From 9a3a2942240065d85e197e04d9612af696b9ea99 Mon Sep 17 00:00:00 2001 From: Matt Turner Date: Tue, 30 Dec 2014 12:18:57 -0800 Subject: [PATCH] i965/fs: Allow flipping cond mod for negated arguments. 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.g.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 Reviewed-by: Jason Ekstrand Reviewed-by: Kenneth Graunke --- .../dri/i965/brw_fs_cmod_propagation.cpp | 9 +++-- .../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 c8eb3a4f8be..8a03315bc4c 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; @@ -74,10 +73,14 @@ opt_cmod_propagation_local(fs_visitor *v, bblock_t *block) scan_inst->dst.reg_offset != inst->src[0].reg_offset) break; + enum brw_conditional_mod cond = + inst->src[0].negate ? brw_swap_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 95d335d9543..fefe515a216 100644 --- a/src/mesa/drivers/dri/i965/test_fs_cmod_propagation.cpp +++ b/src/mesa/drivers/dri/i965/test_fs_cmod_propagation.cpp @@ -350,3 +350,36 @@ 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->vgrf(glsl_type::float_type); + fs_reg src0 = v->vgrf(glsl_type::float_type); + fs_reg src1 = v->vgrf(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.le.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_LE, instruction(block0, 0)->conditional_mod); +} -- 2.30.2