astc_decoder: Refactor for style and more efficient memory use

1 files changed, 51 insertions, 123 deletions

diff --git a/src/video_core/textures/astc.h b/src/video_core/textures/astc.h
index bc8bddaec..c1c73fda5 100644
--- a/src/video_core/textures/astc.h
+++ b/src/video_core/textures/astc.h
@@ -4,20 +4,12 @@
 
 #pragma once
 
-#include <cstdint>
+#include <bit>
+#include "common/common_types.h"
 
 namespace Tegra::Texture::ASTC {
 
-/// Count the number of bits set in a number.
-constexpr u32 Popcnt(u32 n) {
-    u32 c = 0;
-    for (; n; c++) {
-        n &= n - 1;
-    }
-    return c;
-}
-
-enum class IntegerEncoding { JustBits, Qus32, Trit };
+enum class IntegerEncoding { JustBits, Quint, Trit };
 
 struct IntegerEncodedValue {
     constexpr IntegerEncodedValue() = default;
@@ -29,55 +21,55 @@ struct IntegerEncodedValue {
         return encoding == other.encoding && num_bits == other.num_bits;
     }
 
-    // Returns the number of bits required to encode nVals values.
-    u32 GetBitLength(u32 nVals) const {
-        u32 totalBits = num_bits * nVals;
+    // Returns the number of bits required to encode num_vals values.
+    u32 GetBitLength(u32 num_vals) const {
+        u32 total_bits = num_bits * num_vals;
         if (encoding == IntegerEncoding::Trit) {
-            totalBits += (nVals * 8 + 4) / 5;
-        } else if (encoding == IntegerEncoding::Qus32) {
-            totalBits += (nVals * 7 + 2) / 3;
+            total_bits += (num_vals * 8 + 4) / 5;
+        } else if (encoding == IntegerEncoding::Quint) {
+            total_bits += (num_vals * 7 + 2) / 3;
         }
-        return totalBits;
+        return total_bits;
     }
 
     IntegerEncoding encoding{};
     u32 num_bits = 0;
     u32 bit_value = 0;
     union {
-        u32 qus32_value = 0;
+        u32 quint_value = 0;
         u32 trit_value;
     };
 };
 
 // Returns a new instance of this struct that corresponds to the
-// can take no more than maxval values
-static constexpr IntegerEncodedValue CreateEncoding(u32 maxVal) {
-    while (maxVal > 0) {
-        u32 check = maxVal + 1;
+// can take no more than mav_value values
+constexpr IntegerEncodedValue CreateEncoding(u32 mav_value) {
+    while (mav_value > 0) {
+        u32 check = mav_value + 1;
 
-        // Is maxVal a power of two?
+        // Is mav_value a power of two?
         if (!(check & (check - 1))) {
-            return IntegerEncodedValue(IntegerEncoding::JustBits, Popcnt(maxVal));
+            return IntegerEncodedValue(IntegerEncoding::JustBits, std::popcount(mav_value));
         }
 
-        // Is maxVal of the type 3*2^n - 1?
+        // Is mav_value of the type 3*2^n - 1?
         if ((check % 3 == 0) && !((check / 3) & ((check / 3) - 1))) {
-            return IntegerEncodedValue(IntegerEncoding::Trit, Popcnt(check / 3 - 1));
+            return IntegerEncodedValue(IntegerEncoding::Trit, std::popcount(check / 3 - 1));
         }
 
-        // Is maxVal of the type 5*2^n - 1?
+        // Is mav_value of the type 5*2^n - 1?
         if ((check % 5 == 0) && !((check / 5) & ((check / 5) - 1))) {
-            return IntegerEncodedValue(IntegerEncoding::Qus32, Popcnt(check / 5 - 1));
+            return IntegerEncodedValue(IntegerEncoding::Quint, std::popcount(check / 5 - 1));
         }
 
         // Apparently it can't be represented with a bounded integer sequence...
         // just iterate.
-        maxVal--;
+        mav_value--;
     }
     return IntegerEncodedValue(IntegerEncoding::JustBits, 0);
 }
 
-static constexpr std::array<IntegerEncodedValue, 256> MakeEncodedValues() {
+constexpr std::array<IntegerEncodedValue, 256> MakeEncodedValues() {
     std::array<IntegerEncodedValue, 256> encodings{};
     for (std::size_t i = 0; i < encodings.size(); ++i) {
         encodings[i] = CreateEncoding(static_cast<u32>(i));
@@ -85,41 +77,38 @@ static constexpr std::array<IntegerEncodedValue, 256> MakeEncodedValues() {
     return encodings;
 }
 
-static constexpr std::array<IntegerEncodedValue, 256> EncodingsValues = MakeEncodedValues();
+constexpr std::array<IntegerEncodedValue, 256> EncodingsValues = MakeEncodedValues();
 
-// Replicates low numBits such that [(toBit - 1):(toBit - 1 - fromBit)]
-// is the same as [(numBits - 1):0] and repeats all the way down.
+// Replicates low num_bits such that [(to_bit - 1):(to_bit - 1 - from_bit)]
+// is the same as [(num_bits - 1):0] and repeats all the way down.
 template <typename IntType>
-static constexpr IntType Replicate(IntType val, u32 numBits, u32 toBit) {
-    if (numBits == 0) {
-        return 0;
-    }
-    if (toBit == 0) {
+constexpr IntType Replicate(IntType val, u32 num_bits, u32 to_bit) {
+    if (num_bits == 0 || to_bit == 0) {
         return 0;
     }
-    const IntType v = val & static_cast<IntType>((1 << numBits) - 1);
+    const IntType v = val & static_cast<IntType>((1 << num_bits) - 1);
     IntType res = v;
-    u32 reslen = numBits;
-    while (reslen < toBit) {
+    u32 reslen = num_bits;
+    while (reslen < to_bit) {
         u32 comp = 0;
-        if (numBits > toBit - reslen) {
-            u32 newshift = toBit - reslen;
-            comp = numBits - newshift;
-            numBits = newshift;
+        if (num_bits > to_bit - reslen) {
+            u32 newshift = to_bit - reslen;
+            comp = num_bits - newshift;
+            num_bits = newshift;
         }
-        res = static_cast<IntType>(res << numBits);
+        res = static_cast<IntType>(res << num_bits);
         res = static_cast<IntType>(res | (v >> comp));
-        reslen += numBits;
+        reslen += num_bits;
     }
     return res;
 }
 
-static constexpr std::size_t NumReplicateEntries(u32 num_bits) {
+constexpr std::size_t NumReplicateEntries(u32 num_bits) {
     return std::size_t(1) << num_bits;
 }
 
 template <typename IntType, u32 num_bits, u32 to_bit>
-static constexpr auto MakeReplicateTable() {
+constexpr auto MakeReplicateTable() {
     std::array<IntType, NumReplicateEntries(num_bits)> table{};
     for (IntType value = 0; value < static_cast<IntType>(std::size(table)); ++value) {
         table[value] = Replicate(value, num_bits, to_bit);
@@ -127,78 +116,17 @@ static constexpr auto MakeReplicateTable() {
     return table;
 }
 
-static constexpr auto REPLICATE_BYTE_TO_16_TABLE = MakeReplicateTable<u32, 8, 16>();
-static constexpr u32 ReplicateByteTo16(std::size_t value) {
-    return REPLICATE_BYTE_TO_16_TABLE[value];
-}
-
-static constexpr auto REPLICATE_BIT_TO_7_TABLE = MakeReplicateTable<u32, 1, 7>();
-static constexpr u32 ReplicateBitTo7(std::size_t value) {
-    return REPLICATE_BIT_TO_7_TABLE[value];
-}
-
-static constexpr auto REPLICATE_BIT_TO_9_TABLE = MakeReplicateTable<u32, 1, 9>();
-static constexpr u32 ReplicateBitTo9(std::size_t value) {
-    return REPLICATE_BIT_TO_9_TABLE[value];
-}
-
-static constexpr auto REPLICATE_1_BIT_TO_8_TABLE = MakeReplicateTable<u32, 1, 8>();
-static constexpr auto REPLICATE_2_BIT_TO_8_TABLE = MakeReplicateTable<u32, 2, 8>();
-static constexpr auto REPLICATE_3_BIT_TO_8_TABLE = MakeReplicateTable<u32, 3, 8>();
-static constexpr auto REPLICATE_4_BIT_TO_8_TABLE = MakeReplicateTable<u32, 4, 8>();
-static constexpr auto REPLICATE_5_BIT_TO_8_TABLE = MakeReplicateTable<u32, 5, 8>();
-static constexpr auto REPLICATE_6_BIT_TO_8_TABLE = MakeReplicateTable<u32, 6, 8>();
-static constexpr auto REPLICATE_7_BIT_TO_8_TABLE = MakeReplicateTable<u32, 7, 8>();
-static constexpr auto REPLICATE_8_BIT_TO_8_TABLE = MakeReplicateTable<u32, 8, 8>();
-/// Use a precompiled table with the most common usages, if it's not in the expected range, fallback
-/// to the runtime implementation
-static constexpr u32 FastReplicateTo8(u32 value, u32 num_bits) {
-    switch (num_bits) {
-    case 1:
-        return REPLICATE_1_BIT_TO_8_TABLE[value];
-    case 2:
-        return REPLICATE_2_BIT_TO_8_TABLE[value];
-    case 3:
-        return REPLICATE_3_BIT_TO_8_TABLE[value];
-    case 4:
-        return REPLICATE_4_BIT_TO_8_TABLE[value];
-    case 5:
-        return REPLICATE_5_BIT_TO_8_TABLE[value];
-    case 6:
-        return REPLICATE_6_BIT_TO_8_TABLE[value];
-    case 7:
-        return REPLICATE_7_BIT_TO_8_TABLE[value];
-    case 8:
-        return REPLICATE_8_BIT_TO_8_TABLE[value];
-    default:
-        return Replicate(value, num_bits, 8);
-    }
-}
-
-static constexpr auto REPLICATE_1_BIT_TO_6_TABLE = MakeReplicateTable<u32, 1, 6>();
-static constexpr auto REPLICATE_2_BIT_TO_6_TABLE = MakeReplicateTable<u32, 2, 6>();
-static constexpr auto REPLICATE_3_BIT_TO_6_TABLE = MakeReplicateTable<u32, 3, 6>();
-static constexpr auto REPLICATE_4_BIT_TO_6_TABLE = MakeReplicateTable<u32, 4, 6>();
-static constexpr auto REPLICATE_5_BIT_TO_6_TABLE = MakeReplicateTable<u32, 5, 6>();
-
-static constexpr u32 FastReplicateTo6(u32 value, u32 num_bits) {
-    switch (num_bits) {
-    case 1:
-        return REPLICATE_1_BIT_TO_6_TABLE[value];
-    case 2:
-        return REPLICATE_2_BIT_TO_6_TABLE[value];
-    case 3:
-        return REPLICATE_3_BIT_TO_6_TABLE[value];
-    case 4:
-        return REPLICATE_4_BIT_TO_6_TABLE[value];
-    case 5:
-        return REPLICATE_5_BIT_TO_6_TABLE[value];
-    default:
-        return Replicate(value, num_bits, 6);
-    }
-}
-
-void Decompress(std::span<const uint8_t> data, uint32_t width, uint32_t height, uint32_t depth,
-                uint32_t block_width, uint32_t block_height, std::span<uint8_t> output);
+constexpr auto REPLICATE_BYTE_TO_16_TABLE = MakeReplicateTable<u32, 8, 16>();
+constexpr auto REPLICATE_6_BIT_TO_8_TABLE = MakeReplicateTable<u32, 6, 8>();
+constexpr auto REPLICATE_7_BIT_TO_8_TABLE = MakeReplicateTable<u32, 7, 8>();
+constexpr auto REPLICATE_8_BIT_TO_8_TABLE = MakeReplicateTable<u32, 8, 8>();
+
+struct AstcBufferData {
+    decltype(EncodingsValues) encoding_values = EncodingsValues;
+    decltype(REPLICATE_6_BIT_TO_8_TABLE) replicate_6_to_8 = REPLICATE_6_BIT_TO_8_TABLE;
+    decltype(REPLICATE_7_BIT_TO_8_TABLE) replicate_7_to_8 = REPLICATE_7_BIT_TO_8_TABLE;
+    decltype(REPLICATE_8_BIT_TO_8_TABLE) replicate_8_to_8 = REPLICATE_8_BIT_TO_8_TABLE;
+    decltype(REPLICATE_BYTE_TO_16_TABLE) replicate_byte_to_16 = REPLICATE_BYTE_TO_16_TABLE;
+} constexpr ASTC_BUFFER_DATA;
 
 } // namespace Tegra::Texture::ASTC