3 files changed, 33 insertions, 24 deletions

diff --git a/llvm/include/llvm/CodeGen/GlobalISel/LegalizerHelper.h b/llvm/include/llvm/CodeGen/GlobalISel/LegalizerHelper.h
index 5197ba869c0..1fd45b52e3a 100644
--- a/llvm/include/llvm/CodeGen/GlobalISel/LegalizerHelper.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/LegalizerHelper.h
@@ -101,11 +101,11 @@ private:
   const LegalizerInfo &LI;
 };
 
-/// Helper function that replaces \p MI with a libcall.
+/// Helper function that creates the given libcall.
 LegalizerHelper::LegalizeResult
-replaceWithLibcall(MachineInstr &MI, MachineIRBuilder &MIRBuilder,
-                   RTLIB::Libcall Libcall, const CallLowering::ArgInfo &Result,
-                   ArrayRef<CallLowering::ArgInfo> Args);
+createLibcall(MachineIRBuilder &MIRBuilder, RTLIB::Libcall Libcall,
+              const CallLowering::ArgInfo &Result,
+              ArrayRef<CallLowering::ArgInfo> Args);
 
 } // End namespace llvm.
 
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 84b0a0ac415..6b3c5249db1 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -99,23 +99,17 @@ static RTLIB::Libcall getRTLibDesc(unsigned Opcode, unsigned Size) {
   llvm_unreachable("Unknown libcall function");
 }
 
-LegalizerHelper::LegalizeResult llvm::replaceWithLibcall(
-    MachineInstr &MI, MachineIRBuilder &MIRBuilder, RTLIB::Libcall Libcall,
-    const CallLowering::ArgInfo &Result, ArrayRef<CallLowering::ArgInfo> Args) {
+LegalizerHelper::LegalizeResult
+llvm::createLibcall(MachineIRBuilder &MIRBuilder, RTLIB::Libcall Libcall,
+                    const CallLowering::ArgInfo &Result,
+                    ArrayRef<CallLowering::ArgInfo> Args) {
   auto &CLI = *MIRBuilder.getMF().getSubtarget().getCallLowering();
   auto &TLI = *MIRBuilder.getMF().getSubtarget().getTargetLowering();
   const char *Name = TLI.getLibcallName(Libcall);
   MIRBuilder.getMF().getFrameInfo().setHasCalls(true);
-  MIRBuilder.setInstr(MI);
   if (!CLI.lowerCall(MIRBuilder, TLI.getLibcallCallingConv(Libcall),
                      MachineOperand::CreateES(Name), Result, Args))
     return LegalizerHelper::UnableToLegalize;
-
-  // We're about to remove MI, so move the insert point after it.
-  MIRBuilder.setInsertPt(MIRBuilder.getMBB(),
-                         std::next(MIRBuilder.getInsertPt()));
-
-  MI.eraseFromParent();
   return LegalizerHelper::Legalized;
 }
 
@@ -123,10 +117,9 @@ static LegalizerHelper::LegalizeResult
 simpleLibcall(MachineInstr &MI, MachineIRBuilder &MIRBuilder, unsigned Size,
               Type *OpType) {
   auto Libcall = getRTLibDesc(MI.getOpcode(), Size);
-  return replaceWithLibcall(MI, MIRBuilder, Libcall,
-                            {MI.getOperand(0).getReg(), OpType},
-                            {{MI.getOperand(1).getReg(), OpType},
-                             {MI.getOperand(2).getReg(), OpType}});
+  return createLibcall(MIRBuilder, Libcall, {MI.getOperand(0).getReg(), OpType},
+                       {{MI.getOperand(1).getReg(), OpType},
+                        {MI.getOperand(2).getReg(), OpType}});
 }
 
 LegalizerHelper::LegalizeResult
@@ -135,6 +128,8 @@ LegalizerHelper::libcall(MachineInstr &MI) {
   unsigned Size = LLTy.getSizeInBits();
   auto &Ctx = MIRBuilder.getMF().getFunction()->getContext();
 
+  MIRBuilder.setInstr(MI);
+
   switch (MI.getOpcode()) {
   default:
     return UnableToLegalize;
@@ -143,15 +138,24 @@ LegalizerHelper::libcall(MachineInstr &MI) {
   case TargetOpcode::G_SREM:
   case TargetOpcode::G_UREM: {
     Type *HLTy = Type::getInt32Ty(Ctx);
-    return simpleLibcall(MI, MIRBuilder, Size, HLTy);
+    auto Status = simpleLibcall(MI, MIRBuilder, Size, HLTy);
+    if (Status != Legalized)
+      return Status;
+    break;
   }
   case TargetOpcode::G_FADD:
   case TargetOpcode::G_FPOW:
   case TargetOpcode::G_FREM: {
     Type *HLTy = Size == 64 ? Type::getDoubleTy(Ctx) : Type::getFloatTy(Ctx);
-    return simpleLibcall(MI, MIRBuilder, Size, HLTy);
+    auto Status = simpleLibcall(MI, MIRBuilder, Size, HLTy);
+    if (Status != Legalized)
+      return Status;
+    break;
   }
   }
+
+  MI.eraseFromParent();
+  return Legalized;
 }
 
 LegalizerHelper::LegalizeResult LegalizerHelper::narrowScalar(MachineInstr &MI,
diff --git a/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp b/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
index 10fdb286376..af6505c9862 100644
--- a/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
@@ -119,6 +119,8 @@ bool ARMLegalizerInfo::legalizeCustom(MachineInstr &MI,
                                       MachineIRBuilder &MIRBuilder) const {
   using namespace TargetOpcode;
 
+  MIRBuilder.setInstr(MI);
+
   switch (MI.getOpcode()) {
   default:
     return false;
@@ -140,9 +142,9 @@ bool ARMLegalizerInfo::legalizeCustom(MachineInstr &MI,
     auto RetVal = MRI.createGenericVirtualRegister(
         getLLTForType(*RetTy, MIRBuilder.getMF().getDataLayout()));
 
-    auto Status = replaceWithLibcall(MI, MIRBuilder, Libcall, {RetVal, RetTy},
-                                     {{MI.getOperand(1).getReg(), ArgTy},
-                                      {MI.getOperand(2).getReg(), ArgTy}});
+    auto Status = createLibcall(MIRBuilder, Libcall, {RetVal, RetTy},
+                                {{MI.getOperand(1).getReg(), ArgTy},
+                                 {MI.getOperand(2).getReg(), ArgTy}});
     if (Status != LegalizerHelper::Legalized)
       return false;
 
@@ -153,7 +155,10 @@ bool ARMLegalizerInfo::legalizeCustom(MachineInstr &MI,
         {MRI.createGenericVirtualRegister(LLT::scalar(32)), OriginalResult},
         RetVal);
 
-    return LegalizerHelper::Legalized;
+    break;
   }
   }
+
+  MI.eraseFromParent();
+  return true;
 }