Provide packed VkFormat to uint8_t mapping There are only 241 unique format enums at this moment, so they can fit in an 8-bit variable instead of the 32-bit enum. Bug: b/148016460 Change-Id: I00d47a87ac0d053aee44a5d18f3c96d78c0f7cb0 Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/42528 Presubmit-Ready: Nicolas Capens <nicolascapens@google.com> Tested-by: Nicolas Capens <nicolascapens@google.com> Reviewed-by: Alexis Hétu <sugoi@google.com> Reviewed-by: Chris Forbes <chrisforbes@google.com> Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>

diff --git a/src/Vulkan/VkFormat.cpp b/src/Vulkan/VkFormat.cpp
index 2638439..c3cc876 100644
--- a/src/Vulkan/VkFormat.cpp
+++ b/src/Vulkan/VkFormat.cpp

@@ -2567,4 +2567,55 @@
 	return false;
 }
 
+static constexpr uint8_t pack(VkFormat format)
+{
+	if(format > VK_FORMAT_G16_B16_R16_3PLANE_444_UNORM)
+	{
+		return 0;
+	}
+
+	// 0 - 184 direct mapping
+	if(format >= 0 && format <= VK_FORMAT_ASTC_12x12_SRGB_BLOCK)
+	{
+		return uint8_t(format);
+	}
+
+	// 10001560xx -> 185 - 218
+	if(format >= VK_FORMAT_G8B8G8R8_422_UNORM && format <= VK_FORMAT_G16_B16_R16_3PLANE_444_UNORM)
+	{
+		return uint8_t(format - VK_FORMAT_G8B8G8R8_422_UNORM + 185);
+	}
+
+	// 100005400x -> 219 - 226
+	if(format >= VK_FORMAT_PVRTC1_2BPP_UNORM_BLOCK_IMG && format <= VK_FORMAT_PVRTC2_4BPP_SRGB_BLOCK_IMG)
+	{
+		return uint8_t(format - VK_FORMAT_PVRTC1_2BPP_UNORM_BLOCK_IMG + 219);
+	}
+
+	// 10000660xx -> 227 - 240
+	if(format >= VK_FORMAT_ASTC_4x4_SFLOAT_BLOCK_EXT && format <= VK_FORMAT_ASTC_12x12_SFLOAT_BLOCK_EXT)
+	{
+		return uint8_t(format - VK_FORMAT_ASTC_4x4_SFLOAT_BLOCK_EXT + 227);
+	}
+
+	return 0;
+}
+
+static_assert(VK_HEADER_VERSION == 128, "Update VkFormat to uint8_t mapping if needed");
+static_assert(pack(VK_FORMAT_UNDEFINED) == 0, "Incorrect VkFormat packed value");
+static_assert(pack(VK_FORMAT_ASTC_12x12_SRGB_BLOCK) == 184, "Incorrect VkFormat packed value");
+static_assert(pack(VK_FORMAT_G8B8G8R8_422_UNORM) == 185, "Incorrect VkFormat packed value");
+static_assert(pack(VK_FORMAT_G16_B16_R16_3PLANE_444_UNORM) == 218, "Incorrect VkFormat packed value");
+static_assert(pack(VK_FORMAT_PVRTC1_2BPP_UNORM_BLOCK_IMG) == 219, "Incorrect VkFormat packed value");
+static_assert(pack(VK_FORMAT_PVRTC2_4BPP_SRGB_BLOCK_IMG) == 226, "Incorrect VkFormat packed value");
+static_assert(pack(VK_FORMAT_ASTC_4x4_SFLOAT_BLOCK_EXT) == 227, "Incorrect VkFormat packed value");
+static_assert(pack(VK_FORMAT_ASTC_12x12_SFLOAT_BLOCK_EXT) == 240, "Incorrect VkFormat packed value");
+
+uint8_t Format::mapTo8bit(VkFormat format)
+{
+	ASSERT(format <= VK_FORMAT_G16_B16_R16_3PLANE_444_UNORM);
+
+	return pack(format);
+}
+
 }  // namespace vk

diff --git a/src/Vulkan/VkFormat.h b/src/Vulkan/VkFormat.h
index 9e4b1f8..06752e1 100644
--- a/src/Vulkan/VkFormat.h
+++ b/src/Vulkan/VkFormat.h

@@ -12,8 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#ifndef VK_FORMAT_UTILS_HPP_
-#define VK_FORMAT_UTILS_HPP_
+#ifndef VK_FORMAT_HPP_
+#define VK_FORMAT_HPP_
 
 #include "System/Types.hpp"
 
@@ -25,7 +25,9 @@
 {
 public:
 	Format() {}
-	Format(VkFormat format) : format(format) {}
+	Format(VkFormat format)
+	    : format(format)
+	{}
 	inline operator VkFormat() const { return format; }
 
 	bool isUnsignedNormalized() const;
@@ -42,7 +44,7 @@
 	bool isFloatFormat() const;
 	bool isYcbcrFormat() const;
 
-	bool isCompatible(const Format& other) const;
+	bool isCompatible(const Format &other) const;
 	bool isCompressed() const;
 	VkFormat getDecompressedFormat() const;
 	int blockWidth() const;
@@ -65,6 +67,8 @@
 	bool has32bitIntegerTextureComponents() const;
 	bool isRGBComponent(int component) const;
 
+	static uint8_t mapTo8bit(VkFormat format);
+
 private:
 	VkFormat compatibleFormat() const;
 	int sliceBUnpadded(int width, int height, int border, bool target) const;
@@ -74,4 +78,4 @@
 
 }  // namespace vk
 
-#endif // VK_FORMAT_UTILS_HPP_
\ No newline at end of file
+#endif  // VK_FORMAT_HPP_
\ No newline at end of file