Index: test/builtins/Unit/fixunsxfti_test.c
===================================================================
--- test/builtins/Unit/fixunsxfti_test.c
+++ test/builtins/Unit/fixunsxfti_test.c
@@ -18,7 +18,7 @@
 #include "int_lib.h"
 #include <stdio.h>
 
-#ifdef CRT_HAS_128BIT
+#if defined(CRT_HAS_128BIT) && __LDBL_MANT_DIG__ == 64
 
 // Returns: convert a to a unsigned long long, rounding toward zero.
 //          Negative values all become zero.
@@ -56,7 +56,7 @@
 
 int main()
 {
-#ifdef CRT_HAS_128BIT
+#if defined(CRT_HAS_128BIT) && __LDBL_MANT_DIG__ == 64
     if (test__fixunsxfti(0.0, 0))
         return 1;
 
Index: test/builtins/Unit/fixxfti_test.c
===================================================================
--- test/builtins/Unit/fixxfti_test.c
+++ test/builtins/Unit/fixxfti_test.c
@@ -18,7 +18,7 @@
 #include "int_lib.h"
 #include <stdio.h>
 
-#ifdef CRT_HAS_128BIT
+#if defined(CRT_HAS_128BIT) && __LDBL_MANT_DIG__ == 64
 
 // Returns: convert a to a signed long long, rounding toward zero.
 
@@ -54,7 +54,7 @@
 
 int main()
 {
-#ifdef CRT_HAS_128BIT
+#if defined(CRT_HAS_128BIT) && __LDBL_MANT_DIG__ == 64
     if (test__fixxfti(0.0, 0))
         return 1;
 
Index: test/builtins/Unit/floattixf_test.c
===================================================================
--- test/builtins/Unit/floattixf_test.c
+++ test/builtins/Unit/floattixf_test.c
@@ -19,7 +19,7 @@
 #include <float.h>
 #include <stdio.h>
 
-#ifdef CRT_HAS_128BIT
+#if defined(CRT_HAS_128BIT) && __LDBL_MANT_DIG__ == 64
 
 // Returns: convert a to a long double, rounding toward even.
 
@@ -52,7 +52,7 @@
 
 int main()
 {
-#ifdef CRT_HAS_128BIT
+#if defined(CRT_HAS_128BIT) && __LDBL_MANT_DIG__ == 64
     if (test__floattixf(0, 0.0))
         return 1;
 
Index: test/builtins/Unit/floatuntixf_test.c
===================================================================
--- test/builtins/Unit/floatuntixf_test.c
+++ test/builtins/Unit/floatuntixf_test.c
@@ -19,7 +19,7 @@
 #include <float.h>
 #include <stdio.h>
 
-#ifdef CRT_HAS_128BIT
+#if defined(CRT_HAS_128BIT) && __LDBL_MANT_DIG__ == 64
 
 // Returns: convert a to a long double, rounding toward even.
 
@@ -52,7 +52,7 @@
 
 int main()
 {
-#ifdef CRT_HAS_128BIT
+#if defined(CRT_HAS_128BIT) && __LDBL_MANT_DIG__ == 64
     if (test__floatuntixf(0, 0.0))
         return 1;