diff --git a/flang/runtime/complex-reduction.h b/flang/runtime/complex-reduction.h
--- a/flang/runtime/complex-reduction.h
+++ b/flang/runtime/complex-reduction.h
@@ -16,6 +16,7 @@
 #define FORTRAN_RUNTIME_COMPLEX_REDUCTION_H_
 
 #include "entry-names.h"
+#include <complex.h>
 
 struct CppDescriptor; /* dummy type name for Fortran::runtime::Descriptor */
 
diff --git a/flang/runtime/complex-reduction.c b/flang/runtime/complex-reduction.c
--- a/flang/runtime/complex-reduction.c
+++ b/flang/runtime/complex-reduction.c
@@ -9,7 +9,6 @@
 
 #include "complex-reduction.h"
 #include "flang/Common/long-double.h"
-#include <complex.h>
 
 struct CppComplexFloat {
   float r, i;
diff --git a/flang/runtime/numeric.h b/flang/runtime/numeric.h
--- a/flang/runtime/numeric.h
+++ b/flang/runtime/numeric.h
@@ -87,8 +87,10 @@
     CppTypeFor<TypeCategory::Real, 4>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(Ceiling4_8)(
     CppTypeFor<TypeCategory::Real, 4>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Ceiling4_16)(
     CppTypeFor<TypeCategory::Real, 4>);
+#endif
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Ceiling8_1)(
     CppTypeFor<TypeCategory::Real, 8>);
 CppTypeFor<TypeCategory::Integer, 2> RTNAME(Ceiling8_2)(
@@ -97,8 +99,10 @@
     CppTypeFor<TypeCategory::Real, 8>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(Ceiling8_8)(
     CppTypeFor<TypeCategory::Real, 8>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Ceiling8_16)(
     CppTypeFor<TypeCategory::Real, 8>);
+#endif
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Ceiling10_1)(
     CppTypeFor<TypeCategory::Real, 10>);
 CppTypeFor<TypeCategory::Integer, 2> RTNAME(Ceiling10_2)(
@@ -107,8 +111,10 @@
     CppTypeFor<TypeCategory::Real, 10>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(Ceiling10_8)(
     CppTypeFor<TypeCategory::Real, 10>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Ceiling10_16)(
     CppTypeFor<TypeCategory::Real, 10>);
+#endif
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Ceiling16_1)(
     CppTypeFor<TypeCategory::Real, 16>);
 CppTypeFor<TypeCategory::Integer, 2> RTNAME(Ceiling16_2)(
@@ -117,8 +123,10 @@
     CppTypeFor<TypeCategory::Real, 16>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(Ceiling16_8)(
     CppTypeFor<TypeCategory::Real, 16>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Ceiling16_16)(
     CppTypeFor<TypeCategory::Real, 16>);
+#endif
 
 // EXPONENT is defined to return default INTEGER; support INTEGER(4 & 8)
 CppTypeFor<TypeCategory::Integer, 4> RTNAME(Exponent4_4)(
@@ -147,8 +155,10 @@
     CppTypeFor<TypeCategory::Real, 4>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(Floor4_8)(
     CppTypeFor<TypeCategory::Real, 4>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Floor4_16)(
     CppTypeFor<TypeCategory::Real, 4>);
+#endif
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Floor8_1)(
     CppTypeFor<TypeCategory::Real, 8>);
 CppTypeFor<TypeCategory::Integer, 2> RTNAME(Floor8_2)(
@@ -157,8 +167,10 @@
     CppTypeFor<TypeCategory::Real, 8>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(Floor8_8)(
     CppTypeFor<TypeCategory::Real, 8>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Floor8_16)(
     CppTypeFor<TypeCategory::Real, 8>);
+#endif
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Floor10_1)(
     CppTypeFor<TypeCategory::Real, 10>);
 CppTypeFor<TypeCategory::Integer, 2> RTNAME(Floor10_2)(
@@ -167,8 +179,10 @@
     CppTypeFor<TypeCategory::Real, 10>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(Floor10_8)(
     CppTypeFor<TypeCategory::Real, 10>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Floor10_16)(
     CppTypeFor<TypeCategory::Real, 10>);
+#endif
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Floor16_1)(
     CppTypeFor<TypeCategory::Real, 16>);
 CppTypeFor<TypeCategory::Integer, 2> RTNAME(Floor16_2)(
@@ -177,8 +191,10 @@
     CppTypeFor<TypeCategory::Real, 16>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(Floor16_8)(
     CppTypeFor<TypeCategory::Real, 16>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Floor16_16)(
     CppTypeFor<TypeCategory::Real, 16>);
+#endif
 
 // FRACTION
 CppTypeFor<TypeCategory::Real, 4> RTNAME(Fraction4)(
@@ -199,9 +215,11 @@
     CppTypeFor<TypeCategory::Integer, 4>, CppTypeFor<TypeCategory::Integer, 4>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(ModInteger8)(
     CppTypeFor<TypeCategory::Integer, 8>, CppTypeFor<TypeCategory::Integer, 8>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(ModInteger16)(
     CppTypeFor<TypeCategory::Integer, 16>,
     CppTypeFor<TypeCategory::Integer, 16>);
+#endif
 CppTypeFor<TypeCategory::Real, 4> RTNAME(ModReal4)(
     CppTypeFor<TypeCategory::Real, 4>, CppTypeFor<TypeCategory::Real, 4>);
 CppTypeFor<TypeCategory::Real, 8> RTNAME(ModReal8)(
@@ -219,9 +237,11 @@
     CppTypeFor<TypeCategory::Integer, 4>, CppTypeFor<TypeCategory::Integer, 4>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(ModuloInteger8)(
     CppTypeFor<TypeCategory::Integer, 8>, CppTypeFor<TypeCategory::Integer, 8>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(ModuloInteger16)(
     CppTypeFor<TypeCategory::Integer, 16>,
     CppTypeFor<TypeCategory::Integer, 16>);
+#endif
 CppTypeFor<TypeCategory::Real, 4> RTNAME(ModuloReal4)(
     CppTypeFor<TypeCategory::Real, 4>, CppTypeFor<TypeCategory::Real, 4>);
 CppTypeFor<TypeCategory::Real, 8> RTNAME(ModuloReal8)(
@@ -240,8 +260,10 @@
     CppTypeFor<TypeCategory::Real, 4>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(Nint4_8)(
     CppTypeFor<TypeCategory::Real, 4>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Nint4_16)(
     CppTypeFor<TypeCategory::Real, 4>);
+#endif
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Nint8_1)(
     CppTypeFor<TypeCategory::Real, 8>);
 CppTypeFor<TypeCategory::Integer, 2> RTNAME(Nint8_2)(
@@ -250,8 +272,10 @@
     CppTypeFor<TypeCategory::Real, 8>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(Nint8_8)(
     CppTypeFor<TypeCategory::Real, 8>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Nint8_16)(
     CppTypeFor<TypeCategory::Real, 8>);
+#endif
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Nint10_1)(
     CppTypeFor<TypeCategory::Real, 10>);
 CppTypeFor<TypeCategory::Integer, 2> RTNAME(Nint10_2)(
@@ -260,8 +284,10 @@
     CppTypeFor<TypeCategory::Real, 10>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(Nint10_8)(
     CppTypeFor<TypeCategory::Real, 10>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Nint10_16)(
     CppTypeFor<TypeCategory::Real, 10>);
+#endif
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Nint16_1)(
     CppTypeFor<TypeCategory::Real, 16>);
 CppTypeFor<TypeCategory::Integer, 2> RTNAME(Nint16_2)(
@@ -270,8 +296,10 @@
     CppTypeFor<TypeCategory::Real, 16>);
 CppTypeFor<TypeCategory::Integer, 8> RTNAME(Nint16_8)(
     CppTypeFor<TypeCategory::Real, 16>);
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Nint16_16)(
     CppTypeFor<TypeCategory::Real, 16>);
+#endif
 
 // NEAREST
 // The second argument to NEAREST is the result of a comparison
diff --git a/flang/runtime/numeric.cpp b/flang/runtime/numeric.cpp
--- a/flang/runtime/numeric.cpp
+++ b/flang/runtime/numeric.cpp
@@ -284,10 +284,12 @@
     CppTypeFor<TypeCategory::Real, 4> x) {
   return Ceiling<CppTypeFor<TypeCategory::Integer, 8>>(x);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Ceiling4_16)(
     CppTypeFor<TypeCategory::Real, 4> x) {
   return Ceiling<CppTypeFor<TypeCategory::Integer, 16>>(x);
 }
+#endif
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Ceiling8_1)(
     CppTypeFor<TypeCategory::Real, 8> x) {
   return Ceiling<CppTypeFor<TypeCategory::Integer, 1>>(x);
@@ -304,10 +306,12 @@
     CppTypeFor<TypeCategory::Real, 8> x) {
   return Ceiling<CppTypeFor<TypeCategory::Integer, 8>>(x);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Ceiling8_16)(
     CppTypeFor<TypeCategory::Real, 8> x) {
   return Ceiling<CppTypeFor<TypeCategory::Integer, 16>>(x);
 }
+#endif
 #if LONG_DOUBLE == 80
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Ceiling10_1)(
     CppTypeFor<TypeCategory::Real, 10> x) {
@@ -325,10 +329,12 @@
     CppTypeFor<TypeCategory::Real, 10> x) {
   return Ceiling<CppTypeFor<TypeCategory::Integer, 8>>(x);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Ceiling10_16)(
     CppTypeFor<TypeCategory::Real, 10> x) {
   return Ceiling<CppTypeFor<TypeCategory::Integer, 16>>(x);
 }
+#endif
 #else
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Ceiling16_1)(
     CppTypeFor<TypeCategory::Real, 16> x) {
@@ -346,11 +352,13 @@
     CppTypeFor<TypeCategory::Real, 16> x) {
   return Ceiling<CppTypeFor<TypeCategory::Integer, 8>>(x);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Ceiling16_16)(
     CppTypeFor<TypeCategory::Real, 16> x) {
   return Ceiling<CppTypeFor<TypeCategory::Integer, 16>>(x);
 }
 #endif
+#endif
 
 CppTypeFor<TypeCategory::Integer, 4> RTNAME(Exponent4_4)(
     CppTypeFor<TypeCategory::Real, 4> x) {
@@ -404,10 +412,12 @@
     CppTypeFor<TypeCategory::Real, 4> x) {
   return Floor<CppTypeFor<TypeCategory::Integer, 8>>(x);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Floor4_16)(
     CppTypeFor<TypeCategory::Real, 4> x) {
   return Floor<CppTypeFor<TypeCategory::Integer, 16>>(x);
 }
+#endif
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Floor8_1)(
     CppTypeFor<TypeCategory::Real, 8> x) {
   return Floor<CppTypeFor<TypeCategory::Integer, 1>>(x);
@@ -424,10 +434,12 @@
     CppTypeFor<TypeCategory::Real, 8> x) {
   return Floor<CppTypeFor<TypeCategory::Integer, 8>>(x);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Floor8_16)(
     CppTypeFor<TypeCategory::Real, 8> x) {
   return Floor<CppTypeFor<TypeCategory::Integer, 16>>(x);
 }
+#endif
 #if LONG_DOUBLE == 80
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Floor10_1)(
     CppTypeFor<TypeCategory::Real, 10> x) {
@@ -445,10 +457,12 @@
     CppTypeFor<TypeCategory::Real, 10> x) {
   return Floor<CppTypeFor<TypeCategory::Integer, 8>>(x);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Floor10_16)(
     CppTypeFor<TypeCategory::Real, 10> x) {
   return Floor<CppTypeFor<TypeCategory::Integer, 16>>(x);
 }
+#endif
 #else
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Floor16_1)(
     CppTypeFor<TypeCategory::Real, 16> x) {
@@ -466,11 +480,13 @@
     CppTypeFor<TypeCategory::Real, 16> x) {
   return Floor<CppTypeFor<TypeCategory::Integer, 8>>(x);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Floor16_16)(
     CppTypeFor<TypeCategory::Real, 16> x) {
   return Floor<CppTypeFor<TypeCategory::Integer, 16>>(x);
 }
 #endif
+#endif
 
 CppTypeFor<TypeCategory::Real, 4> RTNAME(Fraction4)(
     CppTypeFor<TypeCategory::Real, 4> x) {
@@ -512,11 +528,13 @@
     CppTypeFor<TypeCategory::Integer, 8> p) {
   return IntMod<false>(x, p);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(ModInteger16)(
     CppTypeFor<TypeCategory::Integer, 16> x,
     CppTypeFor<TypeCategory::Integer, 16> p) {
   return IntMod<false>(x, p);
 }
+#endif
 CppTypeFor<TypeCategory::Real, 4> RTNAME(ModReal4)(
     CppTypeFor<TypeCategory::Real, 4> x, CppTypeFor<TypeCategory::Real, 4> p) {
   return RealMod<false>(x, p);
@@ -559,11 +577,13 @@
     CppTypeFor<TypeCategory::Integer, 8> p) {
   return IntMod<true>(x, p);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(ModuloInteger16)(
     CppTypeFor<TypeCategory::Integer, 16> x,
     CppTypeFor<TypeCategory::Integer, 16> p) {
   return IntMod<true>(x, p);
 }
+#endif
 CppTypeFor<TypeCategory::Real, 4> RTNAME(ModuloReal4)(
     CppTypeFor<TypeCategory::Real, 4> x, CppTypeFor<TypeCategory::Real, 4> p) {
   return RealMod<true>(x, p);
@@ -622,10 +642,12 @@
     CppTypeFor<TypeCategory::Real, 4> x) {
   return Anint<CppTypeFor<TypeCategory::Integer, 8>>(x);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Nint4_16)(
     CppTypeFor<TypeCategory::Real, 4> x) {
   return Anint<CppTypeFor<TypeCategory::Integer, 16>>(x);
 }
+#endif
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Nint8_1)(
     CppTypeFor<TypeCategory::Real, 8> x) {
   return Anint<CppTypeFor<TypeCategory::Integer, 1>>(x);
@@ -642,10 +664,12 @@
     CppTypeFor<TypeCategory::Real, 8> x) {
   return Anint<CppTypeFor<TypeCategory::Integer, 8>>(x);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Nint8_16)(
     CppTypeFor<TypeCategory::Real, 8> x) {
   return Anint<CppTypeFor<TypeCategory::Integer, 16>>(x);
 }
+#endif
 #if LONG_DOUBLE == 80
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Nint10_1)(
     CppTypeFor<TypeCategory::Real, 10> x) {
@@ -663,10 +687,12 @@
     CppTypeFor<TypeCategory::Real, 10> x) {
   return Anint<CppTypeFor<TypeCategory::Integer, 8>>(x);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Nint10_16)(
     CppTypeFor<TypeCategory::Real, 10> x) {
   return Anint<CppTypeFor<TypeCategory::Integer, 16>>(x);
 }
+#endif
 #else
 CppTypeFor<TypeCategory::Integer, 1> RTNAME(Nint16_1)(
     CppTypeFor<TypeCategory::Real, 16> x) {
@@ -684,11 +710,13 @@
     CppTypeFor<TypeCategory::Real, 16> x) {
   return Anint<CppTypeFor<TypeCategory::Integer, 8>>(x);
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(Nint16_16)(
     CppTypeFor<TypeCategory::Real, 16> x) {
   return Anint<CppTypeFor<TypeCategory::Integer, 16>>(x);
 }
 #endif
+#endif
 
 CppTypeFor<TypeCategory::Real, 4> RTNAME(RRSpacing4)(
     CppTypeFor<TypeCategory::Real, 4> x) {
diff --git a/flang/runtime/reduction.h b/flang/runtime/reduction.h
--- a/flang/runtime/reduction.h
+++ b/flang/runtime/reduction.h
@@ -51,8 +51,10 @@
     int line, int dim = 0, const Descriptor *mask = nullptr);
 std::int64_t RTNAME(SumInteger8)(const Descriptor &, const char *source,
     int line, int dim = 0, const Descriptor *mask = nullptr);
+#ifdef __SIZEOF_INT128__
 common::int128_t RTNAME(SumInteger16)(const Descriptor &, const char *source,
     int line, int dim = 0, const Descriptor *mask = nullptr);
+#endif
 
 // REAL/COMPLEX(2 & 3) return 32-bit float results for the caller to downconvert
 float RTNAME(SumReal2)(const Descriptor &, const char *source, int line,
@@ -100,9 +102,11 @@
     int line, int dim = 0, const Descriptor *mask = nullptr);
 std::int64_t RTNAME(ProductInteger8)(const Descriptor &, const char *source,
     int line, int dim = 0, const Descriptor *mask = nullptr);
+#ifdef __SIZEOF_INT128__
 common::int128_t RTNAME(ProductInteger16)(const Descriptor &,
     const char *source, int line, int dim = 0,
     const Descriptor *mask = nullptr);
+#endif
 
 // REAL/COMPLEX(2 & 3) return 32-bit float results for the caller to downconvert
 float RTNAME(ProductReal2)(const Descriptor &, const char *source, int line,
@@ -166,8 +170,10 @@
     int line, int dim = 0, const Descriptor *mask = nullptr);
 std::int64_t RTNAME(MaxvalInteger8)(const Descriptor &, const char *source,
     int line, int dim = 0, const Descriptor *mask = nullptr);
+#ifdef __SIZEOF_INT128__
 common::int128_t RTNAME(MaxvalInteger16)(const Descriptor &, const char *source,
     int line, int dim = 0, const Descriptor *mask = nullptr);
+#endif
 float RTNAME(MaxvalReal2)(const Descriptor &, const char *source, int line,
     int dim = 0, const Descriptor *mask = nullptr);
 float RTNAME(MaxvalReal3)(const Descriptor &, const char *source, int line,
@@ -191,8 +197,10 @@
     int line, int dim = 0, const Descriptor *mask = nullptr);
 std::int64_t RTNAME(MivalInteger8)(const Descriptor &, const char *source,
     int line, int dim = 0, const Descriptor *mask = nullptr);
+#ifdef __SIZEOF_INT128__
 common::int128_t RTNAME(MivalInteger16)(const Descriptor &, const char *source,
     int line, int dim = 0, const Descriptor *mask = nullptr);
+#endif
 float RTNAME(MinvalReal2)(const Descriptor &, const char *source, int line,
     int dim = 0, const Descriptor *mask = nullptr);
 float RTNAME(MinvalReal3)(const Descriptor &, const char *source, int line,
diff --git a/flang/runtime/reduction.cpp b/flang/runtime/reduction.cpp
--- a/flang/runtime/reduction.cpp
+++ b/flang/runtime/reduction.cpp
@@ -92,7 +92,11 @@
   using CppType = CppTypeFor<CAT, KIND>;
   DoTotalReduction<CppType>(x, dim, mask, accumulator, intrinsic, terminator);
   CppType result;
+#ifdef _MSC_VER // work around MSVC spurious error
+  accumulator.GetResult(&result);
+#else
   accumulator.template GetResult(&result);
+#endif
   return result;
 }
 
@@ -130,7 +134,11 @@
       break;
     }
   }
+#ifdef _MSC_VER // work around MSVC spurious error
+  accumulator.GetResult(result, zeroBasedDim);
+#else
   accumulator.template GetResult(result, zeroBasedDim);
+#endif
 }
 
 template <typename TYPE, typename ACCUMULATOR>
@@ -154,7 +162,11 @@
       }
     }
   }
+#ifdef _MSC_VER // work around MSVC spurious error
+  accumulator.GetResult(result, zeroBasedDim);
+#else
   accumulator.template GetResult(result, zeroBasedDim);
+#endif
 }
 
 // Utility: establishes & allocates the result array for a partial
@@ -253,11 +265,13 @@
           TypeCategory::Integer, 8>(
           result, x, dim, mask, terminator, intrinsic);
       return;
+#ifdef __SIZEOF_INT128__
     case 16:
       PartialReduction<INTEGER_ACCUM<CppTypeFor<TypeCategory::Integer, 16>>,
           TypeCategory::Integer, 16>(
           result, x, dim, mask, terminator, intrinsic);
       return;
+#endif
     }
     break;
   case TypeCategory::Real:
@@ -416,12 +430,14 @@
   return GetTotalReduction<TypeCategory::Integer, 8>(x, source, line, dim, mask,
       IntegerSumAccumulator<CppTypeFor<TypeCategory::Integer, 8>>{x}, "SUM");
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(SumInteger16)(const Descriptor &x,
     const char *source, int line, int dim, const Descriptor *mask) {
   return GetTotalReduction<TypeCategory::Integer, 16>(x, source, line, dim,
       mask, IntegerSumAccumulator<CppTypeFor<TypeCategory::Integer, 16>>{x},
       "SUM");
 }
+#endif
 
 // TODO: real/complex(2 & 3)
 CppTypeFor<TypeCategory::Real, 4> RTNAME(SumReal4)(const Descriptor &x,
@@ -549,6 +565,7 @@
       NonComplexProductAccumulator<CppTypeFor<TypeCategory::Integer, 8>>{x},
       "PRODUCT");
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(ProductInteger16)(
     const Descriptor &x, const char *source, int line, int dim,
     const Descriptor *mask) {
@@ -557,6 +574,7 @@
       NonComplexProductAccumulator<CppTypeFor<TypeCategory::Integer, 16>>{x},
       "PRODUCT");
 }
+#endif
 
 // TODO: real/complex(2 & 3)
 CppTypeFor<TypeCategory::Real, 4> RTNAME(ProductReal4)(const Descriptor &x,
@@ -725,10 +743,12 @@
     accumulator.GetResult(
         result.OffsetElement<CppTypeFor<TypeCategory::Integer, 8>>());
     break;
+#ifdef __SIZEOF_INT128__
   case 16:
     accumulator.GetResult(
         result.OffsetElement<CppTypeFor<TypeCategory::Integer, 16>>());
     break;
+#endif
   default:
     terminator.Crash("%s: bad KIND=%d", intrinsic, kind);
   }
@@ -786,10 +806,12 @@
       DoMaxOrMinLoc<TypeCategory::Integer, 8, IS_MAX, NumericCompare>(
           intrinsic, result, x, kind, source, line, mask, back);
       return;
+#ifdef __SIZEOF_INT128__
     case 16:
       DoMaxOrMinLoc<TypeCategory::Integer, 16, IS_MAX, NumericCompare>(
           intrinsic, result, x, kind, source, line, mask, back);
       return;
+#endif
     }
     break;
   case TypeCategory::Real:
@@ -875,10 +897,12 @@
     PartialReduction<ExtremumLocAccumulator<COMPARE<CppType, IS_MAX, BACK>>,
         TypeCategory::Integer, 8>(result, x, dim, mask, terminator, intrinsic);
     break;
+#ifdef __SIZEOF_INT128__
   case 16:
     PartialReduction<ExtremumLocAccumulator<COMPARE<CppType, IS_MAX, BACK>>,
         TypeCategory::Integer, 16>(result, x, dim, mask, terminator, intrinsic);
     break;
+#endif
   default:
     terminator.Crash("%s: bad KIND=%d", intrinsic, kind);
   }
@@ -925,10 +949,12 @@
       DoPartialMaxOrMinLoc<TypeCategory::Integer, 8, IS_MAX, NumericCompare>(
           intrinsic, result, x, kind, dim, mask, back, terminator);
       return;
+#ifdef __SIZEOF_INT128__
     case 16:
       DoPartialMaxOrMinLoc<TypeCategory::Integer, 16, IS_MAX, NumericCompare>(
           intrinsic, result, x, kind, dim, mask, back, terminator);
       return;
+#endif
     }
     break;
   case TypeCategory::Real:
@@ -1101,11 +1127,13 @@
           NumericExtremumAccumulator>(
           result, x, dim, mask, intrinsic, terminator);
       return;
+#ifdef __SIZEOF_INT128__
     case 16:
       DoMaxOrMin<TypeCategory::Integer, 16, IS_MAXVAL,
           NumericExtremumAccumulator>(
           result, x, dim, mask, intrinsic, terminator);
       return;
+#endif
     }
     break;
   case TypeCategory::Real:
@@ -1223,12 +1251,14 @@
   return TotalNumericMaxOrMin<TypeCategory::Integer, 8, true>(
       x, source, line, dim, mask, "MAXVAL");
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(MaxvalInteger16)(
     const Descriptor &x, const char *source, int line, int dim,
     const Descriptor *mask) {
   return TotalNumericMaxOrMin<TypeCategory::Integer, 16, true>(
       x, source, line, dim, mask, "MAXVAL");
 }
+#endif
 
 // TODO: REAL(2 & 3)
 CppTypeFor<TypeCategory::Real, 4> RTNAME(MaxvalReal4)(const Descriptor &x,
@@ -1280,12 +1310,14 @@
   return TotalNumericMaxOrMin<TypeCategory::Integer, 8, false>(
       x, source, line, dim, mask, "MINVAL");
 }
+#ifdef __SIZEOF_INT128__
 CppTypeFor<TypeCategory::Integer, 16> RTNAME(MinvalInteger16)(
     const Descriptor &x, const char *source, int line, int dim,
     const Descriptor *mask) {
   return TotalNumericMaxOrMin<TypeCategory::Integer, 16, false>(
       x, source, line, dim, mask, "MINVAL");
 }
+#endif
 
 // TODO: REAL(2 & 3)
 CppTypeFor<TypeCategory::Real, 4> RTNAME(MinvalReal4)(const Descriptor &x,
@@ -1513,9 +1545,11 @@
   case 8:
     CountDimension<8>(result, x, dim, terminator);
     break;
+#ifdef __SIZEOF_INT128__
   case 16:
     CountDimension<16>(result, x, dim, terminator);
     break;
+#endif
   default:
     terminator.Crash("COUNT: bad KIND=%d", kind);
   }