[libc++] <experimental/simd> Reduce compilation time of reference assignment test

[joy2myself]

No description provided.

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: ZhangYin (joy2myself)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/72632.diff

1 Files Affected:

• (modified) libcxx/test/std/experimental/simd/simd.reference/reference_assignment.pass.cpp (+6-10)

diff --git a/libcxx/test/std/experimental/simd/simd.reference/reference_assignment.pass.cpp b/libcxx/test/std/experimental/simd/simd.reference/reference_assignment.pass.cpp
index bf84cc4b04e3d84..3ce632891340fdd 100644
--- a/libcxx/test/std/experimental/simd/simd.reference/reference_assignment.pass.cpp
+++ b/libcxx/test/std/experimental/simd/simd.reference/reference_assignment.pass.cpp
@@ -29,11 +29,9 @@ struct CheckSimdReferenceAssignmentHelper {
   void operator()() const {
     if constexpr (std::is_assignable_v<T&, U&&>) {
       ex::simd<T, SimdAbi> origin_simd([](T i) { return i; });
-      for (size_t i = 0; i < origin_simd.size(); ++i) {
-        static_assert(noexcept(origin_simd[i] = static_cast<U>(i + 1)));
-        origin_simd[i] = static_cast<U>(i + 1);
-        assert(origin_simd[i] == static_cast<T>(std::forward<U>(i + 1)));
-      }
+      static_assert(noexcept(origin_simd[0] = static_cast<U>(5)));
+      origin_simd[0] = static_cast<U>(5);
+      assert(origin_simd[0] == static_cast<T>(std::forward<U>(5)));
     }
   }
 };
@@ -44,11 +42,9 @@ struct CheckMaskReferenceAssignmentHelper {
   void operator()() const {
     if constexpr (std::is_assignable_v<bool&, U&&>) {
       ex::simd_mask<T, SimdAbi> origin_mask(true);
-      for (size_t i = 0; i < origin_mask.size(); ++i) {
-        static_assert(noexcept(origin_mask[i] = static_cast<U>(i + 1)));
-        origin_mask[i] = static_cast<U>(i % 2);
-        assert(origin_mask[i] == static_cast<T>(std::forward<U>(i % 2)));
-      }
+      static_assert(noexcept(origin_mask[0] = false));
+      origin_mask[0] = false;
+      assert(origin_mask[0] == false);
     }
   }
 };

[ldionne]

I don't think this actually reduces the compilation time since there's no additional instantiations being performed here. This is just code running at runtime, and the runtime of the test is not the issue. Did I miss something?

[ldionne]

I'm going to close this since I don't think this achieves the desired results and I'd like to clean up the PR queue a bit.