r340056 - [HIP] Make __hip_gpubin_handle hidden to avoid being merged across different shared libraries

[Yaxun Liu via cfe-commits]

Author: yaxunl
Date: Fri Aug 17 10:47:31 2018
New Revision: 340056

URL: http://llvm.org/viewvc/llvm-project?rev=340056&view=rev
Log:
[HIP] Make __hip_gpubin_handle hidden to avoid being merged across different shared libraries

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

Modified:
    cfe/trunk/lib/CodeGen/CGCUDANV.cpp
    cfe/trunk/test/CodeGenCUDA/device-stub.cu

Modified: cfe/trunk/lib/CodeGen/CGCUDANV.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCUDANV.cpp?rev=340056&r1=340055&r2=340056&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCUDANV.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCUDANV.cpp Fri Aug 17 10:47:31 2018
@@ -459,6 +459,8 @@ llvm::Function *CGNVCUDARuntime::makeMod
         /*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()));

Modified: cfe/trunk/test/CodeGenCUDA/device-stub.cu
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCUDA/device-stub.cu?rev=340056&r1=340055&r2=340056&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCUDA/device-stub.cu (original)
+++ cfe/trunk/test/CodeGenCUDA/device-stub.cu Fri Aug 17 10:47:31 2018
@@ -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