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[OpenMP] Prevent AMDGPU from overriding visibility on DT_nohost variables #68264

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Merged
merged 1 commit into from
Oct 5, 2023
Merged

[OpenMP] Prevent AMDGPU from overriding visibility on DT_nohost variables #68264

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13 changes: 13 additions & 0 deletions clang/lib/CodeGen/CodeGenModule.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1390,6 +1390,19 @@ void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
}
if (!D)
return;

// OpenMP declare target variables must be visible to the host so they can
// be registered. We require protected visibility unless the variable has
// the DT_nohost modifier and does not need to be registered.
if (Context.getLangOpts().OpenMP &&
Context.getLangOpts().OpenMPIsTargetDevice && isa<VarDecl>(D) &&
D->hasAttr<OMPDeclareTargetDeclAttr>() &&
D->getAttr<OMPDeclareTargetDeclAttr>()->getDevType() !=
OMPDeclareTargetDeclAttr::DT_NoHost) {
GV->setVisibility(llvm::GlobalValue::ProtectedVisibility);
return;
}

// Set visibility for definitions, and for declarations if requested globally
// or set explicitly.
LinkageInfo LV = D->getLinkageAndVisibility();
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13 changes: 7 additions & 6 deletions clang/lib/CodeGen/Targets/AMDGPU.cpp
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Expand Up @@ -308,12 +308,13 @@ static bool requiresAMDGPUProtectedVisibility(const Decl *D,
if (GV->getVisibility() != llvm::GlobalValue::HiddenVisibility)
return false;

return D->hasAttr<OpenCLKernelAttr>() ||
(isa<FunctionDecl>(D) && D->hasAttr<CUDAGlobalAttr>()) ||
(isa<VarDecl>(D) &&
(D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
cast<VarDecl>(D)->getType()->isCUDADeviceBuiltinSurfaceType() ||
cast<VarDecl>(D)->getType()->isCUDADeviceBuiltinTextureType()));
return !D->hasAttr<OMPDeclareTargetDeclAttr>() &&
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is this a spurious whitespace change?

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Not here, above there's an extra line. I'll fix that before I land, not worth force pushing.

(D->hasAttr<OpenCLKernelAttr>() ||
(isa<FunctionDecl>(D) && D->hasAttr<CUDAGlobalAttr>()) ||
(isa<VarDecl>(D) &&
(D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
cast<VarDecl>(D)->getType()->isCUDADeviceBuiltinSurfaceType() ||
cast<VarDecl>(D)->getType()->isCUDADeviceBuiltinTextureType())));
}

void AMDGPUTargetCodeGenInfo::setFunctionDeclAttributes(
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2 changes: 1 addition & 1 deletion clang/test/OpenMP/declare_target_codegen.cpp
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Expand Up @@ -31,7 +31,7 @@
// CHECK-DAG: @dy = {{protected | }}global i32 0,
// CHECK-DAG: @bbb = {{protected | }}global i32 0,
// CHECK-DAG: weak constant %struct.__tgt_offload_entry { ptr @bbb,
// CHECK-DAG: @ccc = external global i32,
// CHECK-DAG: @ccc = external {{protected | }}global i32,
// CHECK-DAG: @ddd = {{protected | }}global i32 0,
// CHECK-DAG: @hhh_decl_tgt_ref_ptr = weak global ptr null
// CHECK-DAG: @ggg_decl_tgt_ref_ptr = weak global ptr null
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2 changes: 1 addition & 1 deletion clang/test/OpenMP/declare_target_constexpr_codegen.cpp
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Expand Up @@ -16,7 +16,7 @@ class A {
public:
static constexpr double pi = 3.141592653589793116;
//.
// CHECK: @_ZN1A2piE = linkonce_odr constant double 0x400921FB54442D18, comdat, align 8
// CHECK: @_ZN1A2piE = linkonce_odr protected constant double 0x400921FB54442D18, comdat, align 8
// CHECK: @_ZL9anotherPi = internal constant double 3.140000e+00, align 8
// CHECK: @llvm.compiler.used = appending global [2 x ptr] [ptr @"__ZN1A2piE$ref", ptr @"__ZL9anotherPi$ref"], section "llvm.metadata"
//.
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10 changes: 9 additions & 1 deletion clang/test/OpenMP/target_visibility.cpp
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@@ -1,5 +1,5 @@
// RUN: %clang_cc1 -debug-info-kind=limited -verify -fopenmp -x c++ -triple nvptx64-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -emit-llvm %s -fopenmp-is-target-device -o - | FileCheck %s
// RUN: %clang_cc1 -debug-info-kind=limited -verify -fopenmp -x c++ -triple nvptx-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda -emit-llvm %s -fopenmp-is-target-device -o - | FileCheck %s
// RUN: %clang_cc1 -debug-info-kind=limited -verify -fopenmp -x c++ -triple amdgcn-amd-amdhsa -fopenmp-targets=amdgcn-amd-amdhsa -emit-llvm %s -fopenmp-is-target-device -o - | FileCheck %s
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maybe it is safer to have tests for both amdgcn and nvptx since they behave differently

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I just added --check-prefixes=CHECK,AMDGPU for the differences. Figured it's not worth making a new test just for this.

// expected-no-diagnostics


Expand All @@ -21,6 +21,14 @@ void B::bar() { A a; a.foo(); }
void B::sbar() { A::sfoo(); }
#pragma omp declare target to(B::bar, B::sbar)

[[gnu::visibility("hidden")]] extern const int x = 0;
#pragma omp declare target to(x) device_type(nohost)

[[gnu::visibility("hidden")]] int y = 0;
#pragma omp declare target to(y)

// CHECK-DAG: @x = hidden{{.*}} constant i32 0
// CHECK-DAG: @y = protected{{.*}} i32 0
// CHECK-DAG: define hidden void @_ZN1B4sbarEv()
// CHECK-DAG: define linkonce_odr hidden void @_ZN1A4sfooEv()
// CHECK-DAG: define hidden void @_ZN1B3barEv(
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