Vulkan backend: added SPIRV legalization when compiling from HLSL

1 files changed, 18 insertions, 1 deletions

diff --git a/Graphics/GLSLTools/src/SPIRVUtils.cpp b/Graphics/GLSLTools/src/SPIRVUtils.cpp
index 46e26470..3bdada38 100644
--- a/Graphics/GLSLTools/src/SPIRVUtils.cpp
+++ b/Graphics/GLSLTools/src/SPIRVUtils.cpp
@@ -37,6 +37,8 @@
 #include "DataBlobImpl.h"
 #include "RefCntAutoPtr.h"
 
+#include "spirv-tools/optimizer.hpp"
+
 static const char g_HLSLDefinitions[] = 
 {
     #include "../../GraphicsEngineD3DBase/include/HLSLDefinitions_inc.fxh"
@@ -461,7 +463,22 @@ std::vector<unsigned int> HLSLtoSPIRV(const ShaderCreateInfo& Attribs, IDataBlob
     Shader.setStringsWithLengthsAndNames(ShaderStrings, ShaderStringLenghts, Names, 1);
     
     IncluderImpl Includer(Attribs.pShaderSourceStreamFactory);
-    return CompileShaderInternal(Shader, messages, &Includer, SourceCode, SourceCodeLen, ppCompilerOutput);
+    auto SPIRV = CompileShaderInternal(Shader, messages, &Includer, SourceCode, SourceCodeLen, ppCompilerOutput);
+    
+    // SPIR-V bytecode generated from HLSL must be legalized to 
+    // turn it into a valid vulkan SPIR-V shader
+    spvtools::Optimizer SpirvOptimizer(SPV_ENV_VULKAN_1_0);
+    SpirvOptimizer.RegisterLegalizationPasses();
+    std::vector<uint32_t> LegalizedSPIRV;    
+    if (SpirvOptimizer.Run(SPIRV.data(), SPIRV.size(), &LegalizedSPIRV))
+    {
+        return std::move(LegalizedSPIRV);
+    }
+    else
+    {
+        LOG_ERROR("Failed to legalize SPIR-V shader generated by HLSL front-end. This may result in undefined behavior.");
+        return std::move(SPIRV);
+    }
 }
 
 std::vector<unsigned int> GLSLtoSPIRV(const SHADER_TYPE ShaderType, const char* ShaderSource, int SourceCodeLen, IDataBlob** ppCompilerOutput)