[libc-commits] [libc] [openmp] Revert "[libomptarget][nextgen-plugin] Use SCRELEASE/SCACQUIRE in packet headers" (PR #85950)

[via libc-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libc

Author: Gheorghe-Teodor Bercea (doru1004)

<details>
<summary>Changes</summary>

Reverts llvm/llvm-project#<!-- -->85678

---
Full diff: https://github.com/llvm/llvm-project/pull/85950.diff


2 Files Affected:

- (modified) libc/utils/gpu/loader/amdgpu/Loader.cpp (+1-2) 
- (modified) openmp/libomptarget/plugins-nextgen/amdgpu/src/rtl.cpp (+11-12) 


``````````diff
diff --git a/libc/utils/gpu/loader/amdgpu/Loader.cpp b/libc/utils/gpu/loader/amdgpu/Loader.cpp
index 7fd45acfd47e97..e3911eda2bd82a 100644
--- a/libc/utils/gpu/loader/amdgpu/Loader.cpp
+++ b/libc/utils/gpu/loader/amdgpu/Loader.cpp
@@ -276,8 +276,7 @@ hsa_status_t launch_kernel(hsa_agent_t dev_agent, hsa_executable_t executable,
       (HSA_FENCE_SCOPE_SYSTEM << HSA_PACKET_HEADER_SCACQUIRE_FENCE_SCOPE) |
       (HSA_FENCE_SCOPE_SYSTEM << HSA_PACKET_HEADER_SCRELEASE_FENCE_SCOPE);
   uint32_t header_word = header | (setup << 16u);
-  __atomic_store_n(reinterpret_cast<uint32_t *>(packet), header_word,
-                   __ATOMIC_RELEASE);
+  __atomic_store_n((uint32_t *)&packet->header, header_word, __ATOMIC_RELEASE);
   hsa_signal_store_relaxed(queue->doorbell_signal, packet_id);
 
   // Wait until the kernel has completed execution on the device. Periodically
diff --git a/openmp/libomptarget/plugins-nextgen/amdgpu/src/rtl.cpp b/openmp/libomptarget/plugins-nextgen/amdgpu/src/rtl.cpp
index c147cefe58e9b4..fce7454bf2800d 100644
--- a/openmp/libomptarget/plugins-nextgen/amdgpu/src/rtl.cpp
+++ b/openmp/libomptarget/plugins-nextgen/amdgpu/src/rtl.cpp
@@ -826,15 +826,15 @@ struct AMDGPUQueueTy {
   /// Assumes the queue lock is acquired.
   void publishKernelPacket(uint64_t PacketId, uint16_t Setup,
                            hsa_kernel_dispatch_packet_t *Packet) {
-    uint16_t Header =
-        (HSA_PACKET_TYPE_KERNEL_DISPATCH << HSA_PACKET_HEADER_TYPE) |
-        (HSA_FENCE_SCOPE_SYSTEM << HSA_PACKET_HEADER_SCACQUIRE_FENCE_SCOPE) |
-        (HSA_FENCE_SCOPE_SYSTEM << HSA_PACKET_HEADER_SCRELEASE_FENCE_SCOPE);
+    uint32_t *PacketPtr = reinterpret_cast<uint32_t *>(Packet);
+
+    uint16_t Header = HSA_PACKET_TYPE_KERNEL_DISPATCH << HSA_PACKET_HEADER_TYPE;
+    Header |= HSA_FENCE_SCOPE_SYSTEM << HSA_PACKET_HEADER_ACQUIRE_FENCE_SCOPE;
+    Header |= HSA_FENCE_SCOPE_SYSTEM << HSA_PACKET_HEADER_RELEASE_FENCE_SCOPE;
 
     // Publish the packet. Do not modify the package after this point.
     uint32_t HeaderWord = Header | (Setup << 16u);
-    __atomic_store_n(reinterpret_cast<uint32_t *>(Packet), HeaderWord,
-                     __ATOMIC_RELEASE);
+    __atomic_store_n(PacketPtr, HeaderWord, __ATOMIC_RELEASE);
 
     // Signal the doorbell about the published packet.
     hsa_signal_store_relaxed(Queue->doorbell_signal, PacketId);
@@ -845,16 +845,15 @@ struct AMDGPUQueueTy {
   /// barrier dependencies (signals) are satisfied. Assumes the queue is locked
   void publishBarrierPacket(uint64_t PacketId,
                             hsa_barrier_and_packet_t *Packet) {
+    uint32_t *PacketPtr = reinterpret_cast<uint32_t *>(Packet);
     uint16_t Setup = 0;
-    uint16_t Header =
-        (HSA_PACKET_TYPE_BARRIER_AND << HSA_PACKET_HEADER_TYPE) |
-        (HSA_FENCE_SCOPE_SYSTEM << HSA_PACKET_HEADER_SCACQUIRE_FENCE_SCOPE) |
-        (HSA_FENCE_SCOPE_SYSTEM << HSA_PACKET_HEADER_SCRELEASE_FENCE_SCOPE);
+    uint16_t Header = HSA_PACKET_TYPE_BARRIER_AND << HSA_PACKET_HEADER_TYPE;
+    Header |= HSA_FENCE_SCOPE_SYSTEM << HSA_PACKET_HEADER_ACQUIRE_FENCE_SCOPE;
+    Header |= HSA_FENCE_SCOPE_SYSTEM << HSA_PACKET_HEADER_RELEASE_FENCE_SCOPE;
 
     // Publish the packet. Do not modify the package after this point.
     uint32_t HeaderWord = Header | (Setup << 16u);
-    __atomic_store_n(reinterpret_cast<uint32_t *>(Packet), HeaderWord,
-                     __ATOMIC_RELEASE);
+    __atomic_store_n(PacketPtr, HeaderWord, __ATOMIC_RELEASE);
 
     // Signal the doorbell about the published packet.
     hsa_signal_store_relaxed(Queue->doorbell_signal, PacketId);

``````````

</details>


https://github.com/llvm/llvm-project/pull/85950