diff options
Diffstat (limited to 'source/core/slang-com-ptr.h')
| -rw-r--r-- | source/core/slang-com-ptr.h | 19 |
1 files changed, 8 insertions, 11 deletions
diff --git a/source/core/slang-com-ptr.h b/source/core/slang-com-ptr.h index 729b6b266..9f6651306 100644 --- a/source/core/slang-com-ptr.h +++ b/source/core/slang-com-ptr.h @@ -51,21 +51,18 @@ struct Guid SLANG_FORCE_INLINE bool operator==(const Guid& aIn, const Guid& bIn) { + // Use the largest type the honors the alignment of Guid + typedef uint32_t CmpType; struct GuidCompare { - enum { kNum = sizeof(Guid) / sizeof(size_t) }; Guid guid; - size_t data[kNum]; + CmpType data[sizeof(Guid) / sizeof(CmpType)]; }; - const GuidCompare& a = reinterpret_cast<const GuidCompare&>(aIn); - const GuidCompare& b = reinterpret_cast<const GuidCompare&>(bIn); - - switch (GuidCompare::kNum) - { - case 2: return ((a.data[0] ^ b.data[0]) | (a.data[1] ^ b.data[1])) == 0; - case 4: return ((a.data[0] ^ b.data[0]) | (a.data[1] ^ b.data[1]) | (a.data[2] ^ b.data[2]) | (a.data[3] ^ b.data[3]) ) == 0; - default: return false; - } + // Type pun - so compiler can 'see' the pun and not break aliasing rules + const CmpType* a = reinterpret_cast<const GuidCompare&>(aIn).data; + const CmpType* b = reinterpret_cast<const GuidCompare&>(bIn).data; + // Make the guid comparison a single branch, by not using short circuit + return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2]) | (a[3] ^ b[3])) == 0; } SLANG_FORCE_INLINE bool operator!=(const Guid& a, const Guid& b) |