示例#1
0
void
vec4_generator::generate_gs_prepare_channel_masks(struct brw_reg dst)
{
   /* We want to left shift just DWORD 4 (the x component belonging to the
    * second geometry shader invocation) by 4 bits.  So generate the
    * instruction:
    *
    *     shl(1) dst.4<1>UD dst.4<0,1,0>UD 4UD { align1 WE_all }
    */
   dst = suboffset(vec1(dst), 4);
   brw_push_insn_state(p);
   brw_set_default_access_mode(p, BRW_ALIGN_1);
   brw_set_default_mask_control(p, BRW_MASK_DISABLE);
   brw_SHL(p, dst, dst, brw_imm_ud(4));
   brw_pop_insn_state(p);
}
示例#2
0
/**
 * Generate assembly for a Vec4 IR instruction.
 *
 * \param instruction The Vec4 IR instruction to generate code for.
 * \param dst         The destination register.
 * \param src         An array of up to three source registers.
 */
void
vec4_generator::generate_vec4_instruction(vec4_instruction *instruction,
        struct brw_reg dst,
        struct brw_reg *src)
{
    vec4_instruction *inst = (vec4_instruction *) instruction;

    if (dst.width == BRW_WIDTH_4) {
        /* This happens in attribute fixups for "dual instanced" geometry
         * shaders, since they use attributes that are vec4's.  Since the exec
         * width is only 4, it's essential that the caller set
         * force_writemask_all in order to make sure the instruction is executed
         * regardless of which channels are enabled.
         */
        assert(inst->force_writemask_all);

        /* Fix up any <8;8,1> or <0;4,1> source registers to <4;4,1> to satisfy
         * the following register region restrictions (from Graphics BSpec:
         * 3D-Media-GPGPU Engine > EU Overview > Registers and Register Regions
         * > Register Region Restrictions)
         *
         *     1. ExecSize must be greater than or equal to Width.
         *
         *     2. If ExecSize = Width and HorzStride != 0, VertStride must be set
         *        to Width * HorzStride."
         */
        for (int i = 0; i < 3; i++) {
            if (src[i].file == BRW_GENERAL_REGISTER_FILE)
                src[i] = stride(src[i], 4, 4, 1);
        }
    }

    switch (inst->opcode) {
    case BRW_OPCODE_MOV:
        brw_MOV(p, dst, src[0]);
        break;
    case BRW_OPCODE_ADD:
        brw_ADD(p, dst, src[0], src[1]);
        break;
    case BRW_OPCODE_MUL:
        brw_MUL(p, dst, src[0], src[1]);
        break;
    case BRW_OPCODE_MACH:
        brw_set_acc_write_control(p, 1);
        brw_MACH(p, dst, src[0], src[1]);
        brw_set_acc_write_control(p, 0);
        break;

    case BRW_OPCODE_MAD:
        assert(brw->gen >= 6);
        brw_MAD(p, dst, src[0], src[1], src[2]);
        break;

    case BRW_OPCODE_FRC:
        brw_FRC(p, dst, src[0]);
        break;
    case BRW_OPCODE_RNDD:
        brw_RNDD(p, dst, src[0]);
        break;
    case BRW_OPCODE_RNDE:
        brw_RNDE(p, dst, src[0]);
        break;
    case BRW_OPCODE_RNDZ:
        brw_RNDZ(p, dst, src[0]);
        break;

    case BRW_OPCODE_AND:
        brw_AND(p, dst, src[0], src[1]);
        break;
    case BRW_OPCODE_OR:
        brw_OR(p, dst, src[0], src[1]);
        break;
    case BRW_OPCODE_XOR:
        brw_XOR(p, dst, src[0], src[1]);
        break;
    case BRW_OPCODE_NOT:
        brw_NOT(p, dst, src[0]);
        break;
    case BRW_OPCODE_ASR:
        brw_ASR(p, dst, src[0], src[1]);
        break;
    case BRW_OPCODE_SHR:
        brw_SHR(p, dst, src[0], src[1]);
        break;
    case BRW_OPCODE_SHL:
        brw_SHL(p, dst, src[0], src[1]);
        break;

    case BRW_OPCODE_CMP:
        brw_CMP(p, dst, inst->conditional_mod, src[0], src[1]);
        break;
    case BRW_OPCODE_SEL:
        brw_SEL(p, dst, src[0], src[1]);
        break;

    case BRW_OPCODE_DPH:
        brw_DPH(p, dst, src[0], src[1]);
        break;

    case BRW_OPCODE_DP4:
        brw_DP4(p, dst, src[0], src[1]);
        break;

    case BRW_OPCODE_DP3:
        brw_DP3(p, dst, src[0], src[1]);
        break;

    case BRW_OPCODE_DP2:
        brw_DP2(p, dst, src[0], src[1]);
        break;

    case BRW_OPCODE_F32TO16:
        assert(brw->gen >= 7);
        brw_F32TO16(p, dst, src[0]);
        break;

    case BRW_OPCODE_F16TO32:
        assert(brw->gen >= 7);
        brw_F16TO32(p, dst, src[0]);
        break;

    case BRW_OPCODE_LRP:
        assert(brw->gen >= 6);
        brw_LRP(p, dst, src[0], src[1], src[2]);
        break;

    case BRW_OPCODE_BFREV:
        assert(brw->gen >= 7);
        /* BFREV only supports UD type for src and dst. */
        brw_BFREV(p, retype(dst, BRW_REGISTER_TYPE_UD),
                  retype(src[0], BRW_REGISTER_TYPE_UD));
        break;
    case BRW_OPCODE_FBH:
        assert(brw->gen >= 7);
        /* FBH only supports UD type for dst. */
        brw_FBH(p, retype(dst, BRW_REGISTER_TYPE_UD), src[0]);
        break;
    case BRW_OPCODE_FBL:
        assert(brw->gen >= 7);
        /* FBL only supports UD type for dst. */
        brw_FBL(p, retype(dst, BRW_REGISTER_TYPE_UD), src[0]);
        break;
    case BRW_OPCODE_CBIT:
        assert(brw->gen >= 7);
        /* CBIT only supports UD type for dst. */
        brw_CBIT(p, retype(dst, BRW_REGISTER_TYPE_UD), src[0]);
        break;
    case BRW_OPCODE_ADDC:
        assert(brw->gen >= 7);
        brw_set_acc_write_control(p, 1);
        brw_ADDC(p, dst, src[0], src[1]);
        brw_set_acc_write_control(p, 0);
        break;
    case BRW_OPCODE_SUBB:
        assert(brw->gen >= 7);
        brw_set_acc_write_control(p, 1);
        brw_SUBB(p, dst, src[0], src[1]);
        brw_set_acc_write_control(p, 0);
        break;

    case BRW_OPCODE_BFE:
        assert(brw->gen >= 7);
        brw_BFE(p, dst, src[0], src[1], src[2]);
        break;

    case BRW_OPCODE_BFI1:
        assert(brw->gen >= 7);
        brw_BFI1(p, dst, src[0], src[1]);
        break;
    case BRW_OPCODE_BFI2:
        assert(brw->gen >= 7);
        brw_BFI2(p, dst, src[0], src[1], src[2]);
        break;

    case BRW_OPCODE_IF:
        if (inst->src[0].file != BAD_FILE) {
            /* The instruction has an embedded compare (only allowed on gen6) */
            assert(brw->gen == 6);
            gen6_IF(p, inst->conditional_mod, src[0], src[1]);
        } else {
            struct brw_instruction *brw_inst = brw_IF(p, BRW_EXECUTE_8);
            brw_inst->header.predicate_control = inst->predicate;
        }
        break;

    case BRW_OPCODE_ELSE:
        brw_ELSE(p);
        break;
    case BRW_OPCODE_ENDIF:
        brw_ENDIF(p);
        break;

    case BRW_OPCODE_DO:
        brw_DO(p, BRW_EXECUTE_8);
        break;

    case BRW_OPCODE_BREAK:
        brw_BREAK(p);
        brw_set_predicate_control(p, BRW_PREDICATE_NONE);
        break;
    case BRW_OPCODE_CONTINUE:
        /* FINISHME: We need to write the loop instruction support still. */
        if (brw->gen >= 6)
            gen6_CONT(p);
        else
            brw_CONT(p);
        brw_set_predicate_control(p, BRW_PREDICATE_NONE);
        break;

    case BRW_OPCODE_WHILE:
        brw_WHILE(p);
        break;

    case SHADER_OPCODE_RCP:
    case SHADER_OPCODE_RSQ:
    case SHADER_OPCODE_SQRT:
    case SHADER_OPCODE_EXP2:
    case SHADER_OPCODE_LOG2:
    case SHADER_OPCODE_SIN:
    case SHADER_OPCODE_COS:
        if (brw->gen == 6) {
            generate_math1_gen6(inst, dst, src[0]);
        } else {
            /* Also works for Gen7. */
            generate_math1_gen4(inst, dst, src[0]);
        }
        break;

    case SHADER_OPCODE_POW:
    case SHADER_OPCODE_INT_QUOTIENT:
    case SHADER_OPCODE_INT_REMAINDER:
        if (brw->gen >= 7) {
            generate_math2_gen7(inst, dst, src[0], src[1]);
        } else if (brw->gen == 6) {
            generate_math2_gen6(inst, dst, src[0], src[1]);
        } else {
            generate_math2_gen4(inst, dst, src[0], src[1]);
        }
        break;

    case SHADER_OPCODE_TEX:
    case SHADER_OPCODE_TXD:
    case SHADER_OPCODE_TXF:
    case SHADER_OPCODE_TXF_CMS:
    case SHADER_OPCODE_TXF_MCS:
    case SHADER_OPCODE_TXL:
    case SHADER_OPCODE_TXS:
    case SHADER_OPCODE_TG4:
    case SHADER_OPCODE_TG4_OFFSET:
        generate_tex(inst, dst, src[0]);
        break;

    case VS_OPCODE_URB_WRITE:
        generate_vs_urb_write(inst);
        break;

    case SHADER_OPCODE_GEN4_SCRATCH_READ:
        generate_scratch_read(inst, dst, src[0]);
        break;

    case SHADER_OPCODE_GEN4_SCRATCH_WRITE:
        generate_scratch_write(inst, dst, src[0], src[1]);
        break;

    case VS_OPCODE_PULL_CONSTANT_LOAD:
        generate_pull_constant_load(inst, dst, src[0], src[1]);
        break;

    case VS_OPCODE_PULL_CONSTANT_LOAD_GEN7:
        generate_pull_constant_load_gen7(inst, dst, src[0], src[1]);
        break;

    case GS_OPCODE_URB_WRITE:
        generate_gs_urb_write(inst);
        break;

    case GS_OPCODE_THREAD_END:
        generate_gs_thread_end(inst);
        break;

    case GS_OPCODE_SET_WRITE_OFFSET:
        generate_gs_set_write_offset(dst, src[0], src[1]);
        break;

    case GS_OPCODE_SET_VERTEX_COUNT:
        generate_gs_set_vertex_count(dst, src[0]);
        break;

    case GS_OPCODE_SET_DWORD_2_IMMED:
        generate_gs_set_dword_2_immed(dst, src[0]);
        break;

    case GS_OPCODE_PREPARE_CHANNEL_MASKS:
        generate_gs_prepare_channel_masks(dst);
        break;

    case GS_OPCODE_SET_CHANNEL_MASKS:
        generate_gs_set_channel_masks(dst, src[0]);
        break;

    case GS_OPCODE_GET_INSTANCE_ID:
        generate_gs_get_instance_id(dst);
        break;

    case SHADER_OPCODE_SHADER_TIME_ADD:
        brw_shader_time_add(p, src[0],
                            prog_data->base.binding_table.shader_time_start);
        brw_mark_surface_used(&prog_data->base,
                              prog_data->base.binding_table.shader_time_start);
        break;

    case SHADER_OPCODE_UNTYPED_ATOMIC:
        generate_untyped_atomic(inst, dst, src[0], src[1]);
        break;

    case SHADER_OPCODE_UNTYPED_SURFACE_READ:
        generate_untyped_surface_read(inst, dst, src[0]);
        break;

    case VS_OPCODE_UNPACK_FLAGS_SIMD4X2:
        generate_unpack_flags(inst, dst);
        break;

    default:
        if (inst->opcode < (int) ARRAY_SIZE(opcode_descs)) {
            _mesa_problem(&brw->ctx, "Unsupported opcode in `%s' in vec4\n",
                          opcode_descs[inst->opcode].name);
        } else {
            _mesa_problem(&brw->ctx, "Unsupported opcode %d in vec4", inst->opcode);
        }
        abort();
    }
}
示例#3
0
void brw_emit_anyprim_setup( struct brw_sf_compile *c )
{
    struct brw_compile *p = &c->func;
    struct brw_reg ip = brw_ip_reg();
    struct brw_reg payload_prim = brw_uw1_reg(BRW_GENERAL_REGISTER_FILE, 1, 0);
    struct brw_reg payload_attr = get_element_ud(brw_vec1_reg(BRW_GENERAL_REGISTER_FILE, 1, 0), 0);
    struct brw_reg primmask;
    struct brw_instruction *jmp;
    struct brw_reg v1_null_ud = vec1(retype(brw_null_reg(), BRW_REGISTER_TYPE_UD));

    GLuint saveflag;

    c->nr_verts = 3;
    alloc_regs(c);

    primmask = retype(get_element(c->tmp, 0), BRW_REGISTER_TYPE_UD);

    brw_MOV(p, primmask, brw_imm_ud(1));
    brw_SHL(p, primmask, primmask, payload_prim);

    brw_set_conditionalmod(p, BRW_CONDITIONAL_Z);
    brw_AND(p, v1_null_ud, primmask, brw_imm_ud((1<<_3DPRIM_TRILIST) |
            (1<<_3DPRIM_TRISTRIP) |
            (1<<_3DPRIM_TRIFAN) |
            (1<<_3DPRIM_TRISTRIP_REVERSE) |
            (1<<_3DPRIM_POLYGON) |
            (1<<_3DPRIM_RECTLIST) |
            (1<<_3DPRIM_TRIFAN_NOSTIPPLE)));
    jmp = brw_JMPI(p, ip, ip, brw_imm_d(0));
    {
        saveflag = p->flag_value;
        brw_push_insn_state(p);
        brw_emit_tri_setup( c, GL_FALSE );
        brw_pop_insn_state(p);
        p->flag_value = saveflag;
        /* note - thread killed in subroutine, so must
         * restore the flag which is changed when building
         * the subroutine. fix #13240
         */
    }
    brw_land_fwd_jump(p, jmp);

    brw_set_conditionalmod(p, BRW_CONDITIONAL_Z);
    brw_AND(p, v1_null_ud, primmask, brw_imm_ud((1<<_3DPRIM_LINELIST) |
            (1<<_3DPRIM_LINESTRIP) |
            (1<<_3DPRIM_LINELOOP) |
            (1<<_3DPRIM_LINESTRIP_CONT) |
            (1<<_3DPRIM_LINESTRIP_BF) |
            (1<<_3DPRIM_LINESTRIP_CONT_BF)));
    jmp = brw_JMPI(p, ip, ip, brw_imm_d(0));
    {
        saveflag = p->flag_value;
        brw_push_insn_state(p);
        brw_emit_line_setup( c, GL_FALSE );
        brw_pop_insn_state(p);
        p->flag_value = saveflag;
        /* note - thread killed in subroutine */
    }
    brw_land_fwd_jump(p, jmp);

    brw_set_conditionalmod(p, BRW_CONDITIONAL_Z);
    brw_AND(p, v1_null_ud, payload_attr, brw_imm_ud(1<<BRW_SPRITE_POINT_ENABLE));
    jmp = brw_JMPI(p, ip, ip, brw_imm_d(0));
    {
        saveflag = p->flag_value;
        brw_push_insn_state(p);
        brw_emit_point_sprite_setup( c, GL_FALSE );
        brw_pop_insn_state(p);
        p->flag_value = saveflag;
    }
    brw_land_fwd_jump(p, jmp);

    brw_emit_point_setup( c, GL_FALSE );
}
示例#4
0
void
vec4_generator::generate_tex(vec4_instruction *inst,
                             struct brw_reg dst,
                             struct brw_reg src,
                             struct brw_reg sampler_index)
{
   int msg_type = -1;

   if (brw->gen >= 5) {
      switch (inst->opcode) {
      case SHADER_OPCODE_TEX:
      case SHADER_OPCODE_TXL:
	 if (inst->shadow_compare) {
	    msg_type = GEN5_SAMPLER_MESSAGE_SAMPLE_LOD_COMPARE;
	 } else {
	    msg_type = GEN5_SAMPLER_MESSAGE_SAMPLE_LOD;
	 }
	 break;
      case SHADER_OPCODE_TXD:
         if (inst->shadow_compare) {
            /* Gen7.5+.  Otherwise, lowered by brw_lower_texture_gradients(). */
            assert(brw->gen >= 8 || brw->is_haswell);
            msg_type = HSW_SAMPLER_MESSAGE_SAMPLE_DERIV_COMPARE;
         } else {
            msg_type = GEN5_SAMPLER_MESSAGE_SAMPLE_DERIVS;
         }
	 break;
      case SHADER_OPCODE_TXF:
	 msg_type = GEN5_SAMPLER_MESSAGE_SAMPLE_LD;
	 break;
      case SHADER_OPCODE_TXF_CMS:
         if (brw->gen >= 7)
            msg_type = GEN7_SAMPLER_MESSAGE_SAMPLE_LD2DMS;
         else
            msg_type = GEN5_SAMPLER_MESSAGE_SAMPLE_LD;
         break;
      case SHADER_OPCODE_TXF_MCS:
         assert(brw->gen >= 7);
         msg_type = GEN7_SAMPLER_MESSAGE_SAMPLE_LD_MCS;
         break;
      case SHADER_OPCODE_TXS:
	 msg_type = GEN5_SAMPLER_MESSAGE_SAMPLE_RESINFO;
	 break;
      case SHADER_OPCODE_TG4:
         if (inst->shadow_compare) {
            msg_type = GEN7_SAMPLER_MESSAGE_SAMPLE_GATHER4_C;
         } else {
            msg_type = GEN7_SAMPLER_MESSAGE_SAMPLE_GATHER4;
         }
         break;
      case SHADER_OPCODE_TG4_OFFSET:
         if (inst->shadow_compare) {
            msg_type = GEN7_SAMPLER_MESSAGE_SAMPLE_GATHER4_PO_C;
         } else {
            msg_type = GEN7_SAMPLER_MESSAGE_SAMPLE_GATHER4_PO;
         }
         break;
      default:
	 unreachable("should not get here: invalid vec4 texture opcode");
      }
   } else {
      switch (inst->opcode) {
      case SHADER_OPCODE_TEX:
      case SHADER_OPCODE_TXL:
	 if (inst->shadow_compare) {
	    msg_type = BRW_SAMPLER_MESSAGE_SIMD4X2_SAMPLE_LOD_COMPARE;
	    assert(inst->mlen == 3);
	 } else {
	    msg_type = BRW_SAMPLER_MESSAGE_SIMD4X2_SAMPLE_LOD;
	    assert(inst->mlen == 2);
	 }
	 break;
      case SHADER_OPCODE_TXD:
	 /* There is no sample_d_c message; comparisons are done manually. */
	 msg_type = BRW_SAMPLER_MESSAGE_SIMD4X2_SAMPLE_GRADIENTS;
	 assert(inst->mlen == 4);
	 break;
      case SHADER_OPCODE_TXF:
	 msg_type = BRW_SAMPLER_MESSAGE_SIMD4X2_LD;
	 assert(inst->mlen == 2);
	 break;
      case SHADER_OPCODE_TXS:
	 msg_type = BRW_SAMPLER_MESSAGE_SIMD4X2_RESINFO;
	 assert(inst->mlen == 2);
	 break;
      default:
	 unreachable("should not get here: invalid vec4 texture opcode");
      }
   }

   assert(msg_type != -1);

   assert(sampler_index.type == BRW_REGISTER_TYPE_UD);

   /* Load the message header if present.  If there's a texture offset, we need
    * to set it up explicitly and load the offset bitfield.  Otherwise, we can
    * use an implied move from g0 to the first message register.
    */
   if (inst->header_present) {
      if (brw->gen < 6 && !inst->texture_offset) {
         /* Set up an implied move from g0 to the MRF. */
         src = brw_vec8_grf(0, 0);
      } else {
         struct brw_reg header =
            retype(brw_message_reg(inst->base_mrf), BRW_REGISTER_TYPE_UD);

         /* Explicitly set up the message header by copying g0 to the MRF. */
         brw_push_insn_state(p);
         brw_set_default_mask_control(p, BRW_MASK_DISABLE);
         brw_MOV(p, header, retype(brw_vec8_grf(0, 0), BRW_REGISTER_TYPE_UD));

         brw_set_default_access_mode(p, BRW_ALIGN_1);

         if (inst->texture_offset) {
            /* Set the texel offset bits in DWord 2. */
            brw_MOV(p, get_element_ud(header, 2),
                    brw_imm_ud(inst->texture_offset));
         }

         brw_adjust_sampler_state_pointer(p, header, sampler_index, dst);
         brw_pop_insn_state(p);
      }
   }

   uint32_t return_format;

   switch (dst.type) {
   case BRW_REGISTER_TYPE_D:
      return_format = BRW_SAMPLER_RETURN_FORMAT_SINT32;
      break;
   case BRW_REGISTER_TYPE_UD:
      return_format = BRW_SAMPLER_RETURN_FORMAT_UINT32;
      break;
   default:
      return_format = BRW_SAMPLER_RETURN_FORMAT_FLOAT32;
      break;
   }

   uint32_t base_binding_table_index = (inst->opcode == SHADER_OPCODE_TG4 ||
         inst->opcode == SHADER_OPCODE_TG4_OFFSET)
         ? prog_data->base.binding_table.gather_texture_start
         : prog_data->base.binding_table.texture_start;

   if (sampler_index.file == BRW_IMMEDIATE_VALUE) {
      uint32_t sampler = sampler_index.dw1.ud;

      brw_SAMPLE(p,
                 dst,
                 inst->base_mrf,
                 src,
                 sampler + base_binding_table_index,
                 sampler % 16,
                 msg_type,
                 1, /* response length */
                 inst->mlen,
                 inst->header_present,
                 BRW_SAMPLER_SIMD_MODE_SIMD4X2,
                 return_format);

      brw_mark_surface_used(&prog_data->base, sampler + base_binding_table_index);
   } else {
      /* Non-constant sampler index. */
      /* Note: this clobbers `dst` as a temporary before emitting the send */

      struct brw_reg addr = vec1(retype(brw_address_reg(0), BRW_REGISTER_TYPE_UD));
      struct brw_reg temp = vec1(retype(dst, BRW_REGISTER_TYPE_UD));

      struct brw_reg sampler_reg = vec1(retype(sampler_index, BRW_REGISTER_TYPE_UD));

      brw_push_insn_state(p);
      brw_set_default_mask_control(p, BRW_MASK_DISABLE);
      brw_set_default_access_mode(p, BRW_ALIGN_1);

      /* Some care required: `sampler` and `temp` may alias:
       *    addr = sampler & 0xff
       *    temp = (sampler << 8) & 0xf00
       *    addr = addr | temp
       */
      brw_ADD(p, addr, sampler_reg, brw_imm_ud(base_binding_table_index));
      brw_SHL(p, temp, sampler_reg, brw_imm_ud(8u));
      brw_AND(p, temp, temp, brw_imm_ud(0x0f00));
      brw_AND(p, addr, addr, brw_imm_ud(0x0ff));
      brw_OR(p, addr, addr, temp);

      /* a0.0 |= <descriptor> */
      brw_inst *insn_or = brw_next_insn(p, BRW_OPCODE_OR);
      brw_set_sampler_message(p, insn_or,
                              0 /* surface */,
                              0 /* sampler */,
                              msg_type,
                              1 /* rlen */,
                              inst->mlen /* mlen */,
                              inst->header_present /* header */,
                              BRW_SAMPLER_SIMD_MODE_SIMD4X2,
                              return_format);
      brw_inst_set_exec_size(p->brw, insn_or, BRW_EXECUTE_1);
      brw_inst_set_src1_reg_type(p->brw, insn_or, BRW_REGISTER_TYPE_UD);
      brw_set_src0(p, insn_or, addr);
      brw_set_dest(p, insn_or, addr);


      /* dst = send(offset, a0.0) */
      brw_inst *insn_send = brw_next_insn(p, BRW_OPCODE_SEND);
      brw_set_dest(p, insn_send, dst);
      brw_set_src0(p, insn_send, src);
      brw_set_indirect_send_descriptor(p, insn_send, BRW_SFID_SAMPLER, addr);

      brw_pop_insn_state(p);

      /* visitor knows more than we do about the surface limit required,
       * so has already done marking.
       */
   }
}
示例#5
0
void
vec4_generator::generate_code(exec_list *instructions)
{
   int last_native_insn_offset = 0;
   const char *last_annotation_string = NULL;
   const void *last_annotation_ir = NULL;

   if (unlikely(INTEL_DEBUG & DEBUG_VS)) {
      if (shader) {
         printf("Native code for vertex shader %d:\n", prog->Name);
      } else {
         printf("Native code for vertex program %d:\n", c->vp->program.Base.Id);
      }
   }

   foreach_list(node, instructions) {
      vec4_instruction *inst = (vec4_instruction *)node;
      struct brw_reg src[3], dst;

      if (unlikely(INTEL_DEBUG & DEBUG_VS)) {
	 if (last_annotation_ir != inst->ir) {
	    last_annotation_ir = inst->ir;
	    if (last_annotation_ir) {
	       printf("   ");
               if (shader) {
                  ((ir_instruction *) last_annotation_ir)->print();
               } else {
                  const prog_instruction *vpi;
                  vpi = (const prog_instruction *) inst->ir;
                  printf("%d: ", (int)(vpi - vp->Base.Instructions));
                  _mesa_fprint_instruction_opt(stdout, vpi, 0,
                                               PROG_PRINT_DEBUG, NULL);
               }
	       printf("\n");
	    }
	 }
	 if (last_annotation_string != inst->annotation) {
	    last_annotation_string = inst->annotation;
	    if (last_annotation_string)
	       printf("   %s\n", last_annotation_string);
	 }
      }

      for (unsigned int i = 0; i < 3; i++) {
	 src[i] = inst->get_src(i);
      }
      dst = inst->get_dst();

      brw_set_conditionalmod(p, inst->conditional_mod);
      brw_set_predicate_control(p, inst->predicate);
      brw_set_predicate_inverse(p, inst->predicate_inverse);
      brw_set_saturate(p, inst->saturate);

      switch (inst->opcode) {
      case BRW_OPCODE_MOV:
	 brw_MOV(p, dst, src[0]);
	 break;
      case BRW_OPCODE_ADD:
	 brw_ADD(p, dst, src[0], src[1]);
	 break;
      case BRW_OPCODE_MUL:
	 brw_MUL(p, dst, src[0], src[1]);
	 break;
      case BRW_OPCODE_MACH:
	 brw_set_acc_write_control(p, 1);
	 brw_MACH(p, dst, src[0], src[1]);
	 brw_set_acc_write_control(p, 0);
	 break;

      case BRW_OPCODE_FRC:
	 brw_FRC(p, dst, src[0]);
	 break;
      case BRW_OPCODE_RNDD:
	 brw_RNDD(p, dst, src[0]);
	 break;
      case BRW_OPCODE_RNDE:
	 brw_RNDE(p, dst, src[0]);
	 break;
      case BRW_OPCODE_RNDZ:
	 brw_RNDZ(p, dst, src[0]);
	 break;

      case BRW_OPCODE_AND:
	 brw_AND(p, dst, src[0], src[1]);
	 break;
      case BRW_OPCODE_OR:
	 brw_OR(p, dst, src[0], src[1]);
	 break;
      case BRW_OPCODE_XOR:
	 brw_XOR(p, dst, src[0], src[1]);
	 break;
      case BRW_OPCODE_NOT:
	 brw_NOT(p, dst, src[0]);
	 break;
      case BRW_OPCODE_ASR:
	 brw_ASR(p, dst, src[0], src[1]);
	 break;
      case BRW_OPCODE_SHR:
	 brw_SHR(p, dst, src[0], src[1]);
	 break;
      case BRW_OPCODE_SHL:
	 brw_SHL(p, dst, src[0], src[1]);
	 break;

      case BRW_OPCODE_CMP:
	 brw_CMP(p, dst, inst->conditional_mod, src[0], src[1]);
	 break;
      case BRW_OPCODE_SEL:
	 brw_SEL(p, dst, src[0], src[1]);
	 break;

      case BRW_OPCODE_DPH:
	 brw_DPH(p, dst, src[0], src[1]);
	 break;

      case BRW_OPCODE_DP4:
	 brw_DP4(p, dst, src[0], src[1]);
	 break;

      case BRW_OPCODE_DP3:
	 brw_DP3(p, dst, src[0], src[1]);
	 break;

      case BRW_OPCODE_DP2:
	 brw_DP2(p, dst, src[0], src[1]);
	 break;

      case BRW_OPCODE_IF:
	 if (inst->src[0].file != BAD_FILE) {
	    /* The instruction has an embedded compare (only allowed on gen6) */
	    assert(intel->gen == 6);
	    gen6_IF(p, inst->conditional_mod, src[0], src[1]);
	 } else {
	    struct brw_instruction *brw_inst = brw_IF(p, BRW_EXECUTE_8);
	    brw_inst->header.predicate_control = inst->predicate;
	 }
	 break;

      case BRW_OPCODE_ELSE:
	 brw_ELSE(p);
	 break;
      case BRW_OPCODE_ENDIF:
	 brw_ENDIF(p);
	 break;

      case BRW_OPCODE_DO:
	 brw_DO(p, BRW_EXECUTE_8);
	 break;

      case BRW_OPCODE_BREAK:
	 brw_BREAK(p);
	 brw_set_predicate_control(p, BRW_PREDICATE_NONE);
	 break;
      case BRW_OPCODE_CONTINUE:
	 /* FINISHME: We need to write the loop instruction support still. */
	 if (intel->gen >= 6)
	    gen6_CONT(p);
	 else
	    brw_CONT(p);
	 brw_set_predicate_control(p, BRW_PREDICATE_NONE);
	 break;

      case BRW_OPCODE_WHILE:
	 brw_WHILE(p);
	 break;

      default:
	 generate_vs_instruction(inst, dst, src);
	 break;
      }

      if (unlikely(INTEL_DEBUG & DEBUG_VS)) {
	 brw_dump_compile(p, stdout,
			  last_native_insn_offset, p->next_insn_offset);
      }

      last_native_insn_offset = p->next_insn_offset;
   }