Commit fca49fe8 authored by George Rokos's avatar George Rokos
Browse files

[clang-offload-wrapper] Lower priority of __tgt_register_lib in favor of __tgt_register_requires 

Lower priority of __tgt_register_lib in order to make sure that __tgt_register_requires is called before loading a libomptarget plugin.
We want to know beforehand which requirements the user has asked for so that upon loading the plugin libomptarget can report how many devices there are that can satisfy these requirements.

Differential Revision: https://reviews.llvm.org/D75223
parent 8fc3e5c4

clang/test/Driver/clang-offload-wrapper.c

+2 −2
Original line number Diff line number Diff line
@@ -39,8 +39,8 @@ 


// CHECK-IR: [[DESC:@.+]] = internal constant [[DESCTY]] { i32 1, [[IMAGETY]]* getelementptr inbounds ([1 x [[IMAGETY]]], [1 x [[IMAGETY]]]* [[IMAGES]], i64 0, i64 0), [[ENTTY]]* [[ENTBEGIN]], [[ENTTY]]* [[ENTEND]] }



// CHECK-IR: @llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 0, void ()* [[REGFN:@.+]], i8* null }]

// CHECK-IR: @llvm.global_dtors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 0, void ()* [[UNREGFN:@.+]], i8* null }]

// CHECK-IR: @llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 1, void ()* [[REGFN:@.+]], i8* null }]

// CHECK-IR: @llvm.global_dtors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 1, void ()* [[UNREGFN:@.+]], i8* null }]



// CHECK-IR: define internal void [[REGFN]]()

// CHECK-IR:   call void @__tgt_register_lib([[DESCTY]]* [[DESC]])

clang/tools/clang-offload-wrapper/ClangOffloadWrapper.cpp

+8 −2
Original line number Diff line number Diff line
@@ -262,7 +262,12 @@ private: 
    Builder.CreateRetVoid();



    // Add this function to constructors.

    appendToGlobalCtors(M, Func, 0);

    // Set priority to 1 so that __tgt_register_lib is executed AFTER

    // __tgt_register_requires (we want to know what requirements have been

    // asked for before we load a libomptarget plugin so that by the time the

    // plugin is loaded it can report how many devices there are which can

    // satisfy these requirements).

    appendToGlobalCtors(M, Func, /*Priority*/ 1);

  }



  void createUnregisterFunction(GlobalVariable *BinDesc) {
@@ -283,7 +288,8 @@ private: 
    Builder.CreateRetVoid();



    // Add this function to global destructors.

    appendToGlobalDtors(M, Func, 0);

    // Match priority of __tgt_register_lib

    appendToGlobalDtors(M, Func, /*Priority*/ 1);

  }



public: