Revert "[OFFLOAD][OPENMP] 6.0 compatible interop interface (llvm#143491)"

This reverts commit 66d1c37.

This patch is the runtime library part of a 2-patch piece of work. The
second piece to this is codegen work. For the codegen part, there
currently is no clear timeline. However, without the codegen part, this
patch breaks interop and does not make sense.

I propose to revert this patch for now and clarify the path forward.

Author: jplehr

offload/include/OpenMP/InteropAPI.h

@@ -13,69 +13,17 @@
 
 #include "omp.h"
 
-#include "PerThreadTable.h"
 #include "omptarget.h"
 
 extern "C" {
 
 typedef enum kmp_interop_type_t {
   kmp_interop_type_unknown = -1,
-  kmp_interop_type_target,
-  kmp_interop_type_targetsync,
+  kmp_interop_type_platform,
+  kmp_interop_type_device,
+  kmp_interop_type_tasksync,
 } kmp_interop_type_t;
 
-struct interop_attrs_t {
-  bool inorder : 1;
-  int reserved : 31;
-
-  /// Check if the supported attributes are compatible with the current
-  ///   attributes. Only if an attribute is supported can the value be true,
-  ///   otherwise it needs to be false
-  bool checkSupportedOnly(interop_attrs_t supported) const {
-    return supported.inorder || (!supported.inorder && !inorder);
-  }
-};
-
-struct interop_spec_t {
-  int32_t fr_id;
-  interop_attrs_t attrs; // Common attributes
-  int64_t impl_attrs; // Implementation specific attributes (recognized by each
-                      // plugin)
-};
-
-struct interop_flags_t {
-  bool implicit : 1; // dispatch (true) or interop (false)
-  bool nowait : 1;   // has nowait flag
-  int reserved : 30;
-};
-
-struct interop_ctx_t {
-  uint32_t version; // version of the interface (current is 0)
-  interop_flags_t flags;
-  int gtid;
-};
-
-struct dep_pack_t {
-  int32_t ndeps;
-  int32_t ndeps_noalias;
-  kmp_depend_info_t *deplist;
-  kmp_depend_info_t *noalias_deplist;
-};
-
-struct omp_interop_val_t;
-
-typedef void ompx_interop_cb_t(omp_interop_val_t *interop, void *data);
-
-struct omp_interop_cb_instance_t {
-  ompx_interop_cb_t *cb;
-  void *data;
-
-  omp_interop_cb_instance_t(ompx_interop_cb_t *cb, void *data)
-      : cb(cb), data(data) {}
-
-  void operator()(omp_interop_val_t *interop) { cb(interop, data); }
-};
-
 /// The interop value type, aka. the interop object.
 typedef struct omp_interop_val_t {
   /// Device and interop-type are determined at construction time and fix.
@@ -86,98 +34,10 @@ typedef struct omp_interop_val_t {
   __tgt_device_info device_info;
   const kmp_interop_type_t interop_type;
   const intptr_t device_id;
-  omp_vendor_id_t vendor_id = omp_vendor_llvm;
-  tgt_foreign_runtime_id_t fr_id = tgt_fr_none;
-  interop_attrs_t attrs{false, 0}; // Common prefer specification attributes
-  int64_t impl_attrs = 0; // Implementation prefer specification attributes
-
-  // Constants
-  static constexpr int no_owner = -1; // This interop has no current owner
-
-  void *rtl_property = nullptr; // Plugin dependent information
-  // For implicitly created Interop objects (e.g., from a dispatch construct)
-  // who owns the object
-  int owner_gtid = no_owner;
-  // Marks whether the object was requested since the last time it was synced
-  bool clean = true;
-
-  typedef llvm::SmallVector<omp_interop_cb_instance_t> callback_list_t;
-
-  callback_list_t completion_cbs;
-
-  void reset() {
-    owner_gtid = no_owner;
-    markClean();
-    clearCompletionCbs();
-  }
-
-  llvm::Expected<DeviceTy &> getDevice() const;
-
-  bool hasOwner() const { return owner_gtid != no_owner; }
-
-  void setOwner(int gtid) { owner_gtid = gtid; }
-  bool isOwnedBy(int gtid) { return owner_gtid == gtid; }
-  bool isCompatibleWith(int32_t InteropType, const interop_spec_t &Spec);
-  bool isCompatibleWith(int32_t InteropType, const interop_spec_t &Spec,
-                        int64_t DeviceNum, int gtid);
-  void markClean() { clean = true; }
-  void markDirty() { clean = false; }
-  bool isClean() const { return clean; }
-
-  int32_t flush(DeviceTy &Device);
-  int32_t sync_barrier(DeviceTy &Device);
-  int32_t async_barrier(DeviceTy &Device);
-  int32_t release(DeviceTy &Device);
-
-  void addCompletionCb(ompx_interop_cb_t *cb, void *data) {
-    completion_cbs.push_back(omp_interop_cb_instance_t(cb, data));
-  }
-
-  int numCompletionCbs() const { return completion_cbs.size(); }
-  void clearCompletionCbs() { completion_cbs.clear(); }
-
-  void runCompletionCbs() {
-    for (auto &cbInstance : completion_cbs)
-      cbInstance(this);
-    clearCompletionCbs();
-  }
+  const omp_foreign_runtime_ids_t vendor_id = cuda;
+  const intptr_t backend_type_id = omp_interop_backend_type_cuda_1;
 } omp_interop_val_t;
 
 } // extern "C"
 
-struct InteropTableEntry {
-  using ContainerTy = typename std::vector<omp_interop_val_t *>;
-  using iterator = typename ContainerTy::iterator;
-
-  ContainerTy Interops;
-
-  static constexpr int reservedEntriesPerThread =
-      20; // reserve some entries to avoid reallocation
-
-  void add(omp_interop_val_t *obj) {
-    if (Interops.capacity() == 0)
-      Interops.reserve(reservedEntriesPerThread);
-    Interops.push_back(obj);
-  }
-
-  template <class ClearFuncTy> void clear(ClearFuncTy f) {
-    for (auto &Obj : Interops) {
-      f(Obj);
-    }
-  }
-
-  /// vector interface
-  int size() const { return Interops.size(); }
-  iterator begin() { return Interops.begin(); }
-  iterator end() { return Interops.end(); }
-  iterator erase(iterator it) { return Interops.erase(it); }
-};
-
-struct InteropTblTy
-    : public PerThreadTable<InteropTableEntry, omp_interop_val_t *> {
-  void clear();
-};
-
-void syncImplicitInterops(int gtid, void *event);
-
 #endif // OMPTARGET_OPENMP_INTEROP_API_H

offload/include/OpenMP/omp.h

@@ -80,18 +80,15 @@ typedef enum omp_interop_rc {
   omp_irc_other = -6
 } omp_interop_rc_t;
 
-/* Foreign runtime values from OpenMP Additional Definitions document v2.1 */
-typedef enum tgt_foreign_runtime_id_t {
-  tgt_fr_none = 0,
-  tgt_fr_cuda = 1,
-  tgt_fr_cuda_driver = 2,
-  tgt_fr_opencl = 3,
-  tgt_fr_sycl = 4,
-  tgt_fr_hip = 5,
-  tgt_fr_level_zero = 6,
-  tgt_fr_hsa = 7,
-  tgt_fr_last = 8
-} tgt_foreign_runtime_id_t;
+typedef enum omp_interop_fr {
+  omp_ifr_cuda = 1,
+  omp_ifr_cuda_driver = 2,
+  omp_ifr_opencl = 3,
+  omp_ifr_sycl = 4,
+  omp_ifr_hip = 5,
+  omp_ifr_level_zero = 6,
+  omp_ifr_last = 7
+} omp_interop_fr_t;
 
 typedef void *omp_interop_t;
 
@@ -137,23 +134,19 @@ omp_get_interop_type_desc(const omp_interop_t, omp_interop_property_t);
 extern const char *__KAI_KMPC_CONVENTION
 omp_get_interop_rc_desc(const omp_interop_t, omp_interop_rc_t);
 
-/* Vendor defined values from OpenMP Additional Definitions document v2.1*/
-typedef enum omp_vendor_id {
-  omp_vendor_unknown = 0,
-  omp_vendor_amd = 1,
-  omp_vendor_arm = 2,
-  omp_vendor_bsc = 3,
-  omp_vendor_fujitsu = 4,
-  omp_vendor_gnu = 5,
-  omp_vendor_hpe = 6,
-  omp_vendor_ibm = 7,
-  omp_vendor_intel = 8,
-  omp_vendor_llvm = 9,
-  omp_vendor_nec = 10,
-  omp_vendor_nvidia = 11,
-  omp_vendor_ti = 12,
-  omp_vendor_last = 13
-} omp_vendor_id_t;
+typedef enum omp_interop_backend_type_t {
+  // reserve 0
+  omp_interop_backend_type_cuda_1 = 1,
+} omp_interop_backend_type_t;
+
+typedef enum omp_foreign_runtime_ids {
+  cuda = 1,
+  cuda_driver = 2,
+  opencl = 3,
+  sycl = 4,
+  hip = 5,
+  level_zero = 6,
+} omp_foreign_runtime_ids_t;
 
 ///} InteropAPI
 

offload/include/PerThreadTable.h

@@ -35,8 +35,6 @@
 #include <mutex>
 #include <string>
 
-#include "OpenMP/InteropAPI.h"
-
 using GenericPluginTy = llvm::omp::target::plugin::GenericPluginTy;
 
 /// Struct for the data required to handle plugins
@@ -90,9 +88,6 @@ struct PluginManager {
   HostPtrToTableMapTy HostPtrToTableMap;
   std::mutex TblMapMtx; ///< For HostPtrToTableMap
 
-  /// Table of cached implicit interop objects
-  InteropTblTy InteropTbl;
-
   // Work around for plugins that call dlopen on shared libraries that call
   // tgt_register_lib during their initialisation. Stash the pointers in a
   // vector until the plugins are all initialised and then register them.
@@ -190,6 +185,5 @@ void initRuntime();
 void deinitRuntime();
 
 extern PluginManager *PM;
-extern std::atomic<bool> RTLAlive; // Indicates if the RTL has been initialized
-extern std::atomic<int> RTLOngoingSyncs; // Counts ongoing external syncs
+
 #endif // OMPTARGET_PLUGIN_MANAGER_H

offload/include/PluginManager.h

@@ -37,7 +37,6 @@ struct __tgt_device_image {
 struct __tgt_device_info {
   void *Context = nullptr;
   void *Device = nullptr;
-  void *Platform = nullptr;
 };
 
 /// This struct is a record of all the host code that may be offloaded to a