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authorLiam <byteslice@airmail.cc>2022-07-09 20:33:03 -0400
committerLiam <byteslice@airmail.cc>2022-07-09 22:43:45 -0400
commita1c1ad096d23d76de2924ce299ecd49e66674e77 (patch)
tree2da5d6548a80d05831010160182d07a2f6546aa2 /src
parent313f047f974249c0fa004056ced3f18a8c61eae4 (diff)
common: fix bitfield aliasing on GCC/Clang
Diffstat (limited to 'src')
-rw-r--r--src/common/bit_field.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/src/common/bit_field.h b/src/common/bit_field.h
index 16d805694e..7e1df62b1c 100644
--- a/src/common/bit_field.h
+++ b/src/common/bit_field.h
@@ -146,7 +146,16 @@ public:
}
constexpr void Assign(const T& value) {
+#ifdef _MSC_VER
storage = static_cast<StorageType>((storage & ~mask) | FormatValue(value));
+#else
+ // Explicitly reload with memcpy to avoid compiler aliasing quirks
+ // regarding optimization: GCC/Clang clobber chained stores to
+ // different bitfields in the same struct with the last value.
+ StorageTypeWithEndian storage_;
+ std::memcpy(&storage_, &storage, sizeof(storage_));
+ storage = static_cast<StorageType>((storage_ & ~mask) | FormatValue(value));
+#endif
}
[[nodiscard]] constexpr T Value() const {