i965 hardware doesn't allow immediates in src0. Normally, we have to
promote that to a separate instruction. To avoid this, we can flip
the operands of any commutative instructions.
Signed-off-by: Kenneth Graunke <kenn...@whitecape.org>
---
src/mesa/drivers/dri/i965/brw_fs.cpp | 22 ++++++++++++++++++++++
src/mesa/drivers/dri/i965/brw_fs.h | 1 +
2 files changed, 23 insertions(+)
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp
b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 8702ea8..f53584a 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -2527,6 +2527,27 @@ fs_visitor::opt_algebraic()
}
bool
+fs_visitor::opt_commute_immediates()
+{
+ bool progress = false;
+
+ foreach_block_and_inst(block, fs_inst, inst, cfg) {
+ if (inst->is_commutative() && inst->src[0].file == IMM) {
+ if (inst->src[1].file != IMM) {
+ fs_reg temp = inst->src[1];
+ inst->src[1] = inst->src[0];
+ inst->src[0] = temp;
+ progress = true;
+ } else {
+ perf_debug("shader contains an instruction with two immediates");
+ }
+ }
+ }
+
+ return progress;
+}
+
+bool
fs_visitor::opt_register_renaming()
{
bool progress = false;
@@ -3714,6 +3735,7 @@ fs_visitor::optimize()
OPT(remove_duplicate_mrf_writes);
OPT(opt_algebraic);
+ OPT(opt_commute_immediates);
OPT(opt_cse);
OPT(opt_copy_propagate);
OPT(opt_peephole_predicated_break);
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h
b/src/mesa/drivers/dri/i965/brw_fs.h
index 7716529..09df02b 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -218,6 +218,7 @@ public:
void calculate_live_intervals();
void calculate_register_pressure();
bool opt_algebraic();
+ bool opt_commute_immediates();
bool opt_redundant_discard_jumps();
bool opt_cse();
bool opt_cse_local(bblock_t *block);
--
2.2.2
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