Mesa (master): i965/fs: Consider cmod when propagating to inst with different type.
Matt Turner
mattst88 at kemper.freedesktop.org
Wed Mar 4 20:33:35 UTC 2015
Module: Mesa
Branch: master
Commit: bd5e193eae5ba429b20597f814e0b201c73b6d68
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=bd5e193eae5ba429b20597f814e0b201c73b6d68
Author: Matt Turner <mattst88 at gmail.com>
Date: Fri Feb 27 10:22:21 2015 -0800
i965/fs: Consider cmod when propagating to inst with different type.
We can safely propagate the conditional mod to an instruction with a
different type if the conditional mod does not involve comparing for
equality with zero (or probably NaN, but ignore that for now).
This is because -0.0 and +0.0 are both test equal to zero, but their
integer representations do not.
Cc: 10.5 <mesa-stable at lists.freedesktop.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89317
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
---
.../drivers/dri/i965/brw_fs_cmod_propagation.cpp | 4 ++
.../drivers/dri/i965/test_fs_cmod_propagation.cpp | 67 ++++++++++++++++++++
2 files changed, 71 insertions(+)
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 c6384ab..58890ee 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_cmod_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_cmod_propagation.cpp
@@ -80,6 +80,10 @@ opt_cmod_propagation_local(fs_visitor *v, bblock_t *block)
scan_inst->dst.reg_offset != inst->src[0].reg_offset)
break;
+ /* Comparisons operate differently for ints and floats */
+ if (scan_inst->dst.type != inst->dst.type)
+ break;
+
/* If the instruction generating inst's source also wrote the
* flag, and inst is doing a simple .nz comparison, then inst
* is redundant - the appropriate value is already in the flag
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 fbe4fd9..0287161 100644
--- a/src/mesa/drivers/dri/i965/test_fs_cmod_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/test_fs_cmod_propagation.cpp
@@ -415,3 +415,70 @@ TEST_F(cmod_propagation_test, movnz)
EXPECT_EQ(BRW_OPCODE_CMP, instruction(block0, 0)->opcode);
EXPECT_EQ(BRW_CONDITIONAL_GE, instruction(block0, 0)->conditional_mod);
}
+
+TEST_F(cmod_propagation_test, different_types)
+{
+ fs_reg dest = v->vgrf(glsl_type::int_type);
+ fs_reg src0 = v->vgrf(glsl_type::int_type);
+ fs_reg src1 = v->vgrf(glsl_type::int_type);
+ fs_reg zero(0.0f);
+ v->emit(BRW_OPCODE_ADD, dest, src0, src1);
+ v->emit(BRW_OPCODE_CMP, v->reg_null_f, retype(dest, BRW_REGISTER_TYPE_F),
+ zero)
+ ->conditional_mod = BRW_CONDITIONAL_G;
+
+ /* = Before =
+ *
+ * 0: add(8) dest:D src0:D src1:D
+ * 1: cmp.g.f0(8) null:F dest:F 0.0f
+ *
+ * = After =
+ * 0: add.g.f0(8) dest:D src0:D src1:D
+ */
+
+ 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_G, instruction(block0, 0)->conditional_mod);
+}
+
+TEST_F(cmod_propagation_test, different_types_cmod_with_zero)
+{
+ fs_reg dest = v->vgrf(glsl_type::int_type);
+ fs_reg src0 = v->vgrf(glsl_type::int_type);
+ fs_reg src1 = v->vgrf(glsl_type::int_type);
+ fs_reg zero(0.0f);
+ v->emit(BRW_OPCODE_ADD, dest, src0, src1);
+ v->emit(BRW_OPCODE_CMP, v->reg_null_f, retype(dest, BRW_REGISTER_TYPE_F),
+ zero)
+ ->conditional_mod = BRW_CONDITIONAL_GE;
+
+ /* = Before =
+ *
+ * 0: add(8) dest:D src0:D src1:D
+ * 1: cmp.ge.f0(8) null:F dest:F 0.0f
+ *
+ * = After =
+ * (no changes)
+ */
+
+ v->calculate_cfg();
+ bblock_t *block0 = v->cfg->blocks[0];
+
+ EXPECT_EQ(0, block0->start_ip);
+ EXPECT_EQ(1, block0->end_ip);
+
+ EXPECT_FALSE(cmod_propagation(v));
+ EXPECT_EQ(0, block0->start_ip);
+ EXPECT_EQ(1, block0->end_ip);
+ EXPECT_EQ(BRW_OPCODE_ADD, instruction(block0, 0)->opcode);
+ EXPECT_EQ(BRW_OPCODE_CMP, instruction(block0, 1)->opcode);
+ EXPECT_EQ(BRW_CONDITIONAL_GE, instruction(block0, 1)->conditional_mod);
+}
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