From e968b1c23f53d72a099423bf9dd3be5b71e83b2e Mon Sep 17 00:00:00 2001
From: "Daniel R." <47796739+polybiusproxy@users.noreply.github.com>
Date: Thu, 21 Nov 2024 19:24:13 +0100
Subject: [PATCH] video_core/amdgpu: heuristic for shader binary info

Games can strip the first shader instruction (meant for debugging) which we rely on for obtaining shader information (e.g. LittleBigPlanet 3). For this reason, we start a search through the code start until we arrive at the shader binary info.
---
 src/shader_recompiler/recompiler.cpp          |  4 +-
 src/video_core/amdgpu/liverpool.h             | 42 ++++++++++++++-----
 .../renderer_vulkan/vk_pipeline_cache.cpp     |  4 +-
 3 files changed, 37 insertions(+), 13 deletions(-)

diff --git a/src/shader_recompiler/recompiler.cpp b/src/shader_recompiler/recompiler.cpp
index 19579f66..64f842c4 100644
--- a/src/shader_recompiler/recompiler.cpp
+++ b/src/shader_recompiler/recompiler.cpp
@@ -32,7 +32,9 @@ IR::Program TranslateProgram(std::span<const u32> code, Pools& pools, Info& info
                              const RuntimeInfo& runtime_info, const Profile& profile) {
     // Ensure first instruction is expected.
     constexpr u32 token_mov_vcchi = 0xBEEB03FF;
-    ASSERT_MSG(code[0] == token_mov_vcchi, "First instruction is not s_mov_b32 vcc_hi, #imm");
+    if (code[0] != token_mov_vcchi) {
+        LOG_WARNING(Render_Recompiler, "First instruction is not s_mov_b32 vcc_hi, #imm");
+    }
 
     Gcn::GcnCodeSlice slice(code.data(), code.data() + code.size());
     Gcn::GcnDecodeContext decoder;
diff --git a/src/video_core/amdgpu/liverpool.h b/src/video_core/amdgpu/liverpool.h
index d94e4329..0595a242 100644
--- a/src/video_core/amdgpu/liverpool.h
+++ b/src/video_core/amdgpu/liverpool.h
@@ -88,6 +88,32 @@ struct Liverpool {
         }
     };
 
+    static const BinaryInfo& SearchBinaryInfo(const u32* code, size_t search_limit = 0x1000) {
+        constexpr u32 token_mov_vcchi = 0xBEEB03FF;
+
+        if (code[0] == token_mov_vcchi) {
+            const auto* info = std::bit_cast<const BinaryInfo*>(code + (code[1] + 1) * 2);
+            if (info->Valid()) {
+                return *info;
+            }
+        }
+
+        // First instruction is not s_mov_b32 vcc_hi, #imm,
+        // which means we cannot get the binary info via said instruction.
+        // The easiest solution is to iterate through each dword and break
+        // on the first instance of the binary info.
+        constexpr size_t signature_size = sizeof(BinaryInfo::signature_ref) / sizeof(u8);
+        const u32* end = code + search_limit;
+
+        for (const u32* it = code; it < end; ++it) {
+            if (const BinaryInfo* info = std::bit_cast<const BinaryInfo*>(it); info->Valid()) {
+                return *info;
+            }
+        }
+
+        UNREACHABLE_MSG("Shader binary info not found.");
+    }
+
     struct ShaderProgram {
         u32 address_lo;
         BitField<0, 8, u32> address_hi;
@@ -113,8 +139,7 @@ struct Liverpool {
 
         std::span<const u32> Code() const {
             const u32* code = Address<u32*>();
-            BinaryInfo bininfo;
-            std::memcpy(&bininfo, code + (code[1] + 1) * 2, sizeof(bininfo));
+            const BinaryInfo& bininfo = SearchBinaryInfo(code);
             const u32 num_dwords = bininfo.length / sizeof(u32);
             return std::span{code, num_dwords};
         }
@@ -166,27 +191,24 @@ struct Liverpool {
 
         std::span<const u32> Code() const {
             const u32* code = Address<u32*>();
-            BinaryInfo bininfo;
-            std::memcpy(&bininfo, code + (code[1] + 1) * 2, sizeof(bininfo));
+            const BinaryInfo& bininfo = SearchBinaryInfo(code);
             const u32 num_dwords = bininfo.length / sizeof(u32);
             return std::span{code, num_dwords};
         }
     };
 
     template <typename Shader>
-    static constexpr auto* GetBinaryInfo(const Shader& sh) {
+    static constexpr const BinaryInfo& GetBinaryInfo(const Shader& sh) {
         const auto* code = sh.template Address<u32*>();
-        const auto* bininfo = std::bit_cast<const BinaryInfo*>(code + (code[1] + 1) * 2);
-        // ASSERT_MSG(bininfo->Valid(), "Invalid shader binary header");
-        return bininfo;
+        return SearchBinaryInfo(code);
     }
 
     static constexpr Shader::ShaderParams GetParams(const auto& sh) {
-        auto* bininfo = GetBinaryInfo(sh);
+        auto& bininfo = GetBinaryInfo(sh);
         return {
             .user_data = sh.user_data,
             .code = sh.Code(),
-            .hash = bininfo->shader_hash,
+            .hash = bininfo.shader_hash,
         };
     }
 
diff --git a/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp b/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp
index 960415d0..b576d478 100644
--- a/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp
+++ b/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp
@@ -292,8 +292,8 @@ bool PipelineCache::RefreshGraphicsKey() {
             return false;
         }
 
-        const auto* bininfo = Liverpool::GetBinaryInfo(*pgm);
-        if (!bininfo->Valid()) {
+        const auto& bininfo = Liverpool::GetBinaryInfo(*pgm);
+        if (!bininfo.Valid()) {
             LOG_WARNING(Render_Vulkan, "Invalid binary info structure!");
             key.stage_hashes[stage_out_idx] = 0;
             infos[stage_out_idx] = nullptr;