[Mesa-dev] [PATCH 2/3] i965/fs: Emit compressed 3-source instructions on Haswell.

[Matt Turner]

For commit 4df56177 Paul discovered that the hardware restriction that
Align16 instructions cannot be compressed was lifted on Haswell. This
has prevented us from emitting compressed three-source instructions.

For added confirmation, the bspec lists a work around called
WaBreakSimd16TernaryInstructionsIntoSimd8 that hasn't been applicable
since very early Haswell silicon.
---
 src/mesa/drivers/dri/i965/brw_fs_generator.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
index cc58ff2..a97a016 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
@@ -1404,7 +1404,7 @@ fs_generator::generate_code(exec_list *instructions)
       case BRW_OPCODE_MAD:
          assert(brw->gen >= 6);
 	 brw_set_access_mode(p, BRW_ALIGN_16);
-	 if (dispatch_width == 16) {
+         if (dispatch_width == 16 && !brw->is_haswell) {
 	    brw_set_compression_control(p, BRW_COMPRESSION_NONE);
 	    brw_MAD(p, dst, src[0], src[1], src[2]);
 	    brw_set_compression_control(p, BRW_COMPRESSION_2NDHALF);
@@ -1419,7 +1419,7 @@ fs_generator::generate_code(exec_list *instructions)
       case BRW_OPCODE_LRP:
          assert(brw->gen >= 6);
 	 brw_set_access_mode(p, BRW_ALIGN_16);
-	 if (dispatch_width == 16) {
+         if (dispatch_width == 16 && !brw->is_haswell) {
 	    brw_set_compression_control(p, BRW_COMPRESSION_NONE);
 	    brw_LRP(p, dst, src[0], src[1], src[2]);
 	    brw_set_compression_control(p, BRW_COMPRESSION_2NDHALF);
@@ -1516,7 +1516,7 @@ fs_generator::generate_code(exec_list *instructions)
       case BRW_OPCODE_BFE:
          assert(brw->gen >= 7);
          brw_set_access_mode(p, BRW_ALIGN_16);
-         if (dispatch_width == 16) {
+         if (dispatch_width == 16 && !brw->is_haswell) {
             brw_set_compression_control(p, BRW_COMPRESSION_NONE);
             brw_BFE(p, dst, src[0], src[1], src[2]);
             brw_set_compression_control(p, BRW_COMPRESSION_2NDHALF);
-- 
1.8.3.2