brw_vs_emit.c

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/*
 Copyright (C) Intel Corp.  2006.  All Rights Reserved.
 Intel funded Tungsten Graphics (http://www.tungstengraphics.com) to
 develop this 3D driver.

 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
 "Software"), to deal in the Software without restriction, including
 without limitation the rights to use, copy, modify, merge, publish,
 distribute, sublicense, and/or sell copies of the Software, and to
 permit persons to whom the Software is furnished to do so, subject to
 the following conditions:

 The above copyright notice and this permission notice (including the
 next paragraph) shall be included in all copies or substantial
 portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 **********************************************************************/
 /*
  * Authors:
  *   Keith Whitwell <keith@tungstengraphics.com>
  */

#include "brw_context.h"
#include "brw_vs.h"

#include "pipe/p_shader_tokens.h"
#include "tgsi/tgsi_parse.h"

struct brw_prog_info {
   unsigned num_temps;
   unsigned num_addrs;
   unsigned num_consts;

   unsigned writes_psize;

   unsigned pos_idx;
   unsigned result_edge_idx;
   unsigned edge_flag_idx;
   unsigned psize_idx;
};

/* Do things as simply as possible.  Allocate and populate all regs
 * ahead of time.
 */
static void brw_vs_alloc_regs( struct brw_vs_compile *c,
                               struct brw_prog_info *info )
{
   unsigned i, reg = 0, mrf;
   unsigned nr_params;

   /* r0 -- reserved as usual
    */
   c->r0 = brw_vec8_grf(reg, 0); reg++;

   /* User clip planes from curbe:
    */
   if (c->key.nr_userclip) {
      for (i = 0; i < c->key.nr_userclip; i++) {
         c->userplane[i] = stride( brw_vec4_grf(reg+3+i/2, (i%2) * 4), 0, 4, 1);
      }

      /* Deal with curbe alignment:
       */
      reg += ((6+c->key.nr_userclip+3)/4)*2;
   }

   /* Vertex program parameters from curbe:
    */
   nr_params = c->prog_data.max_const;
   for (i = 0; i < nr_params; i++) {
      c->regs[TGSI_FILE_CONSTANT][i] = stride(brw_vec4_grf(reg+i/2, (i%2) * 4), 0, 4, 1);
   }
   reg += (nr_params+1)/2;
   c->prog_data.curb_read_length = reg - 1;



   /* Allocate input regs:
    */
   c->nr_inputs = c->vp->info.num_inputs;
   for (i = 0; i < c->nr_inputs; i++) {
         c->regs[TGSI_FILE_INPUT][i] = brw_vec8_grf(reg, 0);
         reg++;
   }


   /* Allocate outputs: TODO: could organize the non-position outputs
    * to go straight into message regs.
    */
   c->nr_outputs = 0;
   c->first_output = reg;
   mrf = 4;
   for (i = 0; i < c->vp->info.num_outputs; i++) {
      c->nr_outputs++;
#if 0
      if (i == VERT_RESULT_HPOS) {
         c->regs[TGSI_FILE_OUTPUT][i] = brw_vec8_grf(reg, 0);
         reg++;
      }
      else if (i == VERT_RESULT_PSIZ) {
         c->regs[TGSI_FILE_OUTPUT][i] = brw_vec8_grf(reg, 0);
         reg++;
         mrf++;         /* just a placeholder?  XXX fix later stages & remove this */
      }
      else {
         c->regs[TGSI_FILE_OUTPUT][i] = brw_message_reg(mrf);
         mrf++;
      }
#else
      /*treat pos differently for now */
      if (i == info->pos_idx) {
         c->regs[TGSI_FILE_OUTPUT][i] = brw_vec8_grf(reg, 0);
         reg++;
      } else {
         c->regs[TGSI_FILE_OUTPUT][i] = brw_message_reg(mrf);
         mrf++;
      }
#endif
   }

   /* Allocate program temporaries:
    */
   for (i = 0; i < info->num_temps; i++) {
      c->regs[TGSI_FILE_TEMPORARY][i] = brw_vec8_grf(reg, 0);
      reg++;
   }

   /* Address reg(s).  Don't try to use the internal address reg until
    * deref time.
    */
   for (i = 0; i < info->num_addrs; i++) {
      c->regs[TGSI_FILE_ADDRESS][i] =  brw_reg(BRW_GENERAL_REGISTER_FILE,
                                               reg,
                                               0,
                                               BRW_REGISTER_TYPE_D,
                                               BRW_VERTICAL_STRIDE_8,
                                               BRW_WIDTH_8,
                                               BRW_HORIZONTAL_STRIDE_1,
                                               BRW_SWIZZLE_XXXX,
                                               TGSI_WRITEMASK_X);
      reg++;
   }

   for (i = 0; i < 128; i++) {
      if (c->output_regs[i].used_in_src) {
         c->output_regs[i].reg = brw_vec8_grf(reg, 0);
         reg++;
      }
   }

   c->stack =  brw_uw16_reg(BRW_GENERAL_REGISTER_FILE, reg, 0);
   reg += 2;


   /* Some opcodes need an internal temporary:
    */
   c->first_tmp = reg;
   c->last_tmp = reg;           /* for allocation purposes */

   /* Each input reg holds data from two vertices.  The
    * urb_read_length is the number of registers read from *each*
    * vertex urb, so is half the amount:
    */
   c->prog_data.urb_read_length = (c->nr_inputs+1)/2;

   c->prog_data.urb_entry_size = (c->nr_outputs+2+3)/4;
   c->prog_data.total_grf = reg;
}


static struct brw_reg get_tmp( struct brw_vs_compile *c )
{
   struct brw_reg tmp = brw_vec8_grf(c->last_tmp, 0);

   if (++c->last_tmp > c->prog_data.total_grf)
      c->prog_data.total_grf = c->last_tmp;

   return tmp;
}

static void release_tmp( struct brw_vs_compile *c, struct brw_reg tmp )
{
   if (tmp.nr == c->last_tmp-1)
      c->last_tmp--;
}

static void release_tmps( struct brw_vs_compile *c )
{
   c->last_tmp = c->first_tmp;
}


static void unalias1( struct brw_vs_compile *c,
                      struct brw_reg dst,
                      struct brw_reg arg0,
                      void (*func)( struct brw_vs_compile *,
                                    struct brw_reg,
                                    struct brw_reg ))
{
   if (dst.file == arg0.file && dst.nr == arg0.nr) {
      struct brw_compile *p = &c->func;
      struct brw_reg tmp = brw_writemask(get_tmp(c), dst.dw1.bits.writemask);
      func(c, tmp, arg0);
      brw_MOV(p, dst, tmp);
   }
   else {
      func(c, dst, arg0);
   }
}

static void unalias2( struct brw_vs_compile *c,
                      struct brw_reg dst,
                      struct brw_reg arg0,
                      struct brw_reg arg1,
                      void (*func)( struct brw_vs_compile *,
                                    struct brw_reg,
                                    struct brw_reg,
                                    struct brw_reg ))
{
   if ((dst.file == arg0.file && dst.nr == arg0.nr) ||
       (dst.file == arg1.file && dst.nr == arg1.nr)) {
      struct brw_compile *p = &c->func;
      struct brw_reg tmp = brw_writemask(get_tmp(c), dst.dw1.bits.writemask);
      func(c, tmp, arg0, arg1);
      brw_MOV(p, dst, tmp);
   }
   else {
      func(c, dst, arg0, arg1);
   }
}

static void emit_sop( struct brw_compile *p,
                      struct brw_reg dst,
                      struct brw_reg arg0,
                      struct brw_reg arg1,
                      unsigned cond)
{
   brw_push_insn_state(p);
   brw_CMP(p, brw_null_reg(), cond, arg0, arg1);
   brw_set_predicate_control(p, BRW_PREDICATE_NONE);
   brw_MOV(p, dst, brw_imm_f(1.0f));
   brw_set_predicate_control(p, BRW_PREDICATE_NORMAL);
   brw_MOV(p, dst, brw_imm_f(0.0f));
   brw_pop_insn_state(p);
}

static void emit_seq( struct brw_compile *p,
                      struct brw_reg dst,
                      struct brw_reg arg0,
                      struct brw_reg arg1 )
{
   emit_sop(p, dst, arg0, arg1, BRW_CONDITIONAL_EQ);
}

static void emit_sne( struct brw_compile *p,
                      struct brw_reg dst,
                      struct brw_reg arg0,
                      struct brw_reg arg1 )
{
   emit_sop(p, dst, arg0, arg1, BRW_CONDITIONAL_NEQ);
}
static void emit_slt( struct brw_compile *p,
                      struct brw_reg dst,
                      struct brw_reg arg0,
                      struct brw_reg arg1 )
{
   emit_sop(p, dst, arg0, arg1, BRW_CONDITIONAL_L);
}

static void emit_sle( struct brw_compile *p,
                      struct brw_reg dst,
                      struct brw_reg arg0,
                      struct brw_reg arg1 )
{
   emit_sop(p, dst, arg0, arg1, BRW_CONDITIONAL_LE);
}

static void emit_sgt( struct brw_compile *p,
                      struct brw_reg dst,
                      struct brw_reg arg0,
                      struct brw_reg arg1 )
{
   emit_sop(p, dst, arg0, arg1, BRW_CONDITIONAL_G);
}

static void emit_sge( struct brw_compile *p,
                      struct brw_reg dst,
                      struct brw_reg arg0,
                      struct brw_reg arg1 )
{
  emit_sop(p, dst, arg0, arg1, BRW_CONDITIONAL_GE);
}

static void emit_max( struct brw_compile *p,
                      struct brw_reg dst,
                      struct brw_reg arg0,
                      struct brw_reg arg1 )
{
   brw_CMP(p, brw_null_reg(), BRW_CONDITIONAL_L, arg0, arg1);
   brw_SEL(p, dst, arg1, arg0);
   brw_set_predicate_control(p, BRW_PREDICATE_NONE);
}

static void emit_min( struct brw_compile *p,
                      struct brw_reg dst,
                      struct brw_reg arg0,
                      struct brw_reg arg1 )
{
   brw_CMP(p, brw_null_reg(), BRW_CONDITIONAL_L, arg0, arg1);
   brw_SEL(p, dst, arg0, arg1);
   brw_set_predicate_control(p, BRW_PREDICATE_NONE);
}


static void emit_math1( struct brw_vs_compile *c,
                        unsigned function,
                        struct brw_reg dst,
                        struct brw_reg arg0,
                        unsigned precision)
{
   /* There are various odd behaviours with SEND on the simulator.  In
    * addition there are documented issues with the fact that the GEN4
    * processor doesn't do dependency control properly on SEND
    * results.  So, on balance, this kludge to get around failures
    * with writemasked math results looks like it might be necessary
    * whether that turns out to be a simulator bug or not:
    */
   struct brw_compile *p = &c->func;
   struct brw_reg tmp = dst;
   boolean need_tmp = (dst.dw1.bits.writemask != 0xf ||
                         dst.file != BRW_GENERAL_REGISTER_FILE);

   if (need_tmp)
      tmp = get_tmp(c);

   brw_math(p,
            tmp,
            function,
            BRW_MATH_SATURATE_NONE,
            2,
            arg0,
            BRW_MATH_DATA_SCALAR,
            precision);

   if (need_tmp) {
      brw_MOV(p, dst, tmp);
      release_tmp(c, tmp);
   }
}

static void emit_math2( struct brw_vs_compile *c,
                        unsigned function,
                        struct brw_reg dst,
                        struct brw_reg arg0,
                        struct brw_reg arg1,
                        unsigned precision)
{
   struct brw_compile *p = &c->func;
   struct brw_reg tmp = dst;
   boolean need_tmp = (dst.dw1.bits.writemask != 0xf ||
                         dst.file != BRW_GENERAL_REGISTER_FILE);

   if (need_tmp)
      tmp = get_tmp(c);

   brw_MOV(p, brw_message_reg(3), arg1);

   brw_math(p,
            tmp,
            function,
            BRW_MATH_SATURATE_NONE,
            2,
            arg0,
            BRW_MATH_DATA_SCALAR,
            precision);

   if (need_tmp) {
      brw_MOV(p, dst, tmp);
      release_tmp(c, tmp);
   }
}



static void emit_exp_noalias( struct brw_vs_compile *c,
                              struct brw_reg dst,
                              struct brw_reg arg0 )
{
   struct brw_compile *p = &c->func;


   if (dst.dw1.bits.writemask & TGSI_WRITEMASK_X) {
      struct brw_reg tmp = get_tmp(c);
      struct brw_reg tmp_d = retype(tmp, BRW_REGISTER_TYPE_D);

      /* tmp_d = floor(arg0.x) */
      brw_RNDD(p, tmp_d, brw_swizzle1(arg0, 0));

      /* result[0] = 2.0 ^ tmp */

      /* Adjust exponent for floating point:
       * exp += 127
       */
      brw_ADD(p, brw_writemask(tmp_d, TGSI_WRITEMASK_X), tmp_d, brw_imm_d(127));

      /* Install exponent and sign.
       * Excess drops off the edge:
       */
      brw_SHL(p, brw_writemask(retype(dst, BRW_REGISTER_TYPE_D), TGSI_WRITEMASK_X),
              tmp_d, brw_imm_d(23));

      release_tmp(c, tmp);
   }

   if (dst.dw1.bits.writemask & TGSI_WRITEMASK_Y) {
      /* result[1] = arg0.x - floor(arg0.x) */
      brw_FRC(p, brw_writemask(dst, TGSI_WRITEMASK_Y), brw_swizzle1(arg0, 0));
   }

   if (dst.dw1.bits.writemask & TGSI_WRITEMASK_Z) {
      /* As with the LOG instruction, we might be better off just
       * doing a taylor expansion here, seeing as we have to do all
       * the prep work.
       *
       * If mathbox partial precision is too low, consider also:
       * result[3] = result[0] * EXP(result[1])
       */
      emit_math1(c,
                 BRW_MATH_FUNCTION_EXP,
                 brw_writemask(dst, TGSI_WRITEMASK_Z),
                 brw_swizzle1(arg0, 0),
                 BRW_MATH_PRECISION_PARTIAL);
   }

   if (dst.dw1.bits.writemask & TGSI_WRITEMASK_W) {
      /* result[3] = 1.0; */
      brw_MOV(p, brw_writemask(dst, TGSI_WRITEMASK_W), brw_imm_f(1));
   }
}


static void emit_log_noalias( struct brw_vs_compile *c,
                              struct brw_reg dst,
                              struct brw_reg arg0 )
{
   struct brw_compile *p = &c->func;
   struct brw_reg tmp = dst;
   struct brw_reg tmp_ud = retype(tmp, BRW_REGISTER_TYPE_UD);
   struct brw_reg arg0_ud = retype(arg0, BRW_REGISTER_TYPE_UD);
   boolean need_tmp = (dst.dw1.bits.writemask != 0xf ||
                         dst.file != BRW_GENERAL_REGISTER_FILE);

   if (need_tmp) {
      tmp = get_tmp(c);
      tmp_ud = retype(tmp, BRW_REGISTER_TYPE_UD);
   }

   /* Perform mant = frexpf(fabsf(x), &exp), adjust exp and mnt
    * according to spec:
    *
    * These almost look likey they could be joined up, but not really
    * practical:
    *
    * result[0].f = (x.i & ((1<<31)-1) >> 23) - 127
    * result[1].i = (x.i & ((1<<23)-1)        + (127<<23)
    */
   if (dst.dw1.bits.writemask & TGSI_WRITEMASK_XZ) {
      brw_AND(p,
              brw_writemask(tmp_ud, TGSI_WRITEMASK_X),
              brw_swizzle1(arg0_ud, 0),
              brw_imm_ud((1U<<31)-1));

      brw_SHR(p,
              brw_writemask(tmp_ud, TGSI_WRITEMASK_X),
              tmp_ud,
              brw_imm_ud(23));

      brw_ADD(p,
              brw_writemask(tmp, TGSI_WRITEMASK_X),
              retype(tmp_ud, BRW_REGISTER_TYPE_D),      /* does it matter? */
              brw_imm_d(-127));
   }

   if (dst.dw1.bits.writemask & TGSI_WRITEMASK_YZ) {
      brw_AND(p,
              brw_writemask(tmp_ud, TGSI_WRITEMASK_Y),
              brw_swizzle1(arg0_ud, 0),
              brw_imm_ud((1<<23)-1));

      brw_OR(p,
             brw_writemask(tmp_ud, TGSI_WRITEMASK_Y),
             tmp_ud,
             brw_imm_ud(127<<23));
   }

   if (dst.dw1.bits.writemask & TGSI_WRITEMASK_Z) {
      /* result[2] = result[0] + LOG2(result[1]); */

      /* Why bother?  The above is just a hint how to do this with a
       * taylor series.  Maybe we *should* use a taylor series as by
       * the time all the above has been done it's almost certainly
       * quicker than calling the mathbox, even with low precision.
       *
       * Options are:
       *    - result[0] + mathbox.LOG2(result[1])
       *    - mathbox.LOG2(arg0.x)
       *    - result[0] + inline_taylor_approx(result[1])
       */
      emit_math1(c,
                 BRW_MATH_FUNCTION_LOG,
                 brw_writemask(tmp, TGSI_WRITEMASK_Z),
                 brw_swizzle1(tmp, 1),
                 BRW_MATH_PRECISION_FULL);

      brw_ADD(p,
              brw_writemask(tmp, TGSI_WRITEMASK_Z),
              brw_swizzle1(tmp, 2),
              brw_swizzle1(tmp, 0));
   }

   if (dst.dw1.bits.writemask & TGSI_WRITEMASK_W) {
      /* result[3] = 1.0; */
      brw_MOV(p, brw_writemask(tmp, TGSI_WRITEMASK_W), brw_imm_f(1));
   }

   if (need_tmp) {
      brw_MOV(p, dst, tmp);
      release_tmp(c, tmp);
   }
}




/* Need to unalias - consider swizzles:   r0 = DST r0.xxxx r1
 */
static void emit_dst_noalias( struct brw_vs_compile *c,
                              struct brw_reg dst,
                              struct brw_reg arg0,
                              struct brw_reg arg1)
{
   struct brw_compile *p = &c->func;

   /* There must be a better way to do this:
    */
   if (dst.dw1.bits.writemask & TGSI_WRITEMASK_X)
      brw_MOV(p, brw_writemask(dst, TGSI_WRITEMASK_X), brw_imm_f(1.0));
   if (dst.dw1.bits.writemask & TGSI_WRITEMASK_Y)
      brw_MUL(p, brw_writemask(dst, TGSI_WRITEMASK_Y), arg0, arg1);
   if (dst.dw1.bits.writemask & TGSI_WRITEMASK_Z)
      brw_MOV(p, brw_writemask(dst, TGSI_WRITEMASK_Z), arg0);
   if (dst.dw1.bits.writemask & TGSI_WRITEMASK_W)
      brw_MOV(p, brw_writemask(dst, TGSI_WRITEMASK_W), arg1);
}

static void emit_xpd( struct brw_compile *p,
                      struct brw_reg dst,
                      struct brw_reg t,
                      struct brw_reg u)
{
   brw_MUL(p, brw_null_reg(), brw_swizzle(t, 1,2,0,3),  brw_swizzle(u,2,0,1,3));
   brw_MAC(p, dst,     negate(brw_swizzle(t, 2,0,1,3)), brw_swizzle(u,1,2,0,3));
}



static void emit_lit_noalias( struct brw_vs_compile *c,
                              struct brw_reg dst,
                              struct brw_reg arg0 )
{
   struct brw_compile *p = &c->func;
   struct brw_instruction *if_insn;
   struct brw_reg tmp = dst;
   boolean need_tmp = (dst.file != BRW_GENERAL_REGISTER_FILE);

   if (need_tmp)
      tmp = get_tmp(c);

   brw_MOV(p, brw_writemask(dst, TGSI_WRITEMASK_YZ), brw_imm_f(0));
   brw_MOV(p, brw_writemask(dst, TGSI_WRITEMASK_XW), brw_imm_f(1));

   /* Need to use BRW_EXECUTE_8 and also do an 8-wide compare in order
    * to get all channels active inside the IF.  In the clipping code
    * we run with NoMask, so it's not an option and we can use
    * BRW_EXECUTE_1 for all comparisions.
    */
   brw_CMP(p, brw_null_reg(), BRW_CONDITIONAL_G, brw_swizzle1(arg0,0), brw_imm_f(0));
   if_insn = brw_IF(p, BRW_EXECUTE_8);
   {
      brw_MOV(p, brw_writemask(dst, TGSI_WRITEMASK_Y), brw_swizzle1(arg0,0));

      brw_CMP(p, brw_null_reg(), BRW_CONDITIONAL_G, brw_swizzle1(arg0,1), brw_imm_f(0));
      brw_MOV(p, brw_writemask(tmp, TGSI_WRITEMASK_Z),  brw_swizzle1(arg0,1));
      brw_set_predicate_control(p, BRW_PREDICATE_NONE);

      emit_math2(c,
                 BRW_MATH_FUNCTION_POW,
                 brw_writemask(dst, TGSI_WRITEMASK_Z),
                 brw_swizzle1(tmp, 2),
                 brw_swizzle1(arg0, 3),
                 BRW_MATH_PRECISION_PARTIAL);
   }

   brw_ENDIF(p, if_insn);
}





/* TODO: relative addressing!
 */
static struct brw_reg get_reg( struct brw_vs_compile *c,
                               unsigned file,
                               unsigned index )
{
   switch (file) {
   case TGSI_FILE_TEMPORARY:
   case TGSI_FILE_INPUT:
   case TGSI_FILE_OUTPUT:
      assert(c->regs[file][index].nr != 0);
      return c->regs[file][index];
   case TGSI_FILE_CONSTANT:
      assert(c->regs[TGSI_FILE_CONSTANT][index + c->prog_data.num_imm].nr != 0);
      return c->regs[TGSI_FILE_CONSTANT][index + c->prog_data.num_imm];
   case TGSI_FILE_IMMEDIATE:
      assert(c->regs[TGSI_FILE_CONSTANT][index].nr != 0);
      return c->regs[TGSI_FILE_CONSTANT][index];
   case TGSI_FILE_ADDRESS:
      assert(index == 0);
      return c->regs[file][index];

   case TGSI_FILE_NULL:                 /* undef values */
      return brw_null_reg();

   default:
      assert(0);
      return brw_null_reg();
   }
}



static struct brw_reg deref( struct brw_vs_compile *c,
                             struct brw_reg arg,
                             int offset)
{
   struct brw_compile *p = &c->func;
   struct brw_reg tmp = vec4(get_tmp(c));
   struct brw_reg vp_address = retype(vec1(get_reg(c, TGSI_FILE_ADDRESS, 0)), BRW_REGISTER_TYPE_UW);
   unsigned byte_offset = arg.nr * 32 + arg.subnr + offset * 16;
   struct brw_reg indirect = brw_vec4_indirect(0,0);

   {
      brw_push_insn_state(p);
      brw_set_access_mode(p, BRW_ALIGN_1);

      /* This is pretty clunky - load the address register twice and
       * fetch each 4-dword value in turn.  There must be a way to do
       * this in a single pass, but I couldn't get it to work.
       */
      brw_ADD(p, brw_address_reg(0), vp_address, brw_imm_d(byte_offset));
      brw_MOV(p, tmp, indirect);

      brw_ADD(p, brw_address_reg(0), suboffset(vp_address, 8), brw_imm_d(byte_offset));
      brw_MOV(p, suboffset(tmp, 4), indirect);

      brw_pop_insn_state(p);
   }

   return vec8(tmp);
}


static void emit_arl( struct brw_vs_compile *c,
                      struct brw_reg dst,
                      struct brw_reg arg0 )
{
   struct brw_compile *p = &c->func;
   struct brw_reg tmp = dst;
   boolean need_tmp = (dst.file != BRW_GENERAL_REGISTER_FILE);

   if (need_tmp)
      tmp = get_tmp(c);

   brw_RNDD(p, tmp, arg0);
   brw_MUL(p, dst, tmp, brw_imm_d(16));

   if (need_tmp)
      release_tmp(c, tmp);
}


/* Will return mangled results for SWZ op.  The emit_swz() function
 * ignores this result and recalculates taking extended swizzles into
 * account.
 */
static struct brw_reg get_arg( struct brw_vs_compile *c,
                               struct tgsi_src_register *src )
{
   struct brw_reg reg;

   if (src->File == TGSI_FILE_NULL)
      return brw_null_reg();

#if 0
   if (src->RelAddr)
      reg = deref(c, c->regs[PROGRAM_STATE_VAR][0], src->Index);
   else
#endif
      reg = get_reg(c, src->File, src->Index);

   /* Convert 3-bit swizzle to 2-bit.
    */
   reg.dw1.bits.swizzle = BRW_SWIZZLE4(src->SwizzleX,
                                       src->SwizzleY,
                                       src->SwizzleZ,
                                       src->SwizzleW);

   /* Note this is ok for non-swizzle instructions:
    */
   reg.negate = src->Negate ? 1 : 0;

   return reg;
}


static struct brw_reg get_dst( struct brw_vs_compile *c,
                               const struct tgsi_dst_register *dst )
{
   struct brw_reg reg = get_reg(c, dst->File, dst->Index);

   reg.dw1.bits.writemask = dst->WriteMask;

   return reg;
}




static void emit_swz( struct brw_vs_compile *c,
                      struct brw_reg dst,
                      struct tgsi_src_register src )
{
   struct brw_compile *p = &c->func;
   unsigned zeros_mask = 0;
   unsigned ones_mask = 0;
   unsigned src_mask = 0;
   ubyte src_swz[4];
   boolean need_tmp = (src.Negate &&
                         dst.file != BRW_GENERAL_REGISTER_FILE);
   struct brw_reg tmp = dst;
   unsigned i;

   if (need_tmp)
      tmp = get_tmp(c);

   for (i = 0; i < 4; i++) {
      if (dst.dw1.bits.writemask & (1<<i)) {
         ubyte s = 0;
         switch(i) {
         case 0:
            s = src.SwizzleX;
            break;
            s = src.SwizzleY;
         case 1:
            break;
            s = src.SwizzleZ;
         case 2:
            break;
            s = src.SwizzleW;
         case 3:
            break;
         }
         switch (s) {
         case TGSI_SWIZZLE_X:
         case TGSI_SWIZZLE_Y:
         case TGSI_SWIZZLE_Z:
         case TGSI_SWIZZLE_W:
            src_mask |= 1<<i;
            src_swz[i] = s;
            break;
         case TGSI_EXTSWIZZLE_ZERO:
            zeros_mask |= 1<<i;
            break;
         case TGSI_EXTSWIZZLE_ONE:
            ones_mask |= 1<<i;
            break;
         }
      }
   }

   /* Do src first, in case dst aliases src:
    */
   if (src_mask) {
      struct brw_reg arg0;

#if 0
      if (src.RelAddr)
         arg0 = deref(c, c->regs[PROGRAM_STATE_VAR][0], src.Index);
      else
#endif
         arg0 = get_reg(c, src.File, src.Index);

      arg0 = brw_swizzle(arg0,
                         src_swz[0], src_swz[1],
                         src_swz[2], src_swz[3]);

      brw_MOV(p, brw_writemask(tmp, src_mask), arg0);
   }

   if (zeros_mask)
      brw_MOV(p, brw_writemask(tmp, zeros_mask), brw_imm_f(0));

   if (ones_mask)
      brw_MOV(p, brw_writemask(tmp, ones_mask), brw_imm_f(1));

   if (src.Negate)
      brw_MOV(p, brw_writemask(tmp, src.Negate), negate(tmp));

   if (need_tmp) {
      brw_MOV(p, dst, tmp);
      release_tmp(c, tmp);
   }
}



/* Post-vertex-program processing.  Send the results to the URB.
 */
static void emit_vertex_write( struct brw_vs_compile *c, struct brw_prog_info *info)
{
   struct brw_compile *p = &c->func;
   struct brw_reg m0 = brw_message_reg(0);
   struct brw_reg pos = c->regs[TGSI_FILE_OUTPUT][info->pos_idx];
   struct brw_reg ndc;

   if (c->key.copy_edgeflag) {
      brw_MOV(p,
              get_reg(c, TGSI_FILE_OUTPUT, info->result_edge_idx),
              get_reg(c, TGSI_FILE_INPUT, info->edge_flag_idx));
   }


   /* Build ndc coords?   TODO: Shortcircuit when w is known to be one.
    */
   if (!c->key.know_w_is_one) {
      ndc = get_tmp(c);
      emit_math1(c, BRW_MATH_FUNCTION_INV, ndc, brw_swizzle1(pos, 3), BRW_MATH_PRECISION_FULL);
      brw_MUL(p, brw_writemask(ndc, TGSI_WRITEMASK_XYZ), pos, ndc);
   }
   else {
      ndc = pos;
   }

   /* This includes the workaround for -ve rhw, so is no longer an
    * optional step:
    */
   if (info->writes_psize ||
       c->key.nr_userclip ||
       !c->key.know_w_is_one)
   {
      struct brw_reg header1 = retype(get_tmp(c), BRW_REGISTER_TYPE_UD);
      unsigned i;

      brw_MOV(p, header1, brw_imm_ud(0));

      brw_set_access_mode(p, BRW_ALIGN_16);

      if (info->writes_psize) {
         struct brw_reg psiz = c->regs[TGSI_FILE_OUTPUT][info->psize_idx];
         brw_MUL(p, brw_writemask(header1, TGSI_WRITEMASK_W),
                 brw_swizzle1(psiz, 0), brw_imm_f(1<<11));
         brw_AND(p, brw_writemask(header1, TGSI_WRITEMASK_W), header1,
                 brw_imm_ud(0x7ff<<8));
      }


      for (i = 0; i < c->key.nr_userclip; i++) {
         brw_set_conditionalmod(p, BRW_CONDITIONAL_L);
         brw_DP4(p, brw_null_reg(), pos, c->userplane[i]);
         brw_OR(p, brw_writemask(header1, TGSI_WRITEMASK_W), header1, brw_imm_ud(1<<i));
         brw_set_predicate_control(p, BRW_PREDICATE_NONE);
      }


      /* i965 clipping workaround:
       * 1) Test for -ve rhw
       * 2) If set,
       *      set ndc = (0,0,0,0)
       *      set ucp[6] = 1
       *
       * Later, clipping will detect ucp[6] and ensure the primitive is
       * clipped against all fixed planes.
       */
      if (!c->key.know_w_is_one) {
         brw_CMP(p,
                 vec8(brw_null_reg()),
                 BRW_CONDITIONAL_L,
                 brw_swizzle1(ndc, 3),
                 brw_imm_f(0));

         brw_OR(p, brw_writemask(header1, TGSI_WRITEMASK_W), header1, brw_imm_ud(1<<6));
         brw_MOV(p, ndc, brw_imm_f(0));
         brw_set_predicate_control(p, BRW_PREDICATE_NONE);
      }

      brw_set_access_mode(p, BRW_ALIGN_1);      /* why? */
      brw_MOV(p, retype(brw_message_reg(1), BRW_REGISTER_TYPE_UD), header1);
      brw_set_access_mode(p, BRW_ALIGN_16);

      release_tmp(c, header1);
   }
   else {
      brw_MOV(p, retype(brw_message_reg(1), BRW_REGISTER_TYPE_UD), brw_imm_ud(0));
   }


   /* Emit the (interleaved) headers for the two vertices - an 8-reg
    * of zeros followed by two sets of NDC coordinates:
    */
   brw_set_access_mode(p, BRW_ALIGN_1);
   brw_MOV(p, offset(m0, 2), ndc);
   brw_MOV(p, offset(m0, 3), pos);


   brw_urb_WRITE(p,
                 brw_null_reg(), /* dest */
                 0,             /* starting mrf reg nr */
                 c->r0,         /* src */
                 0,             /* allocate */
                 1,             /* used */
                 c->nr_outputs + 3, /* msg len */
                 0,             /* response len */
                 1,             /* eot */
                 1,             /* writes complete */
                 0,             /* urb destination offset */
                 BRW_URB_SWIZZLE_INTERLEAVE);

}

static void
post_vs_emit( struct brw_vs_compile *c, struct brw_instruction *end_inst )
{
   struct tgsi_parse_context parse;
   const struct tgsi_token *tokens = c->vp->program.tokens;
   tgsi_parse_init(&parse, tokens);
   while (!tgsi_parse_end_of_tokens(&parse)) {
      tgsi_parse_token(&parse);
      if (parse.FullToken.Token.Type == TGSI_TOKEN_TYPE_INSTRUCTION) {
#if 0
         struct brw_instruction *brw_inst1, *brw_inst2;
         const struct tgsi_full_instruction *inst1, *inst2;
         int offset;
         inst1 = &parse.FullToken.FullInstruction;
         brw_inst1 = inst1->Data;
         switch (inst1->Opcode) {
         case TGSI_OPCODE_CAL:
         case TGSI_OPCODE_BRA:
            target_insn = inst1->BranchTarget;
            inst2 = &c->vp->program.Base.Instructions[target_insn];
            brw_inst2 = inst2->Data;
            offset = brw_inst2 - brw_inst1;
            brw_set_src1(brw_inst1, brw_imm_d(offset*16));
            break;
         case TGSI_OPCODE_END:
            offset = end_inst - brw_inst1;
            brw_set_src1(brw_inst1, brw_imm_d(offset*16));
            break;
         default:
            break;
         }
#endif
      }
   }
   tgsi_parse_free(&parse);
}

static void process_declaration(const struct tgsi_full_declaration *decl,
                                struct brw_prog_info *info)
{
   int first = decl->DeclarationRange.First;
   int last = decl->DeclarationRange.Last;
   
   switch(decl->Declaration.File) {
   case TGSI_FILE_CONSTANT: 
      info->num_consts += last - first + 1;
      break;
   case TGSI_FILE_INPUT: {
   }
      break;
   case TGSI_FILE_OUTPUT: {
      assert(last == first);    /* for now */
      if (decl->Declaration.Semantic) {
         switch (decl->Semantic.SemanticName) {
         case TGSI_SEMANTIC_POSITION: {
            info->pos_idx = first;
         }
            break;
         case TGSI_SEMANTIC_COLOR:
            break;
         case TGSI_SEMANTIC_BCOLOR:
            break;
         case TGSI_SEMANTIC_FOG:
            break;
         case TGSI_SEMANTIC_PSIZE: {
            info->writes_psize = TRUE;
            info->psize_idx = first;
         }
            break;
         case TGSI_SEMANTIC_GENERIC:
            break;
         }
      }
   }
      break;
   case TGSI_FILE_TEMPORARY: {
      info->num_temps += (last - first) + 1;
   }
      break;
   case TGSI_FILE_SAMPLER: {
   }
      break;
   case TGSI_FILE_ADDRESS: {
      info->num_addrs += (last - first) + 1;
   }
      break;
   case TGSI_FILE_IMMEDIATE: {
   }
      break;
   case TGSI_FILE_NULL: {
   }
      break;
   }
}

static void process_instruction(struct brw_vs_compile *c,
                                struct tgsi_full_instruction *inst,
                                struct brw_prog_info *info)
{
   struct brw_reg args[3], dst;
   struct brw_compile *p = &c->func;
   /*struct brw_indirect stack_index = brw_indirect(0, 0);*/
   unsigned i;
   unsigned index;
   unsigned file;
   /*FIXME: might not be the only one*/
   const struct tgsi_dst_register *dst_reg = &inst->FullDstRegisters[0].DstRegister;
   /*
   struct brw_instruction *if_inst[MAX_IFSN];
   unsigned insn, if_insn = 0;
   */

   for (i = 0; i < 3; i++) {
      struct tgsi_full_src_register *src = &inst->FullSrcRegisters[i];
      index = src->SrcRegister.Index;
      file = src->SrcRegister.File;
      if (file == TGSI_FILE_OUTPUT && c->output_regs[index].used_in_src)
         args[i] = c->output_regs[index].reg;
      else
         args[i] = get_arg(c, &src->SrcRegister);
   }

   /* Get dest regs.  Note that it is possible for a reg to be both
    * dst and arg, given the static allocation of registers.  So
    * care needs to be taken emitting multi-operation instructions.
    */
   index = dst_reg->Index;
   file = dst_reg->File;
   if (file == TGSI_FILE_OUTPUT && c->output_regs[index].used_in_src)
      dst = c->output_regs[index].reg;
   else
      dst = get_dst(c, dst_reg);

   switch (inst->Instruction.Opcode) {
   case TGSI_OPCODE_ABS:
      brw_MOV(p, dst, brw_abs(args[0]));
      break;
   case TGSI_OPCODE_ADD:
      brw_ADD(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_DP3:
      brw_DP3(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_DP4:
      brw_DP4(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_DPH:
      brw_DPH(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_DST:
      unalias2(c, dst, args[0], args[1], emit_dst_noalias);
      break;
   case TGSI_OPCODE_EXP:
      unalias1(c, dst, args[0], emit_exp_noalias);
      break;
   case TGSI_OPCODE_EX2:
      emit_math1(c, BRW_MATH_FUNCTION_EXP, dst, args[0], BRW_MATH_PRECISION_FULL);
      break;
   case TGSI_OPCODE_ARL:
      emit_arl(c, dst, args[0]);
      break;
   case TGSI_OPCODE_FLR:
      brw_RNDD(p, dst, args[0]);
      break;
   case TGSI_OPCODE_FRC:
      brw_FRC(p, dst, args[0]);
      break;
   case TGSI_OPCODE_LOG:
      unalias1(c, dst, args[0], emit_log_noalias);
      break;
   case TGSI_OPCODE_LG2:
      emit_math1(c, BRW_MATH_FUNCTION_LOG, dst, args[0], BRW_MATH_PRECISION_FULL);
      break;
   case TGSI_OPCODE_LIT:
      unalias1(c, dst, args[0], emit_lit_noalias);
      break;
   case TGSI_OPCODE_MAD:
      brw_MOV(p, brw_acc_reg(), args[2]);
      brw_MAC(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_MAX:
      emit_max(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_MIN:
      emit_min(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_MOV:
   case TGSI_OPCODE_SWZ:
#if 0
      /* The args[0] value can't be used here as it won't have
       * correctly encoded the full swizzle:
       */
      emit_swz(c, dst, inst->SrcReg[0] );
#endif
      brw_MOV(p, dst, args[0]);
      break;
   case TGSI_OPCODE_MUL:
      brw_MUL(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_POW:
      emit_math2(c, BRW_MATH_FUNCTION_POW, dst, args[0], args[1], BRW_MATH_PRECISION_FULL);
      break;
   case TGSI_OPCODE_RCP:
      emit_math1(c, BRW_MATH_FUNCTION_INV, dst, args[0], BRW_MATH_PRECISION_FULL);
      break;
   case TGSI_OPCODE_RSQ:
      emit_math1(c, BRW_MATH_FUNCTION_RSQ, dst, args[0], BRW_MATH_PRECISION_FULL);
      break;

   case TGSI_OPCODE_SEQ:
      emit_seq(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_SNE:
      emit_sne(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_SGE:
      emit_sge(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_SGT:
      emit_sgt(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_SLT:
      emit_slt(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_SLE:
      emit_sle(p, dst, args[0], args[1]);
      break;
   case TGSI_OPCODE_SUB:
      brw_ADD(p, dst, args[0], negate(args[1]));
      break;
   case TGSI_OPCODE_XPD:
      emit_xpd(p, dst, args[0], args[1]);
      break;
#if 0
   case TGSI_OPCODE_IF:
      assert(if_insn < MAX_IFSN);
      if_inst[if_insn++] = brw_IF(p, BRW_EXECUTE_8);
      break;
   case TGSI_OPCODE_ELSE:
      if_inst[if_insn-1] = brw_ELSE(p, if_inst[if_insn-1]);
      break;
   case TGSI_OPCODE_ENDIF:
      assert(if_insn > 0);
      brw_ENDIF(p, if_inst[--if_insn]);
      break;
   case TGSI_OPCODE_BRA:
      brw_set_predicate_control(p, BRW_PREDICATE_NORMAL);
      brw_ADD(p, brw_ip_reg(), brw_ip_reg(), brw_imm_d(1*16));
      brw_set_predicate_control_flag_value(p, 0xff);
      break;
   case TGSI_OPCODE_CAL:
      brw_set_access_mode(p, BRW_ALIGN_1);
      brw_ADD(p, deref_1uw(stack_index, 0), brw_ip_reg(), brw_imm_d(3*16));
      brw_set_access_mode(p, BRW_ALIGN_16);
      brw_ADD(p, get_addr_reg(stack_index),
              get_addr_reg(stack_index), brw_imm_d(4));
      inst->Data = &p->store[p->nr_insn];
      brw_ADD(p, brw_ip_reg(), brw_ip_reg(), brw_imm_d(1*16));
      break;
#endif
   case TGSI_OPCODE_RET:
#if 0
      brw_ADD(p, get_addr_reg(stack_index),
              get_addr_reg(stack_index), brw_imm_d(-4));
      brw_set_access_mode(p, BRW_ALIGN_1);
      brw_MOV(p, brw_ip_reg(), deref_1uw(stack_index, 0));
      brw_set_access_mode(p, BRW_ALIGN_16);
#else
      /*brw_ADD(p, brw_ip_reg(), brw_ip_reg(), brw_imm_d(1*16));*/
#endif
      break;
   case TGSI_OPCODE_END:
      brw_ADD(p, brw_ip_reg(), brw_ip_reg(), brw_imm_d(1*16));
      break;
   case TGSI_OPCODE_BGNSUB:
   case TGSI_OPCODE_ENDSUB:
      break;
   default:
      debug_printf("Unsupport opcode %d in vertex shader\n", inst->Instruction.Opcode);
      break;
   }

   if (dst_reg->File == TGSI_FILE_OUTPUT
       && dst_reg->Index != info->pos_idx
       && c->output_regs[dst_reg->Index].used_in_src)
      brw_MOV(p, get_dst(c, dst_reg), dst);

   release_tmps(c);
}

/* Emit the fragment program instructions here.
 */
void brw_vs_emit(struct brw_vs_compile *c)
{
#define MAX_IFSN 32
   struct brw_compile *p = &c->func;
   struct brw_instruction *end_inst;
   struct tgsi_parse_context parse;
   struct brw_indirect stack_index = brw_indirect(0, 0);
   const struct tgsi_token *tokens = c->vp->program.tokens;
   struct brw_prog_info prog_info;
   unsigned allocated_registers = 0;
   memset(&prog_info, 0, sizeof(struct brw_prog_info));

   brw_set_compression_control(p, BRW_COMPRESSION_NONE);
   brw_set_access_mode(p, BRW_ALIGN_16);

   tgsi_parse_init(&parse, tokens);
   /* Message registers can't be read, so copy the output into GRF register
      if they are used in source registers */
   while (!tgsi_parse_end_of_tokens(&parse)) {
      tgsi_parse_token(&parse);
      unsigned i;
      switch (parse.FullToken.Token.Type) {
      case TGSI_TOKEN_TYPE_INSTRUCTION: {
         const struct tgsi_full_instruction *inst = &parse.FullToken.FullInstruction;
         for (i = 0; i < 3; ++i) {
            const struct tgsi_src_register *src = &inst->FullSrcRegisters[i].SrcRegister;
            unsigned index = src->Index;
            unsigned file = src->File;
            if (file == TGSI_FILE_OUTPUT)
               c->output_regs[index].used_in_src = TRUE;
         }
      }
         break;
      default:
         /* nothing */
         break;
      }
   }
   tgsi_parse_free(&parse);

   tgsi_parse_init(&parse, tokens);

   while (!tgsi_parse_end_of_tokens(&parse)) {
      tgsi_parse_token(&parse);

      switch (parse.FullToken.Token.Type) {
      case TGSI_TOKEN_TYPE_DECLARATION: {
         struct tgsi_full_declaration *decl = &parse.FullToken.FullDeclaration;
         process_declaration(decl, &prog_info);
      }
         break;
      case TGSI_TOKEN_TYPE_IMMEDIATE: {
         struct tgsi_full_immediate *imm = &parse.FullToken.FullImmediate;
         /*assert(imm->Immediate.Size == 4);*/
         c->prog_data.imm_buf[c->prog_data.num_imm][0] = imm->u.ImmediateFloat32[0].Float;
         c->prog_data.imm_buf[c->prog_data.num_imm][1] = imm->u.ImmediateFloat32[1].Float;
         c->prog_data.imm_buf[c->prog_data.num_imm][2] = imm->u.ImmediateFloat32[2].Float;
         c->prog_data.imm_buf[c->prog_data.num_imm][3] = imm->u.ImmediateFloat32[3].Float;
         c->prog_data.num_imm++;
      }
         break;
      case TGSI_TOKEN_TYPE_INSTRUCTION: {
         struct tgsi_full_instruction *inst = &parse.FullToken.FullInstruction;
         if (!allocated_registers) {
            /* first instruction (declerations finished).
             * now that we know what vars are being used allocate
             * registers for them.*/
            c->prog_data.num_consts = prog_info.num_consts;
            c->prog_data.max_const = prog_info.num_consts + c->prog_data.num_imm;
            brw_vs_alloc_regs(c, &prog_info);

            brw_set_access_mode(p, BRW_ALIGN_1);
            brw_MOV(p, get_addr_reg(stack_index), brw_address(c->stack));
            brw_set_access_mode(p, BRW_ALIGN_16);
            allocated_registers = 1;
         }
         process_instruction(c, inst, &prog_info);
      }
         break;
      }
   }

   end_inst = &p->store[p->nr_insn];
   emit_vertex_write(c, &prog_info);
   post_vs_emit(c, end_inst);
   tgsi_parse_free(&parse);

}

---