Optimize angle::BitSetIterator.

BUILD.gn

@@ -59,6 +59,13 @@ config("internal_config") {
     "GL_GLEXT_PROTOTYPES",
     "EGL_EGLEXT_PROTOTYPES",
   ]
+
+  if (target_cpu == "x86") {
+    defines += [ "ANGLE_X86_CPU" ]
+  }
+  if (target_cpu == "x64") {
+    defines += [ "ANGLE_X64_CPU" ]
+  }
 }
 
 config("extra_warnings") {

gyp/common.gypi

@@ -281,6 +281,7 @@
                         'TargetMachine': '1', # x86
                     },
                 },
+                'defines': [ 'ANGLE_X86_CPU' ],
             }, # x86_Base
 
             'x64_Base':
@@ -298,6 +299,7 @@
                         'TargetMachine': '17', # x86 - 64
                     },
                 },
+                'defines': [ 'ANGLE_X64_CPU' ],
             },    # x64_Base
 
             # Concrete configurations

src/common/bitset_utils_unittest.cpp

@@ -18,25 +18,25 @@ namespace
 class BitSetIteratorTest : public testing::Test
 {
   protected:
-    std::bitset<40> mStateBits;
+    BitSet<40> mStateBits;
 };
 
 // Simple iterator test.
 TEST_F(BitSetIteratorTest, Iterator)
 {
-    std::set<unsigned long> originalValues;
+    std::set<size_t> originalValues;
     originalValues.insert(2);
     originalValues.insert(6);
     originalValues.insert(8);
     originalValues.insert(35);
 
-    for (unsigned long value : originalValues)
+    for (size_t value : originalValues)
     {
         mStateBits.set(value);
     }
 
-    std::set<unsigned long> readValues;
-    for (unsigned long bit : IterateBitSet(mStateBits))
+    std::set<size_t> readValues;
+    for (size_t bit : mStateBits)
     {
         EXPECT_EQ(1u, originalValues.count(bit));
         EXPECT_EQ(0u, readValues.count(bit));
@@ -52,7 +52,7 @@ TEST_F(BitSetIteratorTest, EmptySet)
     // We don't use the FAIL gtest macro here since it returns immediately,
     // causing an unreachable code warning in MSVS
     bool sawBit = false;
-    for (unsigned long bit : IterateBitSet(mStateBits))
+    for (size_t bit : mStateBits)
     {
         sawBit = true;
         UNUSED_VARIABLE(bit);
@@ -63,7 +63,7 @@ TEST_F(BitSetIteratorTest, EmptySet)
 // Test iterating a result of combining two bitsets.
 TEST_F(BitSetIteratorTest, NonLValueBitset)
 {
-    std::bitset<40> otherBits;
+    BitSet<40> otherBits;
 
     mStateBits.set(1);
     mStateBits.set(2);
@@ -75,9 +75,10 @@ TEST_F(BitSetIteratorTest, NonLValueBitset)
     otherBits.set(3);
     otherBits.set(5);
 
-    std::set<unsigned long> seenBits;
+    std::set<size_t> seenBits;
 
-    for (unsigned long bit : IterateBitSet(mStateBits & otherBits))
+    angle::BitSet<40> maskedBits = (mStateBits & otherBits);
+    for (size_t bit : maskedBits)
     {
         EXPECT_EQ(0u, seenBits.count(bit));
         seenBits.insert(bit);

src/common/mathutil.h

@@ -805,34 +805,73 @@ inline uint32_t BitfieldReverse(uint32_t value)
 }
 
 // Count the 1 bits.
-inline int BitCount(unsigned int bits)
+#if defined(ANGLE_PLATFORM_WINDOWS)
+inline int BitCount(uint32_t bits)
 {
-#if defined(_MSC_VER)
     return static_cast<int>(__popcnt(bits));
-#elif defined(__GNUC__)
+}
+#if defined(ANGLE_X64_CPU)
+inline int BitCount(uint64_t bits)
+{
+    return static_cast<int>(__popcnt64(bits));
+}
+#endif  // defined(ANGLE_X64_CPU)
+#endif  // defined(ANGLE_PLATFORM_WINDOWS)
+
+#if defined(ANGLE_PLATFORM_POSIX)
+inline int BitCount(uint32_t bits)
+{
     return __builtin_popcount(bits);
-#else
-#error Please implement bit count for your platform!
-#endif
 }
 
+#if defined(ANGLE_X64_CPU)
+inline int BitCount(uint64_t bits)
+{
+    return __builtin_popcountll(bits);
+}
+#endif  // defined(ANGLE_X64_CPU)
+#endif  // defined(ANGLE_PLATFORM_POSIX)
+
+#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.
-inline unsigned long ScanForward(unsigned long bits)
+// significant bit. Implemented for different bit widths on different platforms.
+inline unsigned long ScanForward(uint32_t bits)
 {
     ASSERT(bits != 0u);
-#if defined(ANGLE_PLATFORM_WINDOWS)
     unsigned long firstBitIndex = 0ul;
     unsigned char ret           = _BitScanForward(&firstBitIndex, bits);
     ASSERT(ret != 0u);
     return firstBitIndex;
-#elif defined(ANGLE_PLATFORM_POSIX)
-    return static_cast<unsigned long>(__builtin_ctzl(bits));
-#else
-#error Please implement bit-scan-forward for your platform!
-#endif
 }
 
+#if defined(ANGLE_X64_CPU)
+inline unsigned long ScanForward(uint64_t bits)
+{
+    ASSERT(bits != 0u);
+    unsigned long firstBitIndex = 0ul;
+    unsigned char ret           = _BitScanForward64(&firstBitIndex, bits);
+    ASSERT(ret != 0u);
+    return firstBitIndex;
+}
+#endif  // defined(ANGLE_X64_CPU)
+#endif  // defined(ANGLE_PLATFORM_WINDOWS)
+
+#if defined(ANGLE_PLATFORM_POSIX)
+inline unsigned long ScanForward(uint32_t bits)
+{
+    ASSERT(bits != 0u);
+    return static_cast<unsigned long>(__builtin_ctz(bits));
+}
+
+#if defined(ANGLE_X64_CPU)
+inline unsigned long ScanForward(uint64_t bits)
+{
+    ASSERT(bits != 0u);
+    return static_cast<unsigned long>(__builtin_ctzll(bits));
+}
+#endif  // defined(ANGLE_X64_CPU)
+#endif  // defined(ANGLE_PLATFORM_POSIX)
+
 // 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)
@@ -851,8 +890,10 @@ inline unsigned long ScanReverse(unsigned long bits)
 }
 
 // Returns -1 on 0, otherwise the index of the least significant 1 bit as in GLSL.
-inline int FindLSB(uint32_t bits)
+template <typename T>
+int FindLSB(T bits)
 {
+    static_assert(std::is_integral<T>::value, "must be integral type.");
     if (bits == 0u)
     {
         return -1;
@@ -864,8 +905,10 @@ inline int FindLSB(uint32_t bits)
 }
 
 // Returns -1 on 0, otherwise the index of the most significant 1 bit as in GLSL.
-inline int FindMSB(uint32_t bits)
+template <typename T>
+int FindMSB(T bits)
 {
+    static_assert(std::is_integral<T>::value, "must be integral type.");
     if (bits == 0u)
     {
         return -1;

src/common/mathutil_unittest.cpp

@@ -274,14 +274,26 @@ TEST(MathUtilTest, BitCount)
     EXPECT_EQ(0, gl::BitCount(0u));
     EXPECT_EQ(32, gl::BitCount(0xFFFFFFFFu));
     EXPECT_EQ(10, gl::BitCount(0x17103121u));
+
+#if defined(ANGLE_X64_CPU)
+    EXPECT_EQ(0, gl::BitCount(0ull));
+    EXPECT_EQ(32, gl::BitCount(0xFFFFFFFFull));
+    EXPECT_EQ(10, gl::BitCount(0x17103121ull));
+#endif  // defined(ANGLE_X64_CPU)
 }
 
 // Test ScanForward, which scans for the least significant 1 bit from a non-zero integer.
 TEST(MathUtilTest, ScanForward)
 {
-    EXPECT_EQ(0ul, gl::ScanForward(1ul));
-    EXPECT_EQ(16ul, gl::ScanForward(0x80010000ul));
-    EXPECT_EQ(31ul, gl::ScanForward(0x80000000ul));
+    EXPECT_EQ(0ul, gl::ScanForward(1u));
+    EXPECT_EQ(16ul, gl::ScanForward(0x80010000u));
+    EXPECT_EQ(31ul, gl::ScanForward(0x80000000u));
+
+#if defined(ANGLE_X64_CPU)
+    EXPECT_EQ(0ul, gl::ScanForward(1ull));
+    EXPECT_EQ(16ul, gl::ScanForward(0x80010000ull));
+    EXPECT_EQ(31ul, gl::ScanForward(0x80000000ull));
+#endif  // defined(ANGLE_X64_CPU)
 }
 
 // Test ScanReverse, which scans for the most significant 1 bit from a non-zero integer.

src/libANGLE/Framebuffer.cpp

@@ -1263,7 +1263,7 @@ bool Framebuffer::formsRenderingFeedbackLoopWith(const State &state) const
     }
 
     // The bitset will skip inactive draw buffers.
-    for (GLuint drawIndex : angle::IterateBitSet(mState.mEnabledDrawBuffers))
+    for (size_t drawIndex : mState.mEnabledDrawBuffers)
     {
         const FramebufferAttachment *attachment = getDrawBuffer(drawIndex);
         if (attachment && attachment->type() == GL_TEXTURE)

src/libANGLE/Framebuffer.h

@@ -100,7 +100,7 @@ class FramebufferState final : angle::NonCopyable
 
     std::vector<GLenum> mDrawBufferStates;
     GLenum mReadBufferState;
-    std::bitset<IMPLEMENTATION_MAX_DRAW_BUFFERS> mEnabledDrawBuffers;
+    angle::BitSet<IMPLEMENTATION_MAX_DRAW_BUFFERS> mEnabledDrawBuffers;
 
     GLint mDefaultWidth;
     GLint mDefaultHeight;
@@ -259,7 +259,7 @@ class Framebuffer final : public LabeledObject, public OnAttachmentDirtyReceiver
         DIRTY_BIT_MAX = DIRTY_BIT_UNKNOWN
     };
 
-    typedef std::bitset<DIRTY_BIT_MAX> DirtyBits;
+    typedef angle::BitSet<DIRTY_BIT_MAX> DirtyBits;
     bool hasAnyDirtyBit() const { return mDirtyBits.any(); }
 
     void syncState(const Context *context);

src/libANGLE/Program.h

@@ -260,7 +260,7 @@ class ProgramState final : angle::NonCopyable
     UniformBlockBindingMask mActiveUniformBlockBindings;
 
     std::vector<sh::Attribute> mAttributes;
-    std::bitset<MAX_VERTEX_ATTRIBS> mActiveAttribLocationsMask;
+    angle::BitSet<MAX_VERTEX_ATTRIBS> mActiveAttribLocationsMask;
 
     // Uniforms are sorted in order:
     //  1. Non-sampler uniforms

src/libANGLE/State.cpp

@@ -1370,9 +1370,9 @@ void State::setVertexAttribDivisor(GLuint index, GLuint divisor)
     mDirtyObjects.set(DIRTY_OBJECT_VERTEX_ARRAY);
 }
 
-const VertexAttribCurrentValueData &State::getVertexAttribCurrentValue(unsigned int attribNum) const
+const VertexAttribCurrentValueData &State::getVertexAttribCurrentValue(size_t attribNum) const
 {
-    ASSERT(static_cast<size_t>(attribNum) < mVertexAttribCurrentValues.size());
+    ASSERT(attribNum < mVertexAttribCurrentValues.size());
     return mVertexAttribCurrentValues[attribNum];
 }
 
@@ -2114,7 +2114,7 @@ void State::syncDirtyObjects(const Context *context)
 
 void State::syncDirtyObjects(const Context *context, const DirtyObjects &bitset)
 {
-    for (auto dirtyObject : angle::IterateBitSet(bitset))
+    for (auto dirtyObject : bitset)
     {
         switch (dirtyObject)
         {

src/libANGLE/State.h

@@ -13,6 +13,7 @@
 #include <memory>
 
 #include "common/angleutils.h"
+#include "common/bitset_utils.h"
 #include "common/Color.h"
 #include "libANGLE/Debug.h"
 #include "libANGLE/Program.h"
@@ -266,7 +267,7 @@ class State : angle::NonCopyable
     void setVertexAttribState(unsigned int attribNum, Buffer *boundBuffer, GLint size, GLenum type,
                               bool normalized, bool pureInteger, GLsizei stride, const void *pointer);
     void setVertexAttribDivisor(GLuint index, GLuint divisor);
-    const VertexAttribCurrentValueData &getVertexAttribCurrentValue(unsigned int attribNum) const;
+    const VertexAttribCurrentValueData &getVertexAttribCurrentValue(size_t attribNum) const;
     const void *getVertexAttribPointer(unsigned int attribNum) const;
     void bindVertexBuffer(GLuint bindingIndex,
                           Buffer *boundBuffer,
@@ -425,13 +426,13 @@ class State : angle::NonCopyable
         DIRTY_OBJECT_MAX = DIRTY_OBJECT_UNKNOWN,
     };
 
-    typedef std::bitset<DIRTY_BIT_MAX> DirtyBits;
+    typedef angle::BitSet<DIRTY_BIT_MAX> DirtyBits;
     const DirtyBits &getDirtyBits() const { return mDirtyBits; }
     void clearDirtyBits() { mDirtyBits.reset(); }
     void clearDirtyBits(const DirtyBits &bitset) { mDirtyBits &= ~bitset; }
     void setAllDirtyBits() { mDirtyBits.set(); }
 
-    typedef std::bitset<DIRTY_OBJECT_MAX> DirtyObjects;
+    typedef angle::BitSet<DIRTY_OBJECT_MAX> DirtyObjects;
     void clearDirtyObjects() { mDirtyObjects.reset(); }
     void setAllDirtyObjects() { mDirtyObjects.set(); }
     void syncDirtyObjects(const Context *context);

src/libANGLE/Texture.h

@@ -395,7 +395,7 @@ class Texture final : public egl::ImageSibling,
 
         DIRTY_BIT_COUNT,
     };
-    using DirtyBits = std::bitset<DIRTY_BIT_COUNT>;
+    using DirtyBits = angle::BitSet<DIRTY_BIT_COUNT>;
 
     void syncImplState();
     bool hasAnyDirtyBit() const { return mDirtyBits.any(); }

src/libANGLE/VertexArray.cpp

@@ -93,7 +93,7 @@ const VertexBinding &VertexArray::getVertexBinding(size_t bindingIndex) const
     return mState.mVertexBindings[bindingIndex];
 }
 
-size_t VertexArray::GetAttribIndex(unsigned long dirtyBit)
+size_t VertexArray::GetAttribIndex(size_t dirtyBit)
 {
     static_assert(gl::MAX_VERTEX_ATTRIBS == gl::MAX_VERTEX_ATTRIB_BINDINGS,
                   "The stride of vertex attributes should equal to that of vertex bindings.");

src/libANGLE/VertexArray.h

@@ -168,9 +168,9 @@ class VertexArray final : public LabeledObject
         DIRTY_BIT_MAX     = DIRTY_BIT_UNKNOWN,
     };
 
-    typedef std::bitset<DIRTY_BIT_MAX> DirtyBits;
+    typedef angle::BitSet<DIRTY_BIT_MAX> DirtyBits;
 
-    static size_t GetAttribIndex(unsigned long dirtyBit);
+    static size_t GetAttribIndex(size_t dirtyBit);
 
     void syncImplState(const Context *context);
     bool hasAnyDirtyBit() const { return mDirtyBits.any(); }

src/libANGLE/VertexArray_unittest.cpp

@@ -26,7 +26,7 @@ TEST(VertexArrayTest, VerifyGetAttribIndex)
         dirtyBits.set(bits[i]);
     }
 
-    for (unsigned long dirtyBit : angle::IterateBitSet(dirtyBits))
+    for (size_t dirtyBit : dirtyBits)
     {
         size_t index = VertexArray::GetAttribIndex(dirtyBit);
         if (dirtyBit < VertexArray::DIRTY_BIT_ATTRIB_MAX_ENABLED)

src/libANGLE/angletypes.h

@@ -9,6 +9,7 @@
 #ifndef LIBANGLE_ANGLETYPES_H_
 #define LIBANGLE_ANGLETYPES_H_
 
+#include "common/bitset_utils.h"
 #include "libANGLE/Constants.h"
 #include "libANGLE/RefCountObject.h"
 
@@ -253,10 +254,10 @@ struct PixelPackState : PixelStoreStateBase
 };
 
 // Used in Program and VertexArray.
-typedef std::bitset<MAX_VERTEX_ATTRIBS> AttributesMask;
+using AttributesMask = angle::BitSet<MAX_VERTEX_ATTRIBS>;
 
 // Use in Program
-typedef std::bitset<IMPLEMENTATION_MAX_COMBINED_SHADER_UNIFORM_BUFFERS> UniformBlockBindingMask;
+using UniformBlockBindingMask = angle::BitSet<IMPLEMENTATION_MAX_COMBINED_SHADER_UNIFORM_BUFFERS>;
 
 // A map of GL objects indexed by object ID. The specific map implementation may change.
 // Client code should treat it as a std::map.

src/libANGLE/renderer/d3d/FramebufferD3D.cpp

@@ -306,7 +306,7 @@ void FramebufferD3D::syncState(ContextImpl *contextImpl,
         invalidateColorAttachmentCache = true;
     }
 
-    for (auto dirtyBit : angle::IterateBitSet(dirtyBits))
+    for (auto dirtyBit : dirtyBits)
     {
         if ((dirtyBit >= gl::Framebuffer::DIRTY_BIT_COLOR_ATTACHMENT_0 &&
              dirtyBit < gl::Framebuffer::DIRTY_BIT_COLOR_ATTACHMENT_MAX) ||

src/libANGLE/renderer/d3d/ProgramD3D.cpp

@@ -2359,7 +2359,7 @@ void ProgramD3D::updateCachedInputLayout(const gl::State &state)
     mCachedInputLayout.clear();
     const auto &vertexAttributes = state.getVertexArray()->getVertexAttributes();
 
-    for (unsigned int locationIndex : IterateBitSet(mState.getActiveAttribLocationsMask()))
+    for (size_t locationIndex : mState.getActiveAttribLocationsMask())
     {
         int d3dSemantic = mAttribLocationToD3DSemantic[locationIndex];
 

src/libANGLE/renderer/d3d/VertexDataManager.cpp

@@ -241,8 +241,7 @@ gl::Error VertexDataManager::prepareVertexData(const gl::State &state,
         translatedAttribs->resize(attribIndex + 1);
 
         TranslatedAttribute *translated = &(*translatedAttribs)[attribIndex];
-        auto currentValueData =
-            state.getVertexAttribCurrentValue(static_cast<unsigned int>(attribIndex));
+        auto currentValueData           = state.getVertexAttribCurrentValue(attribIndex);
 
         // Record the attribute now
         translated->active           = true;
@@ -401,14 +400,14 @@ gl::Error VertexDataManager::storeDynamicAttribs(
     StreamingBufferUnmapper localUnmapper(mStreamingBuffer);
 
     // Reserve the required space for the dynamic buffers.
-    for (auto attribIndex : IterateBitSet(dynamicAttribsMask))
+    for (auto attribIndex : dynamicAttribsMask)
     {
         const auto &dynamicAttrib = (*translatedAttribs)[attribIndex];
         ANGLE_TRY(reserveSpaceForAttrib(dynamicAttrib, count, instances));
     }
 
     // Store dynamic attributes
-    for (auto attribIndex : IterateBitSet(dynamicAttribsMask))
+    for (auto attribIndex : dynamicAttribsMask)
     {
         auto *dynamicAttrib = &(*translatedAttribs)[attribIndex];
         ANGLE_TRY(storeDynamicAttrib(dynamicAttrib, start, count, instances));
@@ -422,7 +421,7 @@ void VertexDataManager::PromoteDynamicAttribs(
     const gl::AttributesMask &dynamicAttribsMask,
     GLsizei count)
 {
-    for (auto attribIndex : IterateBitSet(dynamicAttribsMask))
+    for (auto attribIndex : dynamicAttribsMask)
     {
         const auto &dynamicAttrib = translatedAttribs[attribIndex];
         const auto &binding       = *dynamicAttrib.binding;

src/libANGLE/renderer/d3d/d3d11/Framebuffer11.cpp

@@ -384,7 +384,7 @@ void Framebuffer11::syncState(ContextImpl *contextImpl, const gl::Framebuffer::D
     const auto &mergedDirtyBits = dirtyBits | mInternalDirtyBits;
     mInternalDirtyBits.reset();
 
-    for (auto dirtyBit : IterateBitSet(mergedDirtyBits))
+    for (auto dirtyBit : mergedDirtyBits)
     {
         switch (dirtyBit)
         {

src/libANGLE/renderer/d3d/d3d11/InputLayoutCache.cpp

@@ -47,7 +47,7 @@ gl::InputLayout GetInputLayout(const std::vector<const TranslatedAttribute *> &t
     return inputLayout;
 }
 
-GLenum GetGLSLAttributeType(const std::vector<sh::Attribute> &shaderAttributes, int index)
+GLenum GetGLSLAttributeType(const std::vector<sh::Attribute> &shaderAttributes, size_t index)
 {
     // Count matrices differently
     for (const sh::Attribute &attrib : shaderAttributes)
@@ -59,8 +59,9 @@ GLenum GetGLSLAttributeType(const std::vector<sh::Attribute> &shaderAttributes,
 
         GLenum transposedType = gl::TransposeMatrixType(attrib.type);
         int rows              = gl::VariableRowCount(transposedType);
+        int intIndex          = static_cast<int>(index);
 
-        if (index >= attrib.location && index < attrib.location + rows)
+        if (intIndex >= attrib.location && intIndex < attrib.location + rows)
         {
             return transposedType;
         }
@@ -105,7 +106,7 @@ void SortAttributesByLayout(const gl::Program *program,
     const auto &locationToSemantic =
         GetImplAs<ProgramD3D>(program)->getAttribLocationToD3DSemantics();
 
-    for (auto locationIndex : angle::IterateBitSet(program->getActiveAttribLocationsMask()))
+    for (auto locationIndex : program->getActiveAttribLocationsMask())
     {
         int d3dSemantic = locationToSemantic[locationIndex];
         if (sortedAttributesOut->size() <= static_cast<size_t>(d3dSemantic))
@@ -485,7 +486,7 @@ gl::Error InputLayoutCache::updateInputLayout(const gl::State &state,
     const auto &bindings           = state.getVertexArray()->getVertexBindings();
     const auto &locationToSemantic = programD3D->getAttribLocationToD3DSemantics();
 
-    for (unsigned long attribIndex : angle::IterateBitSet(program->getActiveAttribLocationsMask()))
+    for (size_t attribIndex : program->getActiveAttribLocationsMask())
     {
         // Record the type of the associated vertex shader vector in our key
         // This will prevent mismatched vertex shaders from using the same input layout
@@ -495,7 +496,8 @@ gl::Error InputLayoutCache::updateInputLayout(const gl::State &state,
         const auto &binding = bindings[attrib.bindingIndex];
         int d3dSemantic    = locationToSemantic[attribIndex];
 
-        const auto &currentValue              = state.getVertexAttribCurrentValue(attribIndex);
+        const auto &currentValue =
+            state.getVertexAttribCurrentValue(static_cast<unsigned int>(attribIndex));
         gl::VertexFormatType vertexFormatType = gl::GetVertexFormatType(attrib, currentValue.Type);
 
         layout.addAttributeData(glslElementType, d3dSemantic, vertexFormatType, binding.divisor);

src/libANGLE/renderer/d3d/d3d11/StateManager11.cpp

@@ -253,7 +253,7 @@ void StateManager11::syncState(const gl::State &state, const gl::State::DirtyBit
         return;
     }
 
-    for (auto dirtyBit : angle::IterateBitSet(dirtyBits))
+    for (auto dirtyBit : dirtyBits)
     {
         switch (dirtyBit)
         {
@@ -1103,15 +1103,14 @@ gl::Error StateManager11::updateCurrentValueAttribs(const gl::State &state,
     const auto &dirtyActiveAttribs = (activeAttribsMask & mDirtyCurrentValueAttribs);
     const auto &vertexAttributes   = state.getVertexArray()->getVertexAttributes();
 
-    for (auto attribIndex : angle::IterateBitSet(dirtyActiveAttribs))
+    for (auto attribIndex : dirtyActiveAttribs)
     {
         if (vertexAttributes[attribIndex].enabled)
             continue;
 
         mDirtyCurrentValueAttribs.reset(attribIndex);
 
-        const auto &currentValue =
-            state.getVertexAttribCurrentValue(static_cast<unsigned int>(attribIndex));
+        const auto &currentValue             = state.getVertexAttribCurrentValue(attribIndex);
         auto currentValueAttrib              = &mCurrentValueAttribs[attribIndex];
         currentValueAttrib->currentValueType = currentValue.Type;
         currentValueAttrib->attribute        = &vertexAttributes[attribIndex];

src/libANGLE/renderer/d3d/d3d11/VertexArray11.cpp

@@ -42,7 +42,7 @@ VertexArray11::~VertexArray11()
 
 void VertexArray11::syncState(ContextImpl *contextImpl, const gl::VertexArray::DirtyBits &dirtyBits)
 {
-    for (auto dirtyBit : angle::IterateBitSet(dirtyBits))
+    for (auto dirtyBit : dirtyBits)
     {
         if (dirtyBit == gl::VertexArray::DIRTY_BIT_ELEMENT_ARRAY_BUFFER)
             continue;
@@ -62,9 +62,9 @@ void VertexArray11::flushAttribUpdates(const gl::State &state)
     if (mAttribsToUpdate.any())
     {
         // Skip attrib locations the program doesn't use.
-        const auto &activeToUpdate = (mAttribsToUpdate & activeLocations);
+        gl::AttributesMask activeToUpdate = mAttribsToUpdate & activeLocations;
 
-        for (auto toUpdateIndex : angle::IterateBitSet(activeToUpdate))
+        for (auto toUpdateIndex : activeToUpdate)
         {
             mAttribsToUpdate.reset(toUpdateIndex);
             updateVertexAttribStorage(toUpdateIndex);
@@ -155,15 +155,14 @@ gl::Error VertexArray11::updateDirtyAndDynamicAttribs(VertexDataManager *vertexD
     if (mAttribsToTranslate.any())
     {
         // Skip attrib locations the program doesn't use, saving for the next frame.
-        const auto &dirtyActiveAttribs = (mAttribsToTranslate & activeLocations);
+        gl::AttributesMask dirtyActiveAttribs = (mAttribsToTranslate & activeLocations);
 
-        for (auto dirtyAttribIndex : angle::IterateBitSet(dirtyActiveAttribs))
+        for (auto dirtyAttribIndex : dirtyActiveAttribs)
         {
             mAttribsToTranslate.reset(dirtyAttribIndex);
 
             auto *translatedAttrib = &mTranslatedAttribs[dirtyAttribIndex];
-            const auto &currentValue =
-                state.getVertexAttribCurrentValue(static_cast<unsigned int>(dirtyAttribIndex));
+            const auto &currentValue = state.getVertexAttribCurrentValue(dirtyAttribIndex);
 
             // Record basic attrib info
             translatedAttrib->attribute = &attribs[dirtyAttribIndex];
@@ -195,11 +194,10 @@ gl::Error VertexArray11::updateDirtyAndDynamicAttribs(VertexDataManager *vertexD
     {
         auto activeDynamicAttribs = (mDynamicAttribsMask & activeLocations);
 
-        for (auto dynamicAttribIndex : angle::IterateBitSet(activeDynamicAttribs))
+        for (auto dynamicAttribIndex : activeDynamicAttribs)
         {
             auto *dynamicAttrib = &mTranslatedAttribs[dynamicAttribIndex];
-            const auto &currentValue =
-                state.getVertexAttribCurrentValue(static_cast<unsigned int>(dynamicAttribIndex));
+            const auto &currentValue = state.getVertexAttribCurrentValue(dynamicAttribIndex);
 
             // Record basic attrib info
             dynamicAttrib->attribute        = &attribs[dynamicAttribIndex];

src/libANGLE/renderer/d3d/d3d9/StateManager9.cpp

@@ -120,7 +120,7 @@ void StateManager9::syncState(const gl::State &state, const gl::State::DirtyBits
         return;
     }
 
-    for (auto dirtyBit : angle::IterateBitSet(dirtyBits))
+    for (auto dirtyBit : dirtyBits)
     {
         switch (dirtyBit)
         {
@@ -396,7 +396,7 @@ gl::Error StateManager9::setBlendDepthRasterStates(const gl::State &glState,
         mCurFrontFaceCCW = frontFaceCCW;
     }
 
-    for (auto dirtyBit : angle::IterateBitSet(mDirtyBits))
+    for (auto dirtyBit : mDirtyBits)
     {
         switch (dirtyBit)
         {

src/libANGLE/renderer/d3d/d3d9/StateManager9.h

@@ -155,7 +155,7 @@ class StateManager9 final : angle::NonCopyable
         DIRTY_BIT_MAX
     };
 
-    typedef std::bitset<DIRTY_BIT_MAX> DirtyBits;
+    using DirtyBits = angle::BitSet<DIRTY_BIT_MAX>;
 
     bool mUsingZeroColorMaskWorkaround;
 

src/libANGLE/renderer/gl/FramebufferGL.cpp

@@ -417,7 +417,7 @@ void FramebufferGL::syncState(ContextImpl *contextImpl, const Framebuffer::Dirty
 
     mStateManager->bindFramebuffer(GL_FRAMEBUFFER, mFramebufferID);
 
-    for (auto dirtyBit : angle::IterateBitSet(dirtyBits))
+    for (auto dirtyBit : dirtyBits)
     {
         switch (dirtyBit)
         {

src/libANGLE/renderer/gl/ProgramGL.cpp

@@ -75,9 +75,10 @@ LinkResult ProgramGL::load(const ContextImpl *contextImpl,
     const WorkaroundsGL &workaroundsGL = GetAs<ContextGL>(contextImpl)->getWorkaroundsGL();
     if (workaroundsGL.reapplyUBOBindingsAfterLoadingBinaryProgram)
     {
-        for (GLuint bindingIndex : angle::IterateBitSet(mState.getActiveUniformBlockBindingsMask()))
+        for (size_t bindingIndex : mState.getActiveUniformBlockBindingsMask())
         {
-            setUniformBlockBinding(bindingIndex, mState.getUniformBlockBinding(bindingIndex));
+            GLuint uintIndex = static_cast<GLuint>(bindingIndex);
+            setUniformBlockBinding(uintIndex, mState.getUniformBlockBinding(uintIndex));
         }
     }
 

src/libANGLE/renderer/gl/StateManagerGL.cpp

@@ -1394,7 +1394,7 @@ void StateManagerGL::syncState(const gl::ContextState &data,
         mLocalDirtyBits.set(gl::State::DIRTY_BIT_FRAMEBUFFER_SRGB);
     }
 
-    const auto &glAndLocalDirtyBits = (glDirtyBits | mLocalDirtyBits);
+    const gl::State::DirtyBits &glAndLocalDirtyBits = (glDirtyBits | mLocalDirtyBits);
 
     if (!glAndLocalDirtyBits.any())
     {
@@ -1402,7 +1402,7 @@ void StateManagerGL::syncState(const gl::ContextState &data,
     }
 
     // TODO(jmadill): Investigate only syncing vertex state for active attributes
-    for (auto dirtyBit : angle::IterateBitSet(glAndLocalDirtyBits))
+    for (auto dirtyBit : glAndLocalDirtyBits)
     {
         switch (dirtyBit)
         {
@@ -1648,8 +1648,8 @@ void StateManagerGL::syncState(const gl::ContextState &data,
                        dirtyBit < gl::State::DIRTY_BIT_CURRENT_VALUE_MAX);
                 size_t attribIndex =
                     static_cast<size_t>(dirtyBit) - gl::State::DIRTY_BIT_CURRENT_VALUE_0;
-                setAttributeCurrentData(attribIndex, state.getVertexAttribCurrentValue(
-                                                         static_cast<unsigned int>(attribIndex)));
+                setAttributeCurrentData(attribIndex,
+                                        state.getVertexAttribCurrentValue(attribIndex));
                 break;
             }
         }

src/libANGLE/renderer/gl/TextureGL.cpp

@@ -942,7 +942,7 @@ void TextureGL::syncState(const gl::Texture::DirtyBits &dirtyBits)
         mLocalDirtyBits |= GetLevelWorkaroundDirtyBits();
     }
 
-    for (auto dirtyBit : angle::IterateBitSet(dirtyBits | mLocalDirtyBits))
+    for (auto dirtyBit : (dirtyBits | mLocalDirtyBits))
     {
         switch (dirtyBit)
         {

src/libANGLE/renderer/gl/VertexArrayGL.cpp

@@ -257,7 +257,10 @@ void VertexArrayGL::computeStreamingAttributeSizes(const gl::AttributesMask &act
 
     const auto &attribs  = mData.getVertexAttributes();
     const auto &bindings = mData.getVertexBindings();
-    for (auto idx : angle::IterateBitSet(mAttributesNeedStreaming & activeAttributesMask))
+
+    gl::AttributesMask attribsToStream = (mAttributesNeedStreaming & activeAttributesMask);
+
+    for (auto idx : attribsToStream)
     {
         const auto &attrib  = attribs[idx];
         const auto &binding = bindings[attrib.bindingIndex];
@@ -320,7 +323,10 @@ gl::Error VertexArrayGL::streamAttributes(const gl::AttributesMask &activeAttrib
 
         const auto &attribs  = mData.getVertexAttributes();
         const auto &bindings = mData.getVertexBindings();
-        for (auto idx : angle::IterateBitSet(mAttributesNeedStreaming & activeAttributesMask))
+
+        gl::AttributesMask attribsToStream = (mAttributesNeedStreaming & activeAttributesMask);
+
+        for (auto idx : attribsToStream)
         {
             const auto &attrib  = attribs[idx];
             const auto &binding = bindings[attrib.bindingIndex];
@@ -526,7 +532,7 @@ void VertexArrayGL::updateAttribDivisor(size_t attribIndex)
 
 void VertexArrayGL::syncState(ContextImpl *contextImpl, const VertexArray::DirtyBits &dirtyBits)
 {
-    for (unsigned long dirtyBit : angle::IterateBitSet(dirtyBits))
+    for (size_t dirtyBit : dirtyBits)
     {
         if (dirtyBit == VertexArray::DIRTY_BIT_ELEMENT_ARRAY_BUFFER)
         {

src/libANGLE/renderer/vulkan/ContextVk.cpp

@@ -99,7 +99,7 @@ gl::Error ContextVk::initPipeline()
     std::vector<VkVertexInputBindingDescription> vertexBindings;
     std::vector<VkVertexInputAttributeDescription> vertexAttribs;
 
-    for (auto attribIndex : angle::IterateBitSet(programGL->getActiveAttribLocationsMask()))
+    for (auto attribIndex : programGL->getActiveAttribLocationsMask())
     {
         const auto &attrib = attribs[attribIndex];
         const auto &binding = bindings[attrib.bindingIndex];
@@ -293,7 +293,7 @@ gl::Error ContextVk::drawArrays(GLenum mode, GLint first, GLsizei count)
     std::vector<VkBuffer> vertexHandles;
     std::vector<VkDeviceSize> vertexOffsets;
 
-    for (auto attribIndex : angle::IterateBitSet(programGL->getActiveAttribLocationsMask()))
+    for (auto attribIndex : programGL->getActiveAttribLocationsMask())
     {
         const auto &attrib  = attribs[attribIndex];
         const auto &binding = bindings[attrib.bindingIndex];

src/tests/angle_perftests.gypi

@@ -19,6 +19,7 @@
             '<(angle_path)/src/tests/perf_tests/ANGLEPerfTest.h',
             '<(angle_path)/src/tests/perf_tests/BlitFramebufferPerf.cpp',
             '<(angle_path)/src/tests/perf_tests/BindingPerf.cpp',
+            '<(angle_path)/src/tests/perf_tests/BitSetIteratorPerf.cpp',
             '<(angle_path)/src/tests/perf_tests/BufferSubData.cpp',
             '<(angle_path)/src/tests/perf_tests/DrawCallPerf.cpp',
             '<(angle_path)/src/tests/perf_tests/DrawCallPerfParams.cpp',

src/tests/perf_tests/BitSetIteratorPerf.cpp

+//
+// Copyright 2015 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// IndexDataManagerPerfTest:
+//   Performance test for index buffer management.
+//
+
+#include "ANGLEPerfTest.h"
+
+#include <gmock/gmock.h>
+
+#include "angle_unittests_utils.h"
+#include "common/bitset_utils.h"
+
+using namespace testing;
+
+namespace
+{
+
+template <typename T>
+class BitSetIteratorPerfTest : public ANGLEPerfTest
+{
+  public:
+    BitSetIteratorPerfTest();
+
+    void step() override;
+
+    T mBits;
+};
+
+template <typename T>
+BitSetIteratorPerfTest<T>::BitSetIteratorPerfTest() : ANGLEPerfTest("BitSetIteratorPerf", "_run")
+{
+}
+
+template <typename T>
+void BitSetIteratorPerfTest<T>::step()
+{
+    mBits.flip();
+
+    for (size_t bit : mBits)
+    {
+        UNUSED_VARIABLE(bit);
+    }
+
+    mBits.reset();
+}
+
+// These type names unfortunately don't get printed correctly in Gtest.
+#if defined(ANGLE_X64_CPU)
+using TestTypes = Types<angle::IterableBitSet<32>, angle::BitSet32<32>, angle::BitSet64<32>>;
+#else
+using TestTypes = Types<angle::IterableBitSet<32>, angle::BitSet32<32>>;
+#endif  // defined(ANGLE_X64_CPU)
+TYPED_TEST_CASE(BitSetIteratorPerfTest, TestTypes);
+
+TYPED_TEST(BitSetIteratorPerfTest, Run)
+{
+    this->run();
+}
+
+}  // anonymous namespace