From 301e23305d03cfb4004f845a1d9dfdc5e5931fd8 Mon Sep 17 00:00:00 2001 From: "Yaxun (Sam) Liu" Date: Tue, 22 Sep 2020 12:52:07 -0400 Subject: [PATCH] [CUDA][HIP] Fix static device var used by host code only A static device variable may be accessed in host code through cudaMemCpyFromSymbol etc. Currently clang does not emit the static device variable if it is only referenced by host code, which causes host code to fail at run time. This patch fixes that. Differential Revision: https://reviews.llvm.org/D88115 --- clang/lib/CodeGen/CodeGenModule.cpp | 5 +++++ clang/test/CodeGenCUDA/static-device-var-no-rdc.cu | 9 +++++++++ 2 files changed, 14 insertions(+) diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp index 3ecc874..6a77f6b 100644 --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -2195,6 +2195,11 @@ void CodeGenModule::EmitDeferred() { assert(DeferredVTables.empty()); } + // Emit CUDA/HIP static device variables referenced by host code only. + if (getLangOpts().CUDA) + for (auto V : getContext().CUDAStaticDeviceVarReferencedByHost) + DeferredDeclsToEmit.push_back(V); + // Stop if we're out of both deferred vtables and deferred declarations. if (DeferredDeclsToEmit.empty()) return; diff --git a/clang/test/CodeGenCUDA/static-device-var-no-rdc.cu b/clang/test/CodeGenCUDA/static-device-var-no-rdc.cu index c7beb4c..9cb1c68 100644 --- a/clang/test/CodeGenCUDA/static-device-var-no-rdc.cu +++ b/clang/test/CodeGenCUDA/static-device-var-no-rdc.cu @@ -63,6 +63,13 @@ static constexpr int z2 = 456; // externalized nor registered. // DEV-DAG: @_ZZ6devfunPPKiE1p = linkonce_odr addrspace(4) constant i32 2, comdat +// Check a static device variable referenced by host function only is externalized. +// DEV-DAG: @_ZL1w = addrspace(1) externally_initialized global i32 0 +// HOST-DAG: @_ZL1w = internal global i32 undef +// HOST-DAG: @[[DEVNAMEW:[0-9]+]] = {{.*}}c"_ZL1w\00" + +static __device__ int w; + inline __device__ void devfun(const int ** b) { const static int p = 2; b[0] = &p; @@ -92,11 +99,13 @@ void foo(const int **a) { getDeviceSymbol(&x); getDeviceSymbol(&x5); getDeviceSymbol(&y); + getDeviceSymbol(&w); z = 123; a[0] = &z2; } // HOST: __hipRegisterVar({{.*}}@_ZL1x {{.*}}@[[DEVNAMEX]] // HOST: __hipRegisterVar({{.*}}@_ZL1y {{.*}}@[[DEVNAMEY]] +// HOST: __hipRegisterVar({{.*}}@_ZL1w {{.*}}@[[DEVNAMEW]] // HOST-NOT: __hipRegisterVar({{.*}}@_ZZ6kernelPiPPKiE1w // HOST-NOT: __hipRegisterVar({{.*}}@_ZZ6devfunPPKiE1p -- 2.7.4