[AMDGPU] Update LiveVariables after killing an immediate def

D114999 added code to kill an immediate def if it was folded into its
only use by convertToThreeAddress. This patch updates LiveVariables when
that happens in order to fix verification failures exposed by D129213.

Differential Revision: https://reviews.llvm.org/D129661

diff --git a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
index c7b835b..799d34e 100644 (file)
--- a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -3335,15 +3335,18 @@ MachineInstr *SIInstrInfo::convertToThreeAddress(MachineInstr &MI,
       (ST.getConstantBusLimit(Opc) > 1 || !Src0->isReg() ||
        !RI.isSGPRReg(MBB.getParent()->getRegInfo(), Src0->getReg()))) {
     MachineInstr *DefMI;
-    const auto killDef = [&DefMI, &MBB, this]() -> void {
+    const auto killDef = [&]() -> void {
       const MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
       // The only user is the instruction which will be killed.
-      if (!MRI.hasOneNonDBGUse(DefMI->getOperand(0).getReg()))
+      Register DefReg = DefMI->getOperand(0).getReg();
+      if (!MRI.hasOneNonDBGUse(DefReg))
         return;
       // We cannot just remove the DefMI here, calling pass will crash.
       DefMI->setDesc(get(AMDGPU::IMPLICIT_DEF));
       for (unsigned I = DefMI->getNumOperands() - 1; I != 0; --I)
         DefMI->removeOperand(I);
+      if (LV)
+        LV->getVarInfo(DefReg).AliveBlocks.clear();
     };
 
     int64_t Imm;