diff --git a/llvm/lib/Target/LoongArch/LoongArchFrameLowering.h b/llvm/lib/Target/LoongArch/LoongArchFrameLowering.h
--- a/llvm/lib/Target/LoongArch/LoongArchFrameLowering.h
+++ b/llvm/lib/Target/LoongArch/LoongArchFrameLowering.h
@@ -34,11 +34,10 @@
   void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
                             RegScavenger *RS) const override;
 
+  bool hasReservedCallFrame(const MachineFunction &MF) const override;
   MachineBasicBlock::iterator
   eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
-                                MachineBasicBlock::iterator MI) const override {
-    return MBB.erase(MI);
-  }
+                                MachineBasicBlock::iterator MI) const override;
 
   StackOffset getFrameIndexReference(const MachineFunction &MF, int FI,
                                      Register &FrameReg) const override;
diff --git a/llvm/lib/Target/LoongArch/LoongArchFrameLowering.cpp b/llvm/lib/Target/LoongArch/LoongArchFrameLowering.cpp
--- a/llvm/lib/Target/LoongArch/LoongArchFrameLowering.cpp
+++ b/llvm/lib/Target/LoongArch/LoongArchFrameLowering.cpp
@@ -87,6 +87,7 @@
 void LoongArchFrameLowering::emitPrologue(MachineFunction &MF,
                                           MachineBasicBlock &MBB) const {
   MachineFrameInfo &MFI = MF.getFrameInfo();
+  auto *LoongArchFI = MF.getInfo<LoongArchMachineFunctionInfo>();
   const LoongArchRegisterInfo *RI = STI.getRegisterInfo();
   const LoongArchInstrInfo *TII = STI.getInstrInfo();
   MachineBasicBlock::iterator MBBI = MBB.begin();
@@ -138,11 +139,14 @@
 
   // Generate new FP.
   if (hasFP(MF)) {
-    adjustReg(MBB, MBBI, DL, FPReg, SPReg, StackSize, MachineInstr::FrameSetup);
-
-    // Emit ".cfi_def_cfa $fp, 0"
-    unsigned CFIIndex = MF.addFrameInst(MCCFIInstruction::cfiDefCfa(
-        nullptr, RI->getDwarfRegNum(FPReg, true), 0));
+    adjustReg(MBB, MBBI, DL, FPReg, SPReg,
+              StackSize - LoongArchFI->getVarArgsSaveSize(),
+              MachineInstr::FrameSetup);
+
+    // Emit ".cfi_def_cfa $fp, LoongArchFI->getVarArgsSaveSize()"
+    unsigned CFIIndex = MF.addFrameInst(
+        MCCFIInstruction::cfiDefCfa(nullptr, RI->getDwarfRegNum(FPReg, true),
+                                    LoongArchFI->getVarArgsSaveSize()));
     BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
         .addCFIIndex(CFIIndex)
         .setMIFlag(MachineInstr::FrameSetup);
@@ -153,6 +157,7 @@
                                           MachineBasicBlock &MBB) const {
   const LoongArchRegisterInfo *RI = STI.getRegisterInfo();
   MachineFrameInfo &MFI = MF.getFrameInfo();
+  auto *LoongArchFI = MF.getInfo<LoongArchMachineFunctionInfo>();
   Register SPReg = LoongArch::R3;
 
   MachineBasicBlock::iterator MBBI = MBB.getFirstTerminator();
@@ -170,7 +175,8 @@
   // Restore the stack pointer.
   if (RI->hasStackRealignment(MF) || MFI.hasVarSizedObjects()) {
     assert(hasFP(MF) && "frame pointer should not have been eliminated");
-    adjustReg(MBB, LastFrameDestroy, DL, SPReg, LoongArch::R22, -StackSize,
+    adjustReg(MBB, LastFrameDestroy, DL, SPReg, LoongArch::R22,
+              -StackSize + LoongArchFI->getVarArgsSaveSize(),
               MachineInstr::FrameDestroy);
   }
 
@@ -193,10 +199,49 @@
     SavedRegs.set(LoongArchABI::getBPReg());
 }
 
+// Do not preserve stack space within prologue for outgoing variables if the
+// function contains variable size objects.
+// Let eliminateCallFramePseudoInstr preserve stack space for it.
+bool LoongArchFrameLowering::hasReservedCallFrame(
+    const MachineFunction &MF) const {
+  return !MF.getFrameInfo().hasVarSizedObjects();
+}
+
+// Eliminate ADJCALLSTACKDOWN, ADJCALLSTACKUP pseudo instructions.
+MachineBasicBlock::iterator
+LoongArchFrameLowering::eliminateCallFramePseudoInstr(
+    MachineFunction &MF, MachineBasicBlock &MBB,
+    MachineBasicBlock::iterator MI) const {
+  Register SPReg = LoongArch::R3;
+  DebugLoc DL = MI->getDebugLoc();
+
+  if (!hasReservedCallFrame(MF)) {
+    // If space has not been reserved for a call frame, ADJCALLSTACKDOWN and
+    // ADJCALLSTACKUP must be converted to instructions manipulating the stack
+    // pointer. This is necessary when there is a variable length stack
+    // allocation (e.g. alloca), which means it's not possible to allocate
+    // space for outgoing arguments from within the function prologue.
+    int64_t Amount = MI->getOperand(0).getImm();
+
+    if (Amount != 0) {
+      // Ensure the stack remains aligned after adjustment.
+      Amount = alignSPAdjust(Amount);
+
+      if (MI->getOpcode() == LoongArch::ADJCALLSTACKDOWN)
+        Amount = -Amount;
+
+      adjustReg(MBB, MI, DL, SPReg, SPReg, Amount, MachineInstr::NoFlags);
+    }
+  }
+
+  return MBB.erase(MI);
+}
+
 StackOffset LoongArchFrameLowering::getFrameIndexReference(
     const MachineFunction &MF, int FI, Register &FrameReg) const {
   const MachineFrameInfo &MFI = MF.getFrameInfo();
   const TargetRegisterInfo *RI = MF.getSubtarget().getRegisterInfo();
+  auto *LoongArchFI = MF.getInfo<LoongArchMachineFunctionInfo>();
 
   // Callee-saved registers should be referenced relative to the stack
   // pointer (positive offset), otherwise use the frame pointer (negative
@@ -213,10 +258,12 @@
     MaxCSFI = CSI[CSI.size() - 1].getFrameIdx();
   }
 
-  FrameReg = RI->getFrameRegister(MF);
   if ((FI >= MinCSFI && FI <= MaxCSFI) || !hasFP(MF)) {
     FrameReg = LoongArch::R3;
     Offset += StackOffset::getFixed(MFI.getStackSize());
+  } else {
+    FrameReg = RI->getFrameRegister(MF);
+    Offset += StackOffset::getFixed(LoongArchFI->getVarArgsSaveSize());
   }
 
   return Offset;
diff --git a/llvm/lib/Target/LoongArch/LoongArchISelLowering.h b/llvm/lib/Target/LoongArch/LoongArchISelLowering.h
--- a/llvm/lib/Target/LoongArch/LoongArchISelLowering.h
+++ b/llvm/lib/Target/LoongArch/LoongArchISelLowering.h
@@ -110,6 +110,7 @@
   SDValue lowerFP_TO_SINT(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerBITCAST(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerUINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;
+  SDValue lowerVASTART(SDValue Op, SelectionDAG &DAG) const;
 
   bool isFPImmLegal(const APFloat &Imm, EVT VT,
                     bool ForCodeSize) const override;
diff --git a/llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp b/llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp
--- a/llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp
+++ b/llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp
@@ -55,6 +55,10 @@
 
   setOperationAction({ISD::GlobalAddress, ISD::ConstantPool}, GRLenVT, Custom);
 
+  setOperationAction(ISD::DYNAMIC_STACKALLOC, GRLenVT, Expand);
+  setOperationAction(ISD::VASTART, MVT::Other, Custom);
+  setOperationAction({ISD::VAARG, ISD::VACOPY, ISD::VAEND}, MVT::Other, Expand);
+
   if (Subtarget.is64Bit()) {
     setOperationAction(ISD::SHL, MVT::i32, Custom);
     setOperationAction(ISD::SRA, MVT::i32, Custom);
@@ -137,9 +141,27 @@
     return SDValue();
   case ISD::UINT_TO_FP:
     return lowerUINT_TO_FP(Op, DAG);
+  case ISD::VASTART:
+    return lowerVASTART(Op, DAG);
   }
 }
 
+SDValue LoongArchTargetLowering::lowerVASTART(SDValue Op,
+                                              SelectionDAG &DAG) const {
+  MachineFunction &MF = DAG.getMachineFunction();
+  auto *FuncInfo = MF.getInfo<LoongArchMachineFunctionInfo>();
+
+  SDLoc DL(Op);
+  SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
+                                 getPointerTy(MF.getDataLayout()));
+
+  // vastart just stores the address of the VarArgsFrameIndex slot into the
+  // memory location argument.
+  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
+  return DAG.getStore(Op.getOperand(0), DL, FI, Op.getOperand(1),
+                      MachinePointerInfo(SV));
+}
+
 SDValue LoongArchTargetLowering::lowerUINT_TO_FP(SDValue Op,
                                                  SelectionDAG &DAG) const {
 
@@ -1174,6 +1196,10 @@
   }
 
   EVT PtrVT = getPointerTy(DAG.getDataLayout());
+  MVT GRLenVT = Subtarget.getGRLenVT();
+  unsigned GRLenInBytes = Subtarget.getGRLen() / 8;
+  // Used with varargs to acumulate store chains.
+  std::vector<SDValue> OutChains;
 
   // Assign locations to all of the incoming arguments.
   SmallVector<CCValAssign> ArgLocs;
@@ -1211,8 +1237,66 @@
   }
 
   if (IsVarArg) {
-    // TODO: Support vararg.
-    report_fatal_error("Not support vararg");
+    ArrayRef<MCPhysReg> ArgRegs = makeArrayRef(ArgGPRs);
+    unsigned Idx = CCInfo.getFirstUnallocated(ArgRegs);
+    const TargetRegisterClass *RC = &LoongArch::GPRRegClass;
+    MachineFrameInfo &MFI = MF.getFrameInfo();
+    MachineRegisterInfo &RegInfo = MF.getRegInfo();
+    auto *LoongArchFI = MF.getInfo<LoongArchMachineFunctionInfo>();
+
+    // Offset of the first variable argument from stack pointer, and size of
+    // the vararg save area. For now, the varargs save area is either zero or
+    // large enough to hold a0-a7.
+    int VaArgOffset, VarArgsSaveSize;
+
+    // If all registers are allocated, then all varargs must be passed on the
+    // stack and we don't need to save any argregs.
+    if (ArgRegs.size() == Idx) {
+      VaArgOffset = CCInfo.getNextStackOffset();
+      VarArgsSaveSize = 0;
+    } else {
+      VarArgsSaveSize = GRLenInBytes * (ArgRegs.size() - Idx);
+      VaArgOffset = -VarArgsSaveSize;
+    }
+
+    // Record the frame index of the first variable argument
+    // which is a value necessary to VASTART.
+    int FI = MFI.CreateFixedObject(GRLenInBytes, VaArgOffset, true);
+    LoongArchFI->setVarArgsFrameIndex(FI);
+
+    // If saving an odd number of registers then create an extra stack slot to
+    // ensure that the frame pointer is 2*GRLen-aligned, which in turn ensures
+    // offsets to even-numbered registered remain 2*GRLen-aligned.
+    if (Idx % 2) {
+      MFI.CreateFixedObject(GRLenInBytes, VaArgOffset - (int)GRLenInBytes,
+                            true);
+      VarArgsSaveSize += GRLenInBytes;
+    }
+
+    // Copy the integer registers that may have been used for passing varargs
+    // to the vararg save area.
+    for (unsigned I = Idx; I < ArgRegs.size();
+         ++I, VaArgOffset += GRLenInBytes) {
+      const Register Reg = RegInfo.createVirtualRegister(RC);
+      RegInfo.addLiveIn(ArgRegs[I], Reg);
+      SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, GRLenVT);
+      FI = MFI.CreateFixedObject(GRLenInBytes, VaArgOffset, true);
+      SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
+      SDValue Store = DAG.getStore(Chain, DL, ArgValue, PtrOff,
+                                   MachinePointerInfo::getFixedStack(MF, FI));
+      cast<StoreSDNode>(Store.getNode())
+          ->getMemOperand()
+          ->setValue((Value *)nullptr);
+      OutChains.push_back(Store);
+    }
+    LoongArchFI->setVarArgsSaveSize(VarArgsSaveSize);
+  }
+
+  // All stores are grouped in one node to allow the matching between
+  // the size of Ins and InVals. This only happens for vararg functions.
+  if (!OutChains.empty()) {
+    OutChains.push_back(Chain);
+    Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, OutChains);
   }
 
   return Chain;
diff --git a/llvm/test/CodeGen/LoongArch/vararg.ll b/llvm/test/CodeGen/LoongArch/vararg.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/LoongArch/vararg.ll
@@ -0,0 +1,356 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc --mtriple=loongarch64 --mattr=+d --target-abi=lp64d < %s \
+; RUN:   | FileCheck --check-prefix=LA64-FPELIM %s
+; RUN: llc --mtriple=loongarch64 --mattr=+d --target-abi=lp64d < %s \
+; RUN:     --frame-pointer=all < %s \
+; RUN:   | FileCheck --check-prefix=LA64-WITHFP %s
+
+declare void @llvm.va_start(ptr)
+declare void @llvm.va_end(ptr)
+
+declare void @notdead(ptr)
+
+define i64 @va1(ptr %fmt, ...) {
+; LA64-FPELIM-LABEL: va1:
+; LA64-FPELIM:       # %bb.0:
+; LA64-FPELIM-NEXT:    addi.d $sp, $sp, -80
+; LA64-FPELIM-NEXT:    .cfi_def_cfa_offset 80
+; LA64-FPELIM-NEXT:    move $a0, $a1
+; LA64-FPELIM-NEXT:    st.d $a7, $sp, 72
+; LA64-FPELIM-NEXT:    st.d $a6, $sp, 64
+; LA64-FPELIM-NEXT:    st.d $a5, $sp, 56
+; LA64-FPELIM-NEXT:    st.d $a4, $sp, 48
+; LA64-FPELIM-NEXT:    st.d $a3, $sp, 40
+; LA64-FPELIM-NEXT:    st.d $a2, $sp, 32
+; LA64-FPELIM-NEXT:    addi.d $a1, $sp, 32
+; LA64-FPELIM-NEXT:    st.d $a1, $sp, 8
+; LA64-FPELIM-NEXT:    st.d $a0, $sp, 24
+; LA64-FPELIM-NEXT:    addi.d $sp, $sp, 80
+; LA64-FPELIM-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-WITHFP-LABEL: va1:
+; LA64-WITHFP:       # %bb.0:
+; LA64-WITHFP-NEXT:    addi.d $sp, $sp, -96
+; LA64-WITHFP-NEXT:    .cfi_def_cfa_offset 96
+; LA64-WITHFP-NEXT:    st.d $ra, $sp, 24 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    st.d $fp, $sp, 16 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    .cfi_offset 1, -72
+; LA64-WITHFP-NEXT:    .cfi_offset 22, -80
+; LA64-WITHFP-NEXT:    addi.d $fp, $sp, 32
+; LA64-WITHFP-NEXT:    .cfi_def_cfa 22, 64
+; LA64-WITHFP-NEXT:    move $a0, $a1
+; LA64-WITHFP-NEXT:    st.d $a7, $fp, 56
+; LA64-WITHFP-NEXT:    st.d $a6, $fp, 48
+; LA64-WITHFP-NEXT:    st.d $a5, $fp, 40
+; LA64-WITHFP-NEXT:    st.d $a4, $fp, 32
+; LA64-WITHFP-NEXT:    st.d $a3, $fp, 24
+; LA64-WITHFP-NEXT:    st.d $a2, $fp, 16
+; LA64-WITHFP-NEXT:    addi.d $a1, $fp, 16
+; LA64-WITHFP-NEXT:    st.d $a1, $fp, -24
+; LA64-WITHFP-NEXT:    st.d $a0, $fp, 8
+; LA64-WITHFP-NEXT:    ld.d $fp, $sp, 16 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    ld.d $ra, $sp, 24 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    addi.d $sp, $sp, 96
+; LA64-WITHFP-NEXT:    jirl $zero, $ra, 0
+  %va = alloca ptr, align 8
+  call void @llvm.va_start(ptr %va)
+  %argp.cur = load ptr, ptr %va, align 8
+  %argp.next = getelementptr inbounds i64, ptr %argp.cur, i32 1
+  store ptr %argp.next, ptr %va, align 8
+  %1 = load i64, ptr %argp.cur, align 8
+  call void @llvm.va_end(ptr %va)
+  ret i64 %1
+}
+
+define i64 @va1_va_arg(ptr %fmt, ...) nounwind {
+; LA64-FPELIM-LABEL: va1_va_arg:
+; LA64-FPELIM:       # %bb.0:
+; LA64-FPELIM-NEXT:    addi.d $sp, $sp, -80
+; LA64-FPELIM-NEXT:    move $a0, $a1
+; LA64-FPELIM-NEXT:    st.d $a7, $sp, 72
+; LA64-FPELIM-NEXT:    st.d $a6, $sp, 64
+; LA64-FPELIM-NEXT:    st.d $a5, $sp, 56
+; LA64-FPELIM-NEXT:    st.d $a4, $sp, 48
+; LA64-FPELIM-NEXT:    st.d $a3, $sp, 40
+; LA64-FPELIM-NEXT:    st.d $a2, $sp, 32
+; LA64-FPELIM-NEXT:    addi.d $a1, $sp, 32
+; LA64-FPELIM-NEXT:    st.d $a1, $sp, 8
+; LA64-FPELIM-NEXT:    st.d $a0, $sp, 24
+; LA64-FPELIM-NEXT:    addi.d $sp, $sp, 80
+; LA64-FPELIM-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-WITHFP-LABEL: va1_va_arg:
+; LA64-WITHFP:       # %bb.0:
+; LA64-WITHFP-NEXT:    addi.d $sp, $sp, -96
+; LA64-WITHFP-NEXT:    st.d $ra, $sp, 24 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    st.d $fp, $sp, 16 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    addi.d $fp, $sp, 32
+; LA64-WITHFP-NEXT:    move $a0, $a1
+; LA64-WITHFP-NEXT:    st.d $a7, $fp, 56
+; LA64-WITHFP-NEXT:    st.d $a6, $fp, 48
+; LA64-WITHFP-NEXT:    st.d $a5, $fp, 40
+; LA64-WITHFP-NEXT:    st.d $a4, $fp, 32
+; LA64-WITHFP-NEXT:    st.d $a3, $fp, 24
+; LA64-WITHFP-NEXT:    st.d $a2, $fp, 16
+; LA64-WITHFP-NEXT:    addi.d $a1, $fp, 16
+; LA64-WITHFP-NEXT:    st.d $a1, $fp, -24
+; LA64-WITHFP-NEXT:    st.d $a0, $fp, 8
+; LA64-WITHFP-NEXT:    ld.d $fp, $sp, 16 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    ld.d $ra, $sp, 24 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    addi.d $sp, $sp, 96
+; LA64-WITHFP-NEXT:    jirl $zero, $ra, 0
+  %va = alloca ptr, align 8
+  call void @llvm.va_start(ptr %va)
+  %1 = va_arg ptr %va, i64
+  call void @llvm.va_end(ptr %va)
+  ret i64 %1
+}
+
+;; Ensure the adjustment when restoring the stack pointer using the frame
+;; pointer is correct
+
+define i64 @va1_va_arg_alloca(ptr %fmt, ...) nounwind {
+; LA64-FPELIM-LABEL: va1_va_arg_alloca:
+; LA64-FPELIM:       # %bb.0:
+; LA64-FPELIM-NEXT:    addi.d $sp, $sp, -96
+; LA64-FPELIM-NEXT:    st.d $ra, $sp, 24 # 8-byte Folded Spill
+; LA64-FPELIM-NEXT:    st.d $fp, $sp, 16 # 8-byte Folded Spill
+; LA64-FPELIM-NEXT:    st.d $s0, $sp, 8 # 8-byte Folded Spill
+; LA64-FPELIM-NEXT:    addi.d $fp, $sp, 32
+; LA64-FPELIM-NEXT:    move $s0, $a1
+; LA64-FPELIM-NEXT:    st.d $a7, $fp, 56
+; LA64-FPELIM-NEXT:    st.d $a6, $fp, 48
+; LA64-FPELIM-NEXT:    st.d $a5, $fp, 40
+; LA64-FPELIM-NEXT:    st.d $a4, $fp, 32
+; LA64-FPELIM-NEXT:    st.d $a3, $fp, 24
+; LA64-FPELIM-NEXT:    st.d $a2, $fp, 16
+; LA64-FPELIM-NEXT:    addi.d $a0, $fp, 16
+; LA64-FPELIM-NEXT:    st.d $a0, $fp, -32
+; LA64-FPELIM-NEXT:    addi.d $a0, $a1, 15
+; LA64-FPELIM-NEXT:    addi.w $a1, $zero, -16
+; LA64-FPELIM-NEXT:    and $a0, $a0, $a1
+; LA64-FPELIM-NEXT:    st.d $s0, $fp, 8
+; LA64-FPELIM-NEXT:    sub.d $a0, $sp, $a0
+; LA64-FPELIM-NEXT:    move $sp, $a0
+; LA64-FPELIM-NEXT:    bl notdead
+; LA64-FPELIM-NEXT:    move $a0, $s0
+; LA64-FPELIM-NEXT:    addi.d $sp, $fp, -32
+; LA64-FPELIM-NEXT:    ld.d $s0, $sp, 8 # 8-byte Folded Reload
+; LA64-FPELIM-NEXT:    ld.d $fp, $sp, 16 # 8-byte Folded Reload
+; LA64-FPELIM-NEXT:    ld.d $ra, $sp, 24 # 8-byte Folded Reload
+; LA64-FPELIM-NEXT:    addi.d $sp, $sp, 96
+; LA64-FPELIM-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-WITHFP-LABEL: va1_va_arg_alloca:
+; LA64-WITHFP:       # %bb.0:
+; LA64-WITHFP-NEXT:    addi.d $sp, $sp, -96
+; LA64-WITHFP-NEXT:    st.d $ra, $sp, 24 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    st.d $fp, $sp, 16 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    st.d $s0, $sp, 8 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    addi.d $fp, $sp, 32
+; LA64-WITHFP-NEXT:    move $s0, $a1
+; LA64-WITHFP-NEXT:    st.d $a7, $fp, 56
+; LA64-WITHFP-NEXT:    st.d $a6, $fp, 48
+; LA64-WITHFP-NEXT:    st.d $a5, $fp, 40
+; LA64-WITHFP-NEXT:    st.d $a4, $fp, 32
+; LA64-WITHFP-NEXT:    st.d $a3, $fp, 24
+; LA64-WITHFP-NEXT:    st.d $a2, $fp, 16
+; LA64-WITHFP-NEXT:    addi.d $a0, $fp, 16
+; LA64-WITHFP-NEXT:    st.d $a0, $fp, -32
+; LA64-WITHFP-NEXT:    addi.d $a0, $a1, 15
+; LA64-WITHFP-NEXT:    addi.w $a1, $zero, -16
+; LA64-WITHFP-NEXT:    and $a0, $a0, $a1
+; LA64-WITHFP-NEXT:    st.d $s0, $fp, 8
+; LA64-WITHFP-NEXT:    sub.d $a0, $sp, $a0
+; LA64-WITHFP-NEXT:    move $sp, $a0
+; LA64-WITHFP-NEXT:    bl notdead
+; LA64-WITHFP-NEXT:    move $a0, $s0
+; LA64-WITHFP-NEXT:    addi.d $sp, $fp, -32
+; LA64-WITHFP-NEXT:    ld.d $s0, $sp, 8 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    ld.d $fp, $sp, 16 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    ld.d $ra, $sp, 24 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    addi.d $sp, $sp, 96
+; LA64-WITHFP-NEXT:    jirl $zero, $ra, 0
+  %va = alloca ptr, align 8
+  call void @llvm.va_start(ptr %va)
+  %1 = va_arg ptr %va, i64
+  %2 = alloca i8, i64 %1
+  call void @notdead(ptr %2)
+  call void @llvm.va_end(ptr %va)
+  ret i64 %1
+}
+
+define void @va1_caller() nounwind {
+; LA64-FPELIM-LABEL: va1_caller:
+; LA64-FPELIM:       # %bb.0:
+; LA64-FPELIM-NEXT:    addi.d $sp, $sp, -16
+; LA64-FPELIM-NEXT:    st.d $ra, $sp, 8 # 8-byte Folded Spill
+; LA64-FPELIM-NEXT:    lu52i.d $a1, $zero, 1023
+; LA64-FPELIM-NEXT:    ori $a2, $zero, 2
+; LA64-FPELIM-NEXT:    bl va1
+; LA64-FPELIM-NEXT:    ld.d $ra, $sp, 8 # 8-byte Folded Reload
+; LA64-FPELIM-NEXT:    addi.d $sp, $sp, 16
+; LA64-FPELIM-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-WITHFP-LABEL: va1_caller:
+; LA64-WITHFP:       # %bb.0:
+; LA64-WITHFP-NEXT:    addi.d $sp, $sp, -16
+; LA64-WITHFP-NEXT:    st.d $ra, $sp, 8 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    st.d $fp, $sp, 0 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    addi.d $fp, $sp, 16
+; LA64-WITHFP-NEXT:    lu52i.d $a1, $zero, 1023
+; LA64-WITHFP-NEXT:    ori $a2, $zero, 2
+; LA64-WITHFP-NEXT:    bl va1
+; LA64-WITHFP-NEXT:    ld.d $fp, $sp, 0 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    ld.d $ra, $sp, 8 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    addi.d $sp, $sp, 16
+; LA64-WITHFP-NEXT:    jirl $zero, $ra, 0
+  %1 = call i64 (ptr, ...) @va1(ptr undef, double 1.0, i64 2)
+  ret void
+}
+
+;; Ensure a named 2*GRLen argument is passed in a1 and a2, while the
+;; vararg long double is passed in a4 and a5 (rather than a3 and a4)
+
+declare i64 @va_aligned_register(i64 %a, i128 %b, ...)
+
+define void @va_aligned_register_caller() nounwind {
+; LA64-FPELIM-LABEL: va_aligned_register_caller:
+; LA64-FPELIM:       # %bb.0:
+; LA64-FPELIM-NEXT:    addi.d $sp, $sp, -16
+; LA64-FPELIM-NEXT:    st.d $ra, $sp, 8 # 8-byte Folded Spill
+; LA64-FPELIM-NEXT:    lu12i.w $a0, 335544
+; LA64-FPELIM-NEXT:    ori $a0, $a0, 1311
+; LA64-FPELIM-NEXT:    lu32i.d $a0, 335544
+; LA64-FPELIM-NEXT:    lu52i.d $a4, $a0, -328
+; LA64-FPELIM-NEXT:    lu12i.w $a0, -503317
+; LA64-FPELIM-NEXT:    ori $a0, $a0, 2129
+; LA64-FPELIM-NEXT:    lu32i.d $a0, 37355
+; LA64-FPELIM-NEXT:    lu52i.d $a5, $a0, 1024
+; LA64-FPELIM-NEXT:    ori $a0, $zero, 2
+; LA64-FPELIM-NEXT:    ori $a1, $zero, 1111
+; LA64-FPELIM-NEXT:    move $a2, $zero
+; LA64-FPELIM-NEXT:    bl va_aligned_register
+; LA64-FPELIM-NEXT:    ld.d $ra, $sp, 8 # 8-byte Folded Reload
+; LA64-FPELIM-NEXT:    addi.d $sp, $sp, 16
+; LA64-FPELIM-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-WITHFP-LABEL: va_aligned_register_caller:
+; LA64-WITHFP:       # %bb.0:
+; LA64-WITHFP-NEXT:    addi.d $sp, $sp, -16
+; LA64-WITHFP-NEXT:    st.d $ra, $sp, 8 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    st.d $fp, $sp, 0 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    addi.d $fp, $sp, 16
+; LA64-WITHFP-NEXT:    lu12i.w $a0, 335544
+; LA64-WITHFP-NEXT:    ori $a0, $a0, 1311
+; LA64-WITHFP-NEXT:    lu32i.d $a0, 335544
+; LA64-WITHFP-NEXT:    lu52i.d $a4, $a0, -328
+; LA64-WITHFP-NEXT:    lu12i.w $a0, -503317
+; LA64-WITHFP-NEXT:    ori $a0, $a0, 2129
+; LA64-WITHFP-NEXT:    lu32i.d $a0, 37355
+; LA64-WITHFP-NEXT:    lu52i.d $a5, $a0, 1024
+; LA64-WITHFP-NEXT:    ori $a0, $zero, 2
+; LA64-WITHFP-NEXT:    ori $a1, $zero, 1111
+; LA64-WITHFP-NEXT:    move $a2, $zero
+; LA64-WITHFP-NEXT:    bl va_aligned_register
+; LA64-WITHFP-NEXT:    ld.d $fp, $sp, 0 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    ld.d $ra, $sp, 8 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    addi.d $sp, $sp, 16
+; LA64-WITHFP-NEXT:    jirl $zero, $ra, 0
+ %1 = call i64 (i64, i128, ...) @va_aligned_register(i64 2, i128 1111,
+   fp128 0xLEB851EB851EB851F400091EB851EB851)
+ ret void
+}
+
+;; Check 2*GRLen values are aligned appropriately when passed on the stack
+;; in a vararg call
+
+declare i32 @va_aligned_stack_callee(i32, ...)
+
+define void @va_aligned_stack_caller() nounwind {
+; LA64-FPELIM-LABEL: va_aligned_stack_caller:
+; LA64-FPELIM:       # %bb.0:
+; LA64-FPELIM-NEXT:    addi.d $sp, $sp, -112
+; LA64-FPELIM-NEXT:    st.d $ra, $sp, 104 # 8-byte Folded Spill
+; LA64-FPELIM-NEXT:    ori $a0, $zero, 17
+; LA64-FPELIM-NEXT:    st.d $a0, $sp, 48
+; LA64-FPELIM-NEXT:    ori $a0, $zero, 16
+; LA64-FPELIM-NEXT:    st.d $a0, $sp, 40
+; LA64-FPELIM-NEXT:    ori $a0, $zero, 15
+; LA64-FPELIM-NEXT:    st.d $a0, $sp, 32
+; LA64-FPELIM-NEXT:    ori $a0, $zero, 14
+; LA64-FPELIM-NEXT:    st.d $a0, $sp, 0
+; LA64-FPELIM-NEXT:    lu12i.w $a0, -503317
+; LA64-FPELIM-NEXT:    ori $a0, $a0, 2129
+; LA64-FPELIM-NEXT:    lu32i.d $a0, 37355
+; LA64-FPELIM-NEXT:    lu52i.d $a0, $a0, 1024
+; LA64-FPELIM-NEXT:    st.d $a0, $sp, 24
+; LA64-FPELIM-NEXT:    lu12i.w $a0, 335544
+; LA64-FPELIM-NEXT:    ori $a0, $a0, 1311
+; LA64-FPELIM-NEXT:    lu32i.d $a0, 335544
+; LA64-FPELIM-NEXT:    lu52i.d $a0, $a0, -328
+; LA64-FPELIM-NEXT:    st.d $a0, $sp, 16
+; LA64-FPELIM-NEXT:    ori $a0, $zero, 1000
+; LA64-FPELIM-NEXT:    st.d $a0, $sp, 64
+; LA64-FPELIM-NEXT:    st.d $zero, $sp, 88
+; LA64-FPELIM-NEXT:    st.d $zero, $sp, 80
+; LA64-FPELIM-NEXT:    st.d $zero, $sp, 72
+; LA64-FPELIM-NEXT:    ori $a1, $zero, 11
+; LA64-FPELIM-NEXT:    addi.d $a2, $sp, 64
+; LA64-FPELIM-NEXT:    ori $a3, $zero, 12
+; LA64-FPELIM-NEXT:    ori $a4, $zero, 13
+; LA64-FPELIM-NEXT:    ori $a0, $zero, 1
+; LA64-FPELIM-NEXT:    move $a6, $zero
+; LA64-FPELIM-NEXT:    move $a7, $a0
+; LA64-FPELIM-NEXT:    bl va_aligned_stack_callee
+; LA64-FPELIM-NEXT:    ld.d $ra, $sp, 104 # 8-byte Folded Reload
+; LA64-FPELIM-NEXT:    addi.d $sp, $sp, 112
+; LA64-FPELIM-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-WITHFP-LABEL: va_aligned_stack_caller:
+; LA64-WITHFP:       # %bb.0:
+; LA64-WITHFP-NEXT:    addi.d $sp, $sp, -112
+; LA64-WITHFP-NEXT:    st.d $ra, $sp, 104 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    st.d $fp, $sp, 96 # 8-byte Folded Spill
+; LA64-WITHFP-NEXT:    addi.d $fp, $sp, 112
+; LA64-WITHFP-NEXT:    ori $a0, $zero, 17
+; LA64-WITHFP-NEXT:    st.d $a0, $sp, 48
+; LA64-WITHFP-NEXT:    ori $a0, $zero, 16
+; LA64-WITHFP-NEXT:    st.d $a0, $sp, 40
+; LA64-WITHFP-NEXT:    ori $a0, $zero, 15
+; LA64-WITHFP-NEXT:    st.d $a0, $sp, 32
+; LA64-WITHFP-NEXT:    ori $a0, $zero, 14
+; LA64-WITHFP-NEXT:    st.d $a0, $sp, 0
+; LA64-WITHFP-NEXT:    lu12i.w $a0, -503317
+; LA64-WITHFP-NEXT:    ori $a0, $a0, 2129
+; LA64-WITHFP-NEXT:    lu32i.d $a0, 37355
+; LA64-WITHFP-NEXT:    lu52i.d $a0, $a0, 1024
+; LA64-WITHFP-NEXT:    st.d $a0, $sp, 24
+; LA64-WITHFP-NEXT:    lu12i.w $a0, 335544
+; LA64-WITHFP-NEXT:    ori $a0, $a0, 1311
+; LA64-WITHFP-NEXT:    lu32i.d $a0, 335544
+; LA64-WITHFP-NEXT:    lu52i.d $a0, $a0, -328
+; LA64-WITHFP-NEXT:    st.d $a0, $sp, 16
+; LA64-WITHFP-NEXT:    ori $a0, $zero, 1000
+; LA64-WITHFP-NEXT:    st.d $a0, $fp, -48
+; LA64-WITHFP-NEXT:    st.d $zero, $fp, -24
+; LA64-WITHFP-NEXT:    st.d $zero, $fp, -32
+; LA64-WITHFP-NEXT:    st.d $zero, $fp, -40
+; LA64-WITHFP-NEXT:    ori $a1, $zero, 11
+; LA64-WITHFP-NEXT:    addi.d $a2, $fp, -48
+; LA64-WITHFP-NEXT:    ori $a3, $zero, 12
+; LA64-WITHFP-NEXT:    ori $a4, $zero, 13
+; LA64-WITHFP-NEXT:    ori $a0, $zero, 1
+; LA64-WITHFP-NEXT:    move $a6, $zero
+; LA64-WITHFP-NEXT:    move $a7, $a0
+; LA64-WITHFP-NEXT:    bl va_aligned_stack_callee
+; LA64-WITHFP-NEXT:    ld.d $fp, $sp, 96 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    ld.d $ra, $sp, 104 # 8-byte Folded Reload
+; LA64-WITHFP-NEXT:    addi.d $sp, $sp, 112
+; LA64-WITHFP-NEXT:    jirl $zero, $ra, 0
+  %1 = call i32 (i32, ...) @va_aligned_stack_callee(i32 1, i32 11,
+    i256 1000, i32 12, i32 13, i128 18446744073709551616, i32 14,
+    fp128 0xLEB851EB851EB851F400091EB851EB851, i64 15,
+    [2 x i64] [i64 16, i64 17])
+  ret void
+}