);
-        FI = FINext;
-      }
-
-      // Kill debug instructions before moving.
-      if (TI->isDebugInstr()) {
-        HoistAndKillDbgInstr(TI);
+      // Move debug instructions and pseudo probes without modifying them.
+      // FIXME: This is the wrong thing to do for debug locations, which
+      // should at least be killed (and hoisted from BOTH blocks).
+      if (TI->isDebugOrPseudoInstr()) {
+        TI->moveBefore(&*Loc);
         continue;
       }
 
-      // If FI is a debug instruction, skip forward to the next non-debug
-      // instruction.
+      // Get the next non-meta instruction in FBB.
       FI = skipDebugInstructionsForward(FI, FE, false);
-      // Pseudo probes are excluded from the range when identifying foldable
-      // instructions, so we don't expect to see one now.
-      assert(!TI->isPseudoProbe() && "Unexpected pseudo probe in range");
       // NOTE: The loop above checks CheckKillDead but we can't do that here as
       // it modifies some kill markers after the check.
       assert(TI->isIdenticalTo(*FI, MachineInstr::CheckDefs) &&
@@ -2148,7 +2111,6 @@ bool BranchFolder::HoistCommonCodeInSuccs(MachineBasicBlock *MBB) {
       ++FI;
     }
   }
-
   FBB->erase(FBB->begin(), FIB);
 
   if (UpdateLiveIns)