Hi!
DECL_IN_CONSTANT_POOL are shared and thus don't really get emitted in the
BLOCK where they are used, so for OpenMP target regions that have initializers
gimplified into copying from them we actually map them at runtime from host to
offload devices. This patch instead marks them as "omp declare target", so
that they are on the target device from the beginning and don't need to be
copied there.
Bootstrapped/regtested on x86_64-linux and i686-linux, tested also with
x86_64-linux to nvptx-none offloading, committed to trunk.
2020-02-09 Jakub Jelinek <ja...@redhat.com>
* gimplify.c (gimplify_adjust_omp_clauses_1): Promote
DECL_IN_CONSTANT_POOL variables into "omp declare target" to avoid
copying them around between host and target.
* testsuite/libgomp.c/target-38.c: New test.
--- gcc/gimplify.c.jj 2020-01-15 11:05:19.248141349 +0100
+++ gcc/gimplify.c 2020-02-07 19:04:05.646917169 +0100
@@ -9902,6 +9902,22 @@ gimplify_adjust_omp_clauses_1 (splay_tre
error ("%<_Atomic%> %qD in implicit %<map%> clause", decl);
return 0;
}
+ if (VAR_P (decl)
+ && DECL_IN_CONSTANT_POOL (decl)
+ && !lookup_attribute ("omp declare target",
+ DECL_ATTRIBUTES (decl)))
+ {
+ tree id = get_identifier ("omp declare target");
+ DECL_ATTRIBUTES (decl)
+ = tree_cons (id, NULL_TREE, DECL_ATTRIBUTES (decl));
+ varpool_node *node = varpool_node::get (decl);
+ if (node)
+ {
+ node->offloadable = 1;
+ if (ENABLE_OFFLOADING)
+ g->have_offload = true;
+ }
+ }
}
else if (flags & GOVD_SHARED)
{
--- libgomp/testsuite/libgomp.c/target-38.c.jj 2020-02-07 19:06:58.717373079
+0100
+++ libgomp/testsuite/libgomp.c/target-38.c 2020-02-07 19:06:32.862753134
+0100
@@ -0,0 +1,28 @@
+#define A(n) n##0, n##1, n##2, n##3, n##4, n##5, n##6, n##7, n##8, n##9
+#define B(n) A(n##0), A(n##1), A(n##2), A(n##3), A(n##4), A(n##5), A(n##6),
A(n##7), A(n##8), A(n##9)
+
+int
+foo (int x)
+{
+ int b[] = { B(4), B(5), B(6) };
+ return b[x];
+}
+
+int v[] = { 1, 2, 3, 4, 5, 6 };
+#pragma omp declare target to (foo, v)
+
+int
+main ()
+{
+ int i = 5;
+ asm ("" : "+g" (i));
+ #pragma omp target map(tofrom:i)
+ {
+ int a[] = { B(1), B(2), B(3) };
+ asm ("" : : "m" (a) : "memory");
+ i = a[i] + foo (i) + v[i & 63];
+ }
+ if (i != 105 + 405 + 6)
+ __builtin_abort ();
+ return 0;
+}
Jakub
