[Offload] Make AMDGPU plugin handle empty allocation properly

[jhuber6]

Summary:
malloc(0) and free(nullptr) are both defined by the standard but we
current trigger erros and assertions on them. Fix that so this works
with empty arguments.

[llvmbot]

@llvm/pr-subscribers-backend-amdgpu

@llvm/pr-subscribers-offload

Author: Joseph Huber (jhuber6)

Changes

Summary:
malloc(0) and free(nullptr) are both defined by the standard but we
current trigger erros and assertions on them. Fix that so this works
with empty arguments.

---

Full diff: https://github.com/llvm/llvm-project/pull/142383.diff

1 Files Affected:

• (modified) offload/plugins-nextgen/amdgpu/src/rtl.cpp (+1-4)

diff --git a/offload/plugins-nextgen/amdgpu/src/rtl.cpp b/offload/plugins-nextgen/amdgpu/src/rtl.cpp
index 2733796611d9b..abb83686151a2 100644
--- a/offload/plugins-nextgen/amdgpu/src/rtl.cpp
+++ b/offload/plugins-nextgen/amdgpu/src/rtl.cpp
@@ -420,7 +420,7 @@ struct AMDGPUMemoryManagerTy : public DeviceAllocatorTy {
     assert(PtrStorage && "Invalid pointer storage");
 
     *PtrStorage = MemoryManager->allocate(Size, nullptr);
-    if (*PtrStorage == nullptr)
+    if (Size && *PtrStorage == nullptr)
       return Plugin::error(ErrorCode::OUT_OF_RESOURCES,
                            "failure to allocate from AMDGPU memory manager");
 
@@ -429,8 +429,6 @@ struct AMDGPUMemoryManagerTy : public DeviceAllocatorTy {
 
   /// Release an allocation to be reused.
   Error deallocate(void *Ptr) {
-    assert(Ptr && "Invalid pointer");
-
     if (MemoryManager->free(Ptr))
       return Plugin::error(ErrorCode::UNKNOWN,
                            "failure to deallocate from AMDGPU memory manager");
@@ -1204,7 +1202,6 @@ struct AMDGPUStreamTy {
     ReleaseBufferArgsTy *Args = reinterpret_cast<ReleaseBufferArgsTy *>(Data);
     assert(Args && "Invalid arguments");
     assert(Args->MemoryManager && "Invalid memory manager");
-    assert(Args->Buffer && "Invalid buffer");
 
     // Release the allocation to the memory manager.
     return Args->MemoryManager->deallocate(Args->Buffer);

[github-actions]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff HEAD~1 HEAD --extensions cpp,c -- offload/plugins-nextgen/amdgpu/src/rtl.cpp offload/test/api/omp_device_memory.c

View the diff from clang-format here.

diff --git a/offload/test/api/omp_device_memory.c b/offload/test/api/omp_device_memory.c
index 8876fc91b..efac80df2 100644
--- a/offload/test/api/omp_device_memory.c
+++ b/offload/test/api/omp_device_memory.c
@@ -1,8 +1,8 @@
 // RUN: %libomptarget-compile-run-and-check-generic
 
+#include <assert.h>
 #include <omp.h>
 #include <stdio.h>
-#include <assert.h>
 
 int main() {
   const int N = 64;