[HIP] Make __hip_gpubin_handle hidden to avoid being merged across different shared...

Different shared libraries contain different fat binary, which is stored in a global variable
__hip_gpubin_handle. Since different compilation units share the same fat binary, this
variable has linkonce linkage. However, it should not be merged across different shared
libraries.

This patch set the visibility of the global variable to be hidden, which will make it invisible
in the shared library, therefore preventing it from being merged.

Differential Revision: https://reviews.llvm.org/D50596

llvm-svn: 340056

diff --git a/clang/lib/CodeGen/CGCUDANV.cpp b/clang/lib/CodeGen/CGCUDANV.cpp
index 5fcc9e0..3f3f2c5 100644 (file)
--- a/clang/lib/CodeGen/CGCUDANV.cpp
+++ b/clang/lib/CodeGen/CGCUDANV.cpp
@@ -459,6 +459,8 @@ llvm::Function *CGNVCUDARuntime::makeModuleCtorFunction() {
         /*Initializer=*/llvm::ConstantPointerNull::get(VoidPtrPtrTy),
         "__hip_gpubin_handle");
     GpuBinaryHandle->setAlignment(CGM.getPointerAlign().getQuantity());
+    // Prevent the weak symbol in different shared libraries being merged.
+    GpuBinaryHandle->setVisibility(llvm::GlobalValue::HiddenVisibility);
     Address GpuBinaryAddr(
         GpuBinaryHandle,
         CharUnits::fromQuantity(GpuBinaryHandle->getAlignment()));

diff --git a/clang/test/CodeGenCUDA/device-stub.cu b/clang/test/CodeGenCUDA/device-stub.cu
index 716381b..06877da 100644 (file)
--- a/clang/test/CodeGenCUDA/device-stub.cu
+++ b/clang/test/CodeGenCUDA/device-stub.cu
@@ -80,7 +80,7 @@ void use_pointers() {
 // HIP-SAME: section ".hipFatBinSegment"
 // * variable to save GPU binary handle after initialization
 // CUDANORDC: @__[[PREFIX]]_gpubin_handle = internal global i8** null
-// HIP: @__[[PREFIX]]_gpubin_handle = linkonce global i8** null
+// HIP: @__[[PREFIX]]_gpubin_handle = linkonce hidden global i8** null
 // * constant unnamed string with NVModuleID
 // RDC: [[MODULE_ID_GLOBAL:@.*]] = private constant
 // CUDARDC-SAME: c"[[MODULE_ID:.+]]\00", section "__nv_module_id", align 32