commit 6c2a018b940d0b132395048b0600f7d897319ee2 Author: Julian Brown Date: Thu Aug 9 20:27:04 2018 -0700 [OpenACC] Add support for gang local storage allocation in shared memory 2019-06-03 Julian Brown Chung-Lin Tang gcc/ * config/nvptx/nvptx.c (tree-hash-traits.h): Include. (gangprivate_shared_size): New global variable. (gangprivate_shared_align): Likewise. (gangprivate_shared_sym): Likewise. (gangprivate_shared_hmap): Likewise. (nvptx_option_override): Initialize gangprivate_shared_sym, gangprivate_shared_align. (nvptx_file_end): Output gangprivate_shared_sym. (nvptx_goacc_expand_accel_var): New function. (nvptx_set_current_function): Initialise gangprivate_shared_hmap. Add function comment. (TARGET_GOACC_EXPAND_ACCEL): Likewise. * doc/tm.texi (TARGET_GOACC_EXPAND_ACCEL_VAR): Document new hook. * doc/tm.texi.in (TARGET_GOACC_EXPAND_ACCEL_VAR): Likewise. * expr.c (expand_expr_real_1): Remap VAR_DECLs marked with the "oacc gangprivate" attribute. * omp-low.c (omp_context): Add oacc_partitioning_level and oacc_addressable_var_decls fields. (maybe_oacc_gangprivate_vars): New global variable. (delete_omp_context): Release oacc_addressable_var_decls in old omp_context. (lower_oacc_head_tail): Record partitioning-level count in omp context. (oacc_record_private_var_clauses, oacc_record_vars_in_bind, mark_oacc_gangprivate): New functions. (lower_omp_for): Call oacc_record_private_var_clauses with OpenACC "for" clauses. (lower_omp_target): Likewise, for OpenACC "target" clauses. Call mark_oacc_gangprivate for offloaded target regions. (process_oacc_gangprivate): New function. (lower_omp_1): Call oacc_record_vars_in_bind for GIMPLE_BIND within OpenACC regions. (execute_lower_omp): Call process_oacc_gangprivate for each OMP context. * target.def (expand_accel_var): New hook. libgomp/ * testsuite/libgomp.oacc-c-c++-common/gang-private-1.c: New test. * testsuite/libgomp.oacc-c-c++-common/loop-gwv-2.c: New test. * testsuite/libgomp.oacc-c/pr85465.c: New test. * testsuite/libgomp.oacc-fortran/gangprivate-attrib-1.f90: New test. * testsuite/libgomp.oacc-fortran/gangprivate-attrib-2.f90: New test. diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c index a28099ac89d..c93fb926609 100644 --- a/gcc/config/nvptx/nvptx.c +++ b/gcc/config/nvptx/nvptx.c @@ -74,6 +74,7 @@ #include "cfgloop.h" #include "fold-const.h" #include "intl.h" +#include "tree-hash-traits.h" /* This file should be included last. */ #include "target-def.h" @@ -166,6 +167,12 @@ static unsigned vector_red_align; static unsigned vector_red_partition; static GTY(()) rtx vector_red_sym; +/* Shared memory block for gang-private variables. */ +static unsigned gangprivate_shared_size; +static unsigned gangprivate_shared_align; +static GTY(()) rtx gangprivate_shared_sym; +static hash_map gangprivate_shared_hmap; + /* Global lock variable, needed for 128bit worker & gang reductions. */ static GTY(()) tree global_lock_var; @@ -247,6 +254,10 @@ nvptx_option_override (void) vector_red_align = GET_MODE_ALIGNMENT (SImode) / BITS_PER_UNIT; vector_red_partition = 0; + gangprivate_shared_sym = gen_rtx_SYMBOL_REF (Pmode, "__gangprivate_shared"); + SET_SYMBOL_DATA_AREA (gangprivate_shared_sym, DATA_AREA_SHARED); + gangprivate_shared_align = GET_MODE_ALIGNMENT (SImode) / BITS_PER_UNIT; + diagnose_openacc_conflict (TARGET_GOMP, "-mgomp"); diagnose_openacc_conflict (TARGET_SOFT_STACK, "-msoft-stack"); diagnose_openacc_conflict (TARGET_UNIFORM_SIMT, "-muniform-simt"); @@ -5237,6 +5248,10 @@ nvptx_file_end (void) write_shared_buffer (asm_out_file, vector_red_sym, vector_red_align, vector_red_size); + if (gangprivate_shared_size) + write_shared_buffer (asm_out_file, gangprivate_shared_sym, + gangprivate_shared_align, gangprivate_shared_size); + if (need_softstack_decl) { write_var_marker (asm_out_file, false, true, "__nvptx_stacks"); @@ -6430,14 +6445,49 @@ nvptx_can_change_mode_class (machine_mode, machine_mode, reg_class_t) return false; } +/* Implement TARGET_GOACC_EXPAND_ACCEL_VAR. Place "oacc gangprivate" + variables in shared memory. */ + +static rtx +nvptx_goacc_expand_accel_var (tree var) +{ + if (VAR_P (var) + && lookup_attribute ("oacc gangprivate", DECL_ATTRIBUTES (var))) + { + unsigned int offset, *poffset; + poffset = gangprivate_shared_hmap.get (var); + if (poffset) + offset = *poffset; + else + { + unsigned HOST_WIDE_INT align = DECL_ALIGN (var); + gangprivate_shared_size + = (gangprivate_shared_size + align - 1) & ~(align - 1); + if (gangprivate_shared_align < align) + gangprivate_shared_align = align; + + offset = gangprivate_shared_size; + bool existed = gangprivate_shared_hmap.put (var, offset); + gcc_assert (!existed); + gangprivate_shared_size += tree_to_uhwi (DECL_SIZE_UNIT (var)); + } + rtx addr = plus_constant (Pmode, gangprivate_shared_sym, offset); + return gen_rtx_MEM (TYPE_MODE (TREE_TYPE (var)), addr); + } + return NULL_RTX; +} + static GTY(()) tree nvptx_previous_fndecl; +/* Implement TARGET_SET_CURRENT_FUNCTION. Reset per-function context. */ + static void nvptx_set_current_function (tree fndecl) { if (!fndecl || fndecl == nvptx_previous_fndecl) return; + gangprivate_shared_hmap.empty (); nvptx_previous_fndecl = fndecl; vector_red_partition = 0; oacc_bcast_partition = 0; @@ -6579,6 +6629,9 @@ nvptx_set_current_function (tree fndecl) #undef TARGET_HAVE_SPECULATION_SAFE_VALUE #define TARGET_HAVE_SPECULATION_SAFE_VALUE speculation_safe_value_not_needed +#undef TARGET_GOACC_EXPAND_ACCEL_VAR +#define TARGET_GOACC_EXPAND_ACCEL_VAR nvptx_goacc_expand_accel_var + #undef TARGET_SET_CURRENT_FUNCTION #define TARGET_SET_CURRENT_FUNCTION nvptx_set_current_function diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index 622e8cf240f..61da9709268 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -6161,6 +6161,14 @@ like @code{cond_add@var{m}}. The default implementation returns a zero constant of type @var{type}. @end deftypefn +@deftypefn {Target Hook} rtx TARGET_GOACC_EXPAND_ACCEL_VAR (tree @var{var}) +This hook, if defined, is used by accelerator target back-ends to expand +specially handled kinds of VAR_DECL expressions. A particular use is to +place variables with specific attributes inside special accelarator +memories. A return value of NULL indicates that the target does not +handle this VAR_DECL, and normal RTL expanding is resumed. +@end deftypefn + @node Anchored Addresses @section Anchored Addresses @cindex anchored addresses diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in index 17560fce6b7..5579623e331 100644 --- a/gcc/doc/tm.texi.in +++ b/gcc/doc/tm.texi.in @@ -4210,6 +4210,8 @@ address; but often a machine-dependent strategy can generate better code. @hook TARGET_PREFERRED_ELSE_VALUE +@hook TARGET_GOACC_EXPAND_ACCEL_VAR + @node Anchored Addresses @section Anchored Addresses @cindex anchored addresses diff --git a/gcc/expr.c b/gcc/expr.c index c78bc74c0d9..34510aab55d 100644 --- a/gcc/expr.c +++ b/gcc/expr.c @@ -9974,8 +9974,19 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode tmode, exp = SSA_NAME_VAR (ssa_name); goto expand_decl_rtl; - case PARM_DECL: case VAR_DECL: + /* Allow accel compiler to handle specific cases of variables, + specifically those tagged with the "oacc gangprivate" attribute, + which may be intended to be placed in special memory in GPUs. */ + if (flag_openacc && targetm.goacc.expand_accel_var) + { + temp = targetm.goacc.expand_accel_var (exp); + if (temp) + return temp; + } + /* ... fall through ... */ + + case PARM_DECL: /* If a static var's type was incomplete when the decl was written, but the type is complete now, lay out the decl now. */ if (DECL_SIZE (exp) == 0 diff --git a/gcc/omp-low.c b/gcc/omp-low.c index a7f35ffe416..67e1e82ec00 100644 --- a/gcc/omp-low.c +++ b/gcc/omp-low.c @@ -141,6 +141,12 @@ struct omp_context /* True if lower_omp_1 should look up lastprivate conditional in parent context. */ bool combined_into_simd_safelen0; + + /* The number of levels of OpenACC partitioning invoked in this context. */ + unsigned oacc_partitioning_levels; + + /* Addressable variable decls in this context. */ + vec oacc_addressable_var_decls; }; static splay_tree all_contexts; @@ -148,6 +154,7 @@ static int taskreg_nesting_level; static int target_nesting_level; static bitmap task_shared_vars; static vec taskreg_contexts; +static bool maybe_oacc_gangprivate_vars; static void scan_omp (gimple_seq *, omp_context *); static tree scan_omp_1_op (tree *, int *, void *); @@ -964,6 +971,7 @@ delete_omp_context (splay_tree_value value) } delete ctx->lastprivate_conditional_map; + ctx->oacc_addressable_var_decls.release (); XDELETE (ctx); } @@ -6881,6 +6889,9 @@ lower_oacc_head_tail (location_t loc, tree clauses, tree join_kind = build_int_cst (unsigned_type_node, IFN_UNIQUE_OACC_JOIN); gcc_assert (count); + + ctx->oacc_partitioning_levels = count; + for (unsigned done = 1; count; count--, done++) { gimple_seq fork_seq = NULL; @@ -8582,6 +8593,77 @@ lower_omp_for_lastprivate (struct omp_for_data *fd, gimple_seq *body_p, } } +/* Record vars listed in private clauses in CLAUSES in CTX. This information + is used to mark up variables that should be made private per-gang. */ + +static void +oacc_record_private_var_clauses (omp_context *ctx, tree clauses) +{ + for (tree c = clauses; c; c = OMP_CLAUSE_CHAIN (c)) + if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE) + { + tree decl = OMP_CLAUSE_DECL (c); + if (VAR_P (decl) && TREE_ADDRESSABLE (decl)) + { + ctx->oacc_addressable_var_decls.safe_push (decl); + maybe_oacc_gangprivate_vars = true; + } + } +} + +/* Record addressable vars declared in BINDVARS in CTX. This information is + used to mark up variables that should be made private per-gang. */ + +static void +oacc_record_vars_in_bind (omp_context *ctx, tree bindvars) +{ + for (tree v = bindvars; v; v = DECL_CHAIN (v)) + if (VAR_P (v) && TREE_ADDRESSABLE (v)) + { + ctx->oacc_addressable_var_decls.safe_push (v); + maybe_oacc_gangprivate_vars = true; + } +} + +/* Mark addressable variables which are declared implicitly or explicitly as + gang private with a special attribute. These may need to have their + declarations altered later on in compilation (e.g. in + execute_oacc_device_lower or the backend, depending on how the OpenACC + execution model is implemented on a given target) to ensure that sharing + semantics are correct. */ + +static void +mark_oacc_gangprivate (vec *decls, omp_context *ctx) +{ + int i; + tree decl; + + FOR_EACH_VEC_ELT (*decls, i, decl) + { + for (omp_context *thisctx = ctx; thisctx; thisctx = thisctx->outer) + { + tree inner_decl = maybe_lookup_decl (decl, thisctx); + if (inner_decl) + { + decl = inner_decl; + break; + } + } + if (!lookup_attribute ("oacc gangprivate", DECL_ATTRIBUTES (decl))) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, + "Setting 'oacc gangprivate' attribute for decl:"); + print_generic_decl (dump_file, decl, TDF_SLIM); + fputc ('\n', dump_file); + } + DECL_ATTRIBUTES (decl) + = tree_cons (get_identifier ("oacc gangprivate"), + NULL, DECL_ATTRIBUTES (decl)); + } + } +} /* Lower code for an OMP loop directive. */ @@ -8599,6 +8681,9 @@ lower_omp_for (gimple_stmt_iterator *gsi_p, omp_context *ctx) push_gimplify_context (); + if (is_gimple_omp_oacc (ctx->stmt)) + oacc_record_private_var_clauses (ctx, gimple_omp_for_clauses (stmt)); + lower_omp (gimple_omp_for_pre_body_ptr (stmt), ctx); block = make_node (BLOCK); @@ -9544,6 +9629,9 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx) clauses = gimple_omp_target_clauses (stmt); + if (is_gimple_omp_oacc (ctx->stmt)) + oacc_record_private_var_clauses (ctx, clauses); + gimple_seq dep_ilist = NULL; gimple_seq dep_olist = NULL; if (omp_find_clause (clauses, OMP_CLAUSE_DEPEND)) @@ -9794,6 +9882,8 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx) if (offloaded) { + mark_oacc_gangprivate (&ctx->oacc_addressable_var_decls, ctx); + /* Declare all the variables created by mapping and the variables declared in the scope of the target body. */ record_vars_into (ctx->block_vars, child_fn); @@ -10645,6 +10735,25 @@ lower_omp_grid_body (gimple_stmt_iterator *gsi_p, omp_context *ctx) gimple_build_omp_return (false)); } +/* Find gang-private variables in a context. */ + +static int +process_oacc_gangprivate (splay_tree_node node, void * ARG_UNUSED (data)) +{ + omp_context *ctx = (omp_context *) node->value; + unsigned level_total = 0; + omp_context *thisctx; + + for (thisctx = ctx; thisctx; thisctx = thisctx->outer) + level_total += thisctx->oacc_partitioning_levels; + + /* If the current context and parent contexts are distributed over a + total of one parallelism level, we have gang partitioning. */ + if (level_total == 1) + mark_oacc_gangprivate (&ctx->oacc_addressable_var_decls, ctx); + + return 0; +} /* Callback for lower_omp_1. Return non-NULL if *tp needs to be regimplified. If DATA is non-NULL, lower_omp_1 is outside @@ -10789,6 +10898,9 @@ lower_omp_1 (gimple_stmt_iterator *gsi_p, omp_context *ctx) ctx); break; case GIMPLE_BIND: + if (ctx && is_gimple_omp_oacc (ctx->stmt)) + oacc_record_vars_in_bind (ctx, + gimple_bind_vars (as_a (stmt))); lower_omp (gimple_bind_body_ptr (as_a (stmt)), ctx); maybe_remove_omp_member_access_dummy_vars (as_a (stmt)); break; @@ -11024,6 +11136,7 @@ execute_lower_omp (void) FOR_EACH_VEC_ELT (taskreg_contexts, i, ctx) finish_taskreg_scan (ctx); taskreg_contexts.release (); + maybe_oacc_gangprivate_vars = false; if (all_contexts->root) { @@ -11036,6 +11149,8 @@ execute_lower_omp (void) if (all_contexts) { + if (maybe_oacc_gangprivate_vars) + splay_tree_foreach (all_contexts, process_oacc_gangprivate, NULL); splay_tree_delete (all_contexts); all_contexts = NULL; } diff --git a/gcc/target.def b/gcc/target.def index 7d52102c815..5334c206afa 100644 --- a/gcc/target.def +++ b/gcc/target.def @@ -1719,6 +1719,16 @@ for allocating any storage for reductions when necessary.", void, (gcall *call), default_goacc_reduction) +DEFHOOK +(expand_accel_var, +"This hook, if defined, is used by accelerator target back-ends to expand\n\ +specially handled kinds of VAR_DECL expressions. A particular use is to\n\ +place variables with specific attributes inside special accelarator\n\ +memories. A return value of NULL indicates that the target does not\n\ +handle this VAR_DECL, and normal RTL expanding is resumed.", +rtx, (tree var), +NULL) + HOOK_VECTOR_END (goacc) /* Functions relating to vectorization. */ diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/gang-private-1.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/gang-private-1.c new file mode 100644 index 00000000000..f378346ed0a --- /dev/null +++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/gang-private-1.c @@ -0,0 +1,38 @@ +#include + +int main (void) +{ + int ret; + + #pragma acc parallel num_gangs(1) num_workers(32) copyout(ret) + { + int w = 0; + + #pragma acc loop worker + for (int i = 0; i < 32; i++) + { + #pragma acc atomic update + w++; + } + + ret = (w == 32); + } + assert (ret); + + #pragma acc parallel num_gangs(1) vector_length(32) copyout(ret) + { + int v = 0; + + #pragma acc loop vector + for (int i = 0; i < 32; i++) + { + #pragma acc atomic update + v++; + } + + ret = (v == 32); + } + assert (ret); + + return 0; +} diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/loop-gwv-2.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/loop-gwv-2.c new file mode 100644 index 00000000000..a4f81a39e24 --- /dev/null +++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/loop-gwv-2.c @@ -0,0 +1,95 @@ +#include +#include +#include +#include +#include +#include + +#if 0 +#define DEBUG(DIM, IDX, VAL) \ + fprintf (stderr, "%sdist[%d] = %d\n", (DIM), (IDX), (VAL)) +#else +#define DEBUG(DIM, IDX, VAL) +#endif + +#define N (32*32*32) + +int +check (const char *dim, int *dist, int dimsize) +{ + int ix; + int exit = 0; + + for (ix = 0; ix < dimsize; ix++) + { + DEBUG(dim, ix, dist[ix]); + if (dist[ix] < (N) / (dimsize + 0.5) + || dist[ix] > (N) / (dimsize - 0.5)) + { + fprintf (stderr, "did not distribute to %ss (%d not between %d " + "and %d)\n", dim, dist[ix], (int) ((N) / (dimsize + 0.5)), + (int) ((N) / (dimsize - 0.5))); + exit |= 1; + } + } + + return exit; +} + +int main () +{ + int ary[N]; + int ix; + int exit = 0; + int gangsize = 0, workersize = 0, vectorsize = 0; + int *gangdist, *workerdist, *vectordist; + + for (ix = 0; ix < N;ix++) + ary[ix] = -1; + +#pragma acc parallel num_gangs(32) num_workers(32) vector_length(32) \ + copy(ary) copyout(gangsize, workersize, vectorsize) + { +#pragma acc loop gang worker vector + for (unsigned ix = 0; ix < N; ix++) + { + int g, w, v; + + g = __builtin_goacc_parlevel_id (GOMP_DIM_GANG); + w = __builtin_goacc_parlevel_id (GOMP_DIM_WORKER); + v = __builtin_goacc_parlevel_id (GOMP_DIM_VECTOR); + + ary[ix] = (g << 16) | (w << 8) | v; + } + + gangsize = __builtin_goacc_parlevel_size (GOMP_DIM_GANG); + workersize = __builtin_goacc_parlevel_size (GOMP_DIM_WORKER); + vectorsize = __builtin_goacc_parlevel_size (GOMP_DIM_VECTOR); + } + + gangdist = (int *) alloca (gangsize * sizeof (int)); + workerdist = (int *) alloca (workersize * sizeof (int)); + vectordist = (int *) alloca (vectorsize * sizeof (int)); + memset (gangdist, 0, gangsize * sizeof (int)); + memset (workerdist, 0, workersize * sizeof (int)); + memset (vectordist, 0, vectorsize * sizeof (int)); + + /* Test that work is shared approximately equally amongst each active + gang/worker/vector. */ + for (ix = 0; ix < N; ix++) + { + int g = (ary[ix] >> 16) & 255; + int w = (ary[ix] >> 8) & 255; + int v = ary[ix] & 255; + + gangdist[g]++; + workerdist[w]++; + vectordist[v]++; + } + + exit = check ("gang", gangdist, gangsize); + exit |= check ("worker", workerdist, workersize); + exit |= check ("vector", vectordist, vectorsize); + + return exit; +} diff --git a/libgomp/testsuite/libgomp.oacc-c/pr85465.c b/libgomp/testsuite/libgomp.oacc-c/pr85465.c new file mode 100644 index 00000000000..329e8a09cf9 --- /dev/null +++ b/libgomp/testsuite/libgomp.oacc-c/pr85465.c @@ -0,0 +1,11 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-w" } */ + +int +main (void) +{ +#pragma acc parallel + foo (); + + return 0; +} diff --git a/libgomp/testsuite/libgomp.oacc-fortran/gangprivate-attrib-1.f90 b/libgomp/testsuite/libgomp.oacc-fortran/gangprivate-attrib-1.f90 new file mode 100644 index 00000000000..5f8a5e650ea --- /dev/null +++ b/libgomp/testsuite/libgomp.oacc-fortran/gangprivate-attrib-1.f90 @@ -0,0 +1,25 @@ +! Test for "oacc gangprivate" attribute on gang-private variables + +! { dg-do run } +! { dg-additional-options "-fdump-tree-omplower-details" } +! { dg-final { scan-tree-dump-times "Setting 'oacc gangprivate' attribute for decl: integer\\(kind=4\\) w;" 1 "omplower" } } */ + +program main + integer :: w, arr(0:31) + + !$acc parallel num_gangs(32) num_workers(32) copyout(arr) + !$acc loop gang private(w) + do j = 0, 31 + w = 0 + !$acc loop seq + do i = 0, 31 + !$acc atomic update + w = w + 1 + !$acc end atomic + end do + arr(j) = w + end do + !$acc end parallel + + if (any (arr .ne. 32)) stop 1 +end program main diff --git a/libgomp/testsuite/libgomp.oacc-fortran/gangprivate-attrib-2.f90 b/libgomp/testsuite/libgomp.oacc-fortran/gangprivate-attrib-2.f90 new file mode 100644 index 00000000000..d147229d91e --- /dev/null +++ b/libgomp/testsuite/libgomp.oacc-fortran/gangprivate-attrib-2.f90 @@ -0,0 +1,23 @@ +! Test for lack of "oacc gangprivate" attribute on worker-private variables + +! { dg-do run } +! { dg-additional-options "-fdump-tree-omplower-details" } +! { dg-final { scan-tree-dump-times "Setting 'oacc gangprivate' attribute for decl" 0 "omplower" } } */ + +program main + integer :: w, arr(0:31) + + !$acc parallel num_gangs(32) num_workers(32) copyout(arr) + !$acc loop gang worker private(w) + do j = 0, 31 + w = 0 + !$acc loop seq + do i = 0, 31 + w = w + 1 + end do + arr(j) = w + end do + !$acc end parallel + + if (any (arr .ne. 32)) stop 1 +end program main