From 6c7509bc070b29293ca9874518b89227ce05361c Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Tue, 22 Nov 2016 18:56:43 +0100 Subject: [PATCH] OpenMP loop cloning for SIMT execution 2016-11-22 Jakub Jelinek Alexander Monakov * internal-fn.c (expand_GOMP_USE_SIMT): New function. * tree.c (omp_clause_num_ops): OMP_CLAUSE__SIMT_ has 0 operands. (omp_clause_code_name): Add _simt_ name. (walk_tree_1): Handle OMP_CLAUSE__SIMT_. * tree-core.h (enum omp_clause_code): Add OMP_CLAUSE__SIMT_. * omp-low.c (scan_sharing_clauses): Handle OMP_CLAUSE__SIMT_. (scan_omp_simd): New function. (scan_omp_1_stmt): Use it in target regions if needed. (omp_max_vf): Don't max with omp_max_simt_vf. (lower_rec_simd_input_clauses): Use omp_max_simt_vf if OMP_CLAUSE__SIMT_ is present. (lower_rec_input_clauses): Compute maybe_simt from presence of OMP_CLAUSE__SIMT_. (lower_lastprivate_clauses): Likewise. (expand_omp_simd): Likewise. (execute_omp_device_lower): Lower IFN_GOMP_USE_SIMT. * internal-fn.def (GOMP_USE_SIMT): New internal function. * tree-pretty-print.c (dump_omp_clause): Handle OMP_CLAUSE__SIMT_. Co-Authored-By: Alexander Monakov From-SVN: r242714 --- gcc/ChangeLog | 22 ++++++++++++ gcc/internal-fn.c | 8 +++++ gcc/internal-fn.def | 1 + gcc/omp-low.c | 79 +++++++++++++++++++++++++++++++++++------ gcc/tree-core.h | 4 +++ gcc/tree-pretty-print.c | 4 +++ gcc/tree.c | 3 ++ 7 files changed, 110 insertions(+), 11 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 8ee26220090..c4cd4c64ded 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,25 @@ +2016-11-22 Jakub Jelinek + Alexander Monakov + + * internal-fn.c (expand_GOMP_USE_SIMT): New function. + * tree.c (omp_clause_num_ops): OMP_CLAUSE__SIMT_ has 0 operands. + (omp_clause_code_name): Add _simt_ name. + (walk_tree_1): Handle OMP_CLAUSE__SIMT_. + * tree-core.h (enum omp_clause_code): Add OMP_CLAUSE__SIMT_. + * omp-low.c (scan_sharing_clauses): Handle OMP_CLAUSE__SIMT_. + (scan_omp_simd): New function. + (scan_omp_1_stmt): Use it in target regions if needed. + (omp_max_vf): Don't max with omp_max_simt_vf. + (lower_rec_simd_input_clauses): Use omp_max_simt_vf if + OMP_CLAUSE__SIMT_ is present. + (lower_rec_input_clauses): Compute maybe_simt from presence of + OMP_CLAUSE__SIMT_. + (lower_lastprivate_clauses): Likewise. + (expand_omp_simd): Likewise. Remove explicit offloaded region check. + (execute_omp_device_lower): Lower IFN_GOMP_USE_SIMT. + * internal-fn.def (GOMP_USE_SIMT): New internal function. + * tree-pretty-print.c (dump_omp_clause): Handle OMP_CLAUSE__SIMT_. + 2016-11-22 Alexander Monakov * internal-fn.c (expand_GOMP_SIMT_LANE): New. diff --git a/gcc/internal-fn.c b/gcc/internal-fn.c index 6cd8522d7c4..b1dbc988b9c 100644 --- a/gcc/internal-fn.c +++ b/gcc/internal-fn.c @@ -158,6 +158,14 @@ expand_ANNOTATE (internal_fn, gcall *) gcc_unreachable (); } +/* This should get expanded in omp_device_lower pass. */ + +static void +expand_GOMP_USE_SIMT (internal_fn, gcall *) +{ + gcc_unreachable (); +} + /* Lane index on SIMT targets: thread index in the warp on NVPTX. On targets without SIMT execution this should be expanded in omp_device_lower pass. */ diff --git a/gcc/internal-fn.def b/gcc/internal-fn.def index f055230f722..9a03e17be23 100644 --- a/gcc/internal-fn.def +++ b/gcc/internal-fn.def @@ -141,6 +141,7 @@ DEF_INTERNAL_INT_FN (FFS, ECF_CONST, ffs, unary) DEF_INTERNAL_INT_FN (PARITY, ECF_CONST, parity, unary) DEF_INTERNAL_INT_FN (POPCOUNT, ECF_CONST, popcount, unary) +DEF_INTERNAL_FN (GOMP_USE_SIMT, ECF_NOVOPS | 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_SIMT_LAST_LANE, ECF_NOVOPS | ECF_LEAF | ECF_NOTHROW, NULL) diff --git a/gcc/omp-low.c b/gcc/omp-low.c index 6c52bff74ba..eab0af5b58d 100644 --- a/gcc/omp-low.c +++ b/gcc/omp-low.c @@ -278,6 +278,7 @@ static bool omp_any_child_fn_dumped; static void scan_omp (gimple_seq *, omp_context *); static tree scan_omp_1_op (tree *, int *, void *); static gphi *find_phi_with_arg_on_edge (tree, edge); +static int omp_max_simt_vf (void); #define WALK_SUBSTMTS \ case GIMPLE_BIND: \ @@ -2192,6 +2193,7 @@ scan_sharing_clauses (tree clauses, omp_context *ctx, case OMP_CLAUSE_INDEPENDENT: case OMP_CLAUSE_AUTO: case OMP_CLAUSE_SEQ: + case OMP_CLAUSE__SIMT_: break; case OMP_CLAUSE_ALIGNED: @@ -2363,6 +2365,7 @@ scan_sharing_clauses (tree clauses, omp_context *ctx, case OMP_CLAUSE_AUTO: case OMP_CLAUSE_SEQ: case OMP_CLAUSE__GRIDDIM_: + case OMP_CLAUSE__SIMT_: break; case OMP_CLAUSE_TILE: @@ -3066,6 +3069,48 @@ scan_omp_for (gomp_for *stmt, omp_context *outer_ctx) scan_omp (gimple_omp_body_ptr (stmt), ctx); } +/* Duplicate #pragma omp simd, one for SIMT, another one for SIMD. */ + +static void +scan_omp_simd (gimple_stmt_iterator *gsi, gomp_for *stmt, + omp_context *outer_ctx) +{ + gbind *bind = gimple_build_bind (NULL, NULL, NULL); + gsi_replace (gsi, bind, false); + gimple_seq seq = NULL; + gimple *g = gimple_build_call_internal (IFN_GOMP_USE_SIMT, 0); + tree cond = create_tmp_var_raw (integer_type_node); + DECL_CONTEXT (cond) = current_function_decl; + DECL_SEEN_IN_BIND_EXPR_P (cond) = 1; + gimple_bind_set_vars (bind, cond); + gimple_call_set_lhs (g, cond); + gimple_seq_add_stmt (&seq, g); + tree lab1 = create_artificial_label (UNKNOWN_LOCATION); + tree lab2 = create_artificial_label (UNKNOWN_LOCATION); + tree lab3 = create_artificial_label (UNKNOWN_LOCATION); + g = gimple_build_cond (NE_EXPR, cond, integer_zero_node, lab1, lab2); + gimple_seq_add_stmt (&seq, g); + g = gimple_build_label (lab1); + gimple_seq_add_stmt (&seq, g); + gimple_seq new_seq = copy_gimple_seq_and_replace_locals (stmt); + gomp_for *new_stmt = as_a (new_seq); + tree clause = build_omp_clause (gimple_location (stmt), OMP_CLAUSE__SIMT_); + OMP_CLAUSE_CHAIN (clause) = gimple_omp_for_clauses (new_stmt); + gimple_omp_for_set_clauses (new_stmt, clause); + gimple_seq_add_stmt (&seq, new_stmt); + g = gimple_build_goto (lab3); + gimple_seq_add_stmt (&seq, g); + g = gimple_build_label (lab2); + gimple_seq_add_stmt (&seq, g); + gimple_seq_add_stmt (&seq, stmt); + g = gimple_build_label (lab3); + gimple_seq_add_stmt (&seq, g); + gimple_bind_set_body (bind, seq); + update_stmt (bind); + scan_omp_for (new_stmt, outer_ctx); + scan_omp_for (stmt, outer_ctx); +} + /* Scan an OpenMP sections directive. */ static void @@ -3969,7 +4014,13 @@ scan_omp_1_stmt (gimple_stmt_iterator *gsi, bool *handled_ops_p, break; case GIMPLE_OMP_FOR: - scan_omp_for (as_a (stmt), ctx); + if (((gimple_omp_for_kind (as_a (stmt)) + & GF_OMP_FOR_KIND_MASK) == GF_OMP_FOR_KIND_SIMD) + && omp_maybe_offloaded_ctx (ctx) + && omp_max_simt_vf ()) + scan_omp_simd (gsi, as_a (stmt), ctx); + else + scan_omp_for (as_a (stmt), ctx); break; case GIMPLE_OMP_SECTIONS: @@ -4316,8 +4367,7 @@ omp_max_vf (void) if (GET_MODE_CLASS (vqimode) == MODE_VECTOR_INT) vf = GET_MODE_NUNITS (vqimode); } - int svf = omp_max_simt_vf (); - return MAX (vf, svf); + return vf; } /* Helper function of lower_rec_input_clauses, used for #pragma omp simd @@ -4329,7 +4379,11 @@ lower_rec_simd_input_clauses (tree new_var, omp_context *ctx, int &max_vf, { if (max_vf == 0) { - max_vf = omp_max_vf (); + if (find_omp_clause (gimple_omp_for_clauses (ctx->stmt), + OMP_CLAUSE__SIMT_)) + max_vf = omp_max_simt_vf (); + else + max_vf = omp_max_vf (); if (max_vf > 1) { tree c = find_omp_clause (gimple_omp_for_clauses (ctx->stmt), @@ -4405,8 +4459,7 @@ lower_rec_input_clauses (tree clauses, gimple_seq *ilist, gimple_seq *dlist, int pass; bool is_simd = (gimple_code (ctx->stmt) == GIMPLE_OMP_FOR && gimple_omp_for_kind (ctx->stmt) & GF_OMP_FOR_SIMD); - bool maybe_simt - = is_simd && omp_maybe_offloaded_ctx (ctx) && omp_max_simt_vf () > 1; + bool maybe_simt = is_simd && find_omp_clause (clauses, OMP_CLAUSE__SIMT_); int max_vf = 0; tree lane = NULL_TREE, idx = NULL_TREE; tree simt_lane = NULL_TREE; @@ -5497,7 +5550,7 @@ lower_lastprivate_clauses (tree clauses, tree predicate, gimple_seq *stmt_list, if (gimple_code (ctx->stmt) == GIMPLE_OMP_FOR && gimple_omp_for_kind (ctx->stmt) & GF_OMP_FOR_SIMD) { - maybe_simt = omp_maybe_offloaded_ctx (ctx) && omp_max_simt_vf () > 1; + maybe_simt = find_omp_clause (orig_clauses, OMP_CLAUSE__SIMT_); simduid = find_omp_clause (orig_clauses, OMP_CLAUSE__SIMDUID_); if (simduid) simduid = OMP_CLAUSE__SIMDUID__DECL (simduid); @@ -10749,10 +10802,9 @@ expand_omp_simd (struct omp_region *region, struct omp_for_data *fd) } tree step = fd->loop.step; - bool offloaded = cgraph_node::get (current_function_decl)->offloadable; - for (struct omp_region *rgn = region; !offloaded && rgn; rgn = rgn->outer) - offloaded = rgn->type == GIMPLE_OMP_TARGET; - bool is_simt = offloaded && omp_max_simt_vf () > 1 && safelen_int > 1; + bool is_simt = (safelen_int > 1 + && find_omp_clause (gimple_omp_for_clauses (fd->for_stmt), + OMP_CLAUSE__SIMT_)); tree simt_lane = NULL_TREE, simt_maxlane = NULL_TREE; if (is_simt) { @@ -15006,6 +15058,8 @@ lower_omp_ordered (gimple_stmt_iterator *gsi_p, omp_context *ctx) gbind *bind; bool simd = find_omp_clause (gimple_omp_ordered_clauses (ord_stmt), OMP_CLAUSE_SIMD); + /* FIXME: this should check presence of OMP_CLAUSE__SIMT_ on the enclosing + loop. */ bool maybe_simt = simd && omp_maybe_offloaded_ctx (ctx) && omp_max_simt_vf () > 1; bool threads = find_omp_clause (gimple_omp_ordered_clauses (ord_stmt), @@ -20167,6 +20221,9 @@ execute_omp_device_lower () tree type = lhs ? TREE_TYPE (lhs) : integer_type_node; switch (gimple_call_internal_fn (stmt)) { + case IFN_GOMP_USE_SIMT: + rhs = vf == 1 ? integer_zero_node : integer_one_node; + break; case IFN_GOMP_SIMT_LANE: case IFN_GOMP_SIMT_LAST_LANE: rhs = vf == 1 ? build_zero_cst (type) : NULL_TREE; diff --git a/gcc/tree-core.h b/gcc/tree-core.h index a3d220df246..eec2d4f35b5 100644 --- a/gcc/tree-core.h +++ b/gcc/tree-core.h @@ -438,6 +438,10 @@ enum omp_clause_code { /* Internally used only clause, holding SIMD uid. */ OMP_CLAUSE__SIMDUID_, + /* Internally used only clause, flag whether this is SIMT simd + loop or not. */ + OMP_CLAUSE__SIMT_, + /* Internally used only clause, holding _Cilk_for # of iterations on OMP_PARALLEL. */ OMP_CLAUSE__CILK_FOR_COUNT_, diff --git a/gcc/tree-pretty-print.c b/gcc/tree-pretty-print.c index 096eefdd4f6..95db7100428 100644 --- a/gcc/tree-pretty-print.c +++ b/gcc/tree-pretty-print.c @@ -893,6 +893,10 @@ dump_omp_clause (pretty_printer *pp, tree clause, int spc, int flags) pp_right_paren (pp); break; + case OMP_CLAUSE__SIMT_: + pp_string (pp, "_simt_"); + break; + case OMP_CLAUSE_GANG: pp_string (pp, "gang"); if (OMP_CLAUSE_GANG_EXPR (clause) != NULL_TREE) diff --git a/gcc/tree.c b/gcc/tree.c index a4c5b1b968d..9b0b806cb56 100644 --- a/gcc/tree.c +++ b/gcc/tree.c @@ -320,6 +320,7 @@ unsigned const char omp_clause_num_ops[] = 1, /* OMP_CLAUSE_HINT */ 0, /* OMP_CLAUSE_DEFALTMAP */ 1, /* OMP_CLAUSE__SIMDUID_ */ + 0, /* OMP_CLAUSE__SIMT_ */ 1, /* OMP_CLAUSE__CILK_FOR_COUNT_ */ 0, /* OMP_CLAUSE_INDEPENDENT */ 1, /* OMP_CLAUSE_WORKER */ @@ -391,6 +392,7 @@ const char * const omp_clause_code_name[] = "hint", "defaultmap", "_simduid_", + "_simt_", "_Cilk_for_count_", "independent", "worker", @@ -11893,6 +11895,7 @@ walk_tree_1 (tree *tp, walk_tree_fn func, void *data, case OMP_CLAUSE_AUTO: case OMP_CLAUSE_SEQ: case OMP_CLAUSE_TILE: + case OMP_CLAUSE__SIMT_: WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp)); case OMP_CLAUSE_LASTPRIVATE: -- 2.30.2