diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -6334,7 +6334,7 @@
     case BFloat16Rank: llvm_unreachable("Complex bfloat16 is not supported");
     case Float16Rank:
     case HalfRank: llvm_unreachable("Complex half is not supported");
-    case Ibm128Rank: llvm_unreachable("Complex __ibm128 is not supported");
+    case Ibm128Rank:     return getComplexType(Ibm128Ty);
     case FloatRank:      return getComplexType(FloatTy);
     case DoubleRank:     return getComplexType(DoubleTy);
     case LongDoubleRank: return getComplexType(LongDoubleTy);
diff --git a/clang/lib/Sema/DeclSpec.cpp b/clang/lib/Sema/DeclSpec.cpp
--- a/clang/lib/Sema/DeclSpec.cpp
+++ b/clang/lib/Sema/DeclSpec.cpp
@@ -1307,7 +1307,8 @@
       if (!S.getLangOpts().CPlusPlus)
         S.Diag(TSTLoc, diag::ext_integer_complex);
     } else if (TypeSpecType != TST_float && TypeSpecType != TST_double &&
-               TypeSpecType != TST_float128 && TypeSpecType != TST_float16) {
+               TypeSpecType != TST_float128 && TypeSpecType != TST_float16 &&
+               TypeSpecType != TST_ibm128) {
       // FIXME: __fp16?
       S.Diag(TSCLoc, diag::err_invalid_complex_spec)
         << getSpecifierName((TST)TypeSpecType, Policy);
diff --git a/clang/test/CodeGen/ppc64-complex-parms.c b/clang/test/CodeGen/ppc64-complex-parms.c
--- a/clang/test/CodeGen/ppc64-complex-parms.c
+++ b/clang/test/CodeGen/ppc64-complex-parms.c
@@ -33,6 +33,13 @@
 
 // CHECK: define{{.*}} ppc_fp128 @foo_long_double(ppc_fp128 {{[%A-Za-z0-9.]+}}, ppc_fp128 {{[%A-Za-z0-9.]+}}) [[NUW]] {
 
+__ibm128 foo_ibm128(_Complex __ibm128 x) {
+  // We don't have a suffix for explicit __ibm128 type yet. Use *l instead.
+  return creall(x);
+}
+
+// CHECK: define{{.*}} ppc_fp128 @foo_ibm128(ppc_fp128 {{[%A-Za-z0-9.]+}}, ppc_fp128 {{[%A-Za-z0-9.]+}}) [[NUW]] {
+
 int foo_int(_Complex int x) {
   return __real__ x;
 }
@@ -111,6 +118,22 @@
 // CHECK: %[[VAR27:[A-Za-z0-9.]+]] = load ppc_fp128, ppc_fp128* %[[VAR26]], align 16
 // CHECK: %{{[A-Za-z0-9.]+}} = call ppc_fp128 @foo_long_double(ppc_fp128 %[[VAR25]], ppc_fp128 %[[VAR27]])
 
+void bar_ibm128(void) {
+  foo_ibm128(2.0L - 2.5Li);
+}
+
+// CHECK: define{{.*}} void @bar_ibm128() [[NUW]] {
+// CHECK: %[[VAR21:[A-Za-z0-9.]+]] = alloca { ppc_fp128, ppc_fp128 }, align 16
+// CHECK: %[[VAR22:[A-Za-z0-9.]+]] = getelementptr inbounds { ppc_fp128, ppc_fp128 }, { ppc_fp128, ppc_fp128 }* %[[VAR21]], i32 0, i32 0
+// CHECK: %[[VAR23:[A-Za-z0-9.]+]] = getelementptr inbounds { ppc_fp128, ppc_fp128 }, { ppc_fp128, ppc_fp128 }* %[[VAR21]], i32 0, i32 1
+// CHECK: store ppc_fp128 0xM40000000000000000000000000000000, ppc_fp128* %[[VAR22]]
+// CHECK: store ppc_fp128 0xMC0040000000000008000000000000000, ppc_fp128* %[[VAR23]]
+// CHECK: %[[VAR24:[A-Za-z0-9.]+]] = getelementptr inbounds { ppc_fp128, ppc_fp128 }, { ppc_fp128, ppc_fp128 }* %[[VAR21]], i32 0, i32 0
+// CHECK: %[[VAR25:[A-Za-z0-9.]+]] = load ppc_fp128, ppc_fp128* %[[VAR24]], align 16
+// CHECK: %[[VAR26:[A-Za-z0-9.]+]] = getelementptr inbounds { ppc_fp128, ppc_fp128 }, { ppc_fp128, ppc_fp128 }* %[[VAR21]], i32 0, i32 1
+// CHECK: %[[VAR27:[A-Za-z0-9.]+]] = load ppc_fp128, ppc_fp128* %[[VAR26]], align 16
+// CHECK: %{{[A-Za-z0-9.]+}} = call ppc_fp128 @foo_ibm128(ppc_fp128 %[[VAR25]], ppc_fp128 %[[VAR27]])
+
 void bar_int(void) {
   foo_int(2 - 3i);
 }
diff --git a/clang/test/CodeGen/ppc64-complex-return.c b/clang/test/CodeGen/ppc64-complex-return.c
--- a/clang/test/CodeGen/ppc64-complex-return.c
+++ b/clang/test/CodeGen/ppc64-complex-return.c
@@ -34,6 +34,12 @@
 
 // CHECK: define{{.*}} { ppc_fp128, ppc_fp128 } @foo_long_double(ppc_fp128 {{[%A-Za-z0-9.]+}}, ppc_fp128 {{[%A-Za-z0-9.]+}}) [[NUW]] {
 
+_Complex __ibm128 foo_ibm128(_Complex __ibm128 x) {
+  return x;
+}
+
+// CHECK: define{{.*}} { ppc_fp128, ppc_fp128 } @foo_ibm128(ppc_fp128 {{[%A-Za-z0-9.]+}}, ppc_fp128 {{[%A-Za-z0-9.]+}}) [[NUW]] {
+
 _Complex int foo_int(_Complex int x) {
   return x;
 }
@@ -91,6 +97,15 @@
 // CHECK: extractvalue { ppc_fp128, ppc_fp128 } [[VAR3]], 0
 // CHECK: extractvalue { ppc_fp128, ppc_fp128 } [[VAR3]], 1
 
+__ibm128 bar_ibm128(void) {
+  return creall(foo_ibm128(2.0L - 2.5Li));
+}
+
+// CHECK: define{{.*}} ppc_fp128 @bar_ibm128() [[NUW]] {
+// CHECK: [[VAR3:[%A-Za-z0-9.]+]] = call { ppc_fp128, ppc_fp128 } @foo_ibm128
+// CHECK: extractvalue { ppc_fp128, ppc_fp128 } [[VAR3]], 0
+// CHECK: extractvalue { ppc_fp128, ppc_fp128 } [[VAR3]], 1
+
 #ifdef TEST_F128
 __float128 bar_f128(void) {
   return crealf128(foo_f128(2.0Q - 2.5Qi));