diff --git a/libcxx/test/libcxx/diagnostics/math_nodiscard_extensions.verify.cpp b/libcxx/test/libcxx/diagnostics/math_nodiscard_extensions.verify.cpp
--- a/libcxx/test/libcxx/diagnostics/math_nodiscard_extensions.verify.cpp
+++ b/libcxx/test/libcxx/diagnostics/math_nodiscard_extensions.verify.cpp
@@ -11,11 +11,31 @@
 // We don't control the implementation of the math.h functions on windows
 // UNSUPPORTED: windows
 
-// check that const cmath functions are declared [[nodiscard]]
+// Check that functions from `<cmath>` that Clang marks with the `[[gnu::const]]` attribute are declared
+// `[[nodiscard]]`.
 
 #include <cmath>
+#include "test_macros.h"
 
 void test() {
+  // These tests rely on Clang's behaviour of adding `[[gnu::const]]` to the double overload of most of the functions
+  // below.
+  // Without that attribute being added implicitly, this test can't be checked consistently because its result depends
+  // on whether we're getting libc++'s own `std::foo(double)` or the underlying C library's `foo(double)`.
+#ifdef TEST_COMPILER_CLANG
+  std::ceil(0.);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
+  std::fabs(0.);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
+  std::floor(0.);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
+  std::cbrt(0.);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
+  std::copysign(0., 0.);         // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
+  std::fmax(0., 0.);             // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
+  std::fmin(0., 0.);             // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
+  std::nearbyint(0.);            // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
+  std::rint(0.);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
+  std::round(0.);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
+  std::trunc(0.);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
+#endif
+
   std::signbit(0.f);             // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::signbit(0.);              // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::signbit(0.l);             // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
@@ -89,67 +109,56 @@
   std::isunordered(0U, 0U);      // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
 
   std::ceil(0.f);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
-  std::ceil(0.);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::ceil(0.l);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::ceil(0);                  // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::ceil(0U);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
 
   std::fabs(0.f);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
-  std::fabs(0.);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::fabs(0.l);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::fabs(0);                  // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::fabs(0U);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
 
   std::floor(0.f);               // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
-  std::floor(0.);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::floor(0.l);               // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::floor(0);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::floor(0U);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
 
   std::cbrt(0.f);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
-  std::cbrt(0.);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::cbrt(0.l);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::cbrt(0);                  // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::cbrt(0U);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
 
   std::copysign(0.f, 0.f);       // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
-  std::copysign(0., 0.);         // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::copysign(0.l, 0.l);       // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::copysign(0, 0);           // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::copysign(0U, 0U);         // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
 
   std::fmax(0.f, 0.f);           // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
-  std::fmax(0., 0.);             // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::fmax(0.l, 0.l);           // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::fmax(0, 0);               // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::fmax(0U, 0U);             // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
 
   std::fmin(0.f, 0.f);           // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
-  std::fmin(0., 0.);             // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::fmin(0.l, 0.l);           // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::fmin(0, 0);               // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::fmin(0U, 0U);             // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
 
   std::nearbyint(0.f);           // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
-  std::nearbyint(0.);            // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::nearbyint(0.l);           // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::nearbyint(0);             // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::nearbyint(0U);            // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
 
   std::rint(0.f);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
-  std::rint(0.);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::rint(0.l);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::rint(0);                  // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::rint(0U);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
 
   std::round(0.f);               // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
-  std::round(0.);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::round(0.l);               // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::round(0);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::round(0U);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
 
   std::trunc(0.f);               // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
-  std::trunc(0.);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::trunc(0.l);               // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::trunc(0);                 // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}
   std::trunc(0U);                // expected-warning-re {{ignoring return value of function declared with {{.*}} attribute}}