openmp: Fix up firstprivate+lastprivate clause handling [PR99928]

The C/C++ clause splitting happens very early during construct parsing,
but only the FEs later on handle possible instantiations, non-static
member handling and array section lowering.
In the OpenMP 5.0/5.1 rules, whether firstprivate is added to combined
target depends on whether it isn't also mentioned in lastprivate or map
clauses, but unfortunately I think such checks are much better done only
when the FEs perform all the above mentioned changes.
So, this patch arranges for the firstprivate clause to be copied or moved
to combined target construct (as before), but sets flags on that clause,
which tell the FE *finish_omp_clauses and the gimplifier it has been added
only conditionally and let the FEs and gimplifier DTRT for these.

2021-05-21  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/99928
gcc/
	* tree.h (OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT_TARGET): Define.
	* gimplify.c (enum gimplify_omp_var_data): Fix up
	GOVD_MAP_HAS_ATTACHMENTS value, add GOVD_FIRSTPRIVATE_IMPLICIT.
	(omp_lastprivate_for_combined_outer_constructs): If combined target
	has GOVD_FIRSTPRIVATE_IMPLICIT set for the decl, change it to
	GOVD_MAP | GOVD_SEEN.
	(gimplify_scan_omp_clauses): Set GOVD_FIRSTPRIVATE_IMPLICIT for
	firstprivate clauses with OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT.
	(gimplify_adjust_omp_clauses): For firstprivate clauses with
	OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT either clear that bit and
	OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT_TARGET too, or remove it and
	let it be replaced by implicit map clause.
gcc/c-family/
	* c-omp.c (c_omp_split_clauses): Set OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT
	on firstprivate clause copy going to target construct, and for
	target simd set also OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT_TARGET bit.
gcc/c/
	* c-typeck.c (c_finish_omp_clauses): Move firstprivate clauses with
	OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT to the end of the chain.  Don't error
	if a decl is mentioned both in map clause and in such firstprivate
	clause unless OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT_TARGET is also set.
gcc/cp/
	* semantics.c (finish_omp_clauses): Move firstprivate clauses with
	OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT to the end of the chain.  Don't error
	if a decl is mentioned both in map clause and in such firstprivate
	clause unless OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT_TARGET is also set.
gcc/testsuite/
	* c-c++-common/gomp/pr99928-3.c: Remove all xfails.
	* c-c++-common/gomp/pr99928-15.c: New test.

diff --git a/gcc/c-family/c-omp.c b/gcc/c-family/c-omp.c
index fb1a0d6041ec7cd215b83ac6f48bdfdae332f314..0945a1e5cc45372e2e61a1e539f5ac78f8d7878e 100644 (file)
--- a/gcc/c-family/c-omp.c
+++ b/gcc/c-family/c-omp.c
@@ -1733,10 +1733,21 @@ c_omp_split_clauses (location_t loc, enum tree_code code,
                {
                  /* This must be #pragma omp target simd.  */
                  s = C_OMP_CLAUSE_SPLIT_TARGET;
+                 OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT (clauses) = 1;
+                 OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT_TARGET (clauses) = 1;
                  break;
                }
              c = build_omp_clause (OMP_CLAUSE_LOCATION (clauses),
                                    OMP_CLAUSE_FIRSTPRIVATE);
+             /* firstprivate should not be applied to target if it is
+                also lastprivate or on the combined/composite construct,
+                or if it is mentioned in map clause.  OMP_CLAUSE_DECLs
+                may need to go through FE handling though (instantiation,
+                C++ non-static data members, array section lowering), so
+                add the clause with OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT and
+                let *finish_omp_clauses and the gimplifier handle it
+                right.  */
+             OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT (c) = 1;
              OMP_CLAUSE_DECL (c) = OMP_CLAUSE_DECL (clauses);
              OMP_CLAUSE_CHAIN (c) = cclauses[C_OMP_CLAUSE_SPLIT_TARGET];
              cclauses[C_OMP_CLAUSE_SPLIT_TARGET] = c;

diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c
index c3b85da11250a07993b00cc6042ef8edc924ab51..fc64ef96fb8c3eb7fac0cfc4880b575a086874ee 100644 (file)
--- a/gcc/c/c-typeck.c
+++ b/gcc/c/c-typeck.c
@@ -13936,6 +13936,7 @@ c_finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
      has been seen, -2 if mixed inscan/normal reduction diagnosed.  */
   int reduction_seen = 0;
   bool allocate_seen = false;
+  bool firstprivate_implicit_moved = false;
 
   bitmap_obstack_initialize (NULL);
   bitmap_initialize (&generic_head, &bitmap_default_obstack);
@@ -14377,6 +14378,29 @@ c_finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
          break;
 
        case OMP_CLAUSE_FIRSTPRIVATE:
+         if (OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT (c)
+             && !firstprivate_implicit_moved)
+           {
+             firstprivate_implicit_moved = true;
+             /* Move firstprivate clauses with
+                OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT set to the end of
+                clauses chain.  */
+             tree cl = NULL, *pc1 = pc, *pc2 = &cl;
+             while (*pc1)
+               if (OMP_CLAUSE_CODE (*pc1) == OMP_CLAUSE_FIRSTPRIVATE
+                   && OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT (*pc1))
+                 {
+                   *pc2 = *pc1;
+                   pc2 = &OMP_CLAUSE_CHAIN (*pc2);
+                   *pc1 = OMP_CLAUSE_CHAIN (*pc1);
+                 }
+               else
+                 pc1 = &OMP_CLAUSE_CHAIN (*pc1);
+             *pc2 = NULL;
+             *pc1 = cl;
+             if (pc1 != pc)
+               continue;
+           }
          t = OMP_CLAUSE_DECL (c);
          need_complete = true;
          need_implicitly_determined = true;
@@ -14398,6 +14422,9 @@ c_finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
              if (ort == C_ORT_ACC)
                error_at (OMP_CLAUSE_LOCATION (c),
                          "%qD appears more than once in data clauses", t);
+             else if (OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT (c)
+                      && !OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT_TARGET (c))
+               /* Silently drop the clause.  */;
              else
                error_at (OMP_CLAUSE_LOCATION (c),
                          "%qD appears both in data and map clauses", t);

diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 0d590c318fb0d3a5832959eae85c289a53a2b80d..fffbe40613e904e970cadbff513b0c9ae05654fe 100644 (file)
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -6519,6 +6519,7 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
   bool allocate_seen = false;
   tree detach_seen = NULL_TREE;
   bool mergeable_seen = false;
+  bool firstprivate_implicit_moved = false;
 
   bitmap_obstack_initialize (NULL);
   bitmap_initialize (&generic_head, &bitmap_default_obstack);
@@ -6843,6 +6844,29 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
          break;
 
        case OMP_CLAUSE_FIRSTPRIVATE:
+         if (OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT (c)
+             && !firstprivate_implicit_moved)
+           {
+             firstprivate_implicit_moved = true;
+             /* Move firstprivate clauses with
+                OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT set to the end of
+                clauses chain.  */
+             tree cl = NULL, *pc1 = pc, *pc2 = &cl;
+             while (*pc1)
+               if (OMP_CLAUSE_CODE (*pc1) == OMP_CLAUSE_FIRSTPRIVATE
+                   && OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT (*pc1))
+                 {
+                   *pc2 = *pc1;
+                   pc2 = &OMP_CLAUSE_CHAIN (*pc2);
+                   *pc1 = OMP_CLAUSE_CHAIN (*pc1);
+                 }
+               else
+                 pc1 = &OMP_CLAUSE_CHAIN (*pc1);
+             *pc2 = NULL;
+             *pc1 = cl;
+             if (pc1 != pc)
+               continue;
+           }
          t = omp_clause_decl_field (OMP_CLAUSE_DECL (c));
          if (t)
            omp_note_field_privatization (t, OMP_CLAUSE_DECL (c));
@@ -6884,6 +6908,9 @@ finish_omp_clauses (tree clauses, enum c_omp_region_type ort)
              if (ort == C_ORT_ACC)
                error_at (OMP_CLAUSE_LOCATION (c),
                          "%qD appears more than once in data clauses", t);
+             else if (OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT (c)
+                      && !OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT_TARGET (c))
+               /* Silently drop the clause.  */;
              else
                error_at (OMP_CLAUSE_LOCATION (c),
                          "%qD appears both in data and map clauses", t);

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 28bf1b0ba25d2037b0a5e6c4fbcbd6841c98d4ab..b62ea0efc1cb589c0d254f32deefcd197ca8eb5a 100644 (file)
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -126,7 +126,10 @@ enum gimplify_omp_var_data
 
   /* Flag for GOVD_MAP: (struct) vars that have pointer attachments for
      fields.  */
-  GOVD_MAP_HAS_ATTACHMENTS = 8388608,
+  GOVD_MAP_HAS_ATTACHMENTS = 0x4000000,
+
+  /* Flag for GOVD_FIRSTPRIVATE: OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT.  */
+  GOVD_FIRSTPRIVATE_IMPLICIT = 0x8000000,
 
   GOVD_DATA_SHARE_CLASS = (GOVD_SHARED | GOVD_PRIVATE | GOVD_FIRSTPRIVATE
                           | GOVD_LASTPRIVATE | GOVD_REDUCTION | GOVD_LINEAR
@@ -8586,13 +8589,24 @@ omp_lastprivate_for_combined_outer_constructs (struct gimplify_omp_ctx *octx,
          omp_add_variable (octx, decl, GOVD_LASTPRIVATE | GOVD_SEEN);
          continue;
        }
-      if (octx->region_type == ORT_COMBINED_TARGET
-         && splay_tree_lookup (octx->variables,
-                               (splay_tree_key) decl) == NULL)
+      if (octx->region_type == ORT_COMBINED_TARGET)
        {
-         omp_add_variable (octx, decl, GOVD_MAP | GOVD_SEEN);
-         octx = octx->outer_context;
-         break;
+         splay_tree_node n = splay_tree_lookup (octx->variables,
+                                                (splay_tree_key) decl);
+         if (n == NULL)
+           {
+             omp_add_variable (octx, decl, GOVD_MAP | GOVD_SEEN);
+             octx = octx->outer_context;
+           }
+         else if (!implicit_p
+                  && (n->value & GOVD_FIRSTPRIVATE_IMPLICIT))
+           {
+             n->value &= ~(GOVD_FIRSTPRIVATE
+                           | GOVD_FIRSTPRIVATE_IMPLICIT
+                           | GOVD_EXPLICIT);
+             omp_add_variable (octx, decl, GOVD_MAP | GOVD_SEEN);
+             octx = octx->outer_context;
+           }
        }
       break;
     }
@@ -8673,6 +8687,11 @@ gimplify_scan_omp_clauses (tree *list_p, gimple_seq *pre_p,
        case OMP_CLAUSE_FIRSTPRIVATE:
          flags = GOVD_FIRSTPRIVATE | GOVD_EXPLICIT;
          check_non_private = "firstprivate";
+         if (OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT (c))
+           {
+             gcc_assert (code == OMP_TARGET);
+             flags |= GOVD_FIRSTPRIVATE_IMPLICIT;
+           }
          goto do_add;
        case OMP_CLAUSE_LASTPRIVATE:
          if (OMP_CLAUSE_LASTPRIVATE_CONDITIONAL (c))
@@ -10532,6 +10551,18 @@ gimplify_adjust_omp_clauses (gimple_seq *pre_p, gimple_seq body, tree *list_p,
              remove = true;
              break;
            }
+         if (OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT (c))
+           {
+             decl = OMP_CLAUSE_DECL (c);
+             n = splay_tree_lookup (ctx->variables, (splay_tree_key) decl);
+             if ((n->value & GOVD_MAP) != 0)
+               {
+                 remove = true;
+                 break;
+               }
+             OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT_TARGET (c) = 0;
+             OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT (c) = 0;
+           }
          /* FALLTHRU */
        case OMP_CLAUSE_PRIVATE:
        case OMP_CLAUSE_SHARED:

diff --git a/gcc/testsuite/c-c++-common/gomp/pr99928-15.c b/gcc/testsuite/c-c++-common/gomp/pr99928-15.c
new file mode 100644 (file)
index 0000000..f0c6232
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/pr99928-15.c
@@ -0,0 +1,26 @@
+/* PR middle-end/99928 */
+
+int v;
+
+void
+foo (void)
+{
+  #pragma omp target parallel firstprivate (v) map(tofrom: v)  /* { dg-bogus "'v' appears both in data and map clauses" } */
+  v++;
+}
+
+void
+bar (void)
+{
+  #pragma omp target firstprivate (v) map (tofrom: v)  /* { dg-error "'v' appears both in data and map clauses" } */
+  v++;
+}
+
+void
+baz (void)
+{
+  int j;
+  #pragma omp target simd firstprivate (v) map (tofrom: v) private (j) /* { dg-error "'v' appears both in data and map clauses" } */
+  for (int i = 0; i < 1; i++)
+    j = v;
+}

diff --git a/gcc/testsuite/c-c++-common/gomp/pr99928-3.c b/gcc/testsuite/c-c++-common/gomp/pr99928-3.c
index 67f590bb7ef4a40679de965d57ff46876defbdf2..cf9c72d75b88f06c9df740d04e5915f75fae70ab 100644 (file)
--- a/gcc/testsuite/c-c++-common/gomp/pr99928-3.c
+++ b/gcc/testsuite/c-c++-common/gomp/pr99928-3.c
@@ -82,8 +82,8 @@ bar (void)
     #pragma omp section
     l07 = 2;
   }
-  /* { dg-final { scan-tree-dump "omp target\[^\n\r]*map\\(tofrom:l08" "gimple" { xfail *-*-* } } } */
-  /* { dg-final { scan-tree-dump-not "omp target\[^\n\r]*firstprivate\\(l08\\)" "gimple" { xfail *-*-* } } } */
+  /* { dg-final { scan-tree-dump "omp target\[^\n\r]*map\\(tofrom:l08" "gimple" } } */
+  /* { dg-final { scan-tree-dump-not "omp target\[^\n\r]*firstprivate\\(l08\\)" "gimple" } } */
   /* { dg-final { scan-tree-dump "omp parallel\[^\n\r]*firstprivate\\(l08\\)" "gimple" } } *//* FIXME: This should be on for instead.  */
   /* { dg-final { scan-tree-dump "omp parallel\[^\n\r]*lastprivate\\(l08\\)" "gimple" } } *//* FIXME: This should be on for instead.  */
   /* { dg-final { scan-tree-dump-not "omp for\[^\n\r]*firstprivate\\(l08\\)" "gimple" } } *//* FIXME.  */
@@ -91,8 +91,8 @@ bar (void)
   #pragma omp target parallel for firstprivate (l08) lastprivate (l08)
   for (int i = 0; i < 64; i++)
     l08 = i;
-  /* { dg-final { scan-tree-dump "omp target\[^\n\r]*map\\(tofrom:l09" "gimple" { xfail *-*-* } } } */
-  /* { dg-final { scan-tree-dump-not "omp target\[^\n\r]*firstprivate\\(l09\\)" "gimple" { xfail *-*-* } } } */
+  /* { dg-final { scan-tree-dump "omp target\[^\n\r]*map\\(tofrom:l09" "gimple" } } */
+  /* { dg-final { scan-tree-dump-not "omp target\[^\n\r]*firstprivate\\(l09\\)" "gimple" } } */
   /* { dg-final { scan-tree-dump "omp parallel\[^\n\r]*firstprivate\\(l09\\)" "gimple" } } *//* FIXME: This should be on for instead.  */
   /* { dg-final { scan-tree-dump "omp parallel\[^\n\r]*lastprivate\\(l09\\)" "gimple" } } *//* FIXME: This should be on for instead.  */
   /* { dg-final { scan-tree-dump-not "omp for\[^\n\r]*firstprivate\\(l09\\)" "gimple" } } *//* FIXME.  */
@@ -102,8 +102,8 @@ bar (void)
   #pragma omp target parallel for simd firstprivate (l09) lastprivate (l09)
   for (int i = 0; i < 64; i++)
     l09 = i;
-  /* { dg-final { scan-tree-dump "omp target\[^\n\r]*map\\(tofrom:l10" "gimple" { xfail *-*-* } } } */
-  /* { dg-final { scan-tree-dump-not "omp target\[^\n\r]*firstprivate\\(l10\\)" "gimple" { xfail *-*-* } } } */
+  /* { dg-final { scan-tree-dump "omp target\[^\n\r]*map\\(tofrom:l10" "gimple" } } */
+  /* { dg-final { scan-tree-dump-not "omp target\[^\n\r]*firstprivate\\(l10\\)" "gimple" } } */
   /* { dg-final { scan-tree-dump-not "omp simd\[^\n\r]*firstprivate\\(l10\\)" "gimple" } } */
   /* { dg-final { scan-tree-dump "omp simd\[^\n\r]*lastprivate\\(l10\\)" "gimple" } } */
   #pragma omp target simd firstprivate (l10) lastprivate (l10)

diff --git a/gcc/tree.h b/gcc/tree.h
index 64612cfa3680b497c3cffe360132ba0f35aa6af0..37aca8963fe4e61a99f6276b86ef6b5beea287ca 100644 (file)
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -1538,6 +1538,11 @@ class auto_suppress_location_wrappers
 #define OMP_CLAUSE_FIRSTPRIVATE_NO_REFERENCE(NODE) \
   TREE_PRIVATE (OMP_CLAUSE_SUBCODE_CHECK (NODE, OMP_CLAUSE_FIRSTPRIVATE))
 
+/* True on a FIRSTPRIVATE clause with OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT also
+   set if target construct is the only one that accepts the clause.  */
+#define OMP_CLAUSE_FIRSTPRIVATE_IMPLICIT_TARGET(NODE) \
+  TREE_PROTECTED (OMP_CLAUSE_SUBCODE_CHECK (NODE, OMP_CLAUSE_FIRSTPRIVATE))
+
 /* True on a LASTPRIVATE clause if a FIRSTPRIVATE clause for the same
    decl is present in the chain.  */
 #define OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE(NODE) \