[AMDGPU] Avoid put implicit_def into bundle that break reg's liveness (#142563)

Cause:
1. `implicit_def` inside bundle does not count for define of reg in
machineinst verifier
2. Including `implicit_def` will cause relative reg not define, result
in `Bad machine code: Using an undefined physical register` in the
machineinst verifier

Fixes https://github.com/llvm/llvm-project/issues/139102

---------

Co-authored-by: Matt Arsenault <Matthew.Arsenault@amd.com>

1 files changed, 22 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/MachineInstrBundle.cpp b/llvm/lib/CodeGen/MachineInstrBundle.cpp
index 4da0184..d9e8484 100644
--- a/llvm/lib/CodeGen/MachineInstrBundle.cpp
+++ b/llvm/lib/CodeGen/MachineInstrBundle.cpp
@@ -94,6 +94,22 @@ static DebugLoc getDebugLoc(MachineBasicBlock::instr_iterator FirstMI,
   return DebugLoc();
 }
 
+/// Check if target reg is contained in given lists, which are:
+/// LocalDefsV as given list for virtual regs
+/// LocalDefsP as given list for physical regs, in BitVector[RegUnit] form
+static bool containsReg(SmallSetVector<Register, 32> LocalDefsV,
+                        const BitVector &LocalDefsP, Register Reg,
+                        const TargetRegisterInfo *TRI) {
+  if (Reg.isPhysical()) {
+    for (MCRegUnit Unit : TRI->regunits(Reg.asMCReg()))
+      if (!LocalDefsP[Unit])
+        return false;
+
+    return true;
+  }
+  return LocalDefsV.contains(Reg);
+}
+
 /// finalizeBundle - Finalize a machine instruction bundle which includes
 /// a sequence of instructions starting from FirstMI to LastMI (exclusive).
 /// This routine adds a BUNDLE instruction to represent the bundle, it adds
@@ -115,6 +131,7 @@ void llvm::finalizeBundle(MachineBasicBlock &MBB,
   Bundle.prepend(MIB);
 
   SmallSetVector<Register, 32> LocalDefs;
+  BitVector LocalDefsP(TRI->getNumRegUnits());
   SmallSet<Register, 8> DeadDefSet;
   SmallSet<Register, 16> KilledDefSet;
   SmallSetVector<Register, 8> ExternUses;
@@ -130,7 +147,7 @@ void llvm::finalizeBundle(MachineBasicBlock &MBB,
       if (!Reg)
         continue;
 
-      if (LocalDefs.contains(Reg)) {
+      if (containsReg(LocalDefs, LocalDefsP, Reg, TRI)) {
         MO.setIsInternalRead();
         if (MO.isKill()) {
           // Internal def is now killed.
@@ -165,8 +182,10 @@ void llvm::finalizeBundle(MachineBasicBlock &MBB,
         }
       }
 
-      if (!MO.isDead() && Reg.isPhysical())
-        LocalDefs.insert_range(TRI->subregs(Reg));
+      if (!MO.isDead() && Reg.isPhysical()) {
+        for (MCRegUnit Unit : TRI->regunits(Reg.asMCReg()))
+          LocalDefsP.set(Unit);
+      }
     }
 
     // Set FrameSetup/FrameDestroy for the bundle. If any of the instructions