[SYCL][ESIMD] Fix a compilation of mix of unnamed ESIMD and non ESIMD kernels (#6557)

* Fix an issue that causes a program containing ESIMD and non-ESIMD kernels to crash

Author: fineg74

llvm/include/llvm/SYCLLowerIR/ESIMD/ESIMDUtils.h

@@ -16,6 +16,7 @@ namespace llvm {
 namespace esimd {
 
 constexpr char ATTR_DOUBLE_GRF[] = "esimd-double-grf";
+constexpr char ESIMD_MARKER_MD[] = "sycl_explicit_simd";
 
 using CallGraphNodeAction = std::function<void(Function *)>;
 void traverseCallgraphUp(llvm::Function *F, CallGraphNodeAction NodeF,
@@ -34,6 +35,8 @@ void traverseCallgraphUp(Function *F, CallGraphNodeActionF ActionF,
 
 // Tells whether given function is a ESIMD kernel.
 bool isESIMDKernel(const Function &F);
+// Tells whether given function is a ESIMD function.
+bool isESIMD(const Function &F);
 
 /// Reports and error with the message \p Msg concatenated with the optional
 /// \p OptMsg if \p Condition is false.

llvm/include/llvm/SYCLLowerIR/ESIMD/LowerESIMD.h

@@ -76,6 +76,12 @@ class SYCLLowerESIMDKernelPropsPass
   PreservedAnalyses run(Module &M, ModuleAnalysisManager &);
 };
 
+// Fixes ESIMD Kernel attributes for wrapper functions for ESIMD kernels
+class SYCLFixupESIMDKernelWrapperMDPass
+    : public PassInfoMixin<SYCLFixupESIMDKernelWrapperMDPass> {
+public:
+  PreservedAnalyses run(Module &M, ModuleAnalysisManager &);
+};
 } // namespace llvm
 
 #endif // LLVM_SYCLLOWERIR_LOWERESIMD_H

llvm/lib/Passes/PassRegistry.def

@@ -135,6 +135,7 @@ MODULE_PASS("SYCLMutatePrintfAddrspace", SYCLMutatePrintfAddrspacePass())
 MODULE_PASS("SPIRITTAnnotations", SPIRITTAnnotationsPass())
 MODULE_PASS("deadargelim-sycl", DeadArgumentEliminationSYCLPass())
 MODULE_PASS("sycllowerwglocalmemory", SYCLLowerWGLocalMemoryPass())
+MODULE_PASS("lower-esimd-kernel-attrs", SYCLFixupESIMDKernelWrapperMDPass())
 #undef MODULE_PASS
 
 #ifndef MODULE_PASS_WITH_PARAMS

llvm/lib/SYCLLowerIR/CMakeLists.txt

@@ -53,6 +53,7 @@ add_llvm_component_library(LLVMSYCLLowerIR
   ESIMD/LowerESIMDVecArg.cpp
   ESIMD/ESIMDUtils.cpp
   ESIMD/ESIMDVerifier.cpp
+  ESIMD/LowerESIMDKernelAttrs.cpp
   LowerInvokeSimd.cpp
   LowerWGScope.cpp
   LowerWGLocalMemory.cpp

llvm/lib/SYCLLowerIR/ESIMD/ESIMDUtils.cpp

@@ -54,9 +54,10 @@ void traverseCallgraphUp(llvm::Function *F, CallGraphNodeAction ActionF,
       } else {
         auto *CI = cast<CallInst>(FCall);
 
-        if ((CI->getCalledFunction() != CurF) && ErrorOnNonCallUse) {
+        if ((CI->getCalledFunction() != CurF)) {
           // CurF is used in a call, but not as the callee.
-          llvm::report_fatal_error(ErrMsg);
+          if (ErrorOnNonCallUse)
+            llvm::report_fatal_error(ErrMsg);
         } else {
           auto FCaller = CI->getFunction();
 
@@ -69,9 +70,12 @@ void traverseCallgraphUp(llvm::Function *F, CallGraphNodeAction ActionF,
   }
 }
 
+bool isESIMD(const Function &F) {
+  return F.getMetadata(ESIMD_MARKER_MD) != nullptr;
+}
+
 bool isESIMDKernel(const Function &F) {
-  return (F.getCallingConv() == CallingConv::SPIR_KERNEL) &&
-         (F.getMetadata("sycl_explicit_simd") != nullptr);
+  return (F.getCallingConv() == CallingConv::SPIR_KERNEL) && isESIMD(F);
 }
 
 } // namespace esimd

llvm/lib/SYCLLowerIR/ESIMD/LowerESIMD.cpp

@@ -1215,6 +1215,7 @@ translateSpirvGlobalUses(LoadInst *LI, StringRef SpirvGlobalName,
   // TODO: Implement support for the following intrinsics:
   // uint32_t __spirv_BuiltIn NumSubgroups;
   // uint32_t __spirv_BuiltIn SubgroupId;
+  // uint32_t __spirv_BuiltIn GlobalLinearId
 
   // Translate those loads from _scalar_ SPIRV globals that can be replaced with
   // a const value here.
@@ -1227,6 +1228,8 @@ translateSpirvGlobalUses(LoadInst *LI, StringRef SpirvGlobalName,
              SpirvGlobalName == "SubgroupMaxSize") {
     NewInst = llvm::Constant::getIntegerValue(LI->getType(),
                                               llvm::APInt(32, 1, true));
+  } else if (SpirvGlobalName == "GlobalLinearId") {
+    NewInst = llvm::Constant::getNullValue(LI->getType());
   }
   if (NewInst) {
     LI->replaceAllUsesWith(NewInst);

llvm/lib/SYCLLowerIR/ESIMD/LowerESIMDKernelAttrs.cpp

@@ -0,0 +1,42 @@
+//===---- LowerESIMDKernelAttrs - lower __esimd_set_kernel_attributes ---===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// Finds and adds  sycl_explicit_simd attributes to wrapper functions that wrap
+// ESIMD kernel functions
+
+#include "llvm/SYCLLowerIR/ESIMD/ESIMDUtils.h"
+#include "llvm/SYCLLowerIR/ESIMD/LowerESIMD.h"
+
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
+
+#define DEBUG_TYPE "LowerESIMDKernelAttrs"
+
+using namespace llvm;
+
+namespace llvm {
+PreservedAnalyses
+SYCLFixupESIMDKernelWrapperMDPass::run(Module &M, ModuleAnalysisManager &MAM) {
+  bool Modified = false;
+  for (Function &F : M) {
+    if (llvm::esimd::isESIMD(F)) {
+      llvm::esimd::traverseCallgraphUp(
+          &F,
+          [&](Function *GraphNode) {
+            if (!llvm::esimd::isESIMD(*GraphNode)) {
+              GraphNode->setMetadata(
+                  llvm::esimd::ESIMD_MARKER_MD,
+                  llvm::MDNode::get(GraphNode->getContext(), {}));
+              Modified = true;
+            }
+          },
+          false);
+    }
+  }
+  return Modified ? PreservedAnalyses::none() : PreservedAnalyses::all();
+}
+} // namespace llvm

llvm/tools/sycl-post-link/sycl-post-link.cpp

@@ -665,6 +665,10 @@ processInputModule(std::unique_ptr<Module> M) {
   // if none were made.
   bool Modified = false;
 
+  // Propagate ESIMD attribute to wrapper functions to prevent
+  // spurious splits and kernel link errors.
+  Modified |= runModulePass<SYCLFixupESIMDKernelWrapperMDPass>(*M);
+
   // After linking device bitcode "llvm.used" holds references to the kernels
   // that are defined in the device image. But after splitting device image into
   // separate kernels we may end up with having references to kernel declaration