[llvm] [SPIRV] Added new stub pass for NonSemantic DI (PR #97042)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-spir-v

Author: None (bwlodarcz)

<details>
<summary>Changes</summary>

The commit adds new empty pass for emission of NonSemantic.Shader.DebugInfo.100 instructions.
The pass is a basis for future development and can be (and likely will be) a subject of change.
In addition to that there is additional unused function which main purpose is to be basis of accessing global metadata which is inaccessible in MIR. Accessing such metadata is necessary for emitting such instructions like DebugCompilationUnit or DebugSource.

---
Full diff: https://github.com/llvm/llvm-project/pull/97042.diff


4 Files Affected:

- (modified) llvm/lib/Target/SPIRV/CMakeLists.txt (+1) 
- (modified) llvm/lib/Target/SPIRV/SPIRV.h (+2) 
- (added) llvm/lib/Target/SPIRV/SPIRVEmitNonSemanticDI.cpp (+55) 
- (modified) llvm/lib/Target/SPIRV/SPIRVTargetMachine.cpp (+1) 


``````````diff
diff --git a/llvm/lib/Target/SPIRV/CMakeLists.txt b/llvm/lib/Target/SPIRV/CMakeLists.txt
index 14647e92f5d08..5f8aea5fc8d84 100644
--- a/llvm/lib/Target/SPIRV/CMakeLists.txt
+++ b/llvm/lib/Target/SPIRV/CMakeLists.txt
@@ -40,6 +40,7 @@ add_llvm_target(SPIRVCodeGen
   SPIRVSubtarget.cpp
   SPIRVTargetMachine.cpp
   SPIRVUtils.cpp
+  SPIRVEmitNonSemanticDI.cpp
 
   LINK_COMPONENTS
   Analysis
diff --git a/llvm/lib/Target/SPIRV/SPIRV.h b/llvm/lib/Target/SPIRV/SPIRV.h
index e597a1dc8dc06..c32bf6f5a863d 100644
--- a/llvm/lib/Target/SPIRV/SPIRV.h
+++ b/llvm/lib/Target/SPIRV/SPIRV.h
@@ -26,6 +26,7 @@ FunctionPass *createSPIRVRegularizerPass();
 FunctionPass *createSPIRVPreLegalizerPass();
 FunctionPass *createSPIRVPostLegalizerPass();
 ModulePass *createSPIRVEmitIntrinsicsPass(SPIRVTargetMachine *TM);
+MachineFunctionPass *createSPIRVEmitNonSemanticDIPass();
 InstructionSelector *
 createSPIRVInstructionSelector(const SPIRVTargetMachine &TM,
                                const SPIRVSubtarget &Subtarget,
@@ -36,6 +37,7 @@ void initializeSPIRVConvergenceRegionAnalysisWrapperPassPass(PassRegistry &);
 void initializeSPIRVPreLegalizerPass(PassRegistry &);
 void initializeSPIRVPostLegalizerPass(PassRegistry &);
 void initializeSPIRVEmitIntrinsicsPass(PassRegistry &);
+void initializeSPIRVEmitNonSemanticDIPass(PassRegistry &);
 } // namespace llvm
 
 #endif // LLVM_LIB_TARGET_SPIRV_SPIRV_H
diff --git a/llvm/lib/Target/SPIRV/SPIRVEmitNonSemanticDI.cpp b/llvm/lib/Target/SPIRV/SPIRVEmitNonSemanticDI.cpp
new file mode 100644
index 0000000000000..5b938047025d1
--- /dev/null
+++ b/llvm/lib/Target/SPIRV/SPIRVEmitNonSemanticDI.cpp
@@ -0,0 +1,55 @@
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/IR/DebugInfoMetadata.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/PassRegistry.h"
+#include "llvm/Support/Casting.h"
+
+namespace llvm {
+struct SPIRVEmitNonSemanticDI : public MachineFunctionPass {
+  static char ID;
+  SPIRVEmitNonSemanticDI();
+
+  bool runOnMachineFunction(MachineFunction &MF) override;
+};
+
+void initializeSPIRVEmitNonSemanticDIPass(PassRegistry &);
+
+FunctionPass *createSPIRVEmitNonSemanticDIPass() {
+  return new SPIRVEmitNonSemanticDI();
+}
+} // namespace llvm
+
+using namespace llvm;
+
+INITIALIZE_PASS(SPIRVEmitNonSemanticDI, "spirv-nonsemantic-debug-info",
+                "SPIRV NonSemantic.Shader.DebugInfo.100 emitter", false, false)
+
+char SPIRVEmitNonSemanticDI::ID = 0;
+
+SPIRVEmitNonSemanticDI::SPIRVEmitNonSemanticDI() : MachineFunctionPass(ID) {
+  initializeSPIRVEmitNonSemanticDIPass(*PassRegistry::getPassRegistry());
+}
+
+[[maybe_unused]]
+static void findCompileUnitDI(const MachineFunction &MF) {
+  MachineModuleInfo &MMI = MF.getMMI();
+  const Module *M = MMI.getModule();
+  NamedMDNode *DbgCu = M->getNamedMetadata("llvm.dbg.cu");
+  std::string FilePath;
+  if (DbgCu) {
+    unsigned NumOp = DbgCu->getNumOperands();
+    if (NumOp) {
+      if (const auto *CompileUnit =
+              dyn_cast<DICompileUnit>(DbgCu->getOperand(0))) {
+        DIFile *File = CompileUnit->getFile();
+        FilePath = ((File->getDirectory() + "/" + File->getFilename())).str();
+      }
+    }
+  }
+}
+
+bool SPIRVEmitNonSemanticDI::runOnMachineFunction(MachineFunction &MF) {
+  return false;
+}
diff --git a/llvm/lib/Target/SPIRV/SPIRVTargetMachine.cpp b/llvm/lib/Target/SPIRV/SPIRVTargetMachine.cpp
index 52fc6f33b4ef1..ee71190bc02ff 100644
--- a/llvm/lib/Target/SPIRV/SPIRVTargetMachine.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVTargetMachine.cpp
@@ -199,6 +199,7 @@ void SPIRVPassConfig::addPreLegalizeMachineIR() {
 bool SPIRVPassConfig::addLegalizeMachineIR() {
   addPass(new Legalizer());
   addPass(createSPIRVPostLegalizerPass());
+  addPass(createSPIRVEmitNonSemanticDIPass());
   return false;
 }
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/97042