3 files changed, 76 insertions, 2 deletions
diff --git a/source/slang/slang-compiler.cpp b/source/slang/slang-compiler.cpp
index 58cc55e71..3839e0722 100644
--- a/source/slang/slang-compiler.cpp
+++ b/source/slang/slang-compiler.cpp
@@ -2669,6 +2669,12 @@ bool CodeGenContext::shouldDumpIR()
     return getTargetProgram()->getOptionSet().getBoolOption(CompilerOptionName::DumpIr);
 }
 
+bool CodeGenContext::shouldSkipDownstreamLinking()
+{
+    return getTargetProgram()->getOptionSet().getBoolOption(
+        CompilerOptionName::SkipDownstreamLinking);
+}
+
 bool CodeGenContext::shouldReportCheckpointIntermediates()
 {
     return getTargetProgram()->getOptionSet().getBoolOption(
diff --git a/source/slang/slang-compiler.h b/source/slang/slang-compiler.h
index 10da32400..cfcbe816f 100644
--- a/source/slang/slang-compiler.h
+++ b/source/slang/slang-compiler.h
@@ -1384,7 +1384,8 @@ enum class PassThroughMode : SlangPassThroughIntegral
     LLVM = SLANG_PASS_THROUGH_LLVM,                  ///< LLVM 'compiler'
     SpirvOpt = SLANG_PASS_THROUGH_SPIRV_OPT,         ///< pass thorugh spirv to spirv-opt
     MetalC = SLANG_PASS_THROUGH_METAL,
-    Tint = SLANG_PASS_THROUGH_TINT, ///< pass through spirv to Tint API
+    Tint = SLANG_PASS_THROUGH_TINT,            ///< pass through spirv to Tint API
+    SpirvLink = SLANG_PASS_THROUGH_SPIRV_LINK, ///< pass through spirv to spirv-link
     CountOf = SLANG_PASS_THROUGH_COUNT_OF,
 };
 void printDiagnosticArg(StringBuilder& sb, PassThroughMode val);
@@ -2886,6 +2887,12 @@ public:
     // removed between IR linking and target source generation.
     bool removeAvailableInDownstreamIR = false;
 
+    // Determines if program level compilation like getTargetCode() or getEntryPointCode()
+    // should return a fully linked downstream program or just the glue SPIR-V/DXIL that
+    // imports and uses the precompiled SPIR-V/DXIL from constituent modules.
+    // This is a no-op if modules are not precompiled.
+    bool shouldSkipDownstreamLinking();
+
 protected:
     CodeGenTarget m_targetFormat = CodeGenTarget::Unknown;
     ExtensionTracker* m_extensionTracker = nullptr;
diff --git a/source/slang/slang-emit.cpp b/source/slang/slang-emit.cpp
index ddb4ea67a..94ea66d71 100644
--- a/source/slang/slang-emit.cpp
+++ b/source/slang/slang-emit.cpp
@@ -2093,10 +2093,71 @@ SlangResult emitSPIRVForEntryPointsDirectly(
     if (compiler)
     {
 #if 0
-        // Dump the unoptimized SPIRV after lowering from slang IR -> SPIRV
+        // Dump the unoptimized/unlinked SPIRV after lowering from slang IR -> SPIRV
         compiler->disassemble((uint32_t*)spirv.getBuffer(), int(spirv.getCount() / 4));
 #endif
 
+        bool isPrecompilation = codeGenContext->getTargetProgram()->getOptionSet().getBoolOption(
+            CompilerOptionName::EmbedDownstreamIR);
+
+        if (!isPrecompilation && !codeGenContext->shouldSkipDownstreamLinking())
+        {
+            ComPtr<IArtifact> linkedArtifact;
+
+            // collect spirv files
+            List<uint32_t*> spirvFiles;
+            List<uint32_t> spirvSizes;
+
+            // Start with the SPIR-V we just generated.
+            // SPIRV-Tools-link expects the size in 32-bit words
+            // whereas the spirv blob size is in bytes.
+            spirvFiles.add((uint32_t*)spirv.getBuffer());
+            spirvSizes.add(int(spirv.getCount()) / 4);
+
+            // Iterate over all modules in the linkedIR. For each module, if it
+            // contains an embedded downstream ir instruction, add it to the list
+            // of spirv files.
+            auto program = codeGenContext->getProgram();
+
+            program->enumerateIRModules(
+                [&](IRModule* irModule)
+                {
+                    for (auto globalInst : irModule->getModuleInst()->getChildren())
+                    {
+                        if (auto inst = as<IREmbeddedDownstreamIR>(globalInst))
+                        {
+                            if (inst->getTarget() == CodeGenTarget::SPIRV)
+                            {
+                                auto slice = inst->getBlob()->getStringSlice();
+                                spirvFiles.add((uint32_t*)slice.begin());
+                                spirvSizes.add(int(slice.getLength()) / 4);
+                            }
+                        }
+                    }
+                });
+
+            SLANG_ASSERT(int(spirv.getCount()) % 4 == 0);
+            SLANG_ASSERT(spirvFiles.getCount() == spirvSizes.getCount());
+
+            if (spirvFiles.getCount() > 1)
+            {
+                SlangResult linkresult = compiler->link(
+                    (const uint32_t**)spirvFiles.getBuffer(),
+                    (const uint32_t*)spirvSizes.getBuffer(),
+                    (uint32_t)spirvFiles.getCount(),
+                    linkedArtifact.writeRef());
+
+                if (linkresult != SLANG_OK)
+                {
+                    return SLANG_FAIL;
+                }
+
+                ComPtr<ISlangBlob> blob;
+                linkedArtifact->loadBlob(ArtifactKeep::No, blob.writeRef());
+                artifact = _Move(linkedArtifact);
+            }
+        }
+
         if (!codeGenContext->shouldSkipSPIRVValidation())
         {
             StringBuilder runSpirvValEnvVar;