[Mesa-dev] [PATCH 07/15] nir: add a lowering pass for some cross-workgroup intrinsics
Connor Abbott
connora at valvesoftware.com
Tue Aug 8 01:32:33 UTC 2017
From: Connor Abbott <cwabbott0 at gmail.com>
Notably this doesn't include the workgroup reduce intrinsics, since
those are tricky and the right implementation strategy might differ
across different HW. However, it implements all the other ancilliary
stuff needed for the SPIR-V Groups capability, so the driver doesn't
have to handle that stuff. We might want to move the workgroup reduction
(reduce, inclusive scan, and exclusive scan) operations here eventually
though.
---
src/compiler/Makefile.sources | 1 +
src/compiler/nir/nir.h | 2 +
src/compiler/nir/nir_lower_group_reduce.c | 179 ++++++++++++++++++++++++++++++
3 files changed, 182 insertions(+)
create mode 100644 src/compiler/nir/nir_lower_group_reduce.c
diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources
index 734424a..70229ec 100644
--- a/src/compiler/Makefile.sources
+++ b/src/compiler/Makefile.sources
@@ -217,6 +217,7 @@ NIR_FILES = \
nir/nir_lower_double_ops.c \
nir/nir_lower_drawpixels.c \
nir/nir_lower_global_vars_to_local.c \
+ nir/nir_lower_group_reduce.c \
nir/nir_lower_gs_intrinsics.c \
nir/nir_lower_load_const_to_scalar.c \
nir/nir_lower_locals_to_regs.c \
diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index 2836cd1..1a2cc61 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -2743,6 +2743,8 @@ typedef enum {
bool nir_lower_doubles(nir_shader *shader, nir_lower_doubles_options options);
bool nir_lower_64bit_pack(nir_shader *shader);
+bool nir_lower_group_reduce(nir_shader *shader);
+
bool nir_normalize_cubemap_coords(nir_shader *shader);
void nir_live_ssa_defs_impl(nir_function_impl *impl);
diff --git a/src/compiler/nir/nir_lower_group_reduce.c b/src/compiler/nir/nir_lower_group_reduce.c
new file mode 100644
index 0000000..4182f21
--- /dev/null
+++ b/src/compiler/nir/nir_lower_group_reduce.c
@@ -0,0 +1,179 @@
+/*
+ * Copyright © 2017 Valve Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include "nir.h"
+#include "nir_builder.h"
+
+/*
+ * Implement this workgroup operations using operations on shared variables:
+ *
+ * - group_broadcast
+ * - group_any
+ * - group_all
+ */
+
+static nir_ssa_def *
+build_subgroup_any(nir_builder *b, nir_ssa_def *src)
+{
+ nir_intrinsic_instr *instr = nir_intrinsic_instr_create(b->shader,
+ nir_intrinsic_vote_any);
+ nir_ssa_dest_init(&instr->instr, &instr->dest, 1, 32, NULL);
+ instr->src[0] = nir_src_for_ssa(src);
+ nir_builder_instr_insert(b, &instr->instr);
+ return &instr->dest.ssa;
+}
+
+static void
+build_barrier(nir_builder *b)
+{
+ nir_intrinsic_instr *intrin =
+ nir_intrinsic_instr_create(b->shader, nir_intrinsic_barrier);
+ nir_builder_instr_insert(b, &intrin->instr);
+}
+
+/* TODO share this between different instructions */
+
+static nir_variable *
+alloc_shared_temp(nir_shader *shader, unsigned components,
+ unsigned bit_size)
+{
+ enum glsl_base_type base_type;
+ switch (bit_size) {
+ case 32:
+ base_type = GLSL_TYPE_UINT;
+ break;
+ case 64:
+ base_type = GLSL_TYPE_UINT64;
+ break;
+ default:
+ unreachable("bad bit size");
+ }
+
+ const struct glsl_type *type;
+ if (components == 1)
+ type = glsl_scalar_type(base_type);
+ else
+ type = glsl_vector_type(base_type, components);
+ return nir_variable_create(shader, nir_var_shared, type, "shared_temp");
+}
+
+static nir_ssa_def *
+build_group_any(nir_builder *b, nir_ssa_def *src)
+{
+ assert(src->num_components == 1);
+ nir_variable *temp = nir_variable_create(b->shader, nir_var_shared,
+ glsl_bool_type(), "any_temp");
+
+ nir_store_var(b, temp, nir_imm_int(b, NIR_FALSE), 1);
+ build_barrier(b);
+ nir_push_if(b, build_subgroup_any(b, src));
+ nir_store_var(b, temp, nir_imm_int(b, NIR_TRUE), 1);
+ nir_pop_if(b, NULL);
+ build_barrier(b);
+ return nir_load_var(b, temp);
+}
+
+static nir_ssa_def *
+build_group_all(nir_builder *b, nir_ssa_def *src)
+{
+ assert(src->num_components == 1);
+ nir_variable *temp = nir_variable_create(b->shader, nir_var_shared,
+ glsl_bool_type(), "all_temp");
+
+ nir_store_var(b, temp, nir_imm_int(b, NIR_TRUE), 1);
+ build_barrier(b);
+ nir_push_if(b, build_subgroup_any(b, nir_inot(b, src)));
+ nir_store_var(b, temp, nir_imm_int(b, NIR_FALSE), 1);
+ nir_pop_if(b, NULL);
+ build_barrier(b);
+ return nir_load_var(b, temp);
+}
+
+static nir_ssa_def *
+build_group_broadcast(nir_builder *b, nir_ssa_def *src, nir_ssa_def *id)
+{
+ nir_variable *temp = alloc_shared_temp(b->shader, src->num_components,
+ src->bit_size);
+
+ nir_push_if(b, nir_ball_iequal3(b, id, nir_load_local_invocation_id(b)));
+ nir_store_var(b, temp, src, (1 << src->num_components) - 1);
+ nir_pop_if(b, NULL);
+ build_barrier(b);
+ return nir_load_var(b, temp);
+}
+
+static bool
+lower_group_reduce_impl(nir_function_impl *impl,
+ const struct shader_info *info)
+{
+ nir_builder b;
+ nir_builder_init(&b, impl);
+ bool progress = false;
+
+ nir_foreach_block_safe(block, impl) {
+ nir_foreach_instr_safe(instr, block) {
+ if (instr->type != nir_instr_type_intrinsic)
+ continue;
+
+ nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
+ nir_ssa_def *replacement = NULL;
+ b.cursor = nir_before_instr(instr);
+
+ switch (intrin->intrinsic) {
+ case nir_intrinsic_group_any:
+ replacement = build_group_any(&b, intrin->src[0].ssa);
+ break;
+ case nir_intrinsic_group_all:
+ replacement = build_group_all(&b, intrin->src[0].ssa);
+ break;
+ case nir_intrinsic_group_broadcast:
+ replacement = build_group_broadcast(&b, intrin->src[0].ssa,
+ intrin->src[1].ssa);
+ break;
+ default:
+ continue;
+ }
+
+ assert(replacement);
+ nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
+ nir_src_for_ssa(replacement));
+ progress = true;
+ }
+ }
+
+ return progress;
+}
+
+bool
+nir_lower_group_reduce(nir_shader *shader)
+{
+ bool progress = false;
+
+ nir_foreach_function(function, shader) {
+ if (function->impl)
+ progress |= lower_group_reduce_impl(function->impl, &shader->info);
+ }
+
+ return false;
+}
--
2.9.4
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