[Mesa-dev] [PATCH] i965: Add a brw_fs_cmod_propagation unit test with large VGRF writes.

[Kenneth Graunke]

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 .../drivers/dri/i965/test_fs_cmod_propagation.cpp  | 40 ++++++++++++++++++++++
 1 file changed, 40 insertions(+)

Yep, that is indeed broken, and my proposed code fixes it.

Here's a unit test that provokes the problem.  Thanks for putting together
the unit tests - they're quite handy!

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 d5d7b58..cc184aa 100644
--- a/src/mesa/drivers/dri/i965/test_fs_cmod_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/test_fs_cmod_propagation.cpp
@@ -375,3 +375,43 @@ 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, intervening_dest_write)
+{
+   fs_reg dest = v->vgrf(glsl_type::vec4_type);
+   fs_reg src0 = v->vgrf(glsl_type::float_type);
+   fs_reg src1 = v->vgrf(glsl_type::float_type);
+   fs_reg src2 = v->vgrf(glsl_type::vec2_type);
+   fs_reg zero(0.0f);
+   v->emit(BRW_OPCODE_ADD, offset(dest, 2), src0, src1);
+   v->emit(SHADER_OPCODE_TEX, dest, src2)
+      ->regs_written = 4;
+   v->emit(BRW_OPCODE_CMP, v->reg_null_f, offset(dest, 2), zero)
+      ->conditional_mod = BRW_CONDITIONAL_GE;
+
+   /* = Before =
+    *
+    * 0: add(8)        dest+2  src0    src1
+    * 1: tex(8) rlen 4 dest+0  src2
+    * 2: cmp.ge.f0(8)  null    dest+2  0.0f
+    *
+    * = After =
+    * (no changes)
+    */
+
+   v->calculate_cfg();
+   bblock_t *block0 = v->cfg->blocks[0];
+
+   EXPECT_EQ(0, block0->start_ip);
+   EXPECT_EQ(2, block0->end_ip);
+
+   EXPECT_FALSE(cmod_propagation(v));
+   EXPECT_EQ(0, block0->start_ip);
+   EXPECT_EQ(2, block0->end_ip);
+   EXPECT_EQ(BRW_OPCODE_ADD, instruction(block0, 0)->opcode);
+   EXPECT_EQ(BRW_CONDITIONAL_NONE, instruction(block0, 0)->conditional_mod);
+   EXPECT_EQ(SHADER_OPCODE_TEX, instruction(block0, 1)->opcode);
+   EXPECT_EQ(BRW_CONDITIONAL_NONE, instruction(block0, 0)->conditional_mod);
+   EXPECT_EQ(BRW_OPCODE_CMP, instruction(block0, 2)->opcode);
+   EXPECT_EQ(BRW_CONDITIONAL_GE, instruction(block0, 2)->conditional_mod);
+}
-- 
2.2.2