Exemplo n.º 1
0
/**
 * Generate the runtime callable function for the whole fragment pipeline.
 */
static struct lp_fragment_shader_variant *
generate_fragment(struct llvmpipe_context *lp,
                  struct lp_fragment_shader *shader,
                  const struct lp_fragment_shader_variant_key *key)
{
   struct llvmpipe_screen *screen = llvmpipe_screen(lp->pipe.screen);
   struct lp_fragment_shader_variant *variant;
   struct lp_type fs_type;
   struct lp_type blend_type;
   LLVMTypeRef fs_elem_type;
   LLVMTypeRef fs_vec_type;
   LLVMTypeRef fs_int_vec_type;
   LLVMTypeRef blend_vec_type;
   LLVMTypeRef blend_int_vec_type;
   LLVMTypeRef arg_types[9];
   LLVMTypeRef func_type;
   LLVMValueRef context_ptr;
   LLVMValueRef x;
   LLVMValueRef y;
   LLVMValueRef a0_ptr;
   LLVMValueRef dadx_ptr;
   LLVMValueRef dady_ptr;
   LLVMValueRef mask_ptr;
   LLVMValueRef color_ptr;
   LLVMValueRef depth_ptr;
   LLVMBasicBlockRef block;
   LLVMBuilderRef builder;
   LLVMValueRef x0;
   LLVMValueRef y0;
   struct lp_build_sampler_soa *sampler;
   struct lp_build_interp_soa_context interp;
   LLVMValueRef fs_mask[LP_MAX_VECTOR_LENGTH];
   LLVMValueRef fs_out_color[NUM_CHANNELS][LP_MAX_VECTOR_LENGTH];
   LLVMValueRef blend_mask;
   LLVMValueRef blend_in_color[NUM_CHANNELS];
   unsigned num_fs;
   unsigned i;
   unsigned chan;

#ifdef DEBUG
   tgsi_dump(shader->base.tokens, 0);
   if(key->depth.enabled) {
      debug_printf("depth.format = %s\n", pf_name(key->zsbuf_format));
      debug_printf("depth.func = %s\n", debug_dump_func(key->depth.func, TRUE));
      debug_printf("depth.writemask = %u\n", key->depth.writemask);
   }
   if(key->alpha.enabled) {
      debug_printf("alpha.func = %s\n", debug_dump_func(key->alpha.func, TRUE));
      debug_printf("alpha.ref_value = %f\n", key->alpha.ref_value);
   }
   if(key->blend.logicop_enable) {
      debug_printf("blend.logicop_func = %u\n", key->blend.logicop_func);
   }
   else if(key->blend.blend_enable) {
      debug_printf("blend.rgb_func = %s\n",   debug_dump_blend_func  (key->blend.rgb_func, TRUE));
      debug_printf("rgb_src_factor = %s\n",   debug_dump_blend_factor(key->blend.rgb_src_factor, TRUE));
      debug_printf("rgb_dst_factor = %s\n",   debug_dump_blend_factor(key->blend.rgb_dst_factor, TRUE));
      debug_printf("alpha_func = %s\n",       debug_dump_blend_func  (key->blend.alpha_func, TRUE));
      debug_printf("alpha_src_factor = %s\n", debug_dump_blend_factor(key->blend.alpha_src_factor, TRUE));
      debug_printf("alpha_dst_factor = %s\n", debug_dump_blend_factor(key->blend.alpha_dst_factor, TRUE));
   }
   debug_printf("blend.colormask = 0x%x\n", key->blend.colormask);
   for(i = 0; i < PIPE_MAX_SAMPLERS; ++i) {
      if(key->sampler[i].format) {
         debug_printf("sampler[%u] = \n", i);
         debug_printf("  .format = %s\n",
                      pf_name(key->sampler[i].format));
         debug_printf("  .target = %s\n",
                      debug_dump_tex_target(key->sampler[i].target, TRUE));
         debug_printf("  .pot = %u %u %u\n",
                      key->sampler[i].pot_width,
                      key->sampler[i].pot_height,
                      key->sampler[i].pot_depth);
         debug_printf("  .wrap = %s %s %s\n",
                      debug_dump_tex_wrap(key->sampler[i].wrap_s, TRUE),
                      debug_dump_tex_wrap(key->sampler[i].wrap_t, TRUE),
                      debug_dump_tex_wrap(key->sampler[i].wrap_r, TRUE));
         debug_printf("  .min_img_filter = %s\n",
                      debug_dump_tex_filter(key->sampler[i].min_img_filter, TRUE));
         debug_printf("  .min_mip_filter = %s\n",
                      debug_dump_tex_mipfilter(key->sampler[i].min_mip_filter, TRUE));
         debug_printf("  .mag_img_filter = %s\n",
                      debug_dump_tex_filter(key->sampler[i].mag_img_filter, TRUE));
         if(key->sampler[i].compare_mode)
            debug_printf("  .compare_mode = %s\n", debug_dump_func(key->sampler[i].compare_func, TRUE));
         debug_printf("  .normalized_coords = %u\n", key->sampler[i].normalized_coords);
         debug_printf("  .prefilter = %u\n", key->sampler[i].prefilter);
      }
   }

#endif

   variant = CALLOC_STRUCT(lp_fragment_shader_variant);
   if(!variant)
      return NULL;

   variant->shader = shader;
   memcpy(&variant->key, key, sizeof *key);

   /* TODO: actually pick these based on the fs and color buffer
    * characteristics. */

   memset(&fs_type, 0, sizeof fs_type);
   fs_type.floating = TRUE; /* floating point values */
   fs_type.sign = TRUE;     /* values are signed */
   fs_type.norm = FALSE;    /* values are not limited to [0,1] or [-1,1] */
   fs_type.width = 32;      /* 32-bit float */
   fs_type.length = 4;      /* 4 element per vector */
   num_fs = 4;

   memset(&blend_type, 0, sizeof blend_type);
   blend_type.floating = FALSE; /* values are integers */
   blend_type.sign = FALSE;     /* values are unsigned */
   blend_type.norm = TRUE;      /* values are in [0,1] or [-1,1] */
   blend_type.width = 8;        /* 8-bit ubyte values */
   blend_type.length = 16;      /* 16 elements per vector */

   /* 
    * Generate the function prototype. Any change here must be reflected in
    * lp_jit.h's lp_jit_frag_func function pointer type, and vice-versa.
    */

   fs_elem_type = lp_build_elem_type(fs_type);
   fs_vec_type = lp_build_vec_type(fs_type);
   fs_int_vec_type = lp_build_int_vec_type(fs_type);

   blend_vec_type = lp_build_vec_type(blend_type);
   blend_int_vec_type = lp_build_int_vec_type(blend_type);

   arg_types[0] = screen->context_ptr_type;            /* context */
   arg_types[1] = LLVMInt32Type();                     /* x */
   arg_types[2] = LLVMInt32Type();                     /* y */
   arg_types[3] = LLVMPointerType(fs_elem_type, 0);    /* a0 */
   arg_types[4] = LLVMPointerType(fs_elem_type, 0);    /* dadx */
   arg_types[5] = LLVMPointerType(fs_elem_type, 0);    /* dady */
   arg_types[6] = LLVMPointerType(fs_int_vec_type, 0); /* mask */
   arg_types[7] = LLVMPointerType(blend_vec_type, 0);  /* color */
   arg_types[8] = LLVMPointerType(fs_int_vec_type, 0); /* depth */

   func_type = LLVMFunctionType(LLVMVoidType(), arg_types, Elements(arg_types), 0);

   variant->function = LLVMAddFunction(screen->module, "shader", func_type);
   LLVMSetFunctionCallConv(variant->function, LLVMCCallConv);
   for(i = 0; i < Elements(arg_types); ++i)
      if(LLVMGetTypeKind(arg_types[i]) == LLVMPointerTypeKind)
         LLVMAddAttribute(LLVMGetParam(variant->function, i), LLVMNoAliasAttribute);

   context_ptr  = LLVMGetParam(variant->function, 0);
   x            = LLVMGetParam(variant->function, 1);
   y            = LLVMGetParam(variant->function, 2);
   a0_ptr       = LLVMGetParam(variant->function, 3);
   dadx_ptr     = LLVMGetParam(variant->function, 4);
   dady_ptr     = LLVMGetParam(variant->function, 5);
   mask_ptr     = LLVMGetParam(variant->function, 6);
   color_ptr    = LLVMGetParam(variant->function, 7);
   depth_ptr    = LLVMGetParam(variant->function, 8);

   lp_build_name(context_ptr, "context");
   lp_build_name(x, "x");
   lp_build_name(y, "y");
   lp_build_name(a0_ptr, "a0");
   lp_build_name(dadx_ptr, "dadx");
   lp_build_name(dady_ptr, "dady");
   lp_build_name(mask_ptr, "mask");
   lp_build_name(color_ptr, "color");
   lp_build_name(depth_ptr, "depth");

   /*
    * Function body
    */

   block = LLVMAppendBasicBlock(variant->function, "entry");
   builder = LLVMCreateBuilder();
   LLVMPositionBuilderAtEnd(builder, block);

   generate_pos0(builder, x, y, &x0, &y0);

   lp_build_interp_soa_init(&interp, shader->base.tokens, builder, fs_type,
                            a0_ptr, dadx_ptr, dady_ptr,
                            x0, y0, 2, 0);

#if 0
   /* C texture sampling */
   sampler = lp_c_sampler_soa_create(context_ptr);
#else
   /* code generated texture sampling */
   sampler = lp_llvm_sampler_soa_create(key->sampler, context_ptr);
#endif

   for(i = 0; i < num_fs; ++i) {
      LLVMValueRef index = LLVMConstInt(LLVMInt32Type(), i, 0);
      LLVMValueRef out_color[NUM_CHANNELS];
      LLVMValueRef depth_ptr_i;

      if(i != 0)
         lp_build_interp_soa_update(&interp);

      fs_mask[i] = LLVMBuildLoad(builder, LLVMBuildGEP(builder, mask_ptr, &index, 1, ""), "");
      depth_ptr_i = LLVMBuildGEP(builder, depth_ptr, &index, 1, "");

      generate_fs(lp, shader, key,
                  builder,
                  fs_type,
                  context_ptr,
                  i,
                  &interp,
                  sampler,
                  &fs_mask[i],
                  out_color,
                  depth_ptr_i);

      for(chan = 0; chan < NUM_CHANNELS; ++chan)
         fs_out_color[chan][i] = out_color[chan];
   }

   sampler->destroy(sampler);

   /* 
    * Convert the fs's output color and mask to fit to the blending type. 
    */

   for(chan = 0; chan < NUM_CHANNELS; ++chan) {
      lp_build_conv(builder, fs_type, blend_type,
                    fs_out_color[chan], num_fs,
                    &blend_in_color[chan], 1);
      lp_build_name(blend_in_color[chan], "color.%c", "rgba"[chan]);

   }

   lp_build_conv_mask(builder, fs_type, blend_type,
                               fs_mask, num_fs,
                               &blend_mask, 1);

   /*
    * Blending.
    */

   generate_blend(&key->blend,
                  builder,
                  blend_type,
                  context_ptr,
                  blend_mask,
                  blend_in_color,
                  color_ptr);

   LLVMBuildRetVoid(builder);

   LLVMDisposeBuilder(builder);

   /*
    * Translate the LLVM IR into machine code.
    */

   if(LLVMVerifyFunction(variant->function, LLVMPrintMessageAction)) {
      LLVMDumpValue(variant->function);
      abort();
   }

   LLVMRunFunctionPassManager(screen->pass, variant->function);

#ifdef DEBUG
   LLVMDumpValue(variant->function);
   debug_printf("\n");
#endif

   variant->jit_function = (lp_jit_frag_func)LLVMGetPointerToGlobal(screen->engine, variant->function);

#ifdef DEBUG
   lp_disassemble(variant->jit_function);
#endif

   variant->next = shader->variants;
   shader->variants = variant;

   return variant;
}
Exemplo n.º 2
0
/**
 * Generate the runtime callable function for the whole fragment pipeline.
 * Note that the function which we generate operates on a block of 16
 * pixels at at time.  The block contains 2x2 quads.  Each quad contains
 * 2x2 pixels.
 */
static void
generate_fragment(struct llvmpipe_context *lp,
                  struct lp_fragment_shader *shader,
                  struct lp_fragment_shader_variant *variant,
                  unsigned do_tri_test)
{
   struct llvmpipe_screen *screen = llvmpipe_screen(lp->pipe.screen);
   const struct lp_fragment_shader_variant_key *key = &variant->key;
   struct lp_type fs_type;
   struct lp_type blend_type;
   LLVMTypeRef fs_elem_type;
   LLVMTypeRef fs_vec_type;
   LLVMTypeRef fs_int_vec_type;
   LLVMTypeRef blend_vec_type;
   LLVMTypeRef blend_int_vec_type;
   LLVMTypeRef arg_types[14];
   LLVMTypeRef func_type;
   LLVMTypeRef int32_vec4_type = lp_build_int32_vec4_type();
   LLVMValueRef context_ptr;
   LLVMValueRef x;
   LLVMValueRef y;
   LLVMValueRef a0_ptr;
   LLVMValueRef dadx_ptr;
   LLVMValueRef dady_ptr;
   LLVMValueRef color_ptr_ptr;
   LLVMValueRef depth_ptr;
   LLVMValueRef c0, c1, c2, step0_ptr, step1_ptr, step2_ptr;
   LLVMBasicBlockRef block;
   LLVMBuilderRef builder;
   LLVMValueRef x0;
   LLVMValueRef y0;
   struct lp_build_sampler_soa *sampler;
   struct lp_build_interp_soa_context interp;
   LLVMValueRef fs_mask[LP_MAX_VECTOR_LENGTH];
   LLVMValueRef fs_out_color[PIPE_MAX_COLOR_BUFS][NUM_CHANNELS][LP_MAX_VECTOR_LENGTH];
   LLVMValueRef blend_mask;
   LLVMValueRef blend_in_color[NUM_CHANNELS];
   LLVMValueRef function;
   unsigned num_fs;
   unsigned i;
   unsigned chan;
   unsigned cbuf;


   /* TODO: actually pick these based on the fs and color buffer
    * characteristics. */

   memset(&fs_type, 0, sizeof fs_type);
   fs_type.floating = TRUE; /* floating point values */
   fs_type.sign = TRUE;     /* values are signed */
   fs_type.norm = FALSE;    /* values are not limited to [0,1] or [-1,1] */
   fs_type.width = 32;      /* 32-bit float */
   fs_type.length = 4;      /* 4 elements per vector */
   num_fs = 4;              /* number of quads per block */

   memset(&blend_type, 0, sizeof blend_type);
   blend_type.floating = FALSE; /* values are integers */
   blend_type.sign = FALSE;     /* values are unsigned */
   blend_type.norm = TRUE;      /* values are in [0,1] or [-1,1] */
   blend_type.width = 8;        /* 8-bit ubyte values */
   blend_type.length = 16;      /* 16 elements per vector */

   /* 
    * Generate the function prototype. Any change here must be reflected in
    * lp_jit.h's lp_jit_frag_func function pointer type, and vice-versa.
    */

   fs_elem_type = lp_build_elem_type(fs_type);
   fs_vec_type = lp_build_vec_type(fs_type);
   fs_int_vec_type = lp_build_int_vec_type(fs_type);

   blend_vec_type = lp_build_vec_type(blend_type);
   blend_int_vec_type = lp_build_int_vec_type(blend_type);

   arg_types[0] = screen->context_ptr_type;            /* context */
   arg_types[1] = LLVMInt32Type();                     /* x */
   arg_types[2] = LLVMInt32Type();                     /* y */
   arg_types[3] = LLVMPointerType(fs_elem_type, 0);    /* a0 */
   arg_types[4] = LLVMPointerType(fs_elem_type, 0);    /* dadx */
   arg_types[5] = LLVMPointerType(fs_elem_type, 0);    /* dady */
   arg_types[6] = LLVMPointerType(LLVMPointerType(blend_vec_type, 0), 0);  /* color */
   arg_types[7] = LLVMPointerType(fs_int_vec_type, 0); /* depth */
   arg_types[8] = LLVMInt32Type();                     /* c0 */
   arg_types[9] = LLVMInt32Type();                     /* c1 */
   arg_types[10] = LLVMInt32Type();                    /* c2 */
   /* Note: the step arrays are built as int32[16] but we interpret
    * them here as int32_vec4[4].
    */
   arg_types[11] = LLVMPointerType(int32_vec4_type, 0);/* step0 */
   arg_types[12] = LLVMPointerType(int32_vec4_type, 0);/* step1 */
   arg_types[13] = LLVMPointerType(int32_vec4_type, 0);/* step2 */

   func_type = LLVMFunctionType(LLVMVoidType(), arg_types, Elements(arg_types), 0);

   function = LLVMAddFunction(screen->module, "shader", func_type);
   LLVMSetFunctionCallConv(function, LLVMCCallConv);

   variant->function[do_tri_test] = function;


   /* XXX: need to propagate noalias down into color param now we are
    * passing a pointer-to-pointer?
    */
   for(i = 0; i < Elements(arg_types); ++i)
      if(LLVMGetTypeKind(arg_types[i]) == LLVMPointerTypeKind)
         LLVMAddAttribute(LLVMGetParam(function, i), LLVMNoAliasAttribute);

   context_ptr  = LLVMGetParam(function, 0);
   x            = LLVMGetParam(function, 1);
   y            = LLVMGetParam(function, 2);
   a0_ptr       = LLVMGetParam(function, 3);
   dadx_ptr     = LLVMGetParam(function, 4);
   dady_ptr     = LLVMGetParam(function, 5);
   color_ptr_ptr = LLVMGetParam(function, 6);
   depth_ptr    = LLVMGetParam(function, 7);
   c0           = LLVMGetParam(function, 8);
   c1           = LLVMGetParam(function, 9);
   c2           = LLVMGetParam(function, 10);
   step0_ptr    = LLVMGetParam(function, 11);
   step1_ptr    = LLVMGetParam(function, 12);
   step2_ptr    = LLVMGetParam(function, 13);

   lp_build_name(context_ptr, "context");
   lp_build_name(x, "x");
   lp_build_name(y, "y");
   lp_build_name(a0_ptr, "a0");
   lp_build_name(dadx_ptr, "dadx");
   lp_build_name(dady_ptr, "dady");
   lp_build_name(color_ptr_ptr, "color_ptr");
   lp_build_name(depth_ptr, "depth");
   lp_build_name(c0, "c0");
   lp_build_name(c1, "c1");
   lp_build_name(c2, "c2");
   lp_build_name(step0_ptr, "step0");
   lp_build_name(step1_ptr, "step1");
   lp_build_name(step2_ptr, "step2");

   /*
    * Function body
    */

   block = LLVMAppendBasicBlock(function, "entry");
   builder = LLVMCreateBuilder();
   LLVMPositionBuilderAtEnd(builder, block);

   generate_pos0(builder, x, y, &x0, &y0);

   lp_build_interp_soa_init(&interp, 
                            shader->base.tokens,
                            key->flatshade,
                            builder, fs_type,
                            a0_ptr, dadx_ptr, dady_ptr,
                            x0, y0);

   /* code generated texture sampling */
   sampler = lp_llvm_sampler_soa_create(key->sampler, context_ptr);

   /* loop over quads in the block */
   for(i = 0; i < num_fs; ++i) {
      LLVMValueRef index = LLVMConstInt(LLVMInt32Type(), i, 0);
      LLVMValueRef out_color[PIPE_MAX_COLOR_BUFS][NUM_CHANNELS];
      LLVMValueRef depth_ptr_i;
      int cbuf;

      if(i != 0)
         lp_build_interp_soa_update(&interp, i);

      depth_ptr_i = LLVMBuildGEP(builder, depth_ptr, &index, 1, "");

      generate_fs(lp, shader, key,
                  builder,
                  fs_type,
                  context_ptr,
                  i,
                  &interp,
                  sampler,
                  &fs_mask[i], /* output */
                  out_color,
                  depth_ptr_i,
                  do_tri_test,
                  c0, c1, c2,
                  step0_ptr, step1_ptr, step2_ptr);

      for(cbuf = 0; cbuf < key->nr_cbufs; cbuf++)
	 for(chan = 0; chan < NUM_CHANNELS; ++chan)
	    fs_out_color[cbuf][chan][i] = out_color[cbuf][chan];
   }

   sampler->destroy(sampler);

   /* Loop over color outputs / color buffers to do blending.
    */
   for(cbuf = 0; cbuf < key->nr_cbufs; cbuf++) {
      LLVMValueRef color_ptr;
      LLVMValueRef index = LLVMConstInt(LLVMInt32Type(), cbuf, 0);

      /* 
       * Convert the fs's output color and mask to fit to the blending type. 
       */
      for(chan = 0; chan < NUM_CHANNELS; ++chan) {
	 lp_build_conv(builder, fs_type, blend_type,
		       fs_out_color[cbuf][chan], num_fs,
		       &blend_in_color[chan], 1);
	 lp_build_name(blend_in_color[chan], "color%d.%c", cbuf, "rgba"[chan]);
      }

      lp_build_conv_mask(builder, fs_type, blend_type,
			 fs_mask, num_fs,
			 &blend_mask, 1);

      color_ptr = LLVMBuildLoad(builder, 
				LLVMBuildGEP(builder, color_ptr_ptr, &index, 1, ""),
				"");
      lp_build_name(color_ptr, "color_ptr%d", cbuf);

      /*
       * Blending.
       */
      generate_blend(&key->blend,
		     builder,
		     blend_type,
		     context_ptr,
		     blend_mask,
		     blend_in_color,
		     color_ptr);
   }

   LLVMBuildRetVoid(builder);

   LLVMDisposeBuilder(builder);


   /* Verify the LLVM IR.  If invalid, dump and abort */
#ifdef DEBUG
   if(LLVMVerifyFunction(function, LLVMPrintMessageAction)) {
      if (1)
         LLVMDumpValue(function);
      abort();
   }
#endif

   /* Apply optimizations to LLVM IR */
   if (1)
      LLVMRunFunctionPassManager(screen->pass, function);

   if (LP_DEBUG & DEBUG_JIT) {
      /* Print the LLVM IR to stderr */
      LLVMDumpValue(function);
      debug_printf("\n");
   }

   /*
    * Translate the LLVM IR into machine code.
    */
   variant->jit_function[do_tri_test] = (lp_jit_frag_func)LLVMGetPointerToGlobal(screen->engine, function);

   if (LP_DEBUG & DEBUG_ASM)
      lp_disassemble(variant->jit_function[do_tri_test]);
}
Exemplo n.º 3
0
/**
 * Generate the runtime callable function for the whole fragment pipeline.
 * Note that the function which we generate operates on a block of 16
 * pixels at at time.  The block contains 2x2 quads.  Each quad contains
 * 2x2 pixels.
 */
static void
generate_fragment(struct llvmpipe_context *lp,
                  struct lp_fragment_shader *shader,
                  struct lp_fragment_shader_variant *variant,
                  unsigned partial_mask)
{
   struct llvmpipe_screen *screen = llvmpipe_screen(lp->pipe.screen);
   const struct lp_fragment_shader_variant_key *key = &variant->key;
   char func_name[256];
   struct lp_type fs_type;
   struct lp_type blend_type;
   LLVMTypeRef fs_elem_type;
   LLVMTypeRef fs_int_vec_type;
   LLVMTypeRef blend_vec_type;
   LLVMTypeRef arg_types[11];
   LLVMTypeRef func_type;
   LLVMValueRef context_ptr;
   LLVMValueRef x;
   LLVMValueRef y;
   LLVMValueRef a0_ptr;
   LLVMValueRef dadx_ptr;
   LLVMValueRef dady_ptr;
   LLVMValueRef color_ptr_ptr;
   LLVMValueRef depth_ptr;
   LLVMValueRef mask_input;
   LLVMValueRef counter = NULL;
   LLVMBasicBlockRef block;
   LLVMBuilderRef builder;
   struct lp_build_sampler_soa *sampler;
   struct lp_build_interp_soa_context interp;
   LLVMValueRef fs_mask[LP_MAX_VECTOR_LENGTH];
   LLVMValueRef fs_out_color[PIPE_MAX_COLOR_BUFS][NUM_CHANNELS][LP_MAX_VECTOR_LENGTH];
   LLVMValueRef blend_mask;
   LLVMValueRef function;
   LLVMValueRef facing;
   unsigned num_fs;
   unsigned i;
   unsigned chan;
   unsigned cbuf;


   /* TODO: actually pick these based on the fs and color buffer
    * characteristics. */

   memset(&fs_type, 0, sizeof fs_type);
   fs_type.floating = TRUE; /* floating point values */
   fs_type.sign = TRUE;     /* values are signed */
   fs_type.norm = FALSE;    /* values are not limited to [0,1] or [-1,1] */
   fs_type.width = 32;      /* 32-bit float */
   fs_type.length = 4;      /* 4 elements per vector */
   num_fs = 4;              /* number of quads per block */

   memset(&blend_type, 0, sizeof blend_type);
   blend_type.floating = FALSE; /* values are integers */
   blend_type.sign = FALSE;     /* values are unsigned */
   blend_type.norm = TRUE;      /* values are in [0,1] or [-1,1] */
   blend_type.width = 8;        /* 8-bit ubyte values */
   blend_type.length = 16;      /* 16 elements per vector */

   /* 
    * Generate the function prototype. Any change here must be reflected in
    * lp_jit.h's lp_jit_frag_func function pointer type, and vice-versa.
    */

   fs_elem_type = lp_build_elem_type(fs_type);
   fs_int_vec_type = lp_build_int_vec_type(fs_type);

   blend_vec_type = lp_build_vec_type(blend_type);

   util_snprintf(func_name, sizeof(func_name), "fs%u_variant%u_%s", 
		 shader->no, variant->no, partial_mask ? "partial" : "whole");

   arg_types[0] = screen->context_ptr_type;            /* context */
   arg_types[1] = LLVMInt32Type();                     /* x */
   arg_types[2] = LLVMInt32Type();                     /* y */
   arg_types[3] = LLVMFloatType();                     /* facing */
   arg_types[4] = LLVMPointerType(fs_elem_type, 0);    /* a0 */
   arg_types[5] = LLVMPointerType(fs_elem_type, 0);    /* dadx */
   arg_types[6] = LLVMPointerType(fs_elem_type, 0);    /* dady */
   arg_types[7] = LLVMPointerType(LLVMPointerType(blend_vec_type, 0), 0);  /* color */
   arg_types[8] = LLVMPointerType(fs_int_vec_type, 0); /* depth */
   arg_types[9] = LLVMInt32Type();                     /* mask_input */
   arg_types[10] = LLVMPointerType(LLVMInt32Type(), 0);/* counter */

   func_type = LLVMFunctionType(LLVMVoidType(), arg_types, Elements(arg_types), 0);

   function = LLVMAddFunction(screen->module, func_name, func_type);
   LLVMSetFunctionCallConv(function, LLVMCCallConv);

   variant->function[partial_mask] = function;


   /* XXX: need to propagate noalias down into color param now we are
    * passing a pointer-to-pointer?
    */
   for(i = 0; i < Elements(arg_types); ++i)
      if(LLVMGetTypeKind(arg_types[i]) == LLVMPointerTypeKind)
         LLVMAddAttribute(LLVMGetParam(function, i), LLVMNoAliasAttribute);

   context_ptr  = LLVMGetParam(function, 0);
   x            = LLVMGetParam(function, 1);
   y            = LLVMGetParam(function, 2);
   facing       = LLVMGetParam(function, 3);
   a0_ptr       = LLVMGetParam(function, 4);
   dadx_ptr     = LLVMGetParam(function, 5);
   dady_ptr     = LLVMGetParam(function, 6);
   color_ptr_ptr = LLVMGetParam(function, 7);
   depth_ptr    = LLVMGetParam(function, 8);
   mask_input   = LLVMGetParam(function, 9);

   lp_build_name(context_ptr, "context");
   lp_build_name(x, "x");
   lp_build_name(y, "y");
   lp_build_name(a0_ptr, "a0");
   lp_build_name(dadx_ptr, "dadx");
   lp_build_name(dady_ptr, "dady");
   lp_build_name(color_ptr_ptr, "color_ptr_ptr");
   lp_build_name(depth_ptr, "depth");
   lp_build_name(mask_input, "mask_input");

   if (key->occlusion_count) {
      counter = LLVMGetParam(function, 10);
      lp_build_name(counter, "counter");
   }

   /*
    * Function body
    */

   block = LLVMAppendBasicBlock(function, "entry");
   builder = LLVMCreateBuilder();
   LLVMPositionBuilderAtEnd(builder, block);

   /*
    * The shader input interpolation info is not explicitely baked in the
    * shader key, but everything it derives from (TGSI, and flatshade) is
    * already included in the shader key.
    */
   lp_build_interp_soa_init(&interp, 
                            lp->num_inputs,
                            lp->inputs,
                            builder, fs_type,
                            a0_ptr, dadx_ptr, dady_ptr,
                            x, y);

   /* code generated texture sampling */
   sampler = lp_llvm_sampler_soa_create(key->sampler, context_ptr);

   /* loop over quads in the block */
   for(i = 0; i < num_fs; ++i) {
      LLVMValueRef index = LLVMConstInt(LLVMInt32Type(), i, 0);
      LLVMValueRef out_color[PIPE_MAX_COLOR_BUFS][NUM_CHANNELS];
      LLVMValueRef depth_ptr_i;

      if(i != 0)
         lp_build_interp_soa_update(&interp, i);

      depth_ptr_i = LLVMBuildGEP(builder, depth_ptr, &index, 1, "");

      generate_fs(lp, shader, key,
                  builder,
                  fs_type,
                  context_ptr,
                  i,
                  &interp,
                  sampler,
                  &fs_mask[i], /* output */
                  out_color,
                  depth_ptr_i,
                  facing,
                  partial_mask,
                  mask_input,
                  counter);

      for(cbuf = 0; cbuf < key->nr_cbufs; cbuf++)
	 for(chan = 0; chan < NUM_CHANNELS; ++chan)
	    fs_out_color[cbuf][chan][i] = out_color[cbuf][chan];
   }

   sampler->destroy(sampler);

   /* Loop over color outputs / color buffers to do blending.
    */
   for(cbuf = 0; cbuf < key->nr_cbufs; cbuf++) {
      LLVMValueRef color_ptr;
      LLVMValueRef index = LLVMConstInt(LLVMInt32Type(), cbuf, 0);
      LLVMValueRef blend_in_color[NUM_CHANNELS];
      unsigned rt;

      /* 
       * Convert the fs's output color and mask to fit to the blending type. 
       */
      for(chan = 0; chan < NUM_CHANNELS; ++chan) {
	 lp_build_conv(builder, fs_type, blend_type,
		       fs_out_color[cbuf][chan], num_fs,
		       &blend_in_color[chan], 1);
	 lp_build_name(blend_in_color[chan], "color%d.%c", cbuf, "rgba"[chan]);
      }

      if (partial_mask || !variant->opaque) {
         lp_build_conv_mask(builder, fs_type, blend_type,
                            fs_mask, num_fs,
                            &blend_mask, 1);
      } else {
         blend_mask = lp_build_const_int_vec(blend_type, ~0);
      }

      color_ptr = LLVMBuildLoad(builder, 
				LLVMBuildGEP(builder, color_ptr_ptr, &index, 1, ""),
				"");
      lp_build_name(color_ptr, "color_ptr%d", cbuf);

      /* which blend/colormask state to use */
      rt = key->blend.independent_blend_enable ? cbuf : 0;

      /*
       * Blending.
       */
      generate_blend(&key->blend,
                     rt,
		     builder,
		     blend_type,
		     context_ptr,
		     blend_mask,
		     blend_in_color,
		     color_ptr);
   }

#ifdef PIPE_ARCH_X86
   /* Avoid corrupting the FPU stack on 32bit OSes. */
   lp_build_intrinsic(builder, "llvm.x86.mmx.emms", LLVMVoidType(), NULL, 0);
#endif

   LLVMBuildRetVoid(builder);

   LLVMDisposeBuilder(builder);


   /* Verify the LLVM IR.  If invalid, dump and abort */
#ifdef DEBUG
   if(LLVMVerifyFunction(function, LLVMPrintMessageAction)) {
      if (1)
         lp_debug_dump_value(function);
      abort();
   }
#endif

   /* Apply optimizations to LLVM IR */
   LLVMRunFunctionPassManager(screen->pass, function);

   if (gallivm_debug & GALLIVM_DEBUG_IR) {
      /* Print the LLVM IR to stderr */
      lp_debug_dump_value(function);
      debug_printf("\n");
   }

   /*
    * Translate the LLVM IR into machine code.
    */
   {
      void *f = LLVMGetPointerToGlobal(screen->engine, function);

      variant->jit_function[partial_mask] = (lp_jit_frag_func)pointer_to_func(f);

      if (gallivm_debug & GALLIVM_DEBUG_ASM) {
         lp_disassemble(f);
      }
      lp_func_delete_body(function);
   }
}