[OpenMP]Fix PR51349: Remove AlwaysInline for if regions.

[jhuber6]

Summary

After D94315 we add the NoInline attribute to the outlined function to handle
data environments in the OpenMP if clause. This conflicted with the AlwaysInline
attribute added to the outlined function. for better performance in D106799.
The data environments should ideally not require NoInline, but for now this
fixes PR51349.

[mikerice]

Works for the test we have. What about a lit test for this?

[jhuber6]

Adding test

[mikerice]

LGTM.

clang/lib/CodeGen/CGOpenMPRuntime.cpp

auto &&ElseGen = [&M, OutlinedFn, CapturedVars, RTLoc, Loc,
     CGF.InitTempAlloca(ZeroAddrBound, CGF.Builder.getInt32(/*C*/ 0));
     llvm::SmallVector<llvm::Value *, 16> OutlinedFnArgs;
     // ThreadId for serialized parallels is 0.
     OutlinedFnArgs.push_back(ThreadIDAddr.getPointer());
     OutlinedFnArgs.push_back(ZeroAddrBound.getPointer());
     OutlinedFnArgs.append(CapturedVars.begin(), CapturedVars.end());
 
     // Ensure we do not inline the function. This is trivially true for the ones
-    // passed to __kmpc_fork_call but the ones calles in serialized regions
+    // passed to __kmpc_fork_call but the ones called in serialized regions
     // could be inlined. This is not a perfect but it is closer to the invariant
     // we want, namely, every data environment starts with a new function.
     // TODO: We should pass the if condition to the runtime function and do the
     //       handling there. Much cleaner code.
+    OutlinedFn->removeFnAttr(llvm::Attribute::AlwaysInline);
     OutlinedFn->addFnAttr(llvm::Attribute::NoInline);
     RT.emitOutlinedFunctionCall(CGF, Loc, OutlinedFn, OutlinedFnArgs);
 
     // __kmpc_end_serialized_parallel(&Loc, GTid);
     llvm::Value *EndArgs[] = {RT.emitUpdateLocation(CGF, Loc), ThreadID};
     CGF.EmitRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
                             M, OMPRTL___kmpc_end_serialized_parallel),
                         EndArgs);

clang/test/OpenMP/parallel_if_codegen_PR51349.cpp

+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --function-signature --check-attributes --include-generated-funcs
+// RUN: %clang_cc1 -x c++ -O1 -fopenmp-version=45 -disable-llvm-optzns -verify -fopenmp -triple x86_64-unknown-linux -emit-llvm %s -o - | FileCheck %s --check-prefix=CHECK
+// expected-no-diagnostics
+
+#ifndef HEADER
+#define HEADER
+
+void foo() {
+#pragma omp parallel if(0)
+  ;
+}
+
+#endif
+// CHECK: Function Attrs: mustprogress nounwind
+// CHECK-LABEL: define {{[^@]+}}@_Z3foov
+// CHECK-SAME: () #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[DOTTHREADID_TEMP_:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[DOTBOUND_ZERO_ADDR:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    store i32 0, i32* [[DOTBOUND_ZERO_ADDR]], align 4
+// CHECK-NEXT:    [[TMP0:%.*]] = call i32 @__kmpc_global_thread_num(%struct.ident_t* @[[GLOB1:[0-9]+]])
+// CHECK-NEXT:    call void @__kmpc_serialized_parallel(%struct.ident_t* @[[GLOB1]], i32 [[TMP0]])
+// CHECK-NEXT:    store i32 [[TMP0]], i32* [[DOTTHREADID_TEMP_]], align 4, !tbaa [[TBAA3:![0-9]+]]
+// CHECK-NEXT:    call void @.omp_outlined.(i32* [[DOTTHREADID_TEMP_]], i32* [[DOTBOUND_ZERO_ADDR]]) #[[ATTR2:[0-9]+]]
+// CHECK-NEXT:    call void @__kmpc_end_serialized_parallel(%struct.ident_t* @[[GLOB1]], i32 [[TMP0]])
+// CHECK-NEXT:    ret void
+//
+//
+// CHECK: Function Attrs: noinline norecurse nounwind
+// CHECK-LABEL: define {{[^@]+}}@.omp_outlined.
+// CHECK-SAME: (i32* noalias [[DOTGLOBAL_TID_:%.*]], i32* noalias [[DOTBOUND_TID_:%.*]]) #[[ATTR1:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[DOTGLOBAL_TID__ADDR:%.*]] = alloca i32*, align 8
+// CHECK-NEXT:    [[DOTBOUND_TID__ADDR:%.*]] = alloca i32*, align 8
+// CHECK-NEXT:    store i32* [[DOTGLOBAL_TID_]], i32** [[DOTGLOBAL_TID__ADDR]], align 8, !tbaa [[TBAA7:![0-9]+]]
+// CHECK-NEXT:    store i32* [[DOTBOUND_TID_]], i32** [[DOTBOUND_TID__ADDR]], align 8, !tbaa [[TBAA7]]
+// CHECK-NEXT:    ret void
+//