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-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.h1
-rw-r--r--src/mesa/drivers/dri/i965/brw_fs_peephole_predicated_break.cpp96
4 files changed, 99 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/Makefile.sources b/src/mesa/drivers/dri/i965/Makefile.sources
index 6e94dcab24b..43f152e4d45 100644
--- a/src/mesa/drivers/dri/i965/Makefile.sources
+++ b/src/mesa/drivers/dri/i965/Makefile.sources
@@ -60,6 +60,7 @@ i965_FILES = \
brw_fs_fp.cpp \
brw_fs_generator.cpp \
brw_fs_live_variables.cpp \
+ brw_fs_peephole_predicated_break.cpp \
brw_fs_reg_allocate.cpp \
brw_fs_sel_peephole.cpp \
brw_fs_vector_splitting.cpp \
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 3a363a81cff..00dbe318cc3 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -3172,6 +3172,7 @@ fs_visitor::run()
progress = opt_cse() || progress;
progress = opt_copy_propagate() || progress;
progress = opt_peephole_sel() || progress;
+ progress = opt_peephole_predicated_break() || progress;
progress = dead_code_eliminate() || progress;
progress = dead_code_eliminate_local() || progress;
progress = dead_control_flow_eliminate(this) || progress;
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index 19f36923aee..2949c47118f 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -364,6 +364,7 @@ public:
bool try_emit_mad(ir_expression *ir, int mul_arg);
void try_replace_with_sel();
bool opt_peephole_sel();
+ bool opt_peephole_predicated_break();
void emit_bool_to_cond_code(ir_rvalue *condition);
void emit_if_gen6(ir_if *ir);
void emit_unspill(fs_inst *inst, fs_reg reg, uint32_t spill_offset,
diff --git a/src/mesa/drivers/dri/i965/brw_fs_peephole_predicated_break.cpp b/src/mesa/drivers/dri/i965/brw_fs_peephole_predicated_break.cpp
new file mode 100644
index 00000000000..bb0a2ac09a1
--- /dev/null
+++ b/src/mesa/drivers/dri/i965/brw_fs_peephole_predicated_break.cpp
@@ -0,0 +1,96 @@
+/*
+ * Copyright © 2013 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_cfg.h"
+
+/** @file brw_fs_peephole_predicated_break.cpp
+ *
+ * Loops are often structured as
+ *
+ * loop:
+ * CMP.f0
+ * (+f0) IF
+ * BREAK
+ * ENDIF
+ * ...
+ * WHILE loop
+ *
+ * This peephole pass removes the IF and ENDIF instructions and predicates the
+ * BREAK, dropping two instructions from the loop body.
+ */
+
+bool
+fs_visitor::opt_peephole_predicated_break()
+{
+ bool progress = false;
+
+ cfg_t cfg(&instructions);
+
+ for (int b = 0; b < cfg.num_blocks; b++) {
+ bblock_t *block = cfg.blocks[b];
+
+ /* BREAK and CONTINUE instructions, by definition, can only be found at
+ * the ends of basic blocks.
+ */
+ fs_inst *inst = (fs_inst *) block->end;
+ if (inst->opcode != BRW_OPCODE_BREAK && inst->opcode != BRW_OPCODE_CONTINUE)
+ continue;
+
+ fs_inst *if_inst = (fs_inst *) inst->prev;
+ if (if_inst->opcode != BRW_OPCODE_IF)
+ continue;
+
+ fs_inst *endif_inst = (fs_inst *) inst->next;
+ if (endif_inst->opcode != BRW_OPCODE_ENDIF)
+ continue;
+
+ /* For Sandybridge with IF with embedded comparison we need to emit an
+ * instruction to set the flag register.
+ */
+ if (brw->gen == 6 && if_inst->conditional_mod) {
+ fs_inst *cmp_inst = CMP(reg_null_d, if_inst->src[0], if_inst->src[1],
+ if_inst->conditional_mod);
+ if_inst->insert_before(cmp_inst);
+ inst->predicate = BRW_PREDICATE_NORMAL;
+ } else {
+ inst->predicate = if_inst->predicate;
+ inst->predicate_inverse = if_inst->predicate_inverse;
+ }
+
+ if_inst->remove();
+ endif_inst->remove();
+
+ /* By removing the ENDIF instruction we removed a basic block. Skip over
+ * it for the next iteration.
+ */
+ b++;
+
+ progress = true;
+ }
+
+ if (progress)
+ invalidate_live_intervals();
+
+ return progress;
+}