diff --git a/clang/lib/Headers/cpuid.h b/clang/lib/Headers/cpuid.h
--- a/clang/lib/Headers/cpuid.h
+++ b/clang/lib/Headers/cpuid.h
@@ -328,4 +328,10 @@
     return 1;
 }
 
+static __inline void __cpuidex (int __cpu_info[4], int __leaf, int __subleaf)
+{
+  __cpuid_count(__leaf, __subleaf, __cpu_info[0], __cpu_info[1], __cpu_info[2],
+                __cpu_info[3]);
+}
+
 #endif /* __CPUID_H */
diff --git a/clang/test/Headers/cpuid.c b/clang/test/Headers/cpuid.c
--- a/clang/test/Headers/cpuid.c
+++ b/clang/test/Headers/cpuid.c
@@ -6,14 +6,19 @@
 
 // CHECK-64: {{.*}} call { i32, i32, i32, i32 } asm "  xchgq  %rbx,${1:q}\0A cpuid\0A xchgq %rbx,${1:q}", "={ax},=r,={cx},={dx},0,~{dirflag},~{fpsr},~{flags}"(i32 %{{[a-z0-9]+}})
 // CHECK-64: {{.*}} call { i32, i32, i32, i32 } asm "  xchgq  %rbx,${1:q}\0A  cpuid\0A  xchgq  %rbx,${1:q}", "={ax},=r,={cx},={dx},0,2,~{dirflag},~{fpsr},~{flags}"(i32 %{{[a-z0-9]+}}, i32 %{{[a-z0-9]+}})
+// CHECK-64: {{.*}} call { i32, i32, i32, i32 } asm "  xchgq  %rbx,${1:q}\0A  cpuid\0A  xchgq  %rbx,${1:q}", "={ax},=r,={cx},={dx},0,2,~{dirflag},~{fpsr},~{flags}"(i32 %{{[a-z0-9]+}}, i32 %{{[a-z0-9]+}})
 
 // CHECK-32: {{.*}} call { i32, i32, i32, i32 } asm "cpuid", "={ax},={bx},={cx},={dx},0,~{dirflag},~{fpsr},~{flags}"(i32 %{{[a-z0-9]+}})
 // CHECK-32: {{.*}} call { i32, i32, i32, i32 } asm "cpuid", "={ax},={bx},={cx},={dx},0,2,~{dirflag},~{fpsr},~{flags}"(i32 %{{[a-z0-9]+}}, i32 %{{[a-z0-9]+}})
+// CHECK-32: {{.*}} call { i32, i32, i32, i32 } asm "cpuid", "={ax},={bx},={cx},={dx},0,2,~{dirflag},~{fpsr},~{flags}"(i32 %{{[a-z0-9]+}}, i32 %{{[a-z0-9]+}})
 
 unsigned eax0, ebx0, ecx0, edx0;
 unsigned eax1, ebx1, ecx1, edx1;
 
+int cpuid_info[4];
+
 void test_cpuid(unsigned level, unsigned count) {
   __cpuid(level, eax1, ebx1, ecx1, edx1);
   __cpuid_count(level, count, eax0, ebx0, ecx0, edx0);
+  __cpuidex(cpuid_info, level, count);
 }