[OMPIRBuilder] Don't generate DISubprogram for outlined function.

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

@@ -6887,23 +6887,19 @@ static void FixupDebugInfoForOutlinedFunction(
   if (!NewSP)
     return;
 
-  DenseMap<const MDNode *, MDNode *> Cache;
   SmallDenseMap<DILocalVariable *, DILocalVariable *> RemappedVariables;
 
   auto GetUpdatedDIVariable = [&](DILocalVariable *OldVar, unsigned arg) {
-    auto NewSP = Func->getSubprogram();
     DILocalVariable *&NewVar = RemappedVariables[OldVar];
     // Only use cached variable if the arg number matches. This is important
     // so that DIVariable created for privatized variables are not discarded.
     if (NewVar && (arg == NewVar->getArg()))
       return NewVar;
 
-    DILocalScope *NewScope = DILocalScope::cloneScopeForSubprogram(
-        *OldVar->getScope(), *NewSP, Builder.getContext(), Cache);
     NewVar = llvm::DILocalVariable::get(
-        Builder.getContext(), NewScope, OldVar->getName(), OldVar->getFile(),
-        OldVar->getLine(), OldVar->getType(), arg, OldVar->getFlags(),
-        OldVar->getAlignInBits(), OldVar->getAnnotations());
+        Builder.getContext(), OldVar->getScope(), OldVar->getName(),
+        OldVar->getFile(), OldVar->getLine(), OldVar->getType(), arg,
+        OldVar->getFlags(), OldVar->getAlignInBits(), OldVar->getAnnotations());
     return NewVar;
   };
 
@@ -6917,7 +6913,8 @@ static void FixupDebugInfoForOutlinedFunction(
         ArgNo = std::get<1>(Iter->second) + 1;
       }
     }
-    DR->setVariable(GetUpdatedDIVariable(OldVar, ArgNo));
+    if (ArgNo != 0)
+      DR->setVariable(GetUpdatedDIVariable(OldVar, ArgNo));
   };
 
   // The location and scope of variable intrinsics and records still point to
@@ -6996,36 +6993,9 @@ static Expected<Function *> createOutlinedFunction(
 
   // Save insert point.
   IRBuilder<>::InsertPointGuard IPG(Builder);
-  // If there's a DISubprogram associated with current function, then
-  // generate one for the outlined function.
-  if (Function *ParentFunc = BB->getParent()) {
-    if (DISubprogram *SP = ParentFunc->getSubprogram()) {
-      DICompileUnit *CU = SP->getUnit();
-      DIBuilder DB(*M, true, CU);
-      DebugLoc DL = Builder.getCurrentDebugLocation();
-      if (DL) {
-        // TODO: We are using nullopt for arguments at the moment. This will
-        // need to be updated when debug data is being generated for variables.
-        DISubroutineType *Ty =
-            DB.createSubroutineType(DB.getOrCreateTypeArray({}));
-        DISubprogram::DISPFlags SPFlags = DISubprogram::SPFlagDefinition |
-                                          DISubprogram::SPFlagOptimized |
-                                          DISubprogram::SPFlagLocalToUnit;
-
-        DISubprogram *OutlinedSP = DB.createFunction(
-            CU, FuncName, FuncName, SP->getFile(), DL.getLine(), Ty,
-            DL.getLine(), DINode::DIFlags::FlagArtificial, SPFlags);
-
-        // Attach subprogram to the function.
-        Func->setSubprogram(OutlinedSP);
-        // Update the CurrentDebugLocation in the builder so that right scope
-        // is used for things inside outlined function.
-        Builder.SetCurrentDebugLocation(
-            DILocation::get(Func->getContext(), DL.getLine(), DL.getCol(),
-                            OutlinedSP, DL.getInlinedAt()));
-      }
-    }
-  }
+  // We will generate the entries in the outlined function but the debug
+  // location may still be pointing to the parent function. Reset it now.
+  Builder.SetCurrentDebugLocation(llvm::DebugLoc());
 
   // Generate the region into the function.
   BasicBlock *EntryBB = BasicBlock::Create(Builder.getContext(), "entry", Func);

mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp

@@ -5299,9 +5299,27 @@ static LogicalResult
 convertOmpTarget(Operation &opInst, llvm::IRBuilderBase &builder,
                  LLVM::ModuleTranslation &moduleTranslation) {
   auto targetOp = cast<omp::TargetOp>(opInst);
+  // The current debug location already has the DISubprogram for the outlined
+  // function that will be created for the target op. We save it here so that
+  // we can set it on the outlined function.
+  llvm::DebugLoc outlinedFnLoc = builder.getCurrentDebugLocation();
   if (failed(checkImplementationStatus(opInst)))
     return failure();
 
+  // During the handling of target op, we will generate instructions in the
+  // parent function like call to the oulined function or branch to a new
+  // BasicBlock. We set the debug location here to parent function so that those
+  // get the correct debug locations. For outlined functions, the normal MLIR op
+  // conversion will automatically pick the correct location.
+  llvm::BasicBlock *parentBB = builder.GetInsertBlock();
+  assert(parentBB && "No insert block is set for the builder");
+  llvm::Function *parentLLVMFn = parentBB->getParent();
+  assert(parentLLVMFn && "Parent Function must be valid");
+  if (llvm::DISubprogram *SP = parentLLVMFn->getSubprogram())
+    builder.SetCurrentDebugLocation(llvm::DILocation::get(
+        parentLLVMFn->getContext(), outlinedFnLoc.getLine(),
+        outlinedFnLoc.getCol(), SP, outlinedFnLoc.getInlinedAt()));
+
   llvm::OpenMPIRBuilder *ompBuilder = moduleTranslation.getOpenMPBuilder();
   bool isTargetDevice = ompBuilder->Config.isTargetDevice();
   bool isGPU = ompBuilder->Config.isGPU();
@@ -5395,6 +5413,9 @@ convertOmpTarget(Operation &opInst, llvm::IRBuilderBase &builder,
     assert(llvmParentFn && llvmOutlinedFn &&
            "Both parent and outlined functions must exist at this point");
 
+    if (outlinedFnLoc && llvmParentFn->getSubprogram())
+      llvmOutlinedFn->setSubprogram(outlinedFnLoc->getScope()->getSubprogram());
+
     if (auto attr = llvmParentFn->getFnAttribute("target-cpu");
         attr.isStringAttribute())
       llvmOutlinedFn->addFnAttr(attr);

mlir/test/Target/LLVMIR/omptarget-debug-empty.mlir

@@ -0,0 +1,27 @@
+// RUN: mlir-translate -mlir-to-llvmir %s | FileCheck %s
+
+module attributes {omp.is_target_device = false} {
+  llvm.func @test() {
+    omp.target {
+      omp.terminator
+    }  loc(#loc4)
+    llvm.return
+  }  loc(#loc3)
+}
+#file = #llvm.di_file<"target.f90" in "">
+#cu = #llvm.di_compile_unit<id = distinct[0]<>,
+ sourceLanguage = DW_LANG_Fortran95, file = #file, isOptimized = false,
+ emissionKind = Full>
+#sp_ty = #llvm.di_subroutine_type<callingConvention = DW_CC_normal>
+#sp = #llvm.di_subprogram<id = distinct[1]<>, compileUnit = #cu, scope = #file,
+ name = "_QQmain", file = #file, subprogramFlags = "Definition", type = #sp_ty>
+#sp1 = #llvm.di_subprogram<id = distinct[2]<>, compileUnit = #cu, scope = #file,
+ name = "__omp_offloading_target", file = #file, subprogramFlags = "Definition",
+ type = #sp_ty>
+#loc1 = loc("target.f90":1:1)
+#loc2 = loc("target.f90":46:3)
+#loc3 = loc(fused<#sp>[#loc1])
+#loc4 = loc(fused<#sp1>[#loc2])
+
+// CHECK: ![[SP:.*]] = {{.*}}!DISubprogram(name: "__omp_offloading_target"{{.*}})
+

mlir/test/Target/LLVMIR/omptarget-debug-nowait.mlir

@@ -20,7 +20,7 @@ module attributes {omp.is_target_device = false} {
     ^bb3:  // pred: ^bb1
       llvm.store %13, %arg1 : i32, !llvm.ptr
       omp.terminator
-    }
+    } loc(#loc3)
     llvm.return
   } loc(#loc2)
 }
@@ -34,7 +34,10 @@ module attributes {omp.is_target_device = false} {
  types = #di_null_type>
 #sp = #llvm.di_subprogram<compileUnit = #cu, name = "main", file=#file,
  subprogramFlags = "Definition", type = #sp_ty>
+#sp1 = #llvm.di_subprogram<compileUnit = #cu, name = "target", file=#file,
+ subprogramFlags = "Definition", type = #sp_ty>
 
 #loc1 = loc("test.f90":6:7)
 #loc2 = loc(fused<#sp>[#loc1])
+#loc3 = loc(fused<#sp1>[#loc1])
 

mlir/test/Target/LLVMIR/omptarget-debug-var-1.mlir

@@ -19,11 +19,13 @@
 #g_var_expr = #llvm.di_global_variable_expression<var = #g_var>
 #sp = #llvm.di_subprogram<id = distinct[2]<>, compileUnit = #cu, scope = #file,
   name = "test", file = #file, subprogramFlags = "Definition", type = #sp_ty>
-#var_arr = #llvm.di_local_variable<scope = #sp,
+#sp1 = #llvm.di_subprogram<id = distinct[3]<>, compileUnit = #cu, scope = #file,
+  name = "target", file = #file, subprogramFlags = "Definition", type = #sp_ty>
+#var_arr = #llvm.di_local_variable<scope = #sp1,
   name = "arr", file = #file, line = 4, type = #array_ty>
-#var_i = #llvm.di_local_variable<scope = #sp,
+#var_i = #llvm.di_local_variable<scope = #sp1,
   name = "i", file = #file, line = 13, type = #int_ty>
-#var_x = #llvm.di_local_variable<scope = #sp,
+#var_x = #llvm.di_local_variable<scope = #sp1,
  name = "x", file = #file, line = 12, type = #real_ty>
 
 module attributes {dlti.dl_spec = #dlti.dl_spec<#dlti.dl_entry<"dlti.alloca_memory_space", 5 : ui32>>, llvm.target_triple = "amdgcn-amd-amdhsa", omp.is_target_device = true} {
@@ -47,7 +49,7 @@ module attributes {dlti.dl_spec = #dlti.dl_spec<#dlti.dl_entry<"dlti.alloca_memo
       llvm.intr.dbg.declare #var_arr = %arg1 : !llvm.ptr
       llvm.intr.dbg.declare #var_i = %arg2 : !llvm.ptr
       omp.terminator
-    }
+    } loc(#loc5)
     llvm.return
   } loc(#loc3)
   llvm.mlir.global internal @_QFEarr() {addr_space = 0 : i32, dbg_exprs = [#g_var_expr]} : !llvm.array<10 x i32> {
@@ -57,8 +59,9 @@ module attributes {dlti.dl_spec = #dlti.dl_spec<#dlti.dl_entry<"dlti.alloca_memo
 #loc2 = loc("target.f90":11:7)
 #loc3 = loc(fused<#sp>[#loc2])
 #loc4 = loc(fused<#g_var>[#loc1])
+#loc5 = loc(fused<#sp1>[#loc2])
 
-// CHECK: ![[SP:[0-9]+]] = distinct !DISubprogram(name: "__omp_offloading{{.*}}test{{.*}})
+// CHECK: ![[SP:[0-9]+]] = distinct !DISubprogram(name: "target"{{.*}})
 // CHECK: !DILocalVariable(name: "dyn_ptr", arg: 1, scope: ![[SP]]{{.*}}flags: DIFlagArtificial)
 // CHECK: !DILocalVariable(name: "x", arg: 2, scope: ![[SP]]{{.*}})
 // CHECK: !DILocalVariable(name: "arr", arg: 3, scope: ![[SP]]{{.*}})

mlir/test/Target/LLVMIR/omptarget-debug-var-2.mlir

@@ -19,11 +19,13 @@
 #g_var_expr = #llvm.di_global_variable_expression<var = #g_var>
 #sp = #llvm.di_subprogram<id = distinct[2]<>, compileUnit = #cu, scope = #file,
   name = "test", file = #file, subprogramFlags = "Definition", type = #sp_ty>
-#var_arr = #llvm.di_local_variable<scope = #sp,
+#sp1 = #llvm.di_subprogram<id = distinct[3]<>, compileUnit = #cu, scope = #file,
+  name = "target", file = #file, subprogramFlags = "Definition", type = #sp_ty>
+#var_arr = #llvm.di_local_variable<scope = #sp1,
   name = "arr", file = #file, line = 4, type = #array_ty>
-#var_i = #llvm.di_local_variable<scope = #sp,
+#var_i = #llvm.di_local_variable<scope = #sp1,
   name = "i", file = #file, line = 13, type = #int_ty>
-#var_x = #llvm.di_local_variable<scope = #sp,
+#var_x = #llvm.di_local_variable<scope = #sp1,
  name = "x", file = #file, line = 12, type = #real_ty>
 
 module attributes {omp.is_target_device = false} {
@@ -45,7 +47,7 @@ module attributes {omp.is_target_device = false} {
       llvm.intr.dbg.declare #var_arr = %arg1 : !llvm.ptr
       llvm.intr.dbg.declare #var_i = %arg2 : !llvm.ptr
       omp.terminator
-    }
+    }  loc(#loc5)
     llvm.return
   } loc(#loc3)
   llvm.mlir.global internal @_QFEarr() {addr_space = 0 : i32, dbg_exprs = [#g_var_expr]} : !llvm.array<10 x i32> {
@@ -55,8 +57,9 @@ module attributes {omp.is_target_device = false} {
 #loc2 = loc("target.f90":11:7)
 #loc3 = loc(fused<#sp>[#loc2])
 #loc4 = loc(fused<#g_var>[#loc1])
+#loc5 = loc(fused<#sp1>[#loc2])
 
-// CHECK: ![[SP:[0-9]+]] = distinct !DISubprogram(name: "__omp_offloading{{.*}}test{{.*}})
+// CHECK: ![[SP:[0-9]+]] = distinct !DISubprogram(name: "target"{{.*}})
 // CHECK: !DILocalVariable(name: "x", arg: 1, scope: ![[SP]]{{.*}})
 // CHECK: !DILocalVariable(name: "arr", arg: 2, scope: ![[SP]]{{.*}})
 // CHECK: !DILocalVariable(name: "i", arg: 3, scope: ![[SP]]{{.*}})

mlir/test/Target/LLVMIR/omptarget-debug.mlir

@@ -10,7 +10,7 @@ module attributes {dlti.dl_spec = #dlti.dl_spec<#dlti.dl_entry<"dlti.alloca_memo
       %13 = llvm.mlir.constant(1 : i32) : i32
       llvm.store %13, %arg0 : i32, !llvm.ptr loc(#loc2)
       omp.terminator
-    }
+    } loc(#loc4)
     llvm.return
   } loc(#loc3)
 }
@@ -21,9 +21,13 @@ module attributes {dlti.dl_spec = #dlti.dl_spec<#dlti.dl_entry<"dlti.alloca_memo
 #sp_ty = #llvm.di_subroutine_type<callingConvention = DW_CC_normal>
 #sp = #llvm.di_subprogram<id = distinct[1]<>, compileUnit = #cu, scope = #file,
  name = "_QQmain", file = #file, subprogramFlags = "Definition", type = #sp_ty>
+#sp1 = #llvm.di_subprogram<id = distinct[2]<>, compileUnit = #cu, scope = #file,
+ name = "__omp_offloading_target", file = #file, subprogramFlags = "Definition",
+ type = #sp_ty>
 #loc1 = loc("target.f90":1:1)
 #loc2 = loc("target.f90":46:3)
 #loc3 = loc(fused<#sp>[#loc1])
+#loc4 = loc(fused<#sp1>[#loc1])
 
-// CHECK-DAG: ![[SP:.*]] = {{.*}}!DISubprogram(name: "__omp_offloading_{{.*}}"{{.*}})
+// CHECK-DAG: ![[SP:.*]] = {{.*}}!DISubprogram(name: "__omp_offloading_target"{{.*}})
 // CHECK-DAG: !DILocation(line: 46, column: 3, scope: ![[SP]])

mlir/test/Target/LLVMIR/omptarget-debug2.mlir

@@ -11,7 +11,7 @@ module attributes {omp.is_target_device = false} {
       %13 = llvm.mlir.constant(1 : i32) : i32
       llvm.store %13, %arg0 : i32, !llvm.ptr loc(#loc2)
       omp.terminator
-    }
+    }  loc(#loc4)
     llvm.return
   } loc(#loc3)
 }
@@ -22,9 +22,13 @@ module attributes {omp.is_target_device = false} {
 #sp_ty = #llvm.di_subroutine_type<callingConvention = DW_CC_normal>
 #sp = #llvm.di_subprogram<id = distinct[1]<>, compileUnit = #cu, scope = #file,
  name = "_QQmain", file = #file, subprogramFlags = "Definition", type = #sp_ty>
+#sp1 = #llvm.di_subprogram<id = distinct[2]<>, compileUnit = #cu, scope = #file,
+ name = "__omp_offloading_target", file = #file, subprogramFlags = "Definition",
+ type = #sp_ty>
 #loc1 = loc("target.f90":1:1)
 #loc2 = loc("target.f90":46:3)
 #loc3 = loc(fused<#sp>[#loc1])
+#loc4 = loc(fused<#sp1>[#loc1])
 
-// CHECK-DAG: ![[SP:.*]] = {{.*}}!DISubprogram(name: "__omp_offloading_{{.*}}"{{.*}})
+// CHECK-DAG: ![[SP:.*]] = {{.*}}!DISubprogram(name: "__omp_offloading_target"{{.*}})
 // CHECK-DAG: !DILocation(line: 46, column: 3, scope: ![[SP]])

mlir/test/Target/LLVMIR/omptarget-parallel-llvm-debug.mlir

@@ -6,8 +6,10 @@
 #cu = #llvm.di_compile_unit<id = distinct[0]<>, sourceLanguage = DW_LANG_Fortran95, file = #di_file, producer = "flang", isOptimized = false, emissionKind = Full>
 #sp_ty = #llvm.di_subroutine_type<callingConvention = DW_CC_program, types = #di_null_type>
 #sp = #llvm.di_subprogram<compileUnit = #cu, scope = #di_file, name = "test", file = #di_file, subprogramFlags = "Definition", type = #sp_ty>
+#sp1 = #llvm.di_subprogram<compileUnit = #cu, scope = #di_file, name = "kernel", file = #di_file, subprogramFlags = "Definition", type = #sp_ty>
 #int_ty = #llvm.di_basic_type<tag = DW_TAG_base_type, name = "integer", sizeInBits = 32, encoding = DW_ATE_signed>
 #var_x = #llvm.di_local_variable<scope = #sp, name = "x", file = #di_file, type = #int_ty>
+#var_x1 = #llvm.di_local_variable<scope = #sp1, name = "x", file = #di_file, type = #int_ty>
 module attributes {dlti.dl_spec = #dlti.dl_spec<i32 = dense<32> : vector<2xi64>, f16 = dense<16> : vector<2xi64>, f64 = dense<64> : vector<2xi64>, f128 = dense<128> : vector<2xi64>, i128 = dense<128> : vector<2xi64>, i64 = dense<64> : vector<2xi64>, f80 = dense<128> : vector<2xi64>, !llvm.ptr<272> = dense<64> : vector<4xi64>, !llvm.ptr<271> = dense<32> : vector<4xi64>, !llvm.ptr = dense<64> : vector<4xi64>, !llvm.ptr<270> = dense<32> : vector<4xi64>, i1 = dense<8> : vector<2xi64>, i8 = dense<8> : vector<2xi64>, i16 = dense<16> : vector<2xi64>, "dlti.endianness" = "little", "dlti.stack_alignment" = 128 : i64, "dlti.mangling_mode" = "e">, fir.defaultkind = "a1c4d8i4l4r4", fir.kindmap = "", fir.target_cpu = "x86-64", llvm.data_layout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128", llvm.ident = "flang version 21.0.0 (/home/haqadeer/work/src/aomp-llvm-project/flang 793f9220ab32f92fc3b253efec2e332c18090e53)", llvm.target_triple = "x86_64-unknown-linux-gnu", omp.is_gpu = false, omp.is_target_device = false, omp.requires = #omp<clause_requires none>, omp.target_triples = ["amdgcn-amd-amdhsa"], omp.version = #omp.version<version = 52>} {
   llvm.func @_QQmain() attributes {fir.bindc_name = "test", frame_pointer = #llvm.framePointerKind<all>, target_cpu = "x86-64"} {
     %0 = llvm.mlir.constant(1 : i64) : i64
@@ -16,20 +18,22 @@ module attributes {dlti.dl_spec = #dlti.dl_spec<i32 = dense<32> : vector<2xi64>,
     %5 = omp.map.info var_ptr(%1 : !llvm.ptr, i32) map_clauses(implicit, exit_release_or_enter_alloc) capture(ByCopy) -> !llvm.ptr {name = "x"}
     omp.target map_entries(%5 -> %arg0 : !llvm.ptr) {
       %6 = llvm.mlir.constant(1 : i32) : i32
-      llvm.intr.dbg.declare #var_x = %arg0 : !llvm.ptr loc(#loc2)
+      llvm.intr.dbg.declare #var_x1 = %arg0 : !llvm.ptr loc(#loc3)
       omp.parallel {
         %7 = llvm.load %arg0 : !llvm.ptr -> i32
         %8 = llvm.add %7, %6 : i32
         llvm.store %8, %arg0 : i32, !llvm.ptr
         omp.terminator
       }
       omp.terminator
-    }
+    } loc(#loc4)
     llvm.return
   } loc(#loc10)
 }
 #loc1 = loc("target.f90":1:7)
 #loc2 = loc("target.f90":3:18)
+#loc3 = loc("target.f90":6:18)
+#loc4 = loc(fused<#sp1>[#loc3])
 #loc10 = loc(fused<#sp>[#loc1])