Add support for uint8_t and uint16_t bitsets.

src/common/PackedEnums.h

@@ -129,8 +129,8 @@ class PackedEnumMap
 
 // PackedEnumBitSetE> is like an std::bitset<E::EnumCount> but is indexed with enum values. It
 // implements the std::bitset interface except with enum values instead of indices.
-template <typename E>
-using PackedEnumBitSet = BitSetT<EnumSize<E>(), uint32_t, E>;
+template <typename E, typename DataT = uint32_t>
+using PackedEnumBitSet = BitSetT<EnumSize<E>(), DataT, E>;
 
 }  // namespace angle
 
@@ -179,7 +179,8 @@ constexpr size_t kGraphicsShaderCount = static_cast<size_t>(ShaderType::EnumCoun
 constexpr std::array<ShaderType, kGraphicsShaderCount> kAllGraphicsShaderTypes = {
     ShaderType::Vertex, ShaderType::Geometry, ShaderType::Fragment};
 
-using ShaderBitSet = angle::PackedEnumBitSet<ShaderType>;
+using ShaderBitSet = angle::PackedEnumBitSet<ShaderType, uint8_t>;
+static_assert(sizeof(ShaderBitSet) == sizeof(uint8_t), "Unexpected size");
 
 template <typename T>
 using ShaderMap = angle::PackedEnumMap<ShaderType, T>;

src/common/mathutil.h

@@ -956,6 +956,16 @@ inline int BitCount(uint64_t bits)
 #endif  // defined(ANGLE_IS_64_BIT_CPU)
 #endif  // defined(ANGLE_PLATFORM_POSIX)
 
+inline int BitCount(uint8_t bits)
+{
+    return BitCount(static_cast<uint32_t>(bits));
+}
+
+inline int BitCount(uint16_t bits)
+{
+    return BitCount(static_cast<uint32_t>(bits));
+}
+
 #if defined(ANGLE_PLATFORM_WINDOWS)
 // Return the index of the least significant bit set. Indexing is such that bit 0 is the least
 // significant bit. Implemented for different bit widths on different platforms.
@@ -996,6 +1006,16 @@ inline unsigned long ScanForward(uint64_t bits)
 #endif  // defined(ANGLE_IS_64_BIT_CPU)
 #endif  // defined(ANGLE_PLATFORM_POSIX)
 
+inline unsigned long ScanForward(uint8_t bits)
+{
+    return ScanForward(static_cast<uint32_t>(bits));
+}
+
+inline unsigned long ScanForward(uint16_t bits)
+{
+    return ScanForward(static_cast<uint32_t>(bits));
+}
+
 // Return the index of the most significant bit set. Indexing is such that bit 0 is the least
 // significant bit.
 inline unsigned long ScanReverse(unsigned long bits)

src/libANGLE/MemoryProgramCache.cpp

@@ -431,7 +431,7 @@ LinkResult MemoryProgramCache::Deserialize(const Context *context,
 
     static_assert(static_cast<unsigned long>(ShaderType::EnumCount) <= sizeof(unsigned long) * 8,
                   "Too many shader types");
-    state->mLinkedShaderStages = stream.readInt<gl::ShaderBitSet>();
+    state->mLinkedShaderStages = ShaderBitSet(stream.readInt<uint8_t>());
 
     state->updateTransformFeedbackStrides();
 

src/libANGLE/Uniform.cpp

@@ -43,7 +43,7 @@ void ActiveVariable::unionReferencesWith(const ActiveVariable &other)
 
 ShaderType ActiveVariable::getFirstShaderTypeWhereActive() const
 {
-    return static_cast<ShaderType>(gl::ScanForward(mActiveUseBits.bits()));
+    return static_cast<ShaderType>(ScanForward(mActiveUseBits.bits()));
 }
 
 GLuint ActiveVariable::activeShaderCount() const