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authorConnor Abbott <connor.abbott@intel.com>2014-07-30 12:08:13 -0700
committerJason Ekstrand <jason.ekstrand@intel.com>2015-01-15 07:18:58 -0800
commitcff1deff72294b810e4f03b72c7a871aacef8477 (patch)
treeeeecd1cdc4771df63666bd33ac0fbce592202859 /src
parent613bf6818aee4ac706d17d86e0bb421e81051fa3 (diff)
nir: add an optimization to turn global registers into local registers
After linking and inlining, this allows us to convert these registers into SSA values and optimise more code.
Diffstat (limited to 'src')
-rw-r--r--src/glsl/Makefile.sources1
-rw-r--r--src/glsl/nir/nir.h2
-rw-r--r--src/glsl/nir/nir_opt_global_to_local.c103
3 files changed, 106 insertions, 0 deletions
diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources
index 27b4da17034..6bc7cd7cd38 100644
--- a/src/glsl/Makefile.sources
+++ b/src/glsl/Makefile.sources
@@ -24,6 +24,7 @@ NIR_FILES = \
$(GLSL_SRCDIR)/nir/nir_lower_variables_scalar.c \
$(GLSL_SRCDIR)/nir/nir_opcodes.c \
$(GLSL_SRCDIR)/nir/nir_opcodes.h \
+ $(GLSL_SRCDIR)/nir/nir_opt_global_to_local.c \
$(GLSL_SRCDIR)/nir/nir_print.c \
$(GLSL_SRCDIR)/nir/nir_remove_dead_variables.c \
$(GLSL_SRCDIR)/nir/nir_validate.c \
diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
index e14c9d1fcea..7d55948ab86 100644
--- a/src/glsl/nir/nir.h
+++ b/src/glsl/nir/nir.h
@@ -1263,6 +1263,8 @@ void nir_lower_system_values(nir_shader *shader);
void nir_lower_atomics(nir_shader *shader);
+bool nir_opt_global_to_local(nir_shader *shader);
+
#ifdef __cplusplus
} /* extern "C" */
#endif
diff --git a/src/glsl/nir/nir_opt_global_to_local.c b/src/glsl/nir/nir_opt_global_to_local.c
new file mode 100644
index 00000000000..00db37ba79d
--- /dev/null
+++ b/src/glsl/nir/nir_opt_global_to_local.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright © 2014 Intel 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.
+ *
+ * Authors:
+ * Connor Abbott (cwabbott0@gmail.com)
+ *
+ */
+
+#include "nir.h"
+
+static bool
+global_to_local(nir_register *reg)
+{
+ nir_function_impl *impl = NULL;
+
+ assert(reg->is_global);
+
+ struct set_entry *entry;
+ set_foreach(reg->defs, entry) {
+ nir_instr *instr = (nir_instr *) entry->key;
+ nir_function_impl *instr_impl =
+ nir_cf_node_get_function(&instr->block->cf_node);
+ if (impl != NULL) {
+ if (impl != instr_impl)
+ return false;
+ } else {
+ impl = instr_impl;
+ }
+ }
+
+ set_foreach(reg->uses, entry) {
+ nir_instr *instr = (nir_instr *) entry->key;
+ nir_function_impl *instr_impl =
+ nir_cf_node_get_function(&instr->block->cf_node);
+ if (impl != NULL) {
+ if (impl != instr_impl)
+ return false;
+ } else {
+ impl = instr_impl;
+ }
+ }
+
+ set_foreach(reg->if_uses, entry) {
+ nir_if *if_stmt = (nir_if *) entry->key;
+ nir_function_impl *if_impl = nir_cf_node_get_function(&if_stmt->cf_node);
+ if (impl != NULL) {
+ if (impl != if_impl)
+ return false;
+ } else {
+ impl = if_impl;
+ }
+ }
+
+ if (impl == NULL) {
+ /* this instruction is never used/defined, delete it */
+ nir_reg_remove(reg);
+ return true;
+ }
+
+ /*
+ * if we've gotten to this point, the register is always used/defined in
+ * the same implementation so we can move it to be local to that
+ * implementation.
+ */
+
+ exec_node_remove(&reg->node);
+ exec_list_push_tail(&impl->registers, &reg->node);
+ reg->index = impl->reg_alloc++;
+ reg->is_global = false;
+ return true;
+}
+
+bool
+nir_opt_global_to_local(nir_shader *shader)
+{
+ bool progress = false;
+
+ foreach_list_typed_safe(nir_register, reg, node, &shader->registers) {
+ if (global_to_local(reg))
+ progress = true;
+ }
+
+ return progress;
+}