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[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
This commit is contained in:
Yaxun (Sam) Liu 2020-09-22 12:52:07 -04:00
parent bd72ed93d2
commit 301e23305d
2 changed files with 14 additions and 0 deletions
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5
clang/lib/CodeGen/CodeGenModule.cpp
View File

@ -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;

9
clang/test/CodeGenCUDA/static-device-var-no-rdc.cu
View File

@ -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