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authorEric Anholt <[email protected]>2012-05-08 13:01:52 -0700
committerEric Anholt <[email protected]>2012-05-14 16:53:19 -0700
commitd7787adda8006506545256547d8d590a282487af (patch)
tree4b7591444afcbf2a6a76cb2c65cfb1fb8add53f9 /src/mesa/drivers
parentf7a71e2570053205eb603aa04b8c52d4f54d8e4c (diff)
i965/fs: Add support for copy propagation.
We could do more by handling abs/negate and non-GRF sources, but this is a good start. Improves tropics performance 0.30% +/- .17% (n=43). shader-db results: Total instructions: 208032 -> 207184 60/1246 programs affected (4.8%) 23286 -> 22438 instructions in affected programs (3.6% reduction) Reviewed-by: Kenneth Graunke <[email protected]>
Diffstat (limited to 'src/mesa/drivers')
-rw-r--r--src/mesa/drivers/dri/i965/Makefile.sources1
-rw-r--r--src/mesa/drivers/dri/i965/brw_fs.cpp1
-rw-r--r--src/mesa/drivers/dri/i965/brw_fs.h3
-rw-r--r--src/mesa/drivers/dri/i965/brw_fs_cfg.cpp1
-rw-r--r--src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp137
5 files changed, 143 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/Makefile.sources b/src/mesa/drivers/dri/i965/Makefile.sources
index 961e6ad2f99..2d2e85bfd3a 100644
--- a/src/mesa/drivers/dri/i965/Makefile.sources
+++ b/src/mesa/drivers/dri/i965/Makefile.sources
@@ -114,6 +114,7 @@ i965_CXX_FILES = \
brw_fs.cpp \
brw_fs_cfg.cpp \
brw_fs_cse.cpp \
+ brw_fs_copy_propagation.cpp \
brw_fs_emit.cpp \
brw_fs_live_variables.cpp \
brw_fs_visitor.cpp \
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 47dfec2ec29..7176d40bc17 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -1682,6 +1682,7 @@ fs_visitor::run()
progress = propagate_constants() || progress;
progress = opt_algebraic() || progress;
progress = opt_cse() || progress;
+ progress = opt_copy_propagate() || progress;
progress = register_coalesce() || progress;
progress = compute_to_mrf() || progress;
progress = dead_code_eliminate() || progress;
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index 0a9b8aa4038..82ec4a5ce74 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -511,6 +511,9 @@ public:
bool opt_algebraic();
bool opt_cse();
bool opt_cse_local(fs_bblock *block, exec_list *aeb);
+ bool opt_copy_propagate();
+ bool opt_copy_propagate_local(void *mem_ctx, fs_bblock *block,
+ exec_list *acp);
bool register_coalesce();
bool compute_to_mrf();
bool dead_code_eliminate();
diff --git a/src/mesa/drivers/dri/i965/brw_fs_cfg.cpp b/src/mesa/drivers/dri/i965/brw_fs_cfg.cpp
index 7c4c4815376..acc0085284b 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_cfg.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_cfg.cpp
@@ -25,6 +25,7 @@
*
*/
+#include "brw_fs.h"
#include "brw_fs_cfg.h"
/** @file brw_fs_cfg.cpp
diff --git a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
new file mode 100644
index 00000000000..23960514bf0
--- /dev/null
+++ b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
@@ -0,0 +1,137 @@
+/*
+ * Copyright © 2012 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.
+ */
+
+#include "brw_fs.h"
+#include "brw_fs_cfg.h"
+
+namespace { /* avoid conflict with opt_copy_propagation_elements */
+struct acp_entry : public exec_node {
+ fs_reg dst;
+ fs_reg src;
+};
+}
+
+/** @file brw_fs_copy_propagation.cpp
+ *
+ * Support for local copy propagation by walking the list of instructions
+ * and maintaining the ACP table of available copies for propagation.
+ *
+ * See Muchnik's Advanced Compiler Design and Implementation, section
+ * 12.5 (p356).
+ */
+
+/* Walks a basic block and does copy propagation on it using the acp
+ * list.
+ */
+bool
+fs_visitor::opt_copy_propagate_local(void *mem_ctx,
+ fs_bblock *block, exec_list *acp)
+{
+ bool progress = false;
+
+ for (fs_inst *inst = block->start;
+ inst != block->end->next;
+ inst = (fs_inst *)inst->next) {
+
+ /* Try propagating into this instruction. */
+ foreach_list(entry_node, acp) {
+ acp_entry *entry = (acp_entry *)entry_node;
+
+ for (int i = 0; i < 3; i++) {
+ if (inst->src[i].file == entry->dst.file &&
+ inst->src[i].reg == entry->dst.reg &&
+ inst->src[i].reg_offset == entry->dst.reg_offset) {
+ inst->src[i].reg = entry->src.reg;
+ inst->src[i].reg_offset = entry->src.reg_offset;
+ progress = true;
+ }
+ }
+ }
+
+ /* kill the destination from the ACP */
+ if (inst->dst.file == GRF) {
+ int start_offset = inst->dst.reg_offset;
+ int end_offset = start_offset + inst->regs_written();
+
+ foreach_list_safe(entry_node, acp) {
+ acp_entry *entry = (acp_entry *)entry_node;
+
+ if (entry->dst.file == GRF &&
+ entry->dst.reg == inst->dst.reg &&
+ entry->dst.reg_offset >= start_offset &&
+ entry->dst.reg_offset < end_offset) {
+ entry->remove();
+ continue;
+ }
+ if (entry->src.file == GRF &&
+ entry->src.reg == inst->dst.reg &&
+ entry->src.reg_offset >= start_offset &&
+ entry->src.reg_offset < end_offset) {
+ entry->remove();
+ }
+ }
+ }
+
+ /* If this instruction is a raw copy, add it to the ACP. */
+ if (inst->opcode == BRW_OPCODE_MOV &&
+ inst->dst.file == GRF &&
+ inst->src[0].file == GRF &&
+ (inst->src[0].reg != inst->dst.reg ||
+ inst->src[0].reg_offset != inst->dst.reg_offset) &&
+ inst->src[0].type == inst->dst.type &&
+ !inst->saturate &&
+ !inst->predicated &&
+ !inst->force_uncompressed &&
+ !inst->force_sechalf &&
+ inst->src[0].smear == -1 &&
+ !inst->src[0].abs &&
+ !inst->src[0].negate) {
+ acp_entry *entry = ralloc(mem_ctx, acp_entry);
+ entry->dst = inst->dst;
+ entry->src = inst->src[0];
+ acp->push_tail(entry);
+ }
+ }
+
+ return progress;
+}
+
+bool
+fs_visitor::opt_copy_propagate()
+{
+ bool progress = false;
+ void *mem_ctx = ralloc_context(this->mem_ctx);
+
+ fs_cfg cfg(this);
+
+ for (int b = 0; b < cfg.num_blocks; b++) {
+ fs_bblock *block = cfg.blocks[b];
+ exec_list acp;
+
+ progress = opt_copy_propagate_local(mem_ctx, block, &acp) || progress;
+ }
+
+ ralloc_free(mem_ctx);
+
+ return progress;
+}