[OpenMP] Add OpenMP 5.1 omp_calloc function implementation

[AndreyChurbanov]

openmp/runtime/src/kmp_alloc.cpp

1448

This assertion is wrong, as the size is allowed to be 0. Please remove it.

1587

Both nmemb and size can be 0 and their type is unsigned. Please remove the assertions with them.

[Nawrin]

Remove debug assert statements and added new test for size 0.

[AndreyChurbanov]

LGTM

[protze.joachim]

Testing with cmake . -DOPENMP_TEST_FLAGS="-Werror -Wno-#warnings" && ninja check-libomp breaks for the newly added tests.

openmp/runtime/test/api/omp_calloc_def_fb.c

16

The compiler complains:

llvm-project/openmp/runtime/test/api/omp_calloc_def_fb.c:15:43: error: format specifies type 'void *' but the argument has underlying type 'unsigned long' [-Werror,-Wformat]
  printf("allocator large created: %p\n", a);
                                   ~~     ^
                                   %lu

openmp/runtime/test/api/omp_calloc_size_0.c

17

Similarly:

llvm-project/openmp/runtime/test/api/omp_calloc_size_0.c:16:43: error: format specifies type 'void *' but the argument has underlying type 'unsigned long' [-Werror,-Wformat]
  printf("allocator large created: %p\n", a);
                                   ~~     ^
                                   %lu

Cast to (void *) seems reasonable, if you want to print as a pointer.

openmp/runtime/src/dllexports

kmp_set_disp_num_buffers                    890
     omp_free                                895
     omp_get_device_num                      896
     omp_init_allocator                      897
     omp_destroy_allocator                   898
     %ifndef stub
         __kmpc_set_default_allocator
         __kmpc_get_default_allocator
         __kmpc_alloc
+        __kmpc_calloc
         __kmpc_free
         __kmpc_init_allocator
         __kmpc_destroy_allocator
     %endif
     omp_set_affinity_format                 748
     omp_get_affinity_format                 749
     omp_display_affinity                    750
     omp_capture_affinity                    751
     ompc_set_affinity_format                752
     ompc_get_affinity_format                753
     ompc_display_affinity                   754
     ompc_capture_affinity                   755
     omp_pause_resource                      756
     omp_pause_resource_all                  757
     omp_get_supported_active_levels         758
     omp_fulfill_event                       759
     omp_display_env                         733
+    omp_calloc                              776
 
     omp_null_allocator                     DATA
     omp_default_mem_alloc                  DATA
     omp_large_cap_mem_alloc                DATA
     omp_const_mem_alloc                    DATA
     omp_high_bw_mem_alloc                  DATA
     omp_low_lat_mem_alloc                  DATA
     omp_cgroup_mem_alloc                   DATA

openmp/runtime/src/include/omp.h.var

#   endif
     extern omp_allocator_handle_t __KAI_KMPC_CONVENTION omp_init_allocator(omp_memspace_handle_t m,
                                                        int ntraits, omp_alloctrait_t traits[]);
     extern void __KAI_KMPC_CONVENTION omp_destroy_allocator(omp_allocator_handle_t allocator);
 
     extern void __KAI_KMPC_CONVENTION omp_set_default_allocator(omp_allocator_handle_t a);
     extern omp_allocator_handle_t __KAI_KMPC_CONVENTION omp_get_default_allocator(void);
 #   ifdef __cplusplus
     extern void *__KAI_KMPC_CONVENTION omp_alloc(size_t size, omp_allocator_handle_t a = omp_null_allocator);
+    extern void *__KAI_KMPC_CONVENTION omp_calloc(size_t nmemb, size_t size, omp_allocator_handle_t a = omp_null_allocator);
     extern void __KAI_KMPC_CONVENTION omp_free(void * ptr, omp_allocator_handle_t a = omp_null_allocator);
 #   else
     extern void *__KAI_KMPC_CONVENTION omp_alloc(size_t size, omp_allocator_handle_t a);
+    extern void *__KAI_KMPC_CONVENTION omp_calloc(size_t nmemb, size_t size, omp_allocator_handle_t a);
     extern void __KAI_KMPC_CONVENTION omp_free(void *ptr, omp_allocator_handle_t a);
 #   endif
 
     /* OpenMP 5.0 Affinity Format */
     extern void __KAI_KMPC_CONVENTION omp_set_affinity_format(char const *);
     extern size_t __KAI_KMPC_CONVENTION omp_get_affinity_format(char *, size_t);
     extern void __KAI_KMPC_CONVENTION omp_display_affinity(char const *);
     extern size_t __KAI_KMPC_CONVENTION omp_capture_affinity(char *, size_t, char const *);

openmp/runtime/src/kmp.h

 extern omp_allocator_handle_t __kmpc_init_allocator(int gtid,
                                                     omp_memspace_handle_t,
                                                     int ntraits,
                                                     omp_alloctrait_t traits[]);
 extern void __kmpc_destroy_allocator(int gtid, omp_allocator_handle_t al);
 extern void __kmpc_set_default_allocator(int gtid, omp_allocator_handle_t al);
 extern omp_allocator_handle_t __kmpc_get_default_allocator(int gtid);
 extern void *__kmpc_alloc(int gtid, size_t sz, omp_allocator_handle_t al);
+extern void *__kmpc_calloc(int gtid, size_t nmemb, size_t sz,
+                           omp_allocator_handle_t al);
 extern void __kmpc_free(int gtid, void *ptr, omp_allocator_handle_t al);
 
 extern void __kmp_init_memkind();
 extern void __kmp_fini_memkind();
 
 /* ------------------------------------------------------------------------ */
 
 #define KMP_UINT64_MAX                                                         \

openmp/runtime/src/kmp_alloc.cpp

typedef struct kmp_mem_desc { // Memory block descriptor
   kmp_allocator_t *allocator; // allocator
 } kmp_mem_desc_t;
 static int alignment = sizeof(void *); // let's align to pointer size
 
 void *__kmpc_alloc(int gtid, size_t size, omp_allocator_handle_t allocator) {
   void *ptr = NULL;
   kmp_allocator_t *al;
   KMP_DEBUG_ASSERT(__kmp_init_serial);
+
+  if (size == 0)
+    return NULL;
+
   if (allocator == omp_null_allocator)
     allocator = __kmp_threads[gtid]->th.th_def_allocator;
 
   KE_TRACE(25, ("__kmpc_alloc: T#%d (%d, %p)\n", gtid, (int)size, allocator));
   al = RCAST(kmp_allocator_t *, CCAST(omp_allocator_handle_t, allocator));
 
   int sz_desc = sizeof(kmp_mem_desc_t);
   kmp_mem_desc_t desc;
void *__kmpc_alloc(int gtid, size_t size, omp_allocator_handle_t allocator) {
   desc.allocator = al;
   *((kmp_mem_desc_t *)addr_descr) = desc; // save descriptor contents
   KMP_MB();
 
   KE_TRACE(25, ("__kmpc_alloc returns %p, T#%d\n", desc.ptr_align, gtid));
   return desc.ptr_align;
 }
 
+void *__kmpc_calloc(int gtid, size_t nmemb, size_t size,
+                    omp_allocator_handle_t allocator) {
+  void *ptr = NULL;
+  kmp_allocator_t *al;
+  KMP_DEBUG_ASSERT(__kmp_init_serial);
+
+  if (allocator == omp_null_allocator)
+    allocator = __kmp_threads[gtid]->th.th_def_allocator;
+
+  KE_TRACE(25, ("__kmpc_calloc: T#%d (%d, %d, %p)\n", gtid, (int)nmemb,
+                (int)size, allocator));
+
+  al = RCAST(kmp_allocator_t *, CCAST(omp_allocator_handle_t, allocator));
+
+  if (nmemb == 0 || size == 0)
+    return ptr;
+
+  if ((SIZE_MAX - sizeof(kmp_mem_desc_t)) / size < nmemb) {
+    if (al->fb == omp_atv_abort_fb) {
+      KMP_ASSERT(0);
+    }
+    return ptr;
+  }
+
+  ptr = __kmpc_alloc(gtid, nmemb * size, allocator);
+
+  if (ptr) {
+    memset(ptr, 0x00, nmemb * size);
+  }
+  KE_TRACE(25, ("__kmpc_calloc returns %p, T#%d\n", ptr, gtid));
+  return ptr;
+}
+
 void __kmpc_free(int gtid, void *ptr, const omp_allocator_handle_t allocator) {
   KE_TRACE(25, ("__kmpc_free: T#%d free(%p,%p)\n", gtid, ptr, allocator));
   if (ptr == NULL)
     return;
 
   kmp_allocator_t *al;
   omp_allocator_handle_t oal;
   al = RCAST(kmp_allocator_t *, CCAST(omp_allocator_handle_t, allocator));

openmp/runtime/src/kmp_csupport.cpp

void __kmpc_doacross_fini(ident_t *loc, int gtid) {
   }
   // free private resources (need to keep buffer index forever)
   pr_buf->th_doacross_flags = NULL;
   __kmp_thread_free(th, (void *)pr_buf->th_doacross_info);
   pr_buf->th_doacross_info = NULL;
   KA_TRACE(20, ("__kmpc_doacross_fini() exit: T#%d\n", gtid));
 }
 
-/* omp_alloc/omp_free only defined for C/C++, not for Fortran */
+/* omp_alloc/omp_calloc/omp_free only defined for C/C++, not for Fortran */
 void *omp_alloc(size_t size, omp_allocator_handle_t allocator) {
   return __kmpc_alloc(__kmp_entry_gtid(), size, allocator);
 }
 
+void *omp_calloc(size_t nmemb, size_t size, omp_allocator_handle_t allocator) {
+  return __kmpc_calloc(__kmp_entry_gtid(), nmemb, size, allocator);
+}
+
 void omp_free(void *ptr, omp_allocator_handle_t allocator) {
   __kmpc_free(__kmp_entry_gtid(), ptr, allocator);
 }
 
 int __kmpc_get_target_offload(void) {
   if (!__kmp_init_serial) {
     __kmp_serial_initialize();
   }

openmp/runtime/src/kmp_stub.cpp

omp_memspace_handle_t const omp_high_bw_mem_space =
     (omp_memspace_handle_t const)3;
 omp_memspace_handle_t const omp_low_lat_mem_space =
     (omp_memspace_handle_t const)4;
 #endif /* KMP_OS_WINDOWS */
 void *omp_alloc(size_t size, const omp_allocator_handle_t allocator) {
   i;
   return malloc(size);
 }
+void *omp_calloc(size_t nmemb, size_t size,
+                 const omp_allocator_handle_t allocator) {
+  i;
+  return calloc(nmemb, size);
+}
 void omp_free(void *ptr, const omp_allocator_handle_t allocator) {
   i;
   free(ptr);
 }
 /* OpenMP 5.0 Affinity Format */
 void omp_set_affinity_format(char const *format) { i; }
 size_t omp_get_affinity_format(char *buffer, size_t size) {
   i;

openmp/runtime/test/api/omp_calloc_def_fb.c

+// RUN: %libomp-compile-and-run
+
+#include <stdio.h>
+#include <omp.h>
+
+int main() {
+  omp_alloctrait_t at[2];
+  omp_allocator_handle_t a;
+  void *p[2];
+  at[0].key = omp_atk_pool_size;
+  at[0].value = 2 * 1024 * 1024;
+  at[1].key = omp_atk_fallback;
+  at[1].value = omp_atv_default_mem_fb;
+  a = omp_init_allocator(omp_large_cap_mem_space, 2, at);
+  printf("allocator large created: %p\n", a);
+  #pragma omp parallel num_threads(2)
+  {
+    int i = omp_get_thread_num();
+    p[i] = omp_calloc(1024, 1024, a);
+    #pragma omp barrier
+    printf("th %d, ptr %p\n", i, p[i]);
+    omp_free(p[i], a);
+  }
+  // Both pointers should be non-NULL
+  if (p[0] != NULL && p[1] != NULL) {
+    printf("passed\n");
+    return 0;
+  } else {
+    printf("failed: pointers %p %p\n", p[0], p[1]);
+    return 1;
+  }
+}

openmp/runtime/test/api/omp_calloc_size_0.c

+// RUN: %libomp-compile-and-run
+
+#include <stdio.h>
+#include <omp.h>
+
+int main()
+{
+  omp_alloctrait_t at[2];
+  omp_allocator_handle_t a;
+  void *p[2];
+  at[0].key = omp_atk_pool_size;
+  at[0].value = 2*1024*1024;
+  at[1].key = omp_atk_fallback;
+  at[1].value = omp_atv_default_mem_fb;
+  a = omp_init_allocator(omp_large_cap_mem_space, 2, at);
+  printf("allocator large created: %p\n", a);
+  #pragma omp parallel num_threads(2)
+  {
+    int i = omp_get_thread_num();
+    p[i] = omp_calloc(1024, 0, a);
+    #pragma omp barrier
+    printf("th %d, ptr %p\n", i, p[i]);
+    omp_free(p[i], a);
+  }
+  // Both pointers should be NULL
+  if (p[0] == NULL && p[1] == NULL) {
+    printf("passed\n");
+    return 0;
+  } else {
+    printf("failed: pointers %p %p\n", p[0], p[1]);
+    return 1;
+  }
+}