[llvm-branch-commits] [clang] 8d78ac2 - [OpenMP]Fix PR51349: Remove AlwaysInline for if regions.

[Tom Stellard via llvm-branch-commits]

Author: Joseph Huber
Date: 2021-09-17T20:48:53-07:00
New Revision: 8d78ac26f4752b140d47076bf6ba7dd73226784a

URL: https://github.com/llvm/llvm-project/commit/8d78ac26f4752b140d47076bf6ba7dd73226784a
DIFF: https://github.com/llvm/llvm-project/commit/8d78ac26f4752b140d47076bf6ba7dd73226784a.diff

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

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.

Reviewed By: mikerice

Differential Revision: https://reviews.llvm.org/D107649

(cherry picked from commit 41a6b50c25961addc04438b567ee1f4ef9e40f98)

Added: 
    clang/test/OpenMP/parallel_if_codegen_PR51349.cpp

Modified: 
    clang/lib/CodeGen/CGOpenMPRuntime.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index c09797e91b998..ca98c7a574465 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -2120,11 +2120,12 @@ void CGOpenMPRuntime::emitParallelCall(CodeGenFunction &CGF, SourceLocation Loc,
     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);
 

diff  --git a/clang/test/OpenMP/parallel_if_codegen_PR51349.cpp b/clang/test/OpenMP/parallel_if_codegen_PR51349.cpp
new file mode 100644
index 0000000000000..eee2c4fd38bc6
--- /dev/null
+++ b/clang/test/OpenMP/parallel_if_codegen_PR51349.cpp
@@ -0,0 +1,38 @@
+// 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
+//