Mesa (master): i965: Drop bogus F32TO16/ F16TO32 instructions on Broadwell - use MOV.

[Kenneth Graunke]

Module: Mesa
Branch: master
Commit: 850e372fc7ff3377d7ffdf825d5ebcdd72beee1b
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=850e372fc7ff3377d7ffdf825d5ebcdd72beee1b

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Wed Jan 29 14:16:27 2014 -0800

i965: Drop bogus F32TO16/F16TO32 instructions on Broadwell - use MOV.

Broadwell removed the F32TO16 and F16TO32 instructions.  However, it has
actual support for HF values, so they're actually just MOV.

Fixes vs-packHalf2x16 and vs-unpackHalf2x16 tests (both the ARB
extension and ES 3.0 variants).

v2: Emulate F32TO16's align16 zeroing bug, since Chad's front end code
    relies on it happening.  We can probably refactor this code to be
    better later.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Eric Anholt <eric at anholt.net>

---

 src/mesa/drivers/dri/i965/gen8_fs_generator.cpp   |    4 ++--
 src/mesa/drivers/dri/i965/gen8_generator.cpp      |    2 --
 src/mesa/drivers/dri/i965/gen8_vec4_generator.cpp |    6 ++++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/gen8_fs_generator.cpp b/src/mesa/drivers/dri/i965/gen8_fs_generator.cpp
index e5fa3d2..0e1214d 100644
--- a/src/mesa/drivers/dri/i965/gen8_fs_generator.cpp
+++ b/src/mesa/drivers/dri/i965/gen8_fs_generator.cpp
@@ -920,10 +920,10 @@ gen8_fs_generator::generate_code(exec_list *instructions)
          break;
 
       case BRW_OPCODE_F32TO16:
-         F32TO16(dst, src[0]);
+         MOV(retype(dst, BRW_REGISTER_TYPE_HF), src[0]);
          break;
       case BRW_OPCODE_F16TO32:
-         F16TO32(dst, src[0]);
+         MOV(dst, retype(src[0], BRW_REGISTER_TYPE_HF));
          break;
 
       case BRW_OPCODE_CMP:
diff --git a/src/mesa/drivers/dri/i965/gen8_generator.cpp b/src/mesa/drivers/dri/i965/gen8_generator.cpp
index 1e2ac09..ca38af6 100644
--- a/src/mesa/drivers/dri/i965/gen8_generator.cpp
+++ b/src/mesa/drivers/dri/i965/gen8_generator.cpp
@@ -154,8 +154,6 @@ ALU2(ASR)
 ALU3(BFE)
 ALU2(BFI1)
 ALU3(BFI2)
-ALU1(F32TO16)
-ALU1(F16TO32)
 ALU1(BFREV)
 ALU1(CBIT)
 ALU2_ACCUMULATE(ADDC)
diff --git a/src/mesa/drivers/dri/i965/gen8_vec4_generator.cpp b/src/mesa/drivers/dri/i965/gen8_vec4_generator.cpp
index 7ed5d2a..7f6b209 100644
--- a/src/mesa/drivers/dri/i965/gen8_vec4_generator.cpp
+++ b/src/mesa/drivers/dri/i965/gen8_vec4_generator.cpp
@@ -586,11 +586,13 @@ gen8_vec4_generator::generate_vec4_instruction(vec4_instruction *instruction,
       break;
 
    case BRW_OPCODE_F32TO16:
-      F32TO16(dst, src[0]);
+      /* Emulate the Gen7 zeroing bug. */
+      MOV(retype(dst, BRW_REGISTER_TYPE_UD), brw_imm_ud(0u));
+      MOV(retype(dst, BRW_REGISTER_TYPE_HF), src[0]);
       break;
 
    case BRW_OPCODE_F16TO32:
-      F16TO32(dst, src[0]);
+      MOV(dst, retype(src[0], BRW_REGISTER_TYPE_HF));
       break;
 
    case BRW_OPCODE_LRP: