From: Tom de Vries Date: Tue, 6 Oct 2020 11:07:25 +0000 (+0200) Subject: [openacc] Fix acc declare for VLAs X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=3f2e15c2e66af9cca1dfe24ad7e9692f511ebd06;p=gcc.git [openacc] Fix acc declare for VLAs Consider test-case test.c, with VLA A: ... int main (void) { int N = 1000; int A[N]; #pragma acc declare copy(A) return 0; } ... compiled using: ... $ gcc test.c -fopenacc -S -fdump-tree-all ... At original, we have: ... #pragma acc declare map(tofrom:A); ... but at gimple, we have a map (to:A.1), but not a map (from:A.1): ... int[0:D.2074] * A.1; { int A[0:D.2074] [value-expr: *A.1]; saved_stack.2 = __builtin_stack_save (); try { A.1 = __builtin_alloca_with_align (D.2078, 32); #pragma omp target oacc_declare map(to:(*A.1) [len: D.2076]) } finally { __builtin_stack_restore (saved_stack.2); } } ... This is caused by the following incompatibility. When storing the desired from clause in oacc_declare_returns, we use 'A.1' as the key: ... 10898 oacc_declare_returns->put (decl, c); (gdb) call debug_generic_expr (decl) A.1 (gdb) call debug_generic_expr (c) map(from:(*A.1)) ... but when looking it up, we use 'A' as the key: ... (gdb) 1471 tree *c = oacc_declare_returns->get (t); (gdb) call debug_generic_expr (t) A ... Fix this by extracing the 'A.1' lookup key from 'A' using the decl-expr. In addition, unshare the looked up value, to fix avoid running into an "incorrect sharing of tree nodes" error. Using these two fixes, we get our desired: ... finally { + #pragma omp target oacc_declare map(from:(*A.1)) __builtin_stack_restore (saved_stack.2); } ... Build on x86_64-linux with nvptx accelerator, tested libgomp. gcc/ChangeLog: 2020-10-06 Tom de Vries PR middle-end/90861 * gimplify.c (gimplify_bind_expr): Handle lookup in oacc_declare_returns using key with decl-expr. libgomp/ChangeLog: 2020-10-06 Tom de Vries PR middle-end/90861 * testsuite/libgomp.oacc-c-c++-common/declare-vla.c: Remove xfail. --- diff --git a/gcc/gimplify.c b/gcc/gimplify.c index 2dea03cce3d..fa89e797940 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -1468,15 +1468,22 @@ gimplify_bind_expr (tree *expr_p, gimple_seq *pre_p) if (flag_openacc && oacc_declare_returns != NULL) { - tree *c = oacc_declare_returns->get (t); + tree key = t; + if (DECL_HAS_VALUE_EXPR_P (key)) + { + key = DECL_VALUE_EXPR (key); + if (TREE_CODE (key) == INDIRECT_REF) + key = TREE_OPERAND (key, 0); + } + tree *c = oacc_declare_returns->get (key); if (c != NULL) { if (ret_clauses) OMP_CLAUSE_CHAIN (*c) = ret_clauses; - ret_clauses = *c; + ret_clauses = unshare_expr (*c); - oacc_declare_returns->remove (t); + oacc_declare_returns->remove (key); if (oacc_declare_returns->is_empty ()) { diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/declare-vla.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/declare-vla.c index 0f51badca42..714935772c1 100644 --- a/libgomp/testsuite/libgomp.oacc-c-c++-common/declare-vla.c +++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/declare-vla.c @@ -59,8 +59,3 @@ main () return 0; } - - -/* { dg-xfail-run-if "TODO PR90861" { *-*-* } { "-DACC_MEM_SHARED=0" } } - This might XPASS if the compiler happens to put the two 'A' VLAs at the same - address. */