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