Avoid unreachable() in assume_aligned

Another test to attempt to workaround MSVC build problems. Also, don't assume
bit-wise value alignment for pointers as a default fallback.

1 files changed, 6 insertions, 4 deletions

diff --git a/common/opthelpers.h b/common/opthelpers.h
index 04c5f1d0..6b0c8db9 100644
--- a/common/opthelpers.h
+++ b/common/opthelpers.h
@@ -58,14 +58,16 @@ force_inline constexpr auto assume_aligned(T *ptr) noexcept
     return std::assume_aligned<alignment,T>(ptr);
 #elif HAS_BUILTIN(__builtin_assume_aligned)
     return static_cast<T*>(__builtin_assume_aligned(ptr, alignment));
+#elif defined(_MSC_VER)
+    constexpr std::size_t alignment_mask{(1<<alignment) - 1};
+    if((reinterpret_cast<std::uintptr_t>(ptr)&alignment_mask) == 0)
+        return ptr;
+    __assume(0);
 #elif defined(__ICC)
     __assume_aligned(ptr, alignment);
     return ptr;
 #else
-    constexpr std::size_t alignment_mask{(1<<alignment) - 1};
-    if((reinterpret_cast<std::uintptr_t>(ptr)&alignment_mask) == 0)
-        return ptr;
-    unreachable();
+    return ptr;
 #endif
 }