openmp: Add IFN_GOMP_MAX_VF

Delay omp_max_vf call until after the host and device compilers have diverged
so that the max_vf value can be tuned exactly right on both variants.

This change means that the ompdevlow pass must be enabled for functions that
use OpenMP directives with both "simd" and "schedule" enabled.

gcc/ChangeLog:

	* internal-fn.cc (expand_GOMP_MAX_VF): New function.
	* internal-fn.def (GOMP_MAX_VF): New internal function.
	* omp-expand.cc (omp_adjust_chunk_size): Emit IFN_GOMP_MAX_VF when
	called in offload context, otherwise assume host context.
	* omp-offload.cc (execute_omp_device_lower): Expand IFN_GOMP_MAX_VF.

diff --git a/gcc/internal-fn.cc b/gcc/internal-fn.cc
index 1b3fe7be047998f7118a94da74e8d6e1ab6f4938..0ee5f5bc7c55fdea3687f0f6c129f7a09cba4190 100644 (file)
--- a/gcc/internal-fn.cc
+++ b/gcc/internal-fn.cc
@@ -510,6 +510,14 @@ expand_GOMP_SIMT_VF (internal_fn, gcall *)
 
 /* This should get expanded in omp_device_lower pass.  */
 
+static void
+expand_GOMP_MAX_VF (internal_fn, gcall *)
+{
+  gcc_unreachable ();
+}
+
+/* This should get expanded in omp_device_lower pass.  */
+
 static void
 expand_GOMP_TARGET_REV (internal_fn, gcall *)
 {

diff --git a/gcc/internal-fn.def b/gcc/internal-fn.def
index 2d45593827111eabe40ca0afd2d81e2c1411bc4a..c3d0efc0f2c381a1e19097e9757bfb907e1b415c 100644 (file)
--- a/gcc/internal-fn.def
+++ b/gcc/internal-fn.def
@@ -465,6 +465,7 @@ DEF_INTERNAL_FN (GOMP_SIMT_ENTER_ALLOC, ECF_LEAF | ECF_NOTHROW, NULL)
 DEF_INTERNAL_FN (GOMP_SIMT_EXIT, ECF_LEAF | ECF_NOTHROW, NULL)
 DEF_INTERNAL_FN (GOMP_SIMT_LANE, ECF_NOVOPS | ECF_LEAF | ECF_NOTHROW, NULL)
 DEF_INTERNAL_FN (GOMP_SIMT_VF, ECF_NOVOPS | ECF_LEAF | ECF_NOTHROW, NULL)
+DEF_INTERNAL_FN (GOMP_MAX_VF, ECF_CONST | ECF_LEAF | ECF_NOTHROW, NULL)
 DEF_INTERNAL_FN (GOMP_SIMT_LAST_LANE, ECF_NOVOPS | ECF_LEAF | ECF_NOTHROW, NULL)
 DEF_INTERNAL_FN (GOMP_SIMT_ORDERED_PRED, ECF_LEAF | ECF_NOTHROW, NULL)
 DEF_INTERNAL_FN (GOMP_SIMT_VOTE_ANY, ECF_NOVOPS | ECF_LEAF | ECF_NOTHROW, NULL)

diff --git a/gcc/omp-expand.cc b/gcc/omp-expand.cc
index b0f9d375b6c7df869571bacd53905c664f4493e5..80fb1843445d140b36c6e4ed932ce6be5ad6706c 100644 (file)
--- a/gcc/omp-expand.cc
+++ b/gcc/omp-expand.cc
@@ -229,15 +229,29 @@ omp_adjust_chunk_size (tree chunk_size, bool simd_schedule, bool offload)
   if (!simd_schedule || integer_zerop (chunk_size))
     return chunk_size;
 
-  poly_uint64 vf = omp_max_vf (offload);
-  if (known_eq (vf, 1U))
-    return chunk_size;
-
+  tree vf;
   tree type = TREE_TYPE (chunk_size);
-  chunk_size = fold_build2 (PLUS_EXPR, type, chunk_size,
-                           build_int_cst (type, vf - 1));
-  return fold_build2 (BIT_AND_EXPR, type, chunk_size,
-                     build_int_cst (type, -vf));
+
+  if (offload)
+    {
+      cfun->curr_properties &= ~PROP_gimple_lomp_dev;
+      vf = build_call_expr_internal_loc (UNKNOWN_LOCATION, IFN_GOMP_MAX_VF,
+                                        unsigned_type_node, 0);
+      vf = fold_convert (type, vf);
+    }
+  else
+    {
+      poly_uint64 vf_num = omp_max_vf (false);
+      if (known_eq (vf_num, 1U))
+       return chunk_size;
+      vf = build_int_cst (type, vf_num);
+    }
+
+  tree vf_minus_one = fold_build2 (MINUS_EXPR, type, vf,
+                                  build_int_cst (type, 1));
+  tree negative_vf = fold_build1 (NEGATE_EXPR, type, vf);
+  chunk_size = fold_build2 (PLUS_EXPR, type, chunk_size, vf_minus_one);
+  return fold_build2 (BIT_AND_EXPR, type, chunk_size, negative_vf);
 }
 
 /* Collect additional arguments needed to emit a combined

diff --git a/gcc/omp-offload.cc b/gcc/omp-offload.cc
index 25ce8133fe5e6262b70db92ea9d8bf4535139439..372b019f9d601e05f8c313d156780ad0724e72d9 100644 (file)
--- a/gcc/omp-offload.cc
+++ b/gcc/omp-offload.cc
@@ -2754,6 +2754,9 @@ execute_omp_device_lower ()
          case IFN_GOMP_SIMT_VF:
            rhs = build_int_cst (type, vf);
            break;
+         case IFN_GOMP_MAX_VF:
+           rhs = build_int_cst (type, omp_max_vf (false));
+           break;
          case IFN_GOMP_SIMT_ORDERED_PRED:
            rhs = vf == 1 ? integer_zero_node : NULL_TREE;
            if (rhs || !lhs)