[OpenMP][FIX] Consistently use OpenMPIRBuilder if requested

When we use the OpenMPIRBuilder for the parallel region we need to also
use it to get the thread ID (among other things) in the body. This is
because CGOpenMPRuntime::getThreadID() and
CGOpenMPRuntime::emitUpdateLocation implicitly assumes that if they are
called from within a parallel region there is a certain structure to the
code and certain members of the OMPRegionInfo are initialized. It might
make sense to initialize them even if we use the OpenMPIRBuilder but we
would preferably get rid of such state instead.

Bug reported by Anchu Rajendran Sudhakumari.

Depends on D82470.

Reviewed By: anchu-rajendran

Differential Revision: https://reviews.llvm.org/D82822

clang/lib/CodeGen/CGOpenMPRuntime.cpp

@@ -1455,6 +1455,19 @@ void CGOpenMPRuntime::clearLocThreadIdInsertPt(CodeGenFunction &CGF) {
   }
 }
 
+static StringRef getIdentStringFromSourceLocation(CodeGenFunction &CGF,
+                                                  SourceLocation Loc,
+                                                  SmallString<128> &Buffer) {
+  llvm::raw_svector_ostream OS(Buffer);
+  // Build debug location
+  PresumedLoc PLoc = CGF.getContext().getSourceManager().getPresumedLoc(Loc);
+  OS << ";" << PLoc.getFilename() << ";";
+  if (const auto *FD = dyn_cast_or_null<FunctionDecl>(CGF.CurFuncDecl))
+    OS << FD->getQualifiedNameAsString();
+  OS << ";" << PLoc.getLine() << ";" << PLoc.getColumn() << ";;";
+  return OS.str();
+}
+
 llvm::Value *CGOpenMPRuntime::emitUpdateLocation(CodeGenFunction &CGF,
                                                  SourceLocation Loc,
                                                  unsigned Flags) {
@@ -1464,6 +1477,16 @@ llvm::Value *CGOpenMPRuntime::emitUpdateLocation(CodeGenFunction &CGF,
       Loc.isInvalid())
     return getOrCreateDefaultLocation(Flags).getPointer();
 
+  // If the OpenMPIRBuilder is used we need to use it for all location handling
+  // as the clang invariants used below might be broken.
+  if (CGM.getLangOpts().OpenMPIRBuilder) {
+    SmallString<128> Buffer;
+    OMPBuilder.updateToLocation(CGF.Builder.saveIP());
+    auto *SrcLocStr = OMPBuilder.getOrCreateSrcLocStr(
+        getIdentStringFromSourceLocation(CGF, Loc, Buffer));
+    return OMPBuilder.getOrCreateIdent(SrcLocStr, IdentFlag(Flags));
+  }
+
   assert(CGF.CurFn && "No function in current CodeGenFunction.");
 
   CharUnits Align = CGM.getContext().getTypeAlignInChars(IdentQTy);
@@ -1497,15 +1520,9 @@ llvm::Value *CGOpenMPRuntime::emitUpdateLocation(CodeGenFunction &CGF,
 
   llvm::Value *OMPDebugLoc = OpenMPDebugLocMap.lookup(Loc.getRawEncoding());
   if (OMPDebugLoc == nullptr) {
-    SmallString<128> Buffer2;
-    llvm::raw_svector_ostream OS2(Buffer2);
-    // Build debug location
-    PresumedLoc PLoc = CGF.getContext().getSourceManager().getPresumedLoc(Loc);
-    OS2 << ";" << PLoc.getFilename() << ";";
-    if (const auto *FD = dyn_cast_or_null<FunctionDecl>(CGF.CurFuncDecl))
-      OS2 << FD->getQualifiedNameAsString();
-    OS2 << ";" << PLoc.getLine() << ";" << PLoc.getColumn() << ";;";
-    OMPDebugLoc = CGF.Builder.CreateGlobalStringPtr(OS2.str());
+    SmallString<128> Buffer;
+    OMPDebugLoc = CGF.Builder.CreateGlobalStringPtr(
+        getIdentStringFromSourceLocation(CGF, Loc, Buffer));
     OpenMPDebugLocMap[Loc.getRawEncoding()] = OMPDebugLoc;
   }
   // *psource = ";<File>;<Function>;<Line>;<Column>;;";
@@ -1519,6 +1536,16 @@ llvm::Value *CGOpenMPRuntime::emitUpdateLocation(CodeGenFunction &CGF,
 llvm::Value *CGOpenMPRuntime::getThreadID(CodeGenFunction &CGF,
                                           SourceLocation Loc) {
   assert(CGF.CurFn && "No function in current CodeGenFunction.");
+  // If the OpenMPIRBuilder is used we need to use it for all thread id calls as
+  // the clang invariants used below might be broken.
+  if (CGM.getLangOpts().OpenMPIRBuilder) {
+    SmallString<128> Buffer;
+    OMPBuilder.updateToLocation(CGF.Builder.saveIP());
+    auto *SrcLocStr = OMPBuilder.getOrCreateSrcLocStr(
+        getIdentStringFromSourceLocation(CGF, Loc, Buffer));
+    return OMPBuilder.getOrCreateThreadID(
+        OMPBuilder.getOrCreateIdent(SrcLocStr));
+  }
 
   llvm::Value *ThreadID = nullptr;
   // Check whether we've already cached a load of the thread id in this

clang/test/OpenMP/cancel_codegen.cpp

@@ -16,7 +16,6 @@
 
 float flag;
 int main (int argc, char **argv) {
-// ALL: [[GTID:%.+]] = call i32 @__kmpc_global_thread_num(
 #pragma omp parallel
 {
 #pragma omp cancel parallel if(flag)
@@ -42,14 +41,14 @@ int main (int argc, char **argv) {
   }
 }
 // ALL: call void @__kmpc_for_static_init_4(
-// ALL: [[RES:%.+]] = call i32 @__kmpc_cancel(%struct.ident_t* {{[^,]+}}, i32 [[GTID]], i32 3)
+// ALL: [[RES:%.+]] = call i32 @__kmpc_cancel(%struct.ident_t* {{[^,]+}}, i32 [[GTID:%.*]], i32 3)
 // ALL: [[CMP:%.+]] = icmp ne i32 [[RES]], 0
 // ALL: br i1 [[CMP]], label %[[EXIT:[^,].+]], label %[[CONTINUE:.+]]
 // ALL: [[EXIT]]
 // ALL: br label
 // ALL: [[CONTINUE]]
 // ALL: br label
-// ALL: [[RES:%.+]] = call i32 @__kmpc_cancel(%struct.ident_t* {{[^,]+}}, i32 [[GTID]], i32 3)
+// ALL: [[RES:%.+]] = call i32 @__kmpc_cancel(%struct.ident_t* {{[^,]+}}, i32 [[GTID:%.*]], i32 3)
 // ALL: [[CMP:%.+]] = icmp ne i32 [[RES]], 0
 // ALL: br i1 [[CMP]], label %[[EXIT:[^,].+]], label %[[CONTINUE:.+]]
 // ALL: [[EXIT]]
@@ -66,7 +65,7 @@ for (int i = 0; i < argc; ++i) {
 // ALL: [[BOOL:%.+]] = fcmp une float [[FLAG]], 0.000000e+00
 // ALL: br i1 [[BOOL]], label %[[THEN:[^,]+]], label %[[ELSE:[^,]+]]
 // ALL: [[THEN]]
-// ALL: [[RES:%.+]] = call i32 @__kmpc_cancel(%struct.ident_t* {{[^,]+}}, i32 [[GTID]], i32 2)
+// ALL: [[RES:%.+]] = call i32 @__kmpc_cancel(%struct.ident_t* {{[^,]+}}, i32 [[GTID:%.*]], i32 2)
 // ALL: [[CMP:%.+]] = icmp ne i32 [[RES]], 0
 // ALL: br i1 [[CMP]], label %[[EXIT:[^,].+]], label %[[CONTINUE:.+]]
 // ALL: [[EXIT]]
@@ -148,7 +147,7 @@ for (int i = 0; i < argc; ++i) {
 // CHECK: br label
 // CHECK: [[CONTINUE]]
 // CHECK: br label
-// CHECK: [[RES:%.+]] = call i32 @__kmpc_cancel(%struct.ident_t* {{[^,]+}}, i32 [[GTID]], i32 3)
+// CHECK: [[RES:%.+]] = call i32 @__kmpc_cancel(%struct.ident_t* {{[^,]+}}, i32 [[GTID:%.*]], i32 3)
 // CHECK: [[CMP:%.+]] = icmp ne i32 [[RES]], 0
 // CHECK: br i1 [[CMP]], label %[[EXIT:[^,].+]], label %[[CONTINUE:.+]]
 // CHECK: [[EXIT]]