shader/memory_util: Deduplicate code

Deduplicate code shared between vk_pipeline_cache and gl_shader_cache as
well as shader decoder code.

While we are at it, fix a bug in gl_shader_cache where compute shaders
had an start offset of a stage shader.

5 files changed, 127 insertions, 24 deletions

diff --git a/src/video_core/shader/control_flow.cpp b/src/video_core/shader/control_flow.cpp
index e00a3fb70..8d86020f6 100644
--- a/src/video_core/shader/control_flow.cpp
+++ b/src/video_core/shader/control_flow.cpp
@@ -13,6 +13,7 @@
 #include "common/common_types.h"
 #include "video_core/shader/ast.h"
 #include "video_core/shader/control_flow.h"
+#include "video_core/shader/memory_util.h"
 #include "video_core/shader/registry.h"
 #include "video_core/shader/shader_ir.h"
 
@@ -115,17 +116,6 @@ Pred GetPredicate(u32 index, bool negated) {
     return static_cast<Pred>(static_cast<u64>(index) + (negated ? 8ULL : 0ULL));
 }
 
-/**
- * Returns whether the instruction at the specified offset is a 'sched' instruction.
- * Sched instructions always appear before a sequence of 3 instructions.
- */
-constexpr bool IsSchedInstruction(u32 offset, u32 main_offset) {
-    constexpr u32 SchedPeriod = 4;
-    u32 absolute_offset = offset - main_offset;
-
-    return (absolute_offset % SchedPeriod) == 0;
-}
-
 enum class ParseResult : u32 {
     ControlCaught,
     BlockEnd,
diff --git a/src/video_core/shader/decode.cpp b/src/video_core/shader/decode.cpp
index 87ac9ac6c..1167ff4ec 100644
--- a/src/video_core/shader/decode.cpp
+++ b/src/video_core/shader/decode.cpp
@@ -13,6 +13,7 @@
 #include "video_core/engines/shader_bytecode.h"
 #include "video_core/engines/shader_header.h"
 #include "video_core/shader/control_flow.h"
+#include "video_core/shader/memory_util.h"
 #include "video_core/shader/node_helper.h"
 #include "video_core/shader/shader_ir.h"
 
@@ -23,17 +24,6 @@ using Tegra::Shader::OpCode;
 
 namespace {
 
-/**
- * Returns whether the instruction at the specified offset is a 'sched' instruction.
- * Sched instructions always appear before a sequence of 3 instructions.
- */
-constexpr bool IsSchedInstruction(u32 offset, u32 main_offset) {
-    constexpr u32 SchedPeriod = 4;
-    u32 absolute_offset = offset - main_offset;
-
-    return (absolute_offset % SchedPeriod) == 0;
-}
-
 void DeduceTextureHandlerSize(VideoCore::GuestDriverProfile& gpu_driver,
                               const std::list<Sampler>& used_samplers) {
     if (gpu_driver.IsTextureHandlerSizeKnown() || used_samplers.size() <= 1) {
diff --git a/src/video_core/shader/memory_util.cpp b/src/video_core/shader/memory_util.cpp
new file mode 100644
index 000000000..074f21691
--- /dev/null
+++ b/src/video_core/shader/memory_util.cpp
@@ -0,0 +1,77 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <cstddef>
+
+#include <boost/container_hash/hash.hpp>
+
+#include "common/common_types.h"
+#include "core/core.h"
+#include "video_core/engines/maxwell_3d.h"
+#include "video_core/memory_manager.h"
+#include "video_core/shader/memory_util.h"
+#include "video_core/shader/shader_ir.h"
+
+namespace VideoCommon::Shader {
+
+GPUVAddr GetShaderAddress(Core::System& system,
+                          Tegra::Engines::Maxwell3D::Regs::ShaderProgram program) {
+    const auto& gpu{system.GPU().Maxwell3D()};
+    const auto& shader_config{gpu.regs.shader_config[static_cast<std::size_t>(program)]};
+    return gpu.regs.code_address.CodeAddress() + shader_config.offset;
+}
+
+bool IsSchedInstruction(std::size_t offset, std::size_t main_offset) {
+    // Sched instructions appear once every 4 instructions.
+    constexpr std::size_t SchedPeriod = 4;
+    const std::size_t absolute_offset = offset - main_offset;
+    return (absolute_offset % SchedPeriod) == 0;
+}
+
+std::size_t CalculateProgramSize(const ProgramCode& program, bool is_compute) {
+    // This is the encoded version of BRA that jumps to itself. All Nvidia
+    // shaders end with one.
+    static constexpr u64 SELF_JUMPING_BRANCH = 0xE2400FFFFF07000FULL;
+    static constexpr u64 MASK = 0xFFFFFFFFFF7FFFFFULL;
+
+    const std::size_t start_offset = is_compute ? KERNEL_MAIN_OFFSET : STAGE_MAIN_OFFSET;
+    std::size_t offset = start_offset;
+    while (offset < program.size()) {
+        const u64 instruction = program[offset];
+        if (!IsSchedInstruction(offset, start_offset)) {
+            if ((instruction & MASK) == SELF_JUMPING_BRANCH) {
+                // End on Maxwell's "nop" instruction
+                break;
+            }
+            if (instruction == 0) {
+                break;
+            }
+        }
+        ++offset;
+    }
+    // The last instruction is included in the program size
+    return std::min(offset + 1, program.size());
+}
+
+ProgramCode GetShaderCode(Tegra::MemoryManager& memory_manager, GPUVAddr gpu_addr,
+                          const u8* host_ptr, bool is_compute) {
+    ProgramCode code(VideoCommon::Shader::MAX_PROGRAM_LENGTH);
+    ASSERT_OR_EXECUTE(host_ptr != nullptr, { return code; });
+    memory_manager.ReadBlockUnsafe(gpu_addr, code.data(), code.size() * sizeof(u64));
+    code.resize(CalculateProgramSize(code, is_compute));
+    return code;
+}
+
+u64 GetUniqueIdentifier(Tegra::Engines::ShaderType shader_type, bool is_a, const ProgramCode& code,
+                        const ProgramCode& code_b) {
+    u64 unique_identifier = boost::hash_value(code);
+    if (is_a) {
+        // VertexA programs include two programs
+        boost::hash_combine(unique_identifier, boost::hash_value(code_b));
+    }
+    return unique_identifier;
+}
+
+} // namespace VideoCommon::Shader
diff --git a/src/video_core/shader/memory_util.h b/src/video_core/shader/memory_util.h
new file mode 100644
index 000000000..be90d24fd
--- /dev/null
+++ b/src/video_core/shader/memory_util.h
@@ -0,0 +1,47 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <cstddef>
+#include <vector>
+
+#include "common/common_types.h"
+#include "video_core/engines/maxwell_3d.h"
+#include "video_core/engines/shader_type.h"
+
+namespace Core {
+class System;
+}
+
+namespace Tegra {
+class MemoryManager;
+}
+
+namespace VideoCommon::Shader {
+
+using ProgramCode = std::vector<u64>;
+
+constexpr u32 STAGE_MAIN_OFFSET = 10;
+constexpr u32 KERNEL_MAIN_OFFSET = 0;
+
+/// Gets the address for the specified shader stage program
+GPUVAddr GetShaderAddress(Core::System& system,
+                          Tegra::Engines::Maxwell3D::Regs::ShaderProgram program);
+
+/// Gets if the current instruction offset is a scheduler instruction
+bool IsSchedInstruction(std::size_t offset, std::size_t main_offset);
+
+/// Calculates the size of a program stream
+std::size_t CalculateProgramSize(const ProgramCode& program, bool is_compute);
+
+/// Gets the shader program code from memory for the specified address
+ProgramCode GetShaderCode(Tegra::MemoryManager& memory_manager, GPUVAddr gpu_addr,
+                          const u8* host_ptr, bool is_compute);
+
+/// Hashes one (or two) program streams
+u64 GetUniqueIdentifier(Tegra::Engines::ShaderType shader_type, bool is_a, const ProgramCode& code,
+                        const ProgramCode& code_b = {});
+
+} // namespace VideoCommon::Shader
diff --git a/src/video_core/shader/shader_ir.h b/src/video_core/shader/shader_ir.h
index c6e7bdf50..69de5e68b 100644
--- a/src/video_core/shader/shader_ir.h
+++ b/src/video_core/shader/shader_ir.h
@@ -18,6 +18,7 @@
 #include "video_core/engines/shader_header.h"
 #include "video_core/shader/ast.h"
 #include "video_core/shader/compiler_settings.h"
+#include "video_core/shader/memory_util.h"
 #include "video_core/shader/node.h"
 #include "video_core/shader/registry.h"
 
@@ -25,8 +26,6 @@ namespace VideoCommon::Shader {
 
 struct ShaderBlock;
 
-using ProgramCode = std::vector<u64>;
-
 constexpr u32 MAX_PROGRAM_LENGTH = 0x1000;
 
 class ConstBuffer {