[OpenMP] Implement TR8 present map type modifier in runtime (2/2)

This implements OpenMP runtime support for the OpenMP TR8 `present`
map type modifier.  The previous patch in this series implements Clang
front end support.  See that patch summary for behaviors that are not
yet supported.

Reviewed By: grokos, jdoerfert

Differential Revision: https://reviews.llvm.org/D83062

openmp/libomptarget/include/omptarget.h

@@ -49,6 +49,8 @@ enum tgt_map_type {
   OMP_TGT_MAPTYPE_IMPLICIT        = 0x200,
   // copy data to device
   OMP_TGT_MAPTYPE_CLOSE           = 0x400,
+  // runtime error if not already allocated
+  OMP_TGT_MAPTYPE_PRESENT         = 0x1000,
   // member of struct, member given by [16 MSBs] - 1
   OMP_TGT_MAPTYPE_MEMBER_OF       = 0xffff000000000000
 };

openmp/libomptarget/src/device.cpp

@@ -160,8 +160,10 @@ LookupResult DeviceTy::lookupMapping(void *HstPtrBegin, int64_t Size) {
 // If NULL is returned, then either data allocation failed or the user tried
 // to do an illegal mapping.
 void *DeviceTy::getOrAllocTgtPtr(void *HstPtrBegin, void *HstPtrBase,
-    int64_t Size, bool &IsNew, bool &IsHostPtr, bool IsImplicit,
-    bool UpdateRefCount, bool HasCloseModifier) {
+                                 int64_t Size, bool &IsNew, bool &IsHostPtr,
+                                 bool IsImplicit, bool UpdateRefCount,
+                                 bool HasCloseModifier,
+                                 bool HasPresentModifier) {
   void *rc = NULL;
   IsHostPtr = false;
   IsNew = false;
@@ -190,31 +192,40 @@ void *DeviceTy::getOrAllocTgtPtr(void *HstPtrBegin, void *HstPtrBase,
   } else if ((lr.Flags.ExtendsBefore || lr.Flags.ExtendsAfter) && !IsImplicit) {
     // Explicit extension of mapped data - not allowed.
     DP("Explicit extension of mapping is not allowed.\n");
-  } else if (Size) {
-    // If unified shared memory is active, implicitly mapped variables that are not
-    // privatized use host address. Any explicitly mapped variables also use
-    // host address where correctness is not impeded. In all other cases
-    // maps are respected.
-    // In addition to the mapping rules above, the close map
-    // modifier forces the mapping of the variable to the device.
-    if (RTLs->RequiresFlags & OMP_REQ_UNIFIED_SHARED_MEMORY &&
-        !HasCloseModifier) {
+  } else if (RTLs->RequiresFlags & OMP_REQ_UNIFIED_SHARED_MEMORY &&
+             !HasCloseModifier) {
+    // If unified shared memory is active, implicitly mapped variables that are
+    // not privatized use host address. Any explicitly mapped variables also use
+    // host address where correctness is not impeded. In all other cases maps
+    // are respected.
+    // In addition to the mapping rules above, the close map modifier forces the
+    // mapping of the variable to the device.
+    if (Size) {
       DP("Return HstPtrBegin " DPxMOD " Size=%ld RefCount=%s\n",
-         DPxPTR((uintptr_t)HstPtrBegin), Size, (UpdateRefCount ? " updated" : ""));
+         DPxPTR((uintptr_t)HstPtrBegin), Size,
+         (UpdateRefCount ? " updated" : ""));
       IsHostPtr = true;
       rc = HstPtrBegin;
-    } else {
-      // If it is not contained and Size > 0 we should create a new entry for it.
-      IsNew = true;
-      uintptr_t tp = (uintptr_t)RTL->data_alloc(RTLDeviceID, Size, HstPtrBegin);
-      DP("Creating new map entry: HstBase=" DPxMOD ", HstBegin=" DPxMOD ", "
-         "HstEnd=" DPxMOD ", TgtBegin=" DPxMOD "\n", DPxPTR(HstPtrBase),
-         DPxPTR(HstPtrBegin), DPxPTR((uintptr_t)HstPtrBegin + Size), DPxPTR(tp));
-      HostDataToTargetMap.emplace(
-          HostDataToTargetTy((uintptr_t)HstPtrBase, (uintptr_t)HstPtrBegin,
-                             (uintptr_t)HstPtrBegin + Size, tp));
-      rc = (void *)tp;
     }
+  } else if (HasPresentModifier) {
+    DP("Mapping required by 'present' map type modifier does not exist for "
+       "HstPtrBegin=" DPxMOD ", Size=%ld\n",
+       DPxPTR(HstPtrBegin), Size);
+    MESSAGE("device mapping required by 'present' map type modifier does not "
+            "exist for host address " DPxMOD " (%ld bytes)",
+            DPxPTR(HstPtrBegin), Size);
+  } else if (Size) {
+    // If it is not contained and Size > 0, we should create a new entry for it.
+    IsNew = true;
+    uintptr_t tp = (uintptr_t)RTL->data_alloc(RTLDeviceID, Size, HstPtrBegin);
+    DP("Creating new map entry: HstBase=" DPxMOD ", HstBegin=" DPxMOD ", "
+       "HstEnd=" DPxMOD ", TgtBegin=" DPxMOD "\n",
+       DPxPTR(HstPtrBase), DPxPTR(HstPtrBegin),
+       DPxPTR((uintptr_t)HstPtrBegin + Size), DPxPTR(tp));
+    HostDataToTargetMap.emplace(
+        HostDataToTargetTy((uintptr_t)HstPtrBase, (uintptr_t)HstPtrBegin,
+                           (uintptr_t)HstPtrBegin + Size, tp));
+    rc = (void *)tp;
   }
 
   DataMapMtx.unlock();

openmp/libomptarget/src/device.h

@@ -177,8 +177,9 @@ struct DeviceTy {
   uint64_t getMapEntryRefCnt(void *HstPtrBegin);
   LookupResult lookupMapping(void *HstPtrBegin, int64_t Size);
   void *getOrAllocTgtPtr(void *HstPtrBegin, void *HstPtrBase, int64_t Size,
-      bool &IsNew, bool &IsHostPtr, bool IsImplicit, bool UpdateRefCount = true,
-      bool HasCloseModifier = false);
+                         bool &IsNew, bool &IsHostPtr, bool IsImplicit,
+                         bool UpdateRefCount, bool HasCloseModifier,
+                         bool HasPresentModifier);
   void *getTgtPtrBegin(void *HstPtrBegin, int64_t Size);
   void *getTgtPtrBegin(void *HstPtrBegin, int64_t Size, bool &IsLast,
       bool UpdateRefCount, bool &IsHostPtr);

openmp/libomptarget/src/omptarget.cpp

@@ -308,6 +308,7 @@ int target_data_begin(DeviceTy &Device, int32_t arg_num, void **args_base,
     // Force the creation of a device side copy of the data when:
     // a close map modifier was associated with a map that contained a to.
     bool HasCloseModifier = arg_types[i] & OMP_TGT_MAPTYPE_CLOSE;
+    bool HasPresentModifier = arg_types[i] & OMP_TGT_MAPTYPE_PRESENT;
     // UpdateRef is based on MEMBER_OF instead of TARGET_PARAM because if we
     // have reached this point via __tgt_target_data_begin and not __tgt_target
     // then no argument is marked as TARGET_PARAM ("omp target data map" is not
@@ -316,13 +317,26 @@ int target_data_begin(DeviceTy &Device, int32_t arg_num, void **args_base,
     bool UpdateRef = !(arg_types[i] & OMP_TGT_MAPTYPE_MEMBER_OF);
     if (arg_types[i] & OMP_TGT_MAPTYPE_PTR_AND_OBJ) {
       DP("Has a pointer entry: \n");
-      // base is address of pointer.
-      Pointer_TgtPtrBegin = Device.getOrAllocTgtPtr(HstPtrBase, HstPtrBase,
-          sizeof(void *), Pointer_IsNew, IsHostPtr, IsImplicit, UpdateRef,
-          HasCloseModifier);
+      // Base is address of pointer.
+      //
+      // Usually, the pointer is already allocated by this time.  For example:
+      //
+      //   #pragma omp target map(s.p[0:N])
+      //
+      // The map entry for s comes first, and the PTR_AND_OBJ entry comes
+      // afterward, so the pointer is already allocated by the time the
+      // PTR_AND_OBJ entry is handled below, and Pointer_TgtPtrBegin is thus
+      // non-null.  However, "declare target link" can produce a PTR_AND_OBJ
+      // entry for a global that might not already be allocated by the time the
+      // PTR_AND_OBJ entry is handled below, and so the allocation might fail
+      // when HasPresentModifier.
+      Pointer_TgtPtrBegin = Device.getOrAllocTgtPtr(
+          HstPtrBase, HstPtrBase, sizeof(void *), Pointer_IsNew, IsHostPtr,
+          IsImplicit, UpdateRef, HasCloseModifier, HasPresentModifier);
       if (!Pointer_TgtPtrBegin) {
-        DP("Call to getOrAllocTgtPtr returned null pointer (device failure or "
-            "illegal mapping).\n");
+        DP("Call to getOrAllocTgtPtr returned null pointer (%s).\n",
+           HasPresentModifier ? "'present' map type modifier"
+                              : "device failure or illegal mapping");
         return OFFLOAD_FAIL;
       }
       DP("There are %zu bytes allocated at target address " DPxMOD " - is%s new"
@@ -334,13 +348,15 @@ int target_data_begin(DeviceTy &Device, int32_t arg_num, void **args_base,
       UpdateRef = true; // subsequently update ref count of pointee
     }
 
-    void *TgtPtrBegin = Device.getOrAllocTgtPtr(HstPtrBegin, HstPtrBase,
-        data_size, IsNew, IsHostPtr, IsImplicit, UpdateRef, HasCloseModifier);
-    if (!TgtPtrBegin && data_size) {
-      // If data_size==0, then the argument could be a zero-length pointer to
-      // NULL, so getOrAlloc() returning NULL is not an error.
-      DP("Call to getOrAllocTgtPtr returned null pointer (device failure or "
-          "illegal mapping).\n");
+    void *TgtPtrBegin = Device.getOrAllocTgtPtr(
+        HstPtrBegin, HstPtrBase, data_size, IsNew, IsHostPtr, IsImplicit,
+        UpdateRef, HasCloseModifier, HasPresentModifier);
+    // If data_size==0, then the argument could be a zero-length pointer to
+    // NULL, so getOrAlloc() returning NULL is not an error.
+    if (!TgtPtrBegin && (data_size || HasPresentModifier)) {
+      DP("Call to getOrAllocTgtPtr returned null pointer (%s).\n",
+         HasPresentModifier ? "'present' map type modifier"
+                            : "device failure or illegal mapping");
       return OFFLOAD_FAIL;
     }
     DP("There are %" PRId64 " bytes allocated at target address " DPxMOD
@@ -459,13 +475,27 @@ int target_data_end(DeviceTy &Device, int32_t arg_num, void **args_base,
         (arg_types[i] & OMP_TGT_MAPTYPE_PTR_AND_OBJ);
     bool ForceDelete = arg_types[i] & OMP_TGT_MAPTYPE_DELETE;
     bool HasCloseModifier = arg_types[i] & OMP_TGT_MAPTYPE_CLOSE;
+    bool HasPresentModifier = arg_types[i] & OMP_TGT_MAPTYPE_PRESENT;
 
     // If PTR_AND_OBJ, HstPtrBegin is address of pointee
     void *TgtPtrBegin = Device.getTgtPtrBegin(HstPtrBegin, data_size, IsLast,
         UpdateRef, IsHostPtr);
-    DP("There are %" PRId64 " bytes allocated at target address " DPxMOD
-        " - is%s last\n", data_size, DPxPTR(TgtPtrBegin),
-        (IsLast ? "" : " not"));
+    if (!TgtPtrBegin && (data_size || HasPresentModifier)) {
+      DP("Mapping does not exist (%s)\n",
+         (HasPresentModifier ? "'present' map type modifier" : "ignored"));
+      if (HasPresentModifier) {
+        // FIXME: This should not be an error on exit from "omp target data",
+        // but it should be an error upon entering an "omp target exit data".
+        MESSAGE("device mapping required by 'present' map type modifier does "
+                "not exist for host address " DPxMOD " (%ld bytes)",
+                DPxPTR(HstPtrBegin), data_size);
+        return OFFLOAD_FAIL;
+      }
+    } else {
+      DP("There are %" PRId64 " bytes allocated at target address " DPxMOD
+         " - is%s last\n",
+         data_size, DPxPTR(TgtPtrBegin), (IsLast ? "" : " not"));
+    }
 
     bool DelEntry = IsLast || ForceDelete;
 

openmp/libomptarget/src/private.h

@@ -80,9 +80,19 @@ typedef int (*TargetDataFuncPtrTy)(DeviceTy &, int32_t, void **, void **,
     int64_t *, int64_t *, void **, __tgt_async_info *);
 
 ////////////////////////////////////////////////////////////////////////////////
-// implementation for fatal messages
+// implementation for messages
 ////////////////////////////////////////////////////////////////////////////////
 
+#define MESSAGE0(_str)                                                         \
+  do {                                                                         \
+    fprintf(stderr, "Libomptarget message: %s\n", _str);                       \
+  } while (0)
+
+#define MESSAGE(_str, ...)                                                     \
+  do {                                                                         \
+    fprintf(stderr, "Libomptarget message: " _str "\n", __VA_ARGS__);          \
+  } while (0)
+
 #define FATAL_MESSAGE0(_num, _str)                                    \
   do {                                                                \
     fprintf(stderr, "Libomptarget fatal error %d: %s\n", _num, _str); \

openmp/libomptarget/test/mapping/present/target.c

@@ -0,0 +1,42 @@
+// RUN: %libomptarget-compile-aarch64-unknown-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-aarch64-unknown-linux-gnu 2>&1 \
+// RUN: | %fcheck-aarch64-unknown-linux-gnu
+
+// RUN: %libomptarget-compile-powerpc64-ibm-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-powerpc64-ibm-linux-gnu 2>&1 \
+// RUN: | %fcheck-powerpc64-ibm-linux-gnu
+
+// RUN: %libomptarget-compile-powerpc64le-ibm-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-powerpc64le-ibm-linux-gnu 2>&1 \
+// RUN: | %fcheck-powerpc64le-ibm-linux-gnu
+
+// RUN: %libomptarget-compile-x86_64-pc-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-x86_64-pc-linux-gnu 2>&1 \
+// RUN: | %fcheck-x86_64-pc-linux-gnu
+
+#include <stdio.h>
+
+int main() {
+  int i;
+
+  // CHECK: addr=0x[[#%x,HOST_ADDR:]], size=[[#%u,SIZE:]]
+  fprintf(stderr, "addr=%p, size=%ld\n", &i, sizeof i);
+
+  // CHECK-NOT: Libomptarget
+#pragma omp target data map(alloc: i)
+#pragma omp target map(present, alloc: i)
+  ;
+
+  // CHECK: i is present
+  fprintf(stderr, "i is present\n");
+
+  // CHECK: Libomptarget message: device mapping required by 'present' map type modifier does not exist for host address 0x{{0*}}[[#HOST_ADDR]] ([[#SIZE]] bytes)
+  // CHECK: Libomptarget fatal error 1: failure of target construct while offloading is mandatory
+#pragma omp target map(present, alloc: i)
+  ;
+
+  // CHECK-NOT: i is present
+  fprintf(stderr, "i is present\n");
+
+  return 0;
+}

openmp/libomptarget/test/mapping/present/target_data.c

@@ -0,0 +1,42 @@
+// RUN: %libomptarget-compile-aarch64-unknown-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-aarch64-unknown-linux-gnu 2>&1 \
+// RUN: | %fcheck-aarch64-unknown-linux-gnu
+
+// RUN: %libomptarget-compile-powerpc64-ibm-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-powerpc64-ibm-linux-gnu 2>&1 \
+// RUN: | %fcheck-powerpc64-ibm-linux-gnu
+
+// RUN: %libomptarget-compile-powerpc64le-ibm-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-powerpc64le-ibm-linux-gnu 2>&1 \
+// RUN: | %fcheck-powerpc64le-ibm-linux-gnu
+
+// RUN: %libomptarget-compile-x86_64-pc-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-x86_64-pc-linux-gnu 2>&1 \
+// RUN: | %fcheck-x86_64-pc-linux-gnu
+
+#include <stdio.h>
+
+int main() {
+  int i;
+
+  // CHECK: addr=0x[[#%x,HOST_ADDR:]], size=[[#%u,SIZE:]]
+  fprintf(stderr, "addr=%p, size=%ld\n", &i, sizeof i);
+
+  // CHECK-NOT: Libomptarget
+#pragma omp target data map(alloc: i)
+#pragma omp target data map(present, alloc: i)
+  ;
+
+  // CHECK: i is present
+  fprintf(stderr, "i is present\n");
+
+  // CHECK: Libomptarget message: device mapping required by 'present' map type modifier does not exist for host address 0x{{0*}}[[#HOST_ADDR]] ([[#SIZE]] bytes)
+  // CHECK: Libomptarget fatal error 1: failure of target construct while offloading is mandatory
+#pragma omp target data map(present, alloc: i)
+  ;
+
+  // CHECK-NOT: i is present
+  fprintf(stderr, "i is present\n");
+
+  return 0;
+}

openmp/libomptarget/test/mapping/present/target_enter_data.c

@@ -0,0 +1,41 @@
+// RUN: %libomptarget-compile-aarch64-unknown-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-aarch64-unknown-linux-gnu 2>&1 \
+// RUN: | %fcheck-aarch64-unknown-linux-gnu
+
+// RUN: %libomptarget-compile-powerpc64-ibm-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-powerpc64-ibm-linux-gnu 2>&1 \
+// RUN: | %fcheck-powerpc64-ibm-linux-gnu
+
+// RUN: %libomptarget-compile-powerpc64le-ibm-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-powerpc64le-ibm-linux-gnu 2>&1 \
+// RUN: | %fcheck-powerpc64le-ibm-linux-gnu
+
+// RUN: %libomptarget-compile-x86_64-pc-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-x86_64-pc-linux-gnu 2>&1 \
+// RUN: | %fcheck-x86_64-pc-linux-gnu
+
+#include <stdio.h>
+
+int main() {
+  int i;
+
+  // CHECK: addr=0x[[#%x,HOST_ADDR:]], size=[[#%u,SIZE:]]
+  fprintf(stderr, "addr=%p, size=%ld\n", &i, sizeof i);
+
+  // CHECK-NOT: Libomptarget
+#pragma omp target enter data map(alloc: i)
+#pragma omp target enter data map(present, alloc: i)
+#pragma omp target exit data map(delete: i)
+
+  // CHECK: i is present
+  fprintf(stderr, "i is present\n");
+
+  // CHECK: Libomptarget message: device mapping required by 'present' map type modifier does not exist for host address 0x{{0*}}[[#HOST_ADDR]] ([[#SIZE]] bytes)
+  // CHECK: Libomptarget fatal error 1: failure of target construct while offloading is mandatory
+#pragma omp target enter data map(present, alloc: i)
+
+  // CHECK-NOT: i is present
+  fprintf(stderr, "i is present\n");
+
+  return 0;
+}

openmp/libomptarget/test/mapping/present/target_exit_data.c

@@ -0,0 +1,40 @@
+// RUN: %libomptarget-compile-aarch64-unknown-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-aarch64-unknown-linux-gnu 2>&1 \
+// RUN: | %fcheck-aarch64-unknown-linux-gnu
+
+// RUN: %libomptarget-compile-powerpc64-ibm-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-powerpc64-ibm-linux-gnu 2>&1 \
+// RUN: | %fcheck-powerpc64-ibm-linux-gnu
+
+// RUN: %libomptarget-compile-powerpc64le-ibm-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-powerpc64le-ibm-linux-gnu 2>&1 \
+// RUN: | %fcheck-powerpc64le-ibm-linux-gnu
+
+// RUN: %libomptarget-compile-x86_64-pc-linux-gnu -fopenmp-version=51
+// RUN: %libomptarget-run-fail-x86_64-pc-linux-gnu 2>&1 \
+// RUN: | %fcheck-x86_64-pc-linux-gnu
+
+#include <stdio.h>
+
+int main() {
+  int i;
+
+  // CHECK: addr=0x[[#%x,HOST_ADDR:]], size=[[#%u,SIZE:]]
+  fprintf(stderr, "addr=%p, size=%ld\n", &i, sizeof i);
+
+  // CHECK-NOT: Libomptarget
+#pragma omp target enter data map(alloc: i)
+#pragma omp target exit data map(present, release: i)
+
+  // CHECK: i is present
+  fprintf(stderr, "i is present\n");
+
+  // CHECK: Libomptarget message: device mapping required by 'present' map type modifier does not exist for host address 0x{{0*}}[[#HOST_ADDR]] ([[#SIZE]] bytes)
+  // CHECK: Libomptarget fatal error 1: failure of target construct while offloading is mandatory
+#pragma omp target exit data map(present, release: i)
+
+  // CHECK-NOT: i is present
+  fprintf(stderr, "i is present\n");
+
+  return 0;
+}