[DebugInfo] Continue fixing translation of debug info for mem2reged vars

lib/SPIRV/libSPIRV/SPIRVBasicBlock.cpp

@@ -90,12 +90,32 @@ _SPIRV_IMP_ENCDEC1(SPIRVBasicBlock, Id)
 SPIRVInstruction *SPIRVBasicBlock::getVariableInsertionPoint() const {
   auto IP =
       std::find_if(InstVec.begin(), InstVec.end(), [](SPIRVInstruction *Inst) {
-        return !(isa<OpVariable>(Inst) || isa<OpLine>(Inst) ||
-                 isa<OpNoLine>(Inst) ||
-                 // Note: OpVariable and OpPhi instructions do not belong to the
-                 // same block in a valid SPIR-V module.
-                 isa<OpPhi>(Inst) || isa<OpUntypedVariableKHR>(Inst));
+        if (isa<OpVariable>(Inst) || isa<OpLine>(Inst) || isa<OpNoLine>(Inst) ||
+            // Note: OpVariable and OpPhi instructions do not belong to the
+            // same block in a valid SPIR-V module.
+            isa<OpPhi>(Inst) || isa<OpUntypedVariableKHR>(Inst)) {
+          return false;
+        }
+        // There are debug instructions that could describe OpVariable - they
+        // can be in the first block in the function as well.
+        if (Inst->isExtInst()) {
+          const SPIRVExtInst *EI = static_cast<const SPIRVExtInst *>(Inst);
+          auto ExtSetKind = EI->getExtSetKind();
+          auto ExtOp = EI->getExtOp();
+          if ((ExtSetKind == SPIRVEIS_Debug ||
+               ExtSetKind == SPIRVEIS_OpenCL_DebugInfo_100 ||
+               ExtSetKind == SPIRVEIS_NonSemantic_Shader_DebugInfo_100 ||
+               ExtSetKind == SPIRVEIS_NonSemantic_Shader_DebugInfo_200) &&
+              (ExtOp == SPIRVDebug::Declare || ExtOp == SPIRVDebug::Value ||
+               ExtOp == SPIRVDebug::Scope || ExtOp == SPIRVDebug::NoScope ||
+               ExtOp == SPIRVDebug::DebugLine ||
+               ExtOp == SPIRVDebug::DebugNoLine)) {
+            return false;
+          }
+        }
+        return true;
       });
+
   if (IP == InstVec.end())
     return nullptr;
   return *IP;

test/DebugInfo/mem2reged_local_var_func_start.ll

@@ -0,0 +1,44 @@
+; Check if the translator handles #dbg_declare(ptr null ...) correctly:
+; does not get placed after OpVariable, so that the following instructions 
+; do not inherit the debug location (scope and line) from #dbg_declare.
+
+; RUN: llvm-as %s -o %t.bc
+; RUN: llvm-spirv %t.bc -o %t.spv
+; RUN: llvm-spirv -r %t.spv -o - | llvm-dis -o - | FileCheck %s --check-prefix=CHECK-LLVM
+
+; RUN: llvm-spirv %t.bc -o %t.spv --spirv-debug-info-version=nonsemantic-shader-100
+; RUN: llvm-spirv -r %t.spv -o - | llvm-dis -o - | FileCheck %s --check-prefix=CHECK-LLVM
+
+; RUN: llvm-spirv %t.bc -o %t.spv --spirv-debug-info-version=nonsemantic-shader-200
+; RUN: llvm-spirv -r %t.spv -o - | llvm-dis -o - | FileCheck %s --check-prefix=CHECK-LLVM
+
+; CHECK-LLVM-NOT: , !dbg
+; CHECK-LLVM: #dbg_declare(ptr null, ![[#LocalVar:]], !DIExpression(), ![[#Loc:]])
+; CHECK-LLVM-NOT: , !dbg ![[#Loc]]
+; CHECK-LLVM-DAG: ![[#LocalVar]] = !DILocalVariable(name: "total"
+; CHECK-LLVM-DAG: ![[#Loc]] = !DILocation(line: 23
+
+; ModuleID = 'reduced.bc'
+target datalayout = "e-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-n8:16:32:64-G1"
+target triple = "spir64"
+
+define spir_func i32 @first_(ptr addrspace(4) %"first_$NUM1$argptr", ptr %"first_$NUM1$locptr") {
+entry:
+    #dbg_declare(ptr null, !4, !DIExpression(), !8)
+  %"first_$NUM1$locptr1" = alloca ptr addrspace(4), align 8
+  store ptr addrspace(4) %"first_$NUM1$argptr", ptr %"first_$NUM1$locptr", align 8
+  ret i32 0
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_Fortran95, file: !1, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, globals: !2, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "test.f90", directory: "/path/to")
+!2 = !{}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !DILocalVariable(name: "total", scope: !5, file: !1, line: 23, type: !7)
+!5 = distinct !DISubprogram(name: "first", linkageName: "first_", scope: !1, file: !1, line: 23, type: !6, scopeLine: 23, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
+!6 = distinct !DISubroutineType(types: !2)
+!7 = !DIBasicType(name: "INTEGER*4", size: 32, encoding: DW_ATE_signed)
+!8 = !DILocation(line: 23, column: 36, scope: !5)