From 6c1b3bc950d480a21d4957b5b0cab84ffc49769b Mon Sep 17 00:00:00 2001
From: Matt Turner <mattst88@gmail.com>
Date: Wed, 20 Jan 2016 18:56:37 -0800
Subject: [PATCH] i965/fs: Implement support for extract_word.

The vec4 backend will lower it.
---
 src/mesa/drivers/dri/i965/brw_defines.h        | 12 ++++++++++++
 src/mesa/drivers/dri/i965/brw_fs_cse.cpp       |  2 ++
 src/mesa/drivers/dri/i965/brw_fs_generator.cpp | 22 ++++++++++++++++++++++
 src/mesa/drivers/dri/i965/brw_fs_nir.cpp       | 16 ++++++++++++++++
 src/mesa/drivers/dri/i965/brw_shader.cpp       |  4 ++++
 5 files changed, 56 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h
index 10a6d39..01e0c99 100644
--- a/src/mesa/drivers/dri/i965/brw_defines.h
+++ b/src/mesa/drivers/dri/i965/brw_defines.h
@@ -1085,6 +1085,18 @@ enum opcode {
     */
    SHADER_OPCODE_BROADCAST,
 
+   /**
+    * Pick the byte from its first source register given by the index
+    * specified as second source.
+    */
+   SHADER_OPCODE_EXTRACT_BYTE,
+
+   /**
+    * Pick the word from its first source register given by the index
+    * specified as second source.
+    */
+   SHADER_OPCODE_EXTRACT_WORD,
+
    VEC4_OPCODE_MOV_BYTES,
    VEC4_OPCODE_PACK_BYTES,
    VEC4_OPCODE_UNPACK_UNIFORM,
diff --git a/src/mesa/drivers/dri/i965/brw_fs_cse.cpp b/src/mesa/drivers/dri/i965/brw_fs_cse.cpp
index 3b65a38..cde6566 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_cse.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_cse.cpp
@@ -78,6 +78,8 @@ is_expression(const fs_visitor *v, const fs_inst *const inst)
    case FS_OPCODE_LINTERP:
    case SHADER_OPCODE_FIND_LIVE_CHANNEL:
    case SHADER_OPCODE_BROADCAST:
+   case SHADER_OPCODE_EXTRACT_BYTE:
+   case SHADER_OPCODE_EXTRACT_WORD:
    case SHADER_OPCODE_MOV_INDIRECT:
       return true;
    case SHADER_OPCODE_RCP:
diff --git a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
index e05622a..1916a99 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
@@ -2201,6 +2201,28 @@ fs_generator::generate_code(const cfg_t *cfg, int dispatch_width)
          brw_broadcast(p, dst, src[0], src[1]);
          break;
 
+      case SHADER_OPCODE_EXTRACT_BYTE: {
+         assert(src[0].type == BRW_REGISTER_TYPE_D ||
+                src[0].type == BRW_REGISTER_TYPE_UD);
+
+         enum brw_reg_type type =
+            src[0].type == BRW_REGISTER_TYPE_D ? BRW_REGISTER_TYPE_B
+                                               : BRW_REGISTER_TYPE_UB;
+         brw_MOV(p, dst, spread(suboffset(retype(src[0], type), src[1].ud), 4));
+         break;
+      }
+
+      case SHADER_OPCODE_EXTRACT_WORD: {
+         assert(src[0].type == BRW_REGISTER_TYPE_D ||
+                src[0].type == BRW_REGISTER_TYPE_UD);
+
+         enum brw_reg_type type =
+            src[0].type == BRW_REGISTER_TYPE_D ? BRW_REGISTER_TYPE_W
+                                               : BRW_REGISTER_TYPE_UW;
+         brw_MOV(p, dst, spread(suboffset(retype(src[0], type), src[1].ud), 2));
+         break;
+      }
+
       case FS_OPCODE_SET_SAMPLE_ID:
          generate_set_sample_id(inst, dst, src[0], src[1]);
          break;
diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
index d7bcc1c..3efee50 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
@@ -1075,6 +1075,22 @@ fs_visitor::nir_emit_alu(const fs_builder &bld, nir_alu_instr *instr)
       inst->predicate = BRW_PREDICATE_NORMAL;
       break;
 
+   case nir_op_extract_ubyte:
+   case nir_op_extract_ibyte: {
+      nir_const_value *byte = nir_src_as_const_value(instr->src[1].src);
+      bld.emit(SHADER_OPCODE_EXTRACT_BYTE,
+               result, op[0], brw_imm_ud(byte->u[0]));
+      break;
+   }
+
+   case nir_op_extract_uword:
+   case nir_op_extract_iword: {
+      nir_const_value *word = nir_src_as_const_value(instr->src[1].src);
+      bld.emit(SHADER_OPCODE_EXTRACT_WORD,
+               result, op[0], brw_imm_ud(word->u[0]));
+      break;
+   }
+
    default:
       unreachable("unhandled instruction");
    }
diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp b/src/mesa/drivers/dri/i965/brw_shader.cpp
index e42601b..6a6efa9 100644
--- a/src/mesa/drivers/dri/i965/brw_shader.cpp
+++ b/src/mesa/drivers/dri/i965/brw_shader.cpp
@@ -312,6 +312,10 @@ brw_instruction_name(enum opcode op)
    case SHADER_OPCODE_BROADCAST:
       return "broadcast";
 
+   case SHADER_OPCODE_EXTRACT_BYTE:
+      return "extract_byte";
+   case SHADER_OPCODE_EXTRACT_WORD:
+      return "extract_word";
    case VEC4_OPCODE_MOV_BYTES:
       return "mov_bytes";
    case VEC4_OPCODE_PACK_BYTES:
-- 
2.7.4