OpenMP: Add flag for code elision to omp_context_selector_matches.

The "begin declare variant" has different rules for determining
whether a context selector cannot match for purposes of code elision
than we normally use; it excludes the case of a constant false
"condition" selector for the "user" set.

gcc/ChangeLog
	* omp-general.cc (omp_context_selector_matches): Add an optional
	bool argument for the code elision case.
	* omp-general.h (omp_context_selector_matches): Likewise.

diff --git a/gcc/omp-general.cc b/gcc/omp-general.cc
index 194dff3e8923c3fabd474693134e391f10cf9699..5fa0b3958446fe84ede6fc686af3ba6fc53e21ab 100644 (file)
--- a/gcc/omp-general.cc
+++ b/gcc/omp-general.cc
@@ -1744,13 +1744,19 @@ omp_construct_traits_match (tree selector_traits, tree context_traits,
    CONSTRUCT_CONTEXT is known to be complete and not missing constructs
    filled in later during compilation.
 
+   If DECLARE_VARIANT_ELISION_P is true, the function implements the test
+   for elision of preprocessed code in "begin declare variant" constructs,
+   and returns 0 only for failure to match traits in the device and
+   implementation sets.
+
    Dynamic properties (which are evaluated at run-time) should always
    return 1.  */
 
 int
 omp_context_selector_matches (tree ctx,
                              tree construct_context,
-                             bool complete_p)
+                             bool complete_p,
+                             bool declare_variant_elision_p)
 {
   int ret = 1;
   bool maybe_offloaded = omp_maybe_offloaded (construct_context);
@@ -1762,9 +1768,12 @@ omp_context_selector_matches (tree ctx,
 
       /* Immediately reject the match if there are any ignored
         selectors present.  */
-      for (tree ts = selectors; ts; ts = TREE_CHAIN (ts))
-       if (OMP_TS_CODE (ts) == OMP_TRAIT_INVALID)
-         return 0;
+      if (!declare_variant_elision_p
+         || set == OMP_TRAIT_SET_DEVICE
+         || set == OMP_TRAIT_SET_IMPLEMENTATION)
+       for (tree ts = selectors; ts; ts = TREE_CHAIN (ts))
+         if (OMP_TS_CODE (ts) == OMP_TRAIT_INVALID)
+           return 0;
 
       if (set == OMP_TRAIT_SET_CONSTRUCT)
        {
@@ -2118,6 +2127,13 @@ omp_context_selector_matches (tree ctx,
              break;
            case OMP_TRAIT_USER_CONDITION:
              gcc_assert (set == OMP_TRAIT_SET_USER);
+             /* The spec does not include the "user" set in the things that
+                can trigger code elision in "begin declare variant".  */
+             if (declare_variant_elision_p)
+               {
+                 ret = -1;
+                 break;
+               }
              for (tree p = OMP_TS_PROPERTIES (ts); p; p = TREE_CHAIN (p))
                if (OMP_TP_NAME (p) == NULL_TREE)
                  {
@@ -2133,6 +2149,10 @@ omp_context_selector_matches (tree ctx,
                    ret = -1;
                  }
              break;
+           case OMP_TRAIT_INVALID:
+             /* This is only for the declare_variant_elision_p case.  */
+             ret = -1;
+             break;
            default:
              break;
            }

diff --git a/gcc/omp-general.h b/gcc/omp-general.h
index 553230d429e13852eaf0ec6b3698e88852119086..a83f7dcaa795d9b4ee43732ec9c71f646b8d0b04 100644 (file)
--- a/gcc/omp-general.h
+++ b/gcc/omp-general.h
@@ -205,7 +205,7 @@ extern bool omp_check_for_duplicate_variant (location_t loc,
                                             tree base_decl, tree ctx);
 extern void omp_mark_declare_variant (location_t loc, tree variant,
                                      tree construct);
-extern int omp_context_selector_matches (tree, tree, bool);
+extern int omp_context_selector_matches (tree, tree, bool, bool = false);
 extern tree omp_merge_context_selectors (location_t, tree, tree,
                                         enum omp_ctx_directive);
 extern tree resolve_omp_target_device_matches (tree node);