diff --git a/clang/lib/Basic/Targets/PPC.h b/clang/lib/Basic/Targets/PPC.h
--- a/clang/lib/Basic/Targets/PPC.h
+++ b/clang/lib/Basic/Targets/PPC.h
@@ -369,7 +369,8 @@
   }
 
   BuiltinVaListKind getBuiltinVaListKind() const override {
-    // This is the ELF definition, and is overridden by the Darwin sub-target
+    // This is the ELF definition, and is overridden by the Darwin and AIX
+    // sub-targets.
     return TargetInfo::PowerABIBuiltinVaList;
   }
 };
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -4172,14 +4172,15 @@
 
 // PowerPC-32
 namespace {
-/// PPC32_SVR4_ABIInfo - The 32-bit PowerPC ELF (SVR4) ABI information.
-class PPC32_SVR4_ABIInfo : public DefaultABIInfo {
+/// PowerPC32ABIInfo - The 32-bit PowerPC ABI information, used by PowerPC ELF
+/// (SVR4), Darwin, and AIX.
+class PowerPC32ABIInfo : public DefaultABIInfo {
   bool IsSoftFloatABI;
 
   CharUnits getParamTypeAlignment(QualType Ty) const;
 
 public:
-  PPC32_SVR4_ABIInfo(CodeGen::CodeGenTypes &CGT, bool SoftFloatABI)
+  PowerPC32ABIInfo(CodeGen::CodeGenTypes &CGT, bool SoftFloatABI)
       : DefaultABIInfo(CGT), IsSoftFloatABI(SoftFloatABI) {}
 
   Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
@@ -4189,7 +4190,7 @@
 class PPC32TargetCodeGenInfo : public TargetCodeGenInfo {
 public:
   PPC32TargetCodeGenInfo(CodeGenTypes &CGT, bool SoftFloatABI)
-      : TargetCodeGenInfo(new PPC32_SVR4_ABIInfo(CGT, SoftFloatABI)) {}
+      : TargetCodeGenInfo(new PowerPC32ABIInfo(CGT, SoftFloatABI)) {}
 
   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
     // This is recovered from gcc output.
@@ -4201,7 +4202,7 @@
 };
 }
 
-CharUnits PPC32_SVR4_ABIInfo::getParamTypeAlignment(QualType Ty) const {
+CharUnits PowerPC32ABIInfo::getParamTypeAlignment(QualType Ty) const {
   // Complex types are passed just like their elements
   if (const ComplexType *CTy = Ty->getAs<ComplexType>())
     Ty = CTy->getElementType();
@@ -4227,9 +4228,12 @@
 
 // TODO: this implementation is now likely redundant with
 // DefaultABIInfo::EmitVAArg.
-Address PPC32_SVR4_ABIInfo::EmitVAArg(CodeGenFunction &CGF, Address VAList,
+Address PowerPC32ABIInfo::EmitVAArg(CodeGenFunction &CGF, Address VAList,
                                       QualType Ty) const {
-  if (getTarget().getTriple().isOSDarwin()) {
+  // TODO: Add AIX ABI Info. Currently, we are relying on PowerPC32ABIInfo to
+  // emit correct VAArg.
+  if (getTarget().getTriple().isOSDarwin() ||
+      getTarget().getTriple().isOSAIX()) {
     auto TI = getContext().getTypeInfoInChars(Ty);
     TI.second = getParamTypeAlignment(Ty);
 
diff --git a/clang/test/CodeGen/aix-vararg.c b/clang/test/CodeGen/aix-vararg.c
new file mode 100644
--- /dev/null
+++ b/clang/test/CodeGen/aix-vararg.c
@@ -0,0 +1,39 @@
+// REQUIRES: powerpc-registered-target
+// REQUIRES: asserts
+// RUN: %clang_cc1 -triple powerpc-ibm-aix-xcoff -emit-llvm -o - %s | FileCheck %s --check-prefix=32BIT
+//
+void aix_varg(int a, ...) {
+  __builtin_va_list arg;
+  __builtin_va_start(arg, a);
+  __builtin_va_list arg2;
+  __builtin_va_arg(arg, int);
+  __builtin_va_copy(arg2, arg);
+  __builtin_va_end(arg);
+  __builtin_va_end(arg2);
+}
+
+// 32BIT:       define void @aix_varg(i32 %a, ...) #0 {
+// 32BIT-NEXT:  entry:
+// 32BIT-NEXT:    %a.addr = alloca i32, align 4
+// 32BIT-NEXT:    %arg = alloca i8*, align 4
+// 32BIT-NEXT:    %arg2 = alloca i8*, align 4
+// 32BIT-NEXT:    store i32 %a, i32* %a.addr, align 4
+// 32BIT-NEXT:    %arg1 = bitcast i8** %arg to i8*
+// 32BIT-NEXT:    call void @llvm.va_start(i8* %arg1)
+// 32BIT-NEXT:    %argp.cur = load i8*, i8** %arg, align 4
+// 32BIT-NEXT:    %argp.next = getelementptr inbounds i8, i8* %argp.cur, i32 4
+// 32BIT-NEXT:    store i8* %argp.next, i8** %arg, align 4
+// 32BIT-NEXT:    %0 = bitcast i8* %argp.cur to i32*
+// 32BIT-NEXT:    %1 = load i32, i32* %0, align 4
+// 32BIT-NEXT:    %2 = bitcast i8** %arg2 to i8*
+// 32BIT-NEXT:    %3 = bitcast i8** %arg to i8*
+// 32BIT-NEXT:    call void @llvm.va_copy(i8* %2, i8* %3)
+// 32BIT-NEXT:    %arg3 = bitcast i8** %arg to i8*
+// 32BIT-NEXT:    call void @llvm.va_end(i8* %arg3)
+// 32BIT-NEXT:    %arg24 = bitcast i8** %arg2 to i8*
+// 32BIT-NEXT:    call void @llvm.va_end(i8* %arg24)
+// 32BIT-NEXT:    ret void
+// 32BIT-NEXT:  }
+// 32BIT:         declare void @llvm.va_start(i8*) #1
+// 32BIT:         declare void @llvm.va_copy(i8*, i8*) #1
+// 32BIT:         declare void @llvm.va_end(i8*) #1