This allows us to apply the optimization in cases where the CMP's
argument is negated, by flipping the conditional mod. For example, it
allows us to optimize this:
add(8) temp a b
cmp.l.f0(8) null -temp 0.0
into
add.ge.f0(8) temp a b
total instructions in shared programs: 5958360 -> 5955701 (-0.04%)
instructions in affected programs: 466880 -> 464221 (-0.57%)
GAINED: 0
LOST: 1
---
.../drivers/dri/i965/brw_fs_cmod_propagation.cpp | 9 ++++--
.../drivers/dri/i965/test_fs_cmod_propagation.cpp | 33 ++++++++++++++++++++++
2 files changed, 39 insertions(+), 3 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_fs_cmod_propagation.cpp
b/src/mesa/drivers/dri/i965/brw_fs_cmod_propagation.cpp
index 4f350c6..b521350 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_cmod_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_cmod_propagation.cpp
@@ -62,7 +62,6 @@ opt_cmod_propagation_local(fs_visitor *v, bblock_t *block)
!inst->dst.is_null() ||
inst->src[0].file != GRF ||
inst->src[0].abs ||
- inst->src[0].negate ||
!inst->src[1].is_zero())
continue;
@@ -73,10 +72,14 @@ opt_cmod_propagation_local(fs_visitor *v, bblock_t *block)
scan_inst->dst.reg == inst->src[0].reg &&
scan_inst->dst.reg_offset == inst->src[0].reg_offset &&
!scan_inst->is_partial_write()) {
+ enum brw_conditional_mod cond =
+ inst->src[0].negate ? brw_invert_cmod(inst->conditional_mod)
+ : inst->conditional_mod;
+
if (scan_inst->can_do_cmod() &&
((!read_flag && scan_inst->conditional_mod ==
BRW_CONDITIONAL_NONE) ||
- scan_inst->conditional_mod == inst->conditional_mod)) {
- scan_inst->conditional_mod = inst->conditional_mod;
+ scan_inst->conditional_mod == cond)) {
+ scan_inst->conditional_mod = cond;
inst->remove(block);
progress = true;
}
diff --git a/src/mesa/drivers/dri/i965/test_fs_cmod_propagation.cpp
b/src/mesa/drivers/dri/i965/test_fs_cmod_propagation.cpp
index 624e0b3..15f685e 100644
--- a/src/mesa/drivers/dri/i965/test_fs_cmod_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/test_fs_cmod_propagation.cpp
@@ -310,3 +310,36 @@ TEST_F(cmod_propagation_test,
intervening_flag_read_same_value)
EXPECT_EQ(BRW_OPCODE_SEL, instruction(block0, 1)->opcode);
EXPECT_EQ(BRW_PREDICATE_NORMAL, instruction(block0, 1)->predicate);
}
+
+TEST_F(cmod_propagation_test, negate)
+{
+ fs_reg dest(v, glsl_type::float_type);
+ fs_reg src0(v, glsl_type::float_type);
+ fs_reg src1(v, glsl_type::float_type);
+ fs_reg zero(0.0f);
+ v->emit(BRW_OPCODE_ADD, dest, src0, src1);
+ dest.negate = true;
+ v->emit(BRW_OPCODE_CMP, v->reg_null_f, dest, zero)
+ ->conditional_mod = BRW_CONDITIONAL_GE;
+
+ /* = Before =
+ *
+ * 0: add(8) dest src0 src1
+ * 1: cmp.ge.f0(8) null -dest 0.0f
+ *
+ * = After =
+ * 0: add.l.f0(8) dest src0 src1
+ */
+
+ v->calculate_cfg();
+ bblock_t *block0 = v->cfg->blocks[0];
+
+ EXPECT_EQ(0, block0->start_ip);
+ EXPECT_EQ(1, block0->end_ip);
+
+ EXPECT_TRUE(cmod_propagation(v));
+ EXPECT_EQ(0, block0->start_ip);
+ EXPECT_EQ(0, block0->end_ip);
+ EXPECT_EQ(BRW_OPCODE_ADD, instruction(block0, 0)->opcode);
+ EXPECT_EQ(BRW_CONDITIONAL_L, instruction(block0, 0)->conditional_mod);
+}
--
2.0.4
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