On Mon, 13 Aug 2018 11:42:26 -0700
Cesar Philippidis <[email protected]> wrote:
> On 08/13/2018 09:21 AM, Julian Brown wrote:
>
> > 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 0000000..2fa708a --- /dev/null
> > +++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/loop-gwv-2.c
> > @@ -0,0 +1,106 @@
> > +/* { dg-xfail-run-if "gangprivate
> > failure" { openacc_nvidia_accel_selected } { "-O0" } { "" } } */
>
> As a quick comment, I like the approach that you've taken with this
> patch, but the og8 patch only applies the gangprivate attribute in the
> c/c++ FE. I'd have to review the notes, but I seem to recall that
> excluding that clause in fortran was deliberate. Chung-Lin, do you
> recall the rationale behind that?
>
> With that aside, is the above xfail still necessary? It seems to xpass
> for me on nvptx. However, I see this regression on the host:
>
> FAIL: libgomp.oacc-c/../libgomp.oacc-c-c++-common/loop-gwv-2.c
> -DACC_DEVICE_TYPE_host=1 -DACC_MEM_SHARED=1 -O2 execution test
>
> There could be other regressions, but I only tested the new tests
> introduced by the patch so far.
Oops, this was the version of the patch I meant to post (and the one I
tested). The XFAIL on loop-gwv-2.c isn't necessary, plus that test
needed some other fixes to make it pass for NVPTX (it was written for
GCN to start with).
Everything else is the same. I'll see what I can come up with for a
Fortran test.
Thanks,
Julian
commit 7834b2f0dffec3e56e510c04e1663424b778fdfb
Author: Julian Brown <[email protected]>
Date: Thu Aug 9 20:27:04 2018 -0700
[OpenACC] Add support for gang local storage allocation in shared memory
2018-08-10 Julian Brown <[email protected]>
Chung-Lin Tang <[email protected]>
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): New function.
(TARGET_SET_CURRENT_FUNCTION): Define hook.
(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 decls marked with the
"oacc gangprivate" atttribute.
* omp-low.c (omp_context): Add oacc_partitioning_level and oacc_decls
fields.
(new_omp_context): Initialize oacc_decls in new omp_context.
(delete_omp_context): Delete oacc_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 "for"
clauses. Call mark_oacc_gangprivate for gang-partitioned loops.
(lower_omp_target): Call oacc_record_private_var_clauses with "target"
clauses.
Call mark_oacc_gangprivate for offloaded target regions.
(lower_omp_1): Call vars_in_bind for GIMPLE_BIND within OMP regions.
* 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.
diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c
index c0b0a2e..14eb842 100644
--- a/gcc/config/nvptx/nvptx.c
+++ b/gcc/config/nvptx/nvptx.c
@@ -73,6 +73,7 @@
#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"
@@ -137,6 +138,12 @@ static unsigned worker_red_size;
static unsigned worker_red_align;
static GTY(()) rtx worker_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<tree_decl_hash, unsigned int> gangprivate_shared_hmap;
+
/* Global lock variable, needed for 128bit worker & gang reductions. */
static GTY(()) tree global_lock_var;
@@ -210,6 +217,10 @@ nvptx_option_override (void)
SET_SYMBOL_DATA_AREA (worker_red_sym, DATA_AREA_SHARED);
worker_red_align = GET_MODE_ALIGNMENT (SImode) / BITS_PER_UNIT;
+ 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");
@@ -4968,6 +4979,10 @@ nvptx_file_end (void)
write_worker_buffer (asm_out_file, worker_red_sym,
worker_red_align, worker_red_size);
+ if (gangprivate_shared_size)
+ write_worker_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");
@@ -5915,6 +5930,47 @@ nvptx_can_change_mode_class (machine_mode, machine_mode, reg_class_t)
return false;
}
+static rtx
+nvptx_goacc_expand_accel_var (tree var)
+{
+ if (TREE_CODE (var) == VAR_DECL
+ && 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;
+
+static void
+nvptx_set_current_function (tree fndecl)
+{
+ if (!fndecl || fndecl == nvptx_previous_fndecl)
+ return;
+
+ gangprivate_shared_hmap.empty ();
+ nvptx_previous_fndecl = fndecl;
+}
+
#undef TARGET_OPTION_OVERRIDE
#define TARGET_OPTION_OVERRIDE nvptx_option_override
@@ -6051,6 +6107,12 @@ nvptx_can_change_mode_class (machine_mode, machine_mode, reg_class_t)
#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
+
struct gcc_target targetm = TARGET_INITIALIZER;
#include "gt-nvptx.h"
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index a40f45a..fb87f67 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -6064,6 +6064,14 @@ 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 39a214e..beace61 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -4151,6 +4151,8 @@ 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 de6709d..2c62bf9 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -9854,8 +9854,19 @@ 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 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 843c66f..354e182 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -124,6 +124,12 @@ struct omp_context
/* True if this construct can be cancelled. */
bool cancellable;
+
+ /* The number of levels of OpenACC partitioning invoked in this context. */
+ int oacc_partitioning_levels;
+
+ /* Decls in this context. */
+ vec<tree> *oacc_decls;
};
static splay_tree all_contexts;
@@ -850,6 +856,7 @@ new_omp_context (gimple *stmt, omp_context *outer_ctx)
}
ctx->cb.decl_map = new hash_map<tree, tree>;
+ ctx->oacc_decls = new vec<tree> ();
return ctx;
}
@@ -925,6 +932,8 @@ delete_omp_context (splay_tree_value value)
if (is_task_ctx (ctx))
finalize_task_copyfn (as_a <gomp_task *> (ctx->stmt));
+ delete ctx->oacc_decls;
+
XDELETE (ctx);
}
@@ -5716,6 +5725,9 @@ 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;
@@ -6732,6 +6744,66 @@ 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)
+{
+ tree c;
+
+ if (!ctx)
+ return;
+
+ for (c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
+ switch (OMP_CLAUSE_CODE (c))
+ {
+ case OMP_CLAUSE_PRIVATE:
+ {
+ tree decl = OMP_CLAUSE_DECL (c);
+ ctx->oacc_decls->safe_push (decl);
+ }
+ break;
+
+ default:
+ /* Empty. */;
+ }
+}
+
+/* Record 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)
+{
+ if (!ctx)
+ return;
+
+ for (tree v = bindvars; v; v = DECL_CHAIN (v))
+ ctx->oacc_decls->safe_push (v);
+}
+
+/* Mark 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.
+ Only variables which have their address taken need to be considered. */
+
+static void
+mark_oacc_gangprivate (vec<tree> *decls)
+{
+ int i;
+ tree decl;
+
+ FOR_EACH_VEC_ELT (*decls, i, decl)
+ {
+ if (TREE_CODE (decl) == VAR_DECL && TREE_ADDRESSABLE (decl))
+ DECL_ATTRIBUTES (decl)
+ = tree_cons (get_identifier ("oacc gangprivate"),
+ NULL, DECL_ATTRIBUTES (decl));
+ }
+}
/* Lower code for an OMP loop directive. */
@@ -6748,6 +6820,8 @@ lower_omp_for (gimple_stmt_iterator *gsi_p, omp_context *ctx)
push_gimplify_context ();
+ 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);
@@ -6878,7 +6952,20 @@ lower_omp_for (gimple_stmt_iterator *gsi_p, omp_context *ctx)
/* Add OpenACC partitioning and reduction markers just before the loop. */
if (oacc_head)
- gimple_seq_add_seq (&body, oacc_head);
+ {
+ gimple_seq_add_seq (&body, oacc_head);
+
+ int 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_decls);
+ }
lower_omp_for_lastprivate (&fd, &body, &dlist, ctx);
@@ -7511,6 +7598,8 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
clauses = gimple_omp_target_clauses (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))
@@ -7761,6 +7850,8 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
if (offloaded)
{
+ mark_oacc_gangprivate (ctx->oacc_decls);
+
/* 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);
@@ -8755,6 +8846,7 @@ lower_omp_1 (gimple_stmt_iterator *gsi_p, omp_context *ctx)
ctx);
break;
case GIMPLE_BIND:
+ oacc_record_vars_in_bind (ctx, gimple_bind_vars (as_a <gbind *> (stmt)));
lower_omp (gimple_bind_body_ptr (as_a <gbind *> (stmt)), ctx);
maybe_remove_omp_member_access_dummy_vars (as_a <gbind *> (stmt));
break;
diff --git a/gcc/target.def b/gcc/target.def
index c570f38..b3b24b8 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -1701,6 +1701,16 @@ 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 0000000..f378346
--- /dev/null
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/gang-private-1.c
@@ -0,0 +1,38 @@
+#include <assert.h>
+
+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 0000000..a4f81a3
--- /dev/null
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/loop-gwv-2.c
@@ -0,0 +1,95 @@
+#include <stdio.h>
+#include <openacc.h>
+#include <alloca.h>
+#include <string.h>
+#include <gomp-constants.h>
+#include <stdlib.h>
+
+#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 0000000..329e8a0
--- /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;
+}
