Use a constexpr array for es3 copy conversion table.

scripts/run_code_generation.py

@@ -93,12 +93,6 @@ generators = {
         auto_script('scripts/generate_loader.py'),
     'GL/EGL entry points':
         auto_script('scripts/generate_entry_points.py'),
-    'GL copy conversion table': {
-        'inputs': [
-            'src/libANGLE/es3_copy_conversion_formats.json',
-        ],
-        'script': 'src/libANGLE/gen_copy_conversion_table.py',
-    },
     'GL format map': {
         'inputs': [
             'src/libANGLE/es3_format_type_combinations.json',

scripts/run_code_generation_hashes.json

@@ -45,10 +45,6 @@
     "002ad46d144c51fe98d73478aa554ba7",
   "Emulated HLSL functions:src/compiler/translator/gen_emulated_builtin_function_tables.py":
     "6a00c1ba22c35a9b700a154efda6f861",
-  "GL copy conversion table:src/libANGLE/es3_copy_conversion_formats.json":
-    "54608f6f7d9aa7c59a8458ccf3ab9935",
-  "GL copy conversion table:src/libANGLE/gen_copy_conversion_table.py":
-    "ac1afe23d9578bd1d2ef74f4a7aa927a",
   "GL format map:src/libANGLE/es3_format_type_combinations.json":
     "a232823cd6430f14e28793ccabb968ee",
   "GL format map:src/libANGLE/format_map_data.json":

src/common/constexpr_array.h

+//
+// Copyright 2019 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.
+//
+// constexpr_array:
+//   C++14 relaxes constexpr requirements enough that we can support sorting
+//   a constexpr std::array at compile-time. This is useful for defining fast
+//   lookup tables and other data at compile-time.
+//   The code is adapted from https://stackoverflow.com/a/40030044.
+
+#ifndef COMMON_CONSTEXPR_ARRAY_H_
+#define COMMON_CONSTEXPR_ARRAY_H_
+
+#include <algorithm>
+
+namespace angle
+{
+template <class T>
+constexpr void constexpr_swap(T &l, T &r)
+{
+    T tmp = std::move(l);
+    l     = std::move(r);
+    r     = std::move(tmp);
+}
+
+template <typename T, size_t N>
+struct constexpr_array
+{
+    constexpr T &operator[](size_t i) { return arr[i]; }
+
+    constexpr const T &operator[](size_t i) const { return arr[i]; }
+
+    constexpr const T *begin() const { return arr; }
+    constexpr const T *end() const { return arr + N; }
+
+    T arr[N];
+};
+
+namespace priv
+{
+template <typename T, size_t N>
+size_t hoare_partition(constexpr_array<T, N> &arr, size_t left, size_t right)
+{
+    const T pivot = arr[(left + right) >> 1];
+    size_t i      = left - 1;
+    size_t j      = right + 1;
+
+    for (;;)
+    {
+        do
+        {
+            i++;
+        } while (arr[i] < pivot);
+
+        do
+        {
+            j--;
+        } while (arr[j] > pivot);
+
+        if (i >= j)
+        {
+            return j;
+        }
+
+        constexpr_swap(arr[i], arr[j]);
+    }
+
+    return 0;
+}
+
+template <typename T, size_t N>
+void constexpr_sort_impl(constexpr_array<T, N> &arr, size_t left, size_t right)
+{
+    if (left < right)
+    {
+        size_t p = priv::hoare_partition(arr, left, right);
+        constexpr_sort_impl(arr, left, p);
+        constexpr_sort_impl(arr, p + 1, right);
+    }
+}
+}  // namespace priv
+
+// Note that std::sort in constexpr in c++20. So this implementation can be
+// removed given sufficient STL support.
+template <typename T, size_t N>
+constexpr_array<T, N> constexpr_sort(constexpr_array<T, N> arr)
+{
+    auto sorted = arr;
+    priv::constexpr_sort_impl(sorted, 0, N - 1);
+    return sorted;
+}
+
+template <typename T, size_t N>
+bool constexpr_array_contains(const constexpr_array<T, N> &haystack, const T &needle)
+{
+    const T *found = std::lower_bound(haystack.begin(), haystack.end(), needle);
+    return (found && *found == needle);
+}
+}  // namespace angle
+
+#endif  // COMMON_CONSTEXPR_ARRAY_H_

src/libANGLE/es3_copy_conversion_formats.json

-{
-    "From ES 3.0.1 spec, table 3.15":
-    [
-        [ "GL_ALPHA", "GL_RGBA" ],
-        [ "GL_LUMINANCE", "GL_RED" ],
-        [ "GL_LUMINANCE", "GL_RG" ],
-        [ "GL_LUMINANCE", "GL_RGB" ],
-        [ "GL_LUMINANCE", "GL_RGBA" ],
-        [ "GL_LUMINANCE_ALPHA", "GL_RGBA" ],
-        [ "GL_RED", "GL_RED" ],
-        [ "GL_RED", "GL_RG" ],
-        [ "GL_RED", "GL_RGB" ],
-        [ "GL_RED", "GL_RGBA" ],
-        [ "GL_RG", "GL_RG" ],
-        [ "GL_RG", "GL_RGB" ],
-        [ "GL_RG", "GL_RGBA" ],
-        [ "GL_RGB", "GL_RGB" ],
-        [ "GL_RGB", "GL_RGBA" ],
-        [ "GL_RGBA", "GL_RGBA" ]
-    ],
-
-    "Necessary for ANGLE back-buffers":
-    [
-        [ "GL_ALPHA", "GL_BGRA_EXT" ],
-        [ "GL_LUMINANCE", "GL_BGRA_EXT" ],
-        [ "GL_LUMINANCE_ALPHA", "GL_BGRA_EXT" ],
-        [ "GL_RED", "GL_BGRA_EXT" ],
-        [ "GL_RG", "GL_BGRA_EXT" ],
-        [ "GL_RGB", "GL_BGRA_EXT" ],
-        [ "GL_RGBA", "GL_BGRA_EXT" ],
-        [ "GL_BGRA_EXT", "GL_BGRA_EXT" ],
-
-        [ "GL_RED_INTEGER", "GL_RED_INTEGER" ],
-        [ "GL_RED_INTEGER", "GL_RG_INTEGER" ],
-        [ "GL_RED_INTEGER", "GL_RGB_INTEGER" ],
-        [ "GL_RED_INTEGER", "GL_RGBA_INTEGER" ],
-        [ "GL_RG_INTEGER", "GL_RG_INTEGER" ],
-        [ "GL_RG_INTEGER", "GL_RGB_INTEGER" ],
-        [ "GL_RG_INTEGER", "GL_RGBA_INTEGER" ],
-        [ "GL_RGB_INTEGER", "GL_RGB_INTEGER" ],
-        [ "GL_RGB_INTEGER", "GL_RGBA_INTEGER" ],
-        [ "GL_RGBA_INTEGER", "GL_RGBA_INTEGER" ]
-    ]
-}

src/libANGLE/es3_copy_conversion_table_autogen.cpp

-// GENERATED FILE - DO NOT EDIT.
-// Generated by gen_copy_conversion_table.py using data from es3_copy_conversion_formats.json.
-//
-// Copyright 2018 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.
-//
-// format_map:
-//   Determining the sized internal format from a (format,type) pair.
-//   Also check es3 format combinations for validity.
-
-#include "angle_gl.h"
-#include "common/debug.h"
-
-namespace gl
-{
-
-bool ValidES3CopyConversion(GLenum textureFormat, GLenum framebufferFormat)
-{
-    switch (textureFormat)
-    {
-        case GL_ALPHA:
-            switch (framebufferFormat)
-            {
-                case GL_BGRA_EXT:
-                case GL_RGBA:
-                    return true;
-                default:
-                    break;
-            }
-            break;
-
-        case GL_BGRA_EXT:
-            switch (framebufferFormat)
-            {
-                case GL_BGRA_EXT:
-                    return true;
-                default:
-                    break;
-            }
-            break;
-
-        case GL_LUMINANCE:
-            switch (framebufferFormat)
-            {
-                case GL_BGRA_EXT:
-                case GL_RED:
-                case GL_RG:
-                case GL_RGB:
-                case GL_RGBA:
-                    return true;
-                default:
-                    break;
-            }
-            break;
-
-        case GL_LUMINANCE_ALPHA:
-            switch (framebufferFormat)
-            {
-                case GL_BGRA_EXT:
-                case GL_RGBA:
-                    return true;
-                default:
-                    break;
-            }
-            break;
-
-        case GL_RED:
-            switch (framebufferFormat)
-            {
-                case GL_BGRA_EXT:
-                case GL_RED:
-                case GL_RG:
-                case GL_RGB:
-                case GL_RGBA:
-                    return true;
-                default:
-                    break;
-            }
-            break;
-
-        case GL_RED_INTEGER:
-            switch (framebufferFormat)
-            {
-                case GL_RED_INTEGER:
-                case GL_RGBA_INTEGER:
-                case GL_RGB_INTEGER:
-                case GL_RG_INTEGER:
-                    return true;
-                default:
-                    break;
-            }
-            break;
-
-        case GL_RG:
-            switch (framebufferFormat)
-            {
-                case GL_BGRA_EXT:
-                case GL_RG:
-                case GL_RGB:
-                case GL_RGBA:
-                    return true;
-                default:
-                    break;
-            }
-            break;
-
-        case GL_RGB:
-            switch (framebufferFormat)
-            {
-                case GL_BGRA_EXT:
-                case GL_RGB:
-                case GL_RGBA:
-                    return true;
-                default:
-                    break;
-            }
-            break;
-
-        case GL_RGBA:
-            switch (framebufferFormat)
-            {
-                case GL_BGRA_EXT:
-                case GL_RGBA:
-                    return true;
-                default:
-                    break;
-            }
-            break;
-
-        case GL_RGBA_INTEGER:
-            switch (framebufferFormat)
-            {
-                case GL_RGBA_INTEGER:
-                    return true;
-                default:
-                    break;
-            }
-            break;
-
-        case GL_RGB_INTEGER:
-            switch (framebufferFormat)
-            {
-                case GL_RGBA_INTEGER:
-                case GL_RGB_INTEGER:
-                    return true;
-                default:
-                    break;
-            }
-            break;
-
-        case GL_RG_INTEGER:
-            switch (framebufferFormat)
-            {
-                case GL_RGBA_INTEGER:
-                case GL_RGB_INTEGER:
-                case GL_RG_INTEGER:
-                    return true;
-                default:
-                    break;
-            }
-            break;
-
-        default:
-            break;
-    }
-
-    return false;
-}
-
-}  // namespace gl

src/libANGLE/formatutils.h

@@ -269,10 +269,6 @@ bool ValidES3InternalFormat(GLenum internalFormat);
 bool ValidES3Format(GLenum format);
 bool ValidES3Type(GLenum type);
 bool ValidES3FormatCombination(GLenum format, GLenum type, GLenum internalFormat);
-
-// Implemented in es3_copy_conversion_table_autogen.cpp
-bool ValidES3CopyConversion(GLenum textureFormat, GLenum framebufferFormat);
-
 }  // namespace gl
 
 #endif  // LIBANGLE_FORMATUTILS_H_

src/libANGLE/validationES3.cpp

@@ -9,6 +9,7 @@
 #include "libANGLE/validationES3_autogen.h"
 
 #include "anglebase/numerics/safe_conversions.h"
+#include "common/constexpr_array.h"
 #include "common/mathutil.h"
 #include "common/utilities.h"
 #include "libANGLE/Context.h"
@@ -256,6 +257,55 @@ bool ValidateCopyTexture3DCommon(Context *context,
 
     return true;
 }
+
+// Since the unsorted array is only referenced in construction, it should be optimized out.
+using CopyDesc = std::pair<GLenum, GLenum>;
+constexpr angle::constexpr_array<CopyDesc, 34> kUnsortedCopyConversionTable{
+    {// From ES 3.0.1 spec, table 3.15
+     {GL_ALPHA, GL_RGBA},
+     {GL_LUMINANCE, GL_RED},
+     {GL_LUMINANCE, GL_RG},
+     {GL_LUMINANCE, GL_RGB},
+     {GL_LUMINANCE, GL_RGBA},
+     {GL_LUMINANCE_ALPHA, GL_RGBA},
+     {GL_RED, GL_RED},
+     {GL_RED, GL_RG},
+     {GL_RED, GL_RGB},
+     {GL_RED, GL_RGBA},
+     {GL_RG, GL_RG},
+     {GL_RG, GL_RGB},
+     {GL_RG, GL_RGBA},
+     {GL_RGB, GL_RGB},
+     {GL_RGB, GL_RGBA},
+     {GL_RGBA, GL_RGBA},
+
+     // Necessary for ANGLE back-buffers
+     {GL_ALPHA, GL_BGRA_EXT},
+     {GL_LUMINANCE, GL_BGRA_EXT},
+     {GL_LUMINANCE_ALPHA, GL_BGRA_EXT},
+     {GL_RED, GL_BGRA_EXT},
+     {GL_RG, GL_BGRA_EXT},
+     {GL_RGB, GL_BGRA_EXT},
+     {GL_RGBA, GL_BGRA_EXT},
+     {GL_BGRA_EXT, GL_BGRA_EXT},
+
+     {GL_RED_INTEGER, GL_RED_INTEGER},
+     {GL_RED_INTEGER, GL_RG_INTEGER},
+     {GL_RED_INTEGER, GL_RGB_INTEGER},
+     {GL_RED_INTEGER, GL_RGBA_INTEGER},
+     {GL_RG_INTEGER, GL_RG_INTEGER},
+     {GL_RG_INTEGER, GL_RGB_INTEGER},
+     {GL_RG_INTEGER, GL_RGBA_INTEGER},
+     {GL_RGB_INTEGER, GL_RGB_INTEGER},
+     {GL_RGB_INTEGER, GL_RGBA_INTEGER},
+     {GL_RGBA_INTEGER, GL_RGBA_INTEGER}}};
+
+auto kSortedCopyConversionTable = angle::constexpr_sort(kUnsortedCopyConversionTable);
+
+bool ValidES3CopyConversion(GLenum textureFormat, GLenum framebufferFormat)
+{
+    return constexpr_array_contains(kSortedCopyConversionTable, {textureFormat, framebufferFormat});
+}
 }  // anonymous namespace
 
 static bool ValidateTexImageFormatCombination(gl::Context *context,

src/libGLESv2.gni

@@ -24,6 +24,7 @@ libangle_common_sources = [
   "src/common/angleutils.cpp",
   "src/common/angleutils.h",
   "src/common/bitset_utils.h",
+  "src/common/constexpr_array.h",
   "src/common/debug.cpp",
   "src/common/debug.h",
   "src/common/hash_utils.h",
@@ -268,7 +269,6 @@ libangle_sources = [
   "src/libANGLE/angletypes.cpp",
   "src/libANGLE/angletypes.h",
   "src/libANGLE/angletypes.inl",
-  "src/libANGLE/es3_copy_conversion_table_autogen.cpp",
   "src/libANGLE/features.h",
   "src/libANGLE/format_map_autogen.cpp",
   "src/libANGLE/formatutils.cpp",