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/**************************************************************************

 *

 * Copyright 2009-2010 VMware, Inc.

 * All Rights Reserved.

 *

 * 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, sub license, 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 NON-INFRINGEMENT.

 * IN NO EVENT SHALL VMWARE 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.

 *

 **************************************************************************/

/**

 * @file

 * Depth/stencil testing to LLVM IR translation.

 *

 * To be done accurately/efficiently the depth/stencil test must be done with

 * the same type/format of the depth/stencil buffer, which implies massaging

 * the incoming depths to fit into place. Using a more straightforward

 * type/format for depth/stencil values internally and only convert when

 * flushing would avoid this, but it would most likely result in depth fighting

 * artifacts.

 *

 * Since we're using linear layout for everything, but we need to deal with

 * 2x2 quads, we need to load/store multiple values and swizzle them into

 * place (we could avoid this by doing depth/stencil testing in linear format,

 * which would be easy for late depth/stencil test as we could do that after

 * the fragment shader loop just as we do for color buffers, but more tricky

 * for early depth test as we'd need both masks and interpolated depth in

 * linear format).

 *

 *

 * @author Jose Fonseca 

 * @author Brian Paul 

 */

#include "pipe/p_state.h"

#include "util/u_format.h"

#include "util/u_cpu_detect.h"

#include "gallivm/lp_bld_type.h"

#include "gallivm/lp_bld_arit.h"

#include "gallivm/lp_bld_bitarit.h"

#include "gallivm/lp_bld_const.h"

#include "gallivm/lp_bld_conv.h"

#include "gallivm/lp_bld_logic.h"

#include "gallivm/lp_bld_flow.h"

#include "gallivm/lp_bld_intr.h"

#include "gallivm/lp_bld_debug.h"

#include "gallivm/lp_bld_swizzle.h"

#include "gallivm/lp_bld_pack.h"

#include "lp_bld_depth.h"

/** Used to select fields from pipe_stencil_state */

enum stencil_op {

   S_FAIL_OP,

   Z_FAIL_OP,

   Z_PASS_OP

};

/**

 * Do the stencil test comparison (compare FB stencil values against ref value).

 * This will be used twice when generating two-sided stencil code.

 * \param stencil  the front/back stencil state

 * \param stencilRef  the stencil reference value, replicated as a vector

 * \param stencilVals  vector of stencil values from framebuffer

 * \return vector mask of pass/fail values (~0 or 0)

 */

static LLVMValueRef

lp_build_stencil_test_single(struct lp_build_context *bld,

                             const struct pipe_stencil_state *stencil,

                             LLVMValueRef stencilRef,

                             LLVMValueRef stencilVals)

{

   LLVMBuilderRef builder = bld->gallivm->builder;

   const unsigned stencilMax = 255; /* XXX fix */

   struct lp_type type = bld->type;

   LLVMValueRef res;

   /*

    * SSE2 has intrinsics for signed comparisons, but not unsigned ones. Values

    * are between 0..255 so ensure we generate the fastest comparisons for

    * wider elements.

    */

   if (type.width <= 8) {

      assert(!type.sign);

   } else {

      assert(type.sign);

   }

   assert(stencil->enabled);

   if (stencil->valuemask != stencilMax) {

      /* compute stencilRef = stencilRef & valuemask */

      LLVMValueRef valuemask = lp_build_const_int_vec(bld->gallivm, type, stencil->valuemask);

      stencilRef = LLVMBuildAnd(builder, stencilRef, valuemask, "");

      /* compute stencilVals = stencilVals & valuemask */

      stencilVals = LLVMBuildAnd(builder, stencilVals, valuemask, "");

   }

   res = lp_build_cmp(bld, stencil->func, stencilRef, stencilVals);

   return res;

}

/**

 * Do the one or two-sided stencil test comparison.

 * \sa lp_build_stencil_test_single

 * \param front_facing  an integer vector mask, indicating front (~0) or back

 *                      (0) facing polygon. If NULL, assume front-facing.

 */

static LLVMValueRef

lp_build_stencil_test(struct lp_build_context *bld,

                      const struct pipe_stencil_state stencil[2],

                      LLVMValueRef stencilRefs[2],

                      LLVMValueRef stencilVals,

                      LLVMValueRef front_facing)

{

   LLVMValueRef res;

   assert(stencil[0].enabled);

   /* do front face test */

   res = lp_build_stencil_test_single(bld, &stencil[0],

                                      stencilRefs[0], stencilVals);

   if (stencil[1].enabled && front_facing != NULL) {

      /* do back face test */

      LLVMValueRef back_res;

      back_res = lp_build_stencil_test_single(bld, &stencil[1],

                                              stencilRefs[1], stencilVals);

      res = lp_build_select(bld, front_facing, res, back_res);

   }

   return res;

}

/**

 * Apply the stencil operator (add/sub/keep/etc) to the given vector

 * of stencil values.

 * \return  new stencil values vector

 */

static LLVMValueRef

lp_build_stencil_op_single(struct lp_build_context *bld,

                           const struct pipe_stencil_state *stencil,

                           enum stencil_op op,

                           LLVMValueRef stencilRef,

                           LLVMValueRef stencilVals)

{

   LLVMBuilderRef builder = bld->gallivm->builder;

   struct lp_type type = bld->type;

   LLVMValueRef res;

   LLVMValueRef max = lp_build_const_int_vec(bld->gallivm, type, 0xff);

   unsigned stencil_op;

   assert(type.sign);

   switch (op) {

   case S_FAIL_OP:

      stencil_op = stencil->fail_op;

      break;

   case Z_FAIL_OP:

      stencil_op = stencil->zfail_op;

      break;

   case Z_PASS_OP:

      stencil_op = stencil->zpass_op;

      break;

   default:

      assert(0 && "Invalid stencil_op mode");

      stencil_op = PIPE_STENCIL_OP_KEEP;

   }

   switch (stencil_op) {

   case PIPE_STENCIL_OP_KEEP:

      res = stencilVals;

      /* we can return early for this case */

      return res;

   case PIPE_STENCIL_OP_ZERO:

      res = bld->zero;

      break;

   case PIPE_STENCIL_OP_REPLACE:

      res = stencilRef;

      break;

   case PIPE_STENCIL_OP_INCR:

      res = lp_build_add(bld, stencilVals, bld->one);

      res = lp_build_min(bld, res, max);

      break;

   case PIPE_STENCIL_OP_DECR:

      res = lp_build_sub(bld, stencilVals, bld->one);

      res = lp_build_max(bld, res, bld->zero);

      break;

   case PIPE_STENCIL_OP_INCR_WRAP:

      res = lp_build_add(bld, stencilVals, bld->one);

      res = LLVMBuildAnd(builder, res, max, "");

      break;

   case PIPE_STENCIL_OP_DECR_WRAP:

      res = lp_build_sub(bld, stencilVals, bld->one);

      res = LLVMBuildAnd(builder, res, max, "");

      break;

   case PIPE_STENCIL_OP_INVERT:

      res = LLVMBuildNot(builder, stencilVals, "");

      res = LLVMBuildAnd(builder, res, max, "");

      break;

   default:

      assert(0 && "bad stencil op mode");

      res = bld->undef;

   }

   return res;

}

/**

 * Do the one or two-sided stencil test op/update.

 */

static LLVMValueRef

lp_build_stencil_op(struct lp_build_context *bld,

                    const struct pipe_stencil_state stencil[2],

                    enum stencil_op op,

                    LLVMValueRef stencilRefs[2],

                    LLVMValueRef stencilVals,

                    LLVMValueRef mask,

                    LLVMValueRef front_facing)

{

   LLVMBuilderRef builder = bld->gallivm->builder;

   LLVMValueRef res;

   assert(stencil[0].enabled);

   /* do front face op */

   res = lp_build_stencil_op_single(bld, &stencil[0], op,

                                     stencilRefs[0], stencilVals);

   if (stencil[1].enabled && front_facing != NULL) {

      /* do back face op */

      LLVMValueRef back_res;

      back_res = lp_build_stencil_op_single(bld, &stencil[1], op,

                                            stencilRefs[1], stencilVals);

      res = lp_build_select(bld, front_facing, res, back_res);

   }

   if (stencil[0].writemask != 0xff ||

       (stencil[1].enabled && front_facing != NULL && stencil[1].writemask != 0xff)) {

      /* mask &= stencil[0].writemask */

      LLVMValueRef writemask = lp_build_const_int_vec(bld->gallivm, bld->type,

                                                      stencil[0].writemask);

      if (stencil[1].enabled && stencil[1].writemask != stencil[0].writemask && front_facing != NULL) {

         LLVMValueRef back_writemask = lp_build_const_int_vec(bld->gallivm, bld->type,

                                                         stencil[1].writemask);

         writemask = lp_build_select(bld, front_facing, writemask, back_writemask);

      }

      mask = LLVMBuildAnd(builder, mask, writemask, "");

      /* res = (res & mask) | (stencilVals & ~mask) */

      res = lp_build_select_bitwise(bld, mask, res, stencilVals);

   }

   else {

      /* res = mask ? res : stencilVals */

      res = lp_build_select(bld, mask, res, stencilVals);

   }

   return res;

}

/**

 * Return a type that matches the depth/stencil format.

 */

struct lp_type

lp_depth_type(const struct util_format_description *format_desc,

              unsigned length)

{

   struct lp_type type;

   unsigned z_swizzle;

   assert(format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS);

   assert(format_desc->block.width == 1);

   assert(format_desc->block.height == 1);

   memset(&type, 0, sizeof type);

   type.width = format_desc->block.bits;

   z_swizzle = format_desc->swizzle[0];

   if (z_swizzle < 4) {

      if (format_desc->channel[z_swizzle].type == UTIL_FORMAT_TYPE_FLOAT) {

         type.floating = TRUE;

         assert(z_swizzle == 0);

         assert(format_desc->channel[z_swizzle].size == 32);

      }

      else if(format_desc->channel[z_swizzle].type == UTIL_FORMAT_TYPE_UNSIGNED) {

         assert(format_desc->block.bits <= 32);

         assert(format_desc->channel[z_swizzle].normalized);

         if (format_desc->channel[z_swizzle].size < format_desc->block.bits) {

            /* Prefer signed integers when possible, as SSE has less support

             * for unsigned comparison;

             */

            type.sign = TRUE;

         }

      }

      else

         assert(0);

   }

   type.length = length;

   return type;

}

/**

 * Compute bitmask and bit shift to apply to the incoming fragment Z values

 * and the Z buffer values needed before doing the Z comparison.

 *

 * Note that we leave the Z bits in the position that we find them

 * in the Z buffer (typically 0xffffff00 or 0x00ffffff).  That lets us

 * get by with fewer bit twiddling steps.

 */

static boolean

get_z_shift_and_mask(const struct util_format_description *format_desc,

                     unsigned *shift, unsigned *width, unsigned *mask)

{

   unsigned total_bits;

   unsigned z_swizzle;

   assert(format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS);

   assert(format_desc->block.width == 1);

   assert(format_desc->block.height == 1);

   /* 64bit d/s format is special already extracted 32 bits */

   total_bits = format_desc->block.bits > 32 ? 32 : format_desc->block.bits;

   z_swizzle = format_desc->swizzle[0];

   if (z_swizzle == UTIL_FORMAT_SWIZZLE_NONE)

      return FALSE;

   *width = format_desc->channel[z_swizzle].size;

   *shift = format_desc->channel[z_swizzle].shift;

   if (*width == total_bits) {

      *mask = 0xffffffff;

   } else {

      *mask = ((1 << *width) - 1) << *shift;

   }

   return TRUE;

}

/**

 * Compute bitmask and bit shift to apply to the framebuffer pixel values

 * to put the stencil bits in the least significant position.

 * (i.e. 0x000000ff)

 */

static boolean

get_s_shift_and_mask(const struct util_format_description *format_desc,

                     unsigned *shift, unsigned *mask)

{

   unsigned s_swizzle;

   unsigned sz;

   s_swizzle = format_desc->swizzle[1];

   if (s_swizzle == UTIL_FORMAT_SWIZZLE_NONE)

      return FALSE;

   /* just special case 64bit d/s format */

   if (format_desc->block.bits > 32) {

      /* XXX big-endian? */

      assert(format_desc->format == PIPE_FORMAT_Z32_FLOAT_S8X24_UINT);

      *shift = 0;

      *mask = 0xff;

      return TRUE;

   }

   *shift = format_desc->channel[s_swizzle].shift;

   sz = format_desc->channel[s_swizzle].size;

   *mask = (1U << sz) - 1U;

   return TRUE;

}

/**

 * Perform the occlusion test and increase the counter.

 * Test the depth mask. Add the number of channel which has none zero mask

 * into the occlusion counter. e.g. maskvalue is {-1, -1, -1, -1}.

 * The counter will add 4.

 * TODO: could get that out of the fs loop.

 *

 * \param type holds element type of the mask vector.

 * \param maskvalue is the depth test mask.

 * \param counter is a pointer of the uint32 counter.

 */

void

lp_build_occlusion_count(struct gallivm_state *gallivm,

                         struct lp_type type,

                         LLVMValueRef maskvalue,

                         LLVMValueRef counter)

{

   LLVMBuilderRef builder = gallivm->builder;

   LLVMContextRef context = gallivm->context;

   LLVMValueRef countmask = lp_build_const_int_vec(gallivm, type, 1);

   LLVMValueRef count, newcount;

   assert(type.length <= 16);

   assert(type.floating);

   if(util_cpu_caps.has_sse && type.length == 4) {

      const char *movmskintr = "llvm.x86.sse.movmsk.ps";

      const char *popcntintr = "llvm.ctpop.i32";

      LLVMValueRef bits = LLVMBuildBitCast(builder, maskvalue,

                                           lp_build_vec_type(gallivm, type), "");

      bits = lp_build_intrinsic_unary(builder, movmskintr,

                                      LLVMInt32TypeInContext(context), bits);

      count = lp_build_intrinsic_unary(builder, popcntintr,

                                       LLVMInt32TypeInContext(context), bits);

      count = LLVMBuildZExt(builder, count, LLVMIntTypeInContext(context, 64), "");

   }

   else if(util_cpu_caps.has_avx && type.length == 8) {

      const char *movmskintr = "llvm.x86.avx.movmsk.ps.256";

      const char *popcntintr = "llvm.ctpop.i32";

      LLVMValueRef bits = LLVMBuildBitCast(builder, maskvalue,

                                           lp_build_vec_type(gallivm, type), "");

      bits = lp_build_intrinsic_unary(builder, movmskintr,

                                      LLVMInt32TypeInContext(context), bits);

      count = lp_build_intrinsic_unary(builder, popcntintr,

                                       LLVMInt32TypeInContext(context), bits);

      count = LLVMBuildZExt(builder, count, LLVMIntTypeInContext(context, 64), "");

   }

   else {

      unsigned i;

      LLVMValueRef countv = LLVMBuildAnd(builder, maskvalue, countmask, "countv");

      LLVMTypeRef counttype = LLVMIntTypeInContext(context, type.length * 8);

      LLVMTypeRef i8vntype = LLVMVectorType(LLVMInt8TypeInContext(context), type.length * 4);

      LLVMValueRef shufflev, countd;

      LLVMValueRef shuffles[16];

      const char *popcntintr = NULL;

      countv = LLVMBuildBitCast(builder, countv, i8vntype, "");

       for (i = 0; i < type.length; i++) {

          shuffles[i] = lp_build_const_int32(gallivm, 4*i);

       }

       shufflev = LLVMConstVector(shuffles, type.length);

       countd = LLVMBuildShuffleVector(builder, countv, LLVMGetUndef(i8vntype), shufflev, "");

       countd = LLVMBuildBitCast(builder, countd, counttype, "countd");

       /*

        * XXX FIXME

        * this is bad on cpus without popcount (on x86 supported by intel

        * nehalem, amd barcelona, and up - not tied to sse42).

        * Would be much faster to just sum the 4 elements of the vector with

        * some horizontal add (shuffle/add/shuffle/add after the initial and).

        */

       switch (type.length) {

       case 4:

          popcntintr = "llvm.ctpop.i32";

          break;

       case 8:

          popcntintr = "llvm.ctpop.i64";

          break;

       case 16:

          popcntintr = "llvm.ctpop.i128";

          break;

       default:

          assert(0);

       }

       count = lp_build_intrinsic_unary(builder, popcntintr, counttype, countd);

       if (type.length > 8) {

          count = LLVMBuildTrunc(builder, count, LLVMIntTypeInContext(context, 64), "");

       }

       else if (type.length < 8) {

          count = LLVMBuildZExt(builder, count, LLVMIntTypeInContext(context, 64), "");

       }

   }

   newcount = LLVMBuildLoad(builder, counter, "origcount");

   newcount = LLVMBuildAdd(builder, newcount, count, "newcount");

   LLVMBuildStore(builder, newcount, counter);

}

/**

 * Load depth/stencil values.

 * The stored values are linear, swizzle them.

 *

 * \param type  the data type of the fragment depth/stencil values

 * \param format_desc  description of the depth/stencil surface

 * \param is_1d  whether this resource has only one dimension

 * \param loop_counter  the current loop iteration

 * \param depth_ptr  pointer to the depth/stencil values of this 4x4 block

 * \param depth_stride  stride of the depth/stencil buffer

 * \param z_fb  contains z values loaded from fb (may include padding)

 * \param s_fb  contains s values loaded from fb (may include padding)

 */

void

lp_build_depth_stencil_load_swizzled(struct gallivm_state *gallivm,

                                     struct lp_type z_src_type,

                                     const struct util_format_description *format_desc,

                                     boolean is_1d,

                                     LLVMValueRef depth_ptr,

                                     LLVMValueRef depth_stride,

                                     LLVMValueRef *z_fb,

                                     LLVMValueRef *s_fb,

                                     LLVMValueRef loop_counter)

{

   LLVMBuilderRef builder = gallivm->builder;

   LLVMValueRef shuffles[LP_MAX_VECTOR_LENGTH / 4];

   LLVMValueRef zs_dst1, zs_dst2;

   LLVMValueRef zs_dst_ptr;

   LLVMValueRef depth_offset1, depth_offset2;

   LLVMTypeRef load_ptr_type;

   unsigned depth_bytes = format_desc->block.bits / 8;

   struct lp_type zs_type = lp_depth_type(format_desc, z_src_type.length);

   struct lp_type zs_load_type = zs_type;

   zs_load_type.length = zs_load_type.length / 2;

   load_ptr_type = LLVMPointerType(lp_build_vec_type(gallivm, zs_load_type), 0);

   if (z_src_type.length == 4) {

      unsigned i;

      LLVMValueRef looplsb = LLVMBuildAnd(builder, loop_counter,

                                          lp_build_const_int32(gallivm, 1), "");

      LLVMValueRef loopmsb = LLVMBuildAnd(builder, loop_counter,

                                          lp_build_const_int32(gallivm, 2), "");

      LLVMValueRef offset2 = LLVMBuildMul(builder, loopmsb,

                                          depth_stride, "");

      depth_offset1 = LLVMBuildMul(builder, looplsb,

                                   lp_build_const_int32(gallivm, depth_bytes * 2), "");

      depth_offset1 = LLVMBuildAdd(builder, depth_offset1, offset2, "");

      /* just concatenate the loaded 2x2 values into 4-wide vector */

      for (i = 0; i < 4; i++) {

         shuffles[i] = lp_build_const_int32(gallivm, i);

      }

   }

   else {

      unsigned i;

      LLVMValueRef loopx2 = LLVMBuildShl(builder, loop_counter,

                                         lp_build_const_int32(gallivm, 1), "");

      assert(z_src_type.length == 8);

      depth_offset1 = LLVMBuildMul(builder, loopx2, depth_stride, "");

      /*

       * We load 2x4 values, and need to swizzle them (order

       * 0,1,4,5,2,3,6,7) - not so hot with avx unfortunately.

       */

      for (i = 0; i < 8; i++) {

         shuffles[i] = lp_build_const_int32(gallivm, (i&1) + (i&2) * 2 + (i&4) / 2);

      }

   }

   depth_offset2 = LLVMBuildAdd(builder, depth_offset1, depth_stride, "");

   /* Load current z/stencil values from z/stencil buffer */

   zs_dst_ptr = LLVMBuildGEP(builder, depth_ptr, &depth_offset1, 1, "");

   zs_dst_ptr = LLVMBuildBitCast(builder, zs_dst_ptr, load_ptr_type, "");

   zs_dst1 = LLVMBuildLoad(builder, zs_dst_ptr, "");

   if (is_1d) {

      zs_dst2 = lp_build_undef(gallivm, zs_load_type);

   }

   else {

      zs_dst_ptr = LLVMBuildGEP(builder, depth_ptr, &depth_offset2, 1, "");

      zs_dst_ptr = LLVMBuildBitCast(builder, zs_dst_ptr, load_ptr_type, "");

      zs_dst2 = LLVMBuildLoad(builder, zs_dst_ptr, "");

   }

   *z_fb = LLVMBuildShuffleVector(builder, zs_dst1, zs_dst2,

                                  LLVMConstVector(shuffles, zs_type.length), "");

   *s_fb = *z_fb;

   if (format_desc->block.bits < z_src_type.width) {

      /* Extend destination ZS values (e.g., when reading from Z16_UNORM) */

      *z_fb = LLVMBuildZExt(builder, *z_fb,

                            lp_build_int_vec_type(gallivm, z_src_type), "");

   }

   else if (format_desc->block.bits > 32) {

      /* rely on llvm to handle too wide vector we have here nicely */

      unsigned i;

      struct lp_type typex2 = zs_type;

      struct lp_type s_type = zs_type;

      LLVMValueRef shuffles1[LP_MAX_VECTOR_LENGTH / 4];

      LLVMValueRef shuffles2[LP_MAX_VECTOR_LENGTH / 4];

      LLVMValueRef tmp;

      typex2.width = typex2.width / 2;

      typex2.length = typex2.length * 2;

      s_type.width = s_type.width / 2;

      s_type.floating = 0;

      tmp = LLVMBuildBitCast(builder, *z_fb,

                             lp_build_vec_type(gallivm, typex2), "");

      for (i = 0; i < zs_type.length; i++) {

         shuffles1[i] = lp_build_const_int32(gallivm, i * 2);

         shuffles2[i] = lp_build_const_int32(gallivm, i * 2 + 1);

      }

      *z_fb = LLVMBuildShuffleVector(builder, tmp, tmp,

                                     LLVMConstVector(shuffles1, zs_type.length), "");

      *s_fb = LLVMBuildShuffleVector(builder, tmp, tmp,

                                     LLVMConstVector(shuffles2, zs_type.length), "");

      *s_fb = LLVMBuildBitCast(builder, *s_fb,

                               lp_build_vec_type(gallivm, s_type), "");

      lp_build_name(*s_fb, "s_dst");

   }

   lp_build_name(*z_fb, "z_dst");

   lp_build_name(*s_fb, "s_dst");

   lp_build_name(*z_fb, "z_dst");

}

/**

 * Store depth/stencil values.

 * Incoming values are swizzled (typically n 2x2 quads), stored linear.

 * If there's a mask it will do select/store otherwise just store.

 *

 * \param type  the data type of the fragment depth/stencil values

 * \param format_desc  description of the depth/stencil surface

 * \param is_1d  whether this resource has only one dimension

 * \param mask  the alive/dead pixel mask for the quad (vector)

 * \param z_fb  z values read from fb (with padding)

 * \param s_fb  s values read from fb (with padding)

 * \param loop_counter  the current loop iteration

 * \param depth_ptr  pointer to the depth/stencil values of this 4x4 block

 * \param depth_stride  stride of the depth/stencil buffer

 * \param z_value the depth values to store (with padding)

 * \param s_value the stencil values to store (with padding)

 */

void

lp_build_depth_stencil_write_swizzled(struct gallivm_state *gallivm,

                                      struct lp_type z_src_type,

                                      const struct util_format_description *format_desc,

                                      boolean is_1d,

                                      struct lp_build_mask_context *mask,

                                      LLVMValueRef z_fb,

                                      LLVMValueRef s_fb,

                                      LLVMValueRef loop_counter,

                                      LLVMValueRef depth_ptr,

                                      LLVMValueRef depth_stride,

                                      LLVMValueRef z_value,

                                      LLVMValueRef s_value)

{

   struct lp_build_context z_bld;

   LLVMValueRef shuffles[LP_MAX_VECTOR_LENGTH / 4];

   LLVMBuilderRef builder = gallivm->builder;

   LLVMValueRef mask_value = NULL;

   LLVMValueRef zs_dst1, zs_dst2;

   LLVMValueRef zs_dst_ptr1, zs_dst_ptr2;

   LLVMValueRef depth_offset1, depth_offset2;

   LLVMTypeRef load_ptr_type;

   unsigned depth_bytes = format_desc->block.bits / 8;

   struct lp_type zs_type = lp_depth_type(format_desc, z_src_type.length);

   struct lp_type z_type = zs_type;

   struct lp_type zs_load_type = zs_type;

   zs_load_type.length = zs_load_type.length / 2;

   load_ptr_type = LLVMPointerType(lp_build_vec_type(gallivm, zs_load_type), 0);

   z_type.width = z_src_type.width;

   lp_build_context_init(&z_bld, gallivm, z_type);

   /*

    * This is far from ideal, at least for late depth write we should do this

    * outside the fs loop to avoid all the swizzle stuff.

    */

   if (z_src_type.length == 4) {

      LLVMValueRef looplsb = LLVMBuildAnd(builder, loop_counter,

                                          lp_build_const_int32(gallivm, 1), "");

      LLVMValueRef loopmsb = LLVMBuildAnd(builder, loop_counter,

                                          lp_build_const_int32(gallivm, 2), "");

      LLVMValueRef offset2 = LLVMBuildMul(builder, loopmsb,

                                          depth_stride, "");

      depth_offset1 = LLVMBuildMul(builder, looplsb,

                                   lp_build_const_int32(gallivm, depth_bytes * 2), "");

      depth_offset1 = LLVMBuildAdd(builder, depth_offset1, offset2, "");

   }

   else {

      unsigned i;

      LLVMValueRef loopx2 = LLVMBuildShl(builder, loop_counter,

                                         lp_build_const_int32(gallivm, 1), "");

      assert(z_src_type.length == 8);

      depth_offset1 = LLVMBuildMul(builder, loopx2, depth_stride, "");

      /*

       * We load 2x4 values, and need to swizzle them (order

       * 0,1,4,5,2,3,6,7) - not so hot with avx unfortunately.

       */

      for (i = 0; i < 8; i++) {

         shuffles[i] = lp_build_const_int32(gallivm, (i&1) + (i&2) * 2 + (i&4) / 2);

      }

   }

   depth_offset2 = LLVMBuildAdd(builder, depth_offset1, depth_stride, "");

   zs_dst_ptr1 = LLVMBuildGEP(builder, depth_ptr, &depth_offset1, 1, "");

   zs_dst_ptr1 = LLVMBuildBitCast(builder, zs_dst_ptr1, load_ptr_type, "");

   zs_dst_ptr2 = LLVMBuildGEP(builder, depth_ptr, &depth_offset2, 1, "");

   zs_dst_ptr2 = LLVMBuildBitCast(builder, zs_dst_ptr2, load_ptr_type, "");

   if (format_desc->block.bits > 32) {

      s_value = LLVMBuildBitCast(builder, s_value, z_bld.vec_type, "");

   }

   if (mask) {

      mask_value = lp_build_mask_value(mask);

      z_value = lp_build_select(&z_bld, mask_value, z_value, z_fb);

      if (format_desc->block.bits > 32) {

         s_fb = LLVMBuildBitCast(builder, s_fb, z_bld.vec_type, "");

         s_value = lp_build_select(&z_bld, mask_value, s_value, s_fb);

      }

   }

   if (zs_type.width < z_src_type.width) {

      /* Truncate ZS values (e.g., when writing to Z16_UNORM) */

      z_value = LLVMBuildTrunc(builder, z_value,

                               lp_build_int_vec_type(gallivm, zs_type), "");

   }

   if (format_desc->block.bits <= 32) {

      if (z_src_type.length == 4) {

         zs_dst1 = lp_build_extract_range(gallivm, z_value, 0, 2);

         zs_dst2 = lp_build_extract_range(gallivm, z_value, 2, 2);

      }

      else {

         assert(z_src_type.length == 8);

         zs_dst1 = LLVMBuildShuffleVector(builder, z_value, z_value,

                                          LLVMConstVector(&shuffles[0],

                                                          zs_load_type.length), "");

         zs_dst2 = LLVMBuildShuffleVector(builder, z_value, z_value,

                                          LLVMConstVector(&shuffles[4],

                                                          zs_load_type.length), "");

      }

   }

   else {

      if (z_src_type.length == 4) {

         zs_dst1 = lp_build_interleave2(gallivm, z_type,

                                        z_value, s_value, 0);

         zs_dst2 = lp_build_interleave2(gallivm, z_type,

                                        z_value, s_value, 1);

      }

      else {

         unsigned i;

         LLVMValueRef shuffles[LP_MAX_VECTOR_LENGTH / 2];

         assert(z_src_type.length == 8);

         for (i = 0; i < 8; i++) {

            shuffles[i*2] = lp_build_const_int32(gallivm, (i&1) + (i&2) * 2 + (i&4) / 2);

            shuffles[i*2+1] = lp_build_const_int32(gallivm, (i&1) + (i&2) * 2 + (i&4) / 2 +

                                                   z_src_type.length);

         }

         zs_dst1 = LLVMBuildShuffleVector(builder, z_value, s_value,

                                          LLVMConstVector(&shuffles[0],

                                                          z_src_type.length), "");

         zs_dst2 = LLVMBuildShuffleVector(builder, z_value, s_value,

                                          LLVMConstVector(&shuffles[8],

                                                          z_src_type.length), "");

      }

      zs_dst1 = LLVMBuildBitCast(builder, zs_dst1,

                                 lp_build_vec_type(gallivm, zs_load_type), "");

      zs_dst2 = LLVMBuildBitCast(builder, zs_dst2,

                                 lp_build_vec_type(gallivm, zs_load_type), "");

   }

   LLVMBuildStore(builder, zs_dst1, zs_dst_ptr1);

   if (!is_1d) {

      LLVMBuildStore(builder, zs_dst2, zs_dst_ptr2);

   }

}

/**

 * Generate code for performing depth and/or stencil tests.

 * We operate on a vector of values (typically n 2x2 quads).

 *

 * \param depth  the depth test state

 * \param stencil  the front/back stencil state

 * \param type  the data type of the fragment depth/stencil values

 * \param format_desc  description of the depth/stencil surface

 * \param mask  the alive/dead pixel mask for the quad (vector)

 * \param stencil_refs  the front/back stencil ref values (scalar)

 * \param z_src  the incoming depth/stencil values (n 2x2 quad values, float32)

 * \param zs_dst  the depth/stencil values in framebuffer

 * \param face  contains boolean value indicating front/back facing polygon

 */

void

lp_build_depth_stencil_test(struct gallivm_state *gallivm,

                            const struct pipe_depth_state *depth,

                            const struct pipe_stencil_state stencil[2],

                            struct lp_type z_src_type,

                            const struct util_format_description *format_desc,

                            struct lp_build_mask_context *mask,

                            LLVMValueRef stencil_refs[2],

                            LLVMValueRef z_src,

                            LLVMValueRef z_fb,

                            LLVMValueRef s_fb,

                            LLVMValueRef face,

                            LLVMValueRef *z_value,

                            LLVMValueRef *s_value,

                            boolean do_branch)

{

   LLVMBuilderRef builder = gallivm->builder;

   struct lp_type z_type;

   struct lp_build_context z_bld;

   struct lp_build_context s_bld;

   struct lp_type s_type;

   unsigned z_shift = 0, z_width = 0, z_mask = 0;

   LLVMValueRef z_dst = NULL;

   LLVMValueRef stencil_vals = NULL;

   LLVMValueRef z_bitmask = NULL, stencil_shift = NULL;

   LLVMValueRef z_pass = NULL, s_pass_mask = NULL;

   LLVMValueRef current_mask = lp_build_mask_value(mask);

   LLVMValueRef front_facing = NULL;

   boolean have_z, have_s;

   /*

    * Depths are expected to be between 0 and 1, even if they are stored in

    * floats. Setting these bits here will ensure that the lp_build_conv() call

    * below won't try to unnecessarily clamp the incoming values.

    */

   if(z_src_type.floating) {

      z_src_type.sign = FALSE;

      z_src_type.norm = TRUE;

   }

   else {

      assert(!z_src_type.sign);

      assert(z_src_type.norm);

   }

   /* Pick the type matching the depth-stencil format. */

   z_type = lp_depth_type(format_desc, z_src_type.length);

   /* Pick the intermediate type for depth operations. */

   z_type.width = z_src_type.width;

   assert(z_type.length == z_src_type.length);

   /* FIXME: for non-float depth/stencil might generate better code

    * if we'd always split it up to use 128bit operations.

    * For stencil we'd almost certainly want to pack to 8xi16 values,

    * for z just run twice.

    */

   /* Sanity checking */

   {

      const unsigned z_swizzle = format_desc->swizzle[0];

      const unsigned s_swizzle = format_desc->swizzle[1];

      assert(z_swizzle != UTIL_FORMAT_SWIZZLE_NONE ||

             s_swizzle != UTIL_FORMAT_SWIZZLE_NONE);

      assert(depth->enabled || stencil[0].enabled);

      assert(format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS);

      assert(format_desc->block.width == 1);

      assert(format_desc->block.height == 1);

      if (stencil[0].enabled) {

         assert(s_swizzle < 4);

         assert(format_desc->channel[s_swizzle].type == UTIL_FORMAT_TYPE_UNSIGNED);

         assert(format_desc->channel[s_swizzle].pure_integer);

         assert(!format_desc->channel[s_swizzle].normalized);

         assert(format_desc->channel[s_swizzle].size == 8);

      }

      if (depth->enabled) {

         assert(z_swizzle < 4);

         if (z_type.floating) {

            assert(z_swizzle == 0);

            assert(format_desc->channel[z_swizzle].type ==

                   UTIL_FORMAT_TYPE_FLOAT);

            assert(format_desc->channel[z_swizzle].size == 32);

         }

         else {

            assert(format_desc->channel[z_swizzle].type ==

                   UTIL_FORMAT_TYPE_UNSIGNED);

            assert(format_desc->channel[z_swizzle].normalized);

            assert(!z_type.fixed);

         }

      }

   }

   /* Setup build context for Z vals */

   lp_build_context_init(&z_bld, gallivm, z_type);

   /* Setup build context for stencil vals */

   s_type = lp_int_type(z_type);

   lp_build_context_init(&s_bld, gallivm, s_type);

   /* Compute and apply the Z/stencil bitmasks and shifts.

    */

   {

      unsigned s_shift, s_mask;

      z_dst = z_fb;

      stencil_vals = s_fb;

      have_z = get_z_shift_and_mask(format_desc, &z_shift, &z_width, &z_mask);

      have_s = get_s_shift_and_mask(format_desc, &s_shift, &s_mask);

      if (have_z) {

         if (z_mask != 0xffffffff) {

            z_bitmask = lp_build_const_int_vec(gallivm, z_type, z_mask);

         }

         /*

          * Align the framebuffer Z 's LSB to the right.

          */

         if (z_shift) {

            LLVMValueRef shift = lp_build_const_int_vec(gallivm, z_type, z_shift);

            z_dst = LLVMBuildLShr(builder, z_dst, shift, "z_dst");

         } else if (z_bitmask) {

            z_dst = LLVMBuildAnd(builder, z_dst, z_bitmask, "z_dst");

         } else {

            lp_build_name(z_dst, "z_dst");

         }

      }

      if (have_s) {

         if (s_shift) {

            LLVMValueRef shift = lp_build_const_int_vec(gallivm, s_type, s_shift);

            stencil_vals = LLVMBuildLShr(builder, stencil_vals, shift, "");

            stencil_shift = shift;  /* used below */

         }

         if (s_mask != 0xffffffff) {

            LLVMValueRef mask = lp_build_const_int_vec(gallivm, s_type, s_mask);

            stencil_vals = LLVMBuildAnd(builder, stencil_vals, mask, "");

         }

         lp_build_name(stencil_vals, "s_dst");

      }

   }

   if (stencil[0].enabled) {

      if (face) {

         LLVMValueRef zero = lp_build_const_int32(gallivm, 0);

         /* front_facing = face != 0 ? ~0 : 0 */

         front_facing = LLVMBuildICmp(builder, LLVMIntNE, face, zero, "");

         front_facing = LLVMBuildSExt(builder, front_facing,

                                      LLVMIntTypeInContext(gallivm->context,

                                             s_bld.type.length*s_bld.type.width),

                                      "");

         front_facing = LLVMBuildBitCast(builder, front_facing,

                                         s_bld.int_vec_type, "");

      }

      /* convert scalar stencil refs into vectors */

      stencil_refs[0] = lp_build_broadcast_scalar(&s_bld, stencil_refs[0]);

      stencil_refs[1] = lp_build_broadcast_scalar(&s_bld, stencil_refs[1]);

      s_pass_mask = lp_build_stencil_test(&s_bld, stencil,

                                          stencil_refs, stencil_vals,

                                          front_facing);

      /* apply stencil-fail operator */

      {

         LLVMValueRef s_fail_mask = lp_build_andnot(&s_bld, current_mask, s_pass_mask);

         stencil_vals = lp_build_stencil_op(&s_bld, stencil, S_FAIL_OP,

                                            stencil_refs, stencil_vals,

                                            s_fail_mask, front_facing);

      }

   }

   if (depth->enabled) {

      /*

       * Convert fragment Z to the desired type, aligning the LSB to the right.

       */

      assert(z_type.width == z_src_type.width);

      assert(z_type.length == z_src_type.length);

      assert(lp_check_value(z_src_type, z_src));

      if (z_src_type.floating) {

         /*

          * Convert from floating point values

          */

         if (!z_type.floating) {

            z_src = lp_build_clamped_float_to_unsigned_norm(gallivm,

                                                            z_src_type,

                                                            z_width,

                                                            z_src);

         }

      } else {

         /*

          * Convert from unsigned normalized values.

          */

         assert(!z_src_type.sign);

         assert(!z_src_type.fixed);

         assert(z_src_type.norm);

         assert(!z_type.floating);

         if (z_src_type.width > z_width) {

            LLVMValueRef shift = lp_build_const_int_vec(gallivm, z_src_type,

                                                        z_src_type.width - z_width);

            z_src = LLVMBuildLShr(builder, z_src, shift, "");

         }

      }

      assert(lp_check_value(z_type, z_src));

      lp_build_name(z_src, "z_src");

      /* compare src Z to dst Z, returning 'pass' mask */

      z_pass = lp_build_cmp(&z_bld, depth->func, z_src, z_dst);

      /* mask off bits that failed stencil test */

      if (s_pass_mask) {

         current_mask = LLVMBuildAnd(builder, current_mask, s_pass_mask, "");

      }

      if (!stencil[0].enabled) {

         /* We can potentially skip all remaining operations here, but only

          * if stencil is disabled because we still need to update the stencil

          * buffer values.  Don't need to update Z buffer values.

          */

         lp_build_mask_update(mask, z_pass);

         if (do_branch) {

            lp_build_mask_check(mask);

         }

      }

      if (depth->writemask) {

         LLVMValueRef z_pass_mask;

         /* mask off bits that failed Z test */

         z_pass_mask = LLVMBuildAnd(builder, current_mask, z_pass, "");

         /* Mix the old and new Z buffer values.

          * z_dst[i] = zselectmask[i] ? z_src[i] : z_dst[i]

          */

         z_dst = lp_build_select(&z_bld, z_pass_mask, z_src, z_dst);

      }

      if (stencil[0].enabled) {

         /* update stencil buffer values according to z pass/fail result */

         LLVMValueRef z_fail_mask, z_pass_mask;

         /* apply Z-fail operator */

         z_fail_mask = lp_build_andnot(&s_bld, current_mask, z_pass);

         stencil_vals = lp_build_stencil_op(&s_bld, stencil, Z_FAIL_OP,

                                            stencil_refs, stencil_vals,

                                            z_fail_mask, front_facing);

         /* apply Z-pass operator */

         z_pass_mask = LLVMBuildAnd(builder, current_mask, z_pass, "");

         stencil_vals = lp_build_stencil_op(&s_bld, stencil, Z_PASS_OP,

                                            stencil_refs, stencil_vals,

                                            z_pass_mask, front_facing);

      }

   }

   else {

      /* No depth test: apply Z-pass operator to stencil buffer values which

       * passed the stencil test.

       */

      s_pass_mask = LLVMBuildAnd(builder, current_mask, s_pass_mask, "");

      stencil_vals = lp_build_stencil_op(&s_bld, stencil, Z_PASS_OP,

                                         stencil_refs, stencil_vals,

                                         s_pass_mask, front_facing);

   }

   /* Put Z and stencil bits in the right place */

   if (have_z && z_shift) {

      LLVMValueRef shift = lp_build_const_int_vec(gallivm, z_type, z_shift);

      z_dst = LLVMBuildShl(builder, z_dst, shift, "");

   }

   if (stencil_vals && stencil_shift)

      stencil_vals = LLVMBuildShl(builder, stencil_vals,

                                  stencil_shift, "");

   /* Finally, merge the z/stencil values */

   if (format_desc->block.bits <= 32) {

      if (have_z && have_s)

         *z_value = LLVMBuildOr(builder, z_dst, stencil_vals, "");

      else if (have_z)

         *z_value = z_dst;

      else

         *z_value = stencil_vals;

      *s_value = *z_value;

   }

   else {

      *z_value = z_dst;

      *s_value = stencil_vals;

   }

   if (s_pass_mask)

      lp_build_mask_update(mask, s_pass_mask);

   if (depth->enabled && stencil[0].enabled)

      lp_build_mask_update(mask, z_pass);

}