2018-06-29 Cesar Philippidis Nathan Sidwell gcc/ * config/nvptx/nvptx.c (nvptx_propagate_unified): New. (nvptx_split_blocks): Call it for cond_uni insn. (nvptx_expand_cond_uni): New. (enum nvptx_builtins): Add NVPTX_BUILTIN_COND_UNI. (nvptx_init_builtins): Initialize it. (nvptx_expand_builtin): (nvptx_generate_vector_shuffle): Change integral SHIFT operand to tree BITS operand. (nvptx_vector_reduction): New. (nvptx_adjust_reduction_type): New. (nvptx_goacc_reduction_setup): Use it to adjust the type of ref_to_res. (nvptx_goacc_reduction_init): Don't update LHS if it doesn't exist. (nvptx_goacc_reduction_fini): Call nvptx_vector_reduction for vector. Use it to adjust the type of ref_to_res. (nvptx_goacc_reduction_teardown): * config/nvptx/nvptx.md (cond_uni): New pattern. * omp-general.h (enum oacc_loop_flags): Add OLF_REDUCTION enum. * omp-low.c (lower_oacc_reductions): Handle reduction decls mapped with GOMP_MAP_FIRSTPRIVATE_POINTER. (lower_oacc_head_mark): Use OLF_REDUCTION to mark OpenACC reductions. * omp-offload.c (oacc_loop_auto_partitions): Don't assign gang level parallelism to orphan reductions. (default_goacc_reduction): Retype ref_to_res as necessary. --- diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c index 5608bee8a8d..33ec3db1153 100644 --- a/gcc/config/nvptx/nvptx.c +++ b/gcc/config/nvptx/nvptx.c @@ -2863,6 +2863,52 @@ nvptx_reorg_uniform_simt () } } +/* UNIFIED is a cond_uni insn. Find the branch insn it affects, and + mark that as unified. We expect to be in a single block. */ + +static void +nvptx_propagate_unified (rtx_insn *unified) +{ + rtx_insn *probe = unified; + rtx cond_reg = SET_DEST (PATTERN (unified)); + rtx pat = NULL_RTX; + + /* Find the comparison. (We could skip this and simply scan to he + blocks' terminating branch, if we didn't care for self + checking.) */ + for (;;) + { + probe = next_real_insn (probe); + if (!probe) + break; + pat = PATTERN (probe); + + if (GET_CODE (pat) == SET + && GET_RTX_CLASS (GET_CODE (SET_SRC (pat))) == RTX_COMPARE + && XEXP (SET_SRC (pat), 0) == cond_reg) + break; + gcc_assert (NONJUMP_INSN_P (probe)); + } + gcc_assert (pat); + rtx pred_reg = SET_DEST (pat); + + /* Find the branch. */ + do + probe = NEXT_INSN (probe); + while (!JUMP_P (probe)); + + pat = PATTERN (probe); + rtx itec = XEXP (SET_SRC (pat), 0); + gcc_assert (XEXP (itec, 0) == pred_reg); + + /* Mark the branch's condition as unified. */ + rtx unspec = gen_rtx_UNSPEC (BImode, gen_rtvec (1, pred_reg), + UNSPEC_BR_UNIFIED); + bool ok = validate_change (probe, &XEXP (itec, 0), unspec, false); + + gcc_assert (ok); +} + /* Loop structure of the function. The entire function is described as a NULL loop. */ @@ -2964,6 +3010,9 @@ nvptx_split_blocks (bb_insn_map_t *map) continue; switch (recog_memoized (insn)) { + case CODE_FOR_cond_uni: + nvptx_propagate_unified (insn); + /* FALLTHROUGH */ default: seen_insn = true; continue; @@ -5080,6 +5129,21 @@ nvptx_expand_cmp_swap (tree exp, rtx target, return target; } +/* Expander for the compare unified builtin. */ + +static rtx +nvptx_expand_cond_uni (tree exp, rtx target, machine_mode mode, int ignore) +{ + if (ignore) + return target; + + rtx src = expand_expr (CALL_EXPR_ARG (exp, 0), + NULL_RTX, mode, EXPAND_NORMAL); + + emit_insn (gen_cond_uni (target, src)); + + return target; +} /* Codes for all the NVPTX builtins. */ enum nvptx_builtins @@ -5089,6 +5153,7 @@ enum nvptx_builtins NVPTX_BUILTIN_WORKER_ADDR, NVPTX_BUILTIN_CMP_SWAP, NVPTX_BUILTIN_CMP_SWAPLL, + NVPTX_BUILTIN_COND_UNI, NVPTX_BUILTIN_MAX }; @@ -5126,6 +5191,7 @@ nvptx_init_builtins (void) (PTRVOID, ST, UINT, UINT, NULL_TREE)); DEF (CMP_SWAP, "cmp_swap", (UINT, PTRVOID, UINT, UINT, NULL_TREE)); DEF (CMP_SWAPLL, "cmp_swapll", (LLUINT, PTRVOID, LLUINT, LLUINT, NULL_TREE)); + DEF (COND_UNI, "cond_uni", (integer_type_node, integer_type_node, NULL_TREE)); #undef DEF #undef ST @@ -5158,6 +5224,9 @@ nvptx_expand_builtin (tree exp, rtx target, rtx ARG_UNUSED (subtarget), case NVPTX_BUILTIN_CMP_SWAPLL: return nvptx_expand_cmp_swap (exp, target, mode, ignore); + case NVPTX_BUILTIN_COND_UNI: + return nvptx_expand_cond_uni (exp, target, mode, ignore); + default: gcc_unreachable (); } } @@ -5284,7 +5353,7 @@ nvptx_get_worker_red_addr (tree type, tree offset) static void nvptx_generate_vector_shuffle (location_t loc, - tree dest_var, tree var, unsigned shift, + tree dest_var, tree var, tree bits, gimple_seq *seq) { unsigned fn = NVPTX_BUILTIN_SHUFFLE; @@ -5307,7 +5376,6 @@ nvptx_generate_vector_shuffle (location_t loc, } tree call = nvptx_builtin_decl (fn, true); - tree bits = build_int_cst (unsigned_type_node, shift); tree kind = build_int_cst (unsigned_type_node, SHUFFLE_DOWN); tree expr; @@ -5583,6 +5651,126 @@ nvptx_reduction_update (location_t loc, gimple_stmt_iterator *gsi, return nvptx_lockfull_update (loc, gsi, ptr, var, op); } +/* Emit a vector-level reduction loop. OLD_VAR is the incoming + variable to reduce (valid in each vector), OP is the reduction + operator. Return the reduced value (an SSA var). + + The code we generate looks like: + unsigned old_shift = DIM_SIZE(VECTOR); + do + { + shift = PHI (old_shift, new_shift); + var = PHI (old_var, new_var); + new_shift = shift >> 1; + other_var = VSHUFFLE (var, new_shift); + new_var = var OP other_var; + cond_var = builtin_cond_uni (new_shift); + } + while (cond_var > 1); + + The builtin_cond_ini expands to a cond_uni instruction, which is + processed in nvpts_split_blocks to mark the loop's terminating + branch instruction. */ + +static tree +nvptx_vector_reduction (location_t loc, gimple_stmt_iterator *gsi, + tree old_var, tree_code op) +{ + tree var_type = TREE_TYPE (old_var); + + /* Emit old_shift = DIM_SIZE(VECTOR) */ + tree old_shift = make_ssa_name (integer_type_node); + tree dim = build_int_cst (integer_type_node, GOMP_DIM_VECTOR); + gcall *call = gimple_build_call_internal (IFN_GOACC_DIM_SIZE, 1, dim); + gimple_set_lhs (call, old_shift); + gimple_set_location (call, loc); + gsi_insert_before (gsi, call, GSI_SAME_STMT); + + /* Split the block just after the init stmts. */ + basic_block pre_bb = gsi_bb (*gsi); + edge pre_edge = split_block (pre_bb, call); + basic_block loop_bb = pre_edge->dest; + pre_bb = pre_edge->src; + /* Reset the iterator. */ + *gsi = gsi_for_stmt (gsi_stmt (*gsi)); + + tree shift = make_ssa_name (integer_type_node); + tree new_shift = make_ssa_name (integer_type_node); + tree var = make_ssa_name (var_type); + tree other_var = make_ssa_name (var_type); + tree new_var = make_ssa_name (var_type); + + /* Build and insert the loop body. */ + gimple_seq loop_seq = NULL; + + /* new_shift = shift >> 1 */ + tree shift_expr = fold_build2 (RSHIFT_EXPR, integer_type_node, + shift, integer_one_node); + gimplify_assign (new_shift, shift_expr, &loop_seq); + + /* other_var = shuffle (var, shift) */ + nvptx_generate_vector_shuffle (loc, other_var, var, new_shift, &loop_seq); + /* new_var = var OP other_var */ + tree red_expr = fold_build2 (op, var_type, var, other_var); + gimplify_assign (new_var, red_expr, &loop_seq); + + /* Mark the iterator variable as unified. */ + tree cond_var = make_ssa_name (integer_type_node); + tree uni_fn = nvptx_builtin_decl (NVPTX_BUILTIN_COND_UNI, true); + tree uni_expr = build_call_expr_loc (loc, uni_fn, 1, new_shift); + gimplify_assign (cond_var, uni_expr, &loop_seq); + + gcond *cond = gimple_build_cond (LE_EXPR, cond_var, integer_one_node, + NULL_TREE, NULL_TREE); + gimple_seq_add_stmt (&loop_seq, cond); + + gsi_insert_seq_before (gsi, loop_seq, GSI_SAME_STMT); + + /* Split the block just after the loop stmts. */ + edge post_edge = split_block (loop_bb, cond); + basic_block post_bb = post_edge->dest; + loop_bb = post_edge->src; + *gsi = gsi_for_stmt (gsi_stmt (*gsi)); + + /* Create the loop. */ + post_edge->flags ^= EDGE_TRUE_VALUE | EDGE_FALLTHRU; + edge loop_edge = make_edge (loop_bb, loop_bb, EDGE_FALSE_VALUE); + set_immediate_dominator (CDI_DOMINATORS, loop_bb, pre_bb); + set_immediate_dominator (CDI_DOMINATORS, post_bb, loop_bb); + + gphi *shift_phi = create_phi_node (shift, loop_bb); + add_phi_arg (shift_phi, old_shift, pre_edge, loc); + add_phi_arg (shift_phi, new_shift, loop_edge, loc); + + gphi *var_phi = create_phi_node (var, loop_bb); + add_phi_arg (var_phi, old_var, pre_edge, loc); + add_phi_arg (var_phi, new_var, loop_edge, loc); + + loop *loop = alloc_loop (); + loop->header = loop_bb; + loop->latch = loop_bb; + add_loop (loop, loop_bb->loop_father); + + return new_var; +} + +/* Dummy reduction vars that have GOMP_MAP_FIRSTPRIVATE_POINTER data + mappings gets retyped to (void *). Adjust the type of VAR to TYPE + as appropriate. */ + +static tree +nvptx_adjust_reduction_type (tree var, tree type, gimple_seq *seq) +{ + if (TREE_TYPE (TREE_TYPE (var)) == type) + return var; + + tree ptype = build_pointer_type (type); + tree t = make_ssa_name (ptype); + tree expr = fold_build1 (NOP_EXPR, ptype, var); + gimple_seq_add_stmt (seq, gimple_build_assign (t, expr)); + return t; +} + /* NVPTX implementation of GOACC_REDUCTION_SETUP. */ static void @@ -5602,7 +5790,11 @@ nvptx_goacc_reduction_setup (gcall *call) tree ref_to_res = gimple_call_arg (call, 1); if (!integer_zerop (ref_to_res)) - var = build_simple_mem_ref (ref_to_res); + { + ref_to_res = nvptx_adjust_reduction_type (ref_to_res, TREE_TYPE (var), + &seq); + var = build_simple_mem_ref (ref_to_res); + } } if (level == GOMP_DIM_WORKER) @@ -5702,7 +5894,11 @@ nvptx_goacc_reduction_init (gcall *call) init = var; } - gimplify_assign (lhs, init, &seq); + /* The LHS may be NULL if a reduction variable on a parallel + construct is initialized to some constant inside the parallel + region. */ + if (lhs) + gimplify_assign (lhs, init, &seq); } pop_gimplify_context (NULL); @@ -5727,22 +5923,7 @@ nvptx_goacc_reduction_fini (gcall *call) push_gimplify_context (true); if (level == GOMP_DIM_VECTOR) - { - /* Emit binary shuffle tree. TODO. Emit this as an actual loop, - but that requires a method of emitting a unified jump at the - gimple level. */ - for (int shfl = PTX_VECTOR_LENGTH / 2; shfl > 0; shfl = shfl >> 1) - { - tree other_var = make_ssa_name (TREE_TYPE (var)); - nvptx_generate_vector_shuffle (gimple_location (call), - other_var, var, shfl, &seq); - - r = make_ssa_name (TREE_TYPE (var)); - gimplify_assign (r, fold_build2 (op, TREE_TYPE (var), - var, other_var), &seq); - var = r; - } - } + r = nvptx_vector_reduction (gimple_location (call), &gsi, var, op); else { tree accum = NULL_TREE; @@ -5760,7 +5941,11 @@ nvptx_goacc_reduction_fini (gcall *call) else if (integer_zerop (ref_to_res)) r = var; else - accum = ref_to_res; + { + ref_to_res = nvptx_adjust_reduction_type (ref_to_res, TREE_TYPE (var), + &seq); + accum = ref_to_res; + } if (accum) { @@ -5809,7 +5994,11 @@ nvptx_goacc_reduction_teardown (gcall *call) tree ref_to_res = gimple_call_arg (call, 1); if (!integer_zerop (ref_to_res)) - gimplify_assign (build_simple_mem_ref (ref_to_res), var, &seq); + { + ref_to_res = nvptx_adjust_reduction_type (ref_to_res, TREE_TYPE (var), + &seq); + gimplify_assign (build_simple_mem_ref (ref_to_res), var, &seq); + } } if (lhs) diff --git a/gcc/config/nvptx/nvptx.md b/gcc/config/nvptx/nvptx.md index 2988f5dfa91..79c4c061841 100644 --- a/gcc/config/nvptx/nvptx.md +++ b/gcc/config/nvptx/nvptx.md @@ -600,6 +600,13 @@ "%J0\\tbra.uni\\t%l1;" [(set_attr "predicable" "false")]) +(define_insn "cond_uni" + [(set (match_operand:SI 0 "nvptx_register_operand" "=R") + (unspec:SI [(match_operand:SI 1 "nvptx_nonmemory_operand" "R")] + UNSPEC_BR_UNIFIED))] + "" + "%.\\tmov%t0\\t%0, %1; // unified") + (define_expand "cbranch4" [(set (pc) (if_then_else (match_operator 0 "nvptx_comparison_operator" diff --git a/gcc/omp-general.h b/gcc/omp-general.h index 66f0a33c2e2..1a3a7cc728c 100644 --- a/gcc/omp-general.h +++ b/gcc/omp-general.h @@ -32,9 +32,10 @@ enum oacc_loop_flags { OLF_INDEPENDENT = 1u << 2, /* Iterations are known independent. */ OLF_GANG_STATIC = 1u << 3, /* Gang partitioning is static (has op). */ OLF_TILE = 1u << 4, /* Tiled loop. */ - + OLF_REDUCTION = 1u << 5, /* Reduction loop. */ + /* Explicitly specified loop axes. */ - OLF_DIM_BASE = 5, + OLF_DIM_BASE = 6, OLF_DIM_GANG = 1u << (OLF_DIM_BASE + GOMP_DIM_GANG), OLF_DIM_WORKER = 1u << (OLF_DIM_BASE + GOMP_DIM_WORKER), OLF_DIM_VECTOR = 1u << (OLF_DIM_BASE + GOMP_DIM_VECTOR), diff --git a/gcc/omp-low.c b/gcc/omp-low.c index c591231d8f1..792d338f0fd 100644 --- a/gcc/omp-low.c +++ b/gcc/omp-low.c @@ -4855,6 +4855,7 @@ lower_oacc_reductions (location_t loc, tree clauses, tree level, bool inner, tree ref_to_res = NULL_TREE; tree incoming, outgoing, v1, v2, v3; bool is_private = false; + bool is_fpp = false; enum tree_code rcode = OMP_CLAUSE_REDUCTION_CODE (c); if (rcode == MINUS_EXPR) @@ -4913,19 +4914,37 @@ lower_oacc_reductions (location_t loc, tree clauses, tree level, bool inner, is_private = true; goto do_lookup; } + else if (OMP_CLAUSE_CODE (cls) == OMP_CLAUSE_MAP + && (OMP_CLAUSE_MAP_KIND (cls) + == GOMP_MAP_FIRSTPRIVATE_POINTER) + && orig == OMP_CLAUSE_DECL (cls)) + { + is_fpp = true; + goto do_lookup; + } } do_lookup: /* This is the outermost construct with this reduction, see if there's a mapping for it. */ if (gimple_code (outer->stmt) == GIMPLE_OMP_TARGET - && maybe_lookup_field (orig, outer) && !is_private) + && (maybe_lookup_field (orig, outer) || is_fpp) && !is_private) { - ref_to_res = build_receiver_ref (orig, false, outer); - if (omp_is_reference (orig)) - ref_to_res = build_simple_mem_ref (ref_to_res); - tree type = TREE_TYPE (var); + + if (is_fpp) + { + tree x = create_tmp_var (type); + gimplify_assign (x, lookup_decl (orig, outer), fork_seq); + ref_to_res = x; + } + else + { + ref_to_res = build_receiver_ref (orig, false, outer); + if (omp_is_reference (orig)) + ref_to_res = build_simple_mem_ref (ref_to_res); + } + if (POINTER_TYPE_P (type)) type = TREE_TYPE (type); @@ -5633,6 +5652,10 @@ lower_oacc_head_mark (location_t loc, tree ddvar, tree clauses, tag |= OLF_TILE; break; + case OMP_CLAUSE_REDUCTION: + tag |= OLF_REDUCTION; + break; + default: continue; } diff --git a/gcc/omp-offload.c b/gcc/omp-offload.c index 0abf0283c9e..07ca759a7d8 100644 --- a/gcc/omp-offload.c +++ b/gcc/omp-offload.c @@ -1280,6 +1280,13 @@ oacc_loop_auto_partitions (oacc_loop *loop, unsigned outer_mask, non-innermost available level. */ unsigned this_mask = GOMP_DIM_MASK (GOMP_DIM_GANG); + /* Orphan reductions cannot have gang partitioning. */ + if ((loop->flags & OLF_REDUCTION) + && oacc_get_fn_attrib (current_function_decl) + && !lookup_attribute ("omp target entrypoint", + DECL_ATTRIBUTES (current_function_decl))) + this_mask = GOMP_DIM_MASK (GOMP_DIM_WORKER); + /* Find the first outermost available partition. */ while (this_mask <= outer_mask) this_mask <<= 1; @@ -1431,6 +1438,17 @@ default_goacc_reduction (gcall *call) if (!integer_zerop (ref_to_res)) { + /* Dummy reduction vars that have GOMP_MAP_FIRSTPRIVATE_POINTER data + mappings gets retyped to (void *). Adjust the type of ref_to_res + as appropriate. */ + if (TREE_TYPE (TREE_TYPE (ref_to_res)) != TREE_TYPE (var)) + { + tree ptype = build_pointer_type (TREE_TYPE (var)); + tree t = make_ssa_name (ptype); + tree expr = fold_build1 (NOP_EXPR, ptype, ref_to_res); + gimple_seq_add_stmt (&seq, gimple_build_assign (t, expr)); + ref_to_res = t; + } tree dst = build_simple_mem_ref (ref_to_res); tree src = var;