src/gallium/drivers/llvmpipe/lp_tex_sample.c

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   3  * Copyright 2009 VMware, Inc.
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  16  * of the Software.
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  27
  28 /**
  29  * Texture sampling code generation
  30  *
  31  * This file is nothing more than ugly glue between three largely independent
  32  * entities:
  33  * - TGSI -> LLVM translation (i.e., lp_build_tgsi_soa)
  34  * - texture sampling code generation (i.e., lp_build_sample_soa)
  35  * - LLVM pipe driver
  36  *
  37  * All interesting code is in the functions mentioned above. There is really
  38  * nothing to see here.
  39  *
  40  * @author Jose Fonseca <jfonseca@vmware.com>
  41  */
  42
  43 #include "pipe/p_defines.h"
  44 #include "pipe/p_shader_tokens.h"
  45 #include "gallivm/lp_bld_debug.h"
  46 #include "gallivm/lp_bld_type.h"
  47 #include "gallivm/lp_bld_sample.h"
  48 #include "gallivm/lp_bld_tgsi.h"
  49 #include "lp_jit.h"
  50 #include "lp_tex_sample.h"
  51 #include "lp_debug.h"
  52
  53
  54 /**
  55  * This provides the bridge between the sampler state store in
  56  * lp_jit_context and lp_jit_texture and the sampler code
  57  * generator. It provides the texture layout information required by
  58  * the texture sampler code generator in terms of the state stored in
  59  * lp_jit_context and lp_jit_texture in runtime.
  60  */
  61 struct llvmpipe_sampler_dynamic_state
  62 {
  63    struct lp_sampler_dynamic_state base;
  64
  65    const struct lp_sampler_static_state *static_state;
  66
  67    LLVMValueRef context_ptr;
  68 };
  69
  70
  71 /**
  72  * This is the bridge between our sampler and the TGSI translator.
  73  */
  74 struct lp_llvm_sampler_soa
  75 {
  76    struct lp_build_sampler_soa base;
  77
  78    struct llvmpipe_sampler_dynamic_state dynamic_state;
  79 };
  80
  81
  82 /**
  83  * Fetch the specified member of the lp_jit_texture structure.
  84  * \param emit_load  if TRUE, emit the LLVM load instruction to actually
  85  *                   fetch the field's value.  Otherwise, just emit the
  86  *                   GEP code to address the field.
  87  *
  88  * @sa http://llvm.org/docs/GetElementPtr.html
  89  */
  90 static LLVMValueRef
  91 lp_llvm_texture_member(const struct lp_sampler_dynamic_state *base,
  92                        LLVMBuilderRef builder,
  93                        unsigned unit,
  94                        unsigned member_index,
  95                        const char *member_name,
  96                        boolean emit_load)
  97 {
  98    struct llvmpipe_sampler_dynamic_state *state =
  99       (struct llvmpipe_sampler_dynamic_state *)base;
 100    LLVMValueRef indices[4];
 101    LLVMValueRef ptr;
 102    LLVMValueRef res;
 103
 104    assert(unit < PIPE_MAX_SAMPLERS);
 105
 106    /* context[0] */
 107    indices[0] = LLVMConstInt(LLVMInt32Type(), 0, 0);
 108    /* context[0].textures */
 109    indices[1] = LLVMConstInt(LLVMInt32Type(), LP_JIT_CTX_TEXTURES, 0);
 110    /* context[0].textures[unit] */
 111    indices[2] = LLVMConstInt(LLVMInt32Type(), unit, 0);
 112    /* context[0].textures[unit].member */
 113    indices[3] = LLVMConstInt(LLVMInt32Type(), member_index, 0);
 114
 115    ptr = LLVMBuildGEP(builder, state->context_ptr, indices, Elements(indices), "");
 116
 117    if (emit_load)
 118       res = LLVMBuildLoad(builder, ptr, "");
 119    else
 120       res = ptr;
 121
 122    lp_build_name(res, "context.texture%u.%s", unit, member_name);
 123
 124    return res;
 125 }
 126
 127
 128 /**
 129  * Helper macro to instantiate the functions that generate the code to
 130  * fetch the members of lp_jit_texture to fulfill the sampler code
 131  * generator requests.
 132  *
 133  * This complexity is the price we have to pay to keep the texture
 134  * sampler code generator a reusable module without dependencies to
 135  * llvmpipe internals.
 136  */
 137 #define LP_LLVM_TEXTURE_MEMBER(_name, _index, _emit_load)  \
 138    static LLVMValueRef \
 139    lp_llvm_texture_##_name( const struct lp_sampler_dynamic_state *base, \
 140                             LLVMBuilderRef builder, \
 141                             unsigned unit) \
 142    { \
 143       return lp_llvm_texture_member(base, builder, unit, _index, #_name, _emit_load ); \
 144    }
 145
 146
 147 LP_LLVM_TEXTURE_MEMBER(width,      LP_JIT_TEXTURE_WIDTH, TRUE)
 148 LP_LLVM_TEXTURE_MEMBER(height,     LP_JIT_TEXTURE_HEIGHT, TRUE)
 149 LP_LLVM_TEXTURE_MEMBER(depth,      LP_JIT_TEXTURE_DEPTH, TRUE)
 150 LP_LLVM_TEXTURE_MEMBER(last_level, LP_JIT_TEXTURE_LAST_LEVEL, TRUE)
 151 LP_LLVM_TEXTURE_MEMBER(row_stride, LP_JIT_TEXTURE_ROW_STRIDE, FALSE)
 152 LP_LLVM_TEXTURE_MEMBER(img_stride, LP_JIT_TEXTURE_IMG_STRIDE, FALSE)
 153 LP_LLVM_TEXTURE_MEMBER(data_ptr,   LP_JIT_TEXTURE_DATA, FALSE)
 154 LP_LLVM_TEXTURE_MEMBER(min_lod,    LP_JIT_TEXTURE_MIN_LOD, TRUE)
 155 LP_LLVM_TEXTURE_MEMBER(max_lod,    LP_JIT_TEXTURE_MAX_LOD, TRUE)
 156 LP_LLVM_TEXTURE_MEMBER(lod_bias,   LP_JIT_TEXTURE_LOD_BIAS, TRUE)
 157
 158
 159 static void
 160 lp_llvm_sampler_soa_destroy(struct lp_build_sampler_soa *sampler)
 161 {
 162    FREE(sampler);
 163 }
 164
 165
 166 /**
 167  * Fetch filtered values from texture.
 168  * The 'texel' parameter returns four vectors corresponding to R, G, B, A.
 169  */
 170 static void
 171 lp_llvm_sampler_soa_emit_fetch_texel(const struct lp_build_sampler_soa *base,
 172                                      LLVMBuilderRef builder,
 173                                      struct lp_type type,
 174                                      unsigned unit,
 175                                      unsigned num_coords,
 176                                      const LLVMValueRef *coords,
 177                                      const LLVMValueRef *ddx,
 178                                      const LLVMValueRef *ddy,
 179                                      LLVMValueRef lod_bias, /* optional */
 180                                      LLVMValueRef explicit_lod, /* optional */
 181                                      LLVMValueRef *texel)
 182 {
 183    struct lp_llvm_sampler_soa *sampler = (struct lp_llvm_sampler_soa *)base;
 184
 185    assert(unit < PIPE_MAX_SAMPLERS);
 186
 187    if (LP_PERF & PERF_NO_TEX) {
 188       lp_build_sample_nop(type, texel);
 189       return;
 190    }
 191
 192    lp_build_sample_soa(builder,
 193                        &sampler->dynamic_state.static_state[unit],
 194                        &sampler->dynamic_state.base,
 195                        type,
 196                        unit,
 197                        num_coords, coords,
 198                        ddx, ddy,
 199                        lod_bias, explicit_lod,
 200                        texel);
 201 }
 202
 203
 204 struct lp_build_sampler_soa *
 205 lp_llvm_sampler_soa_create(const struct lp_sampler_static_state *static_state,
 206                            LLVMValueRef context_ptr)
 207 {
 208    struct lp_llvm_sampler_soa *sampler;
 209
 210    sampler = CALLOC_STRUCT(lp_llvm_sampler_soa);
 211    if(!sampler)
 212       return NULL;
 213
 214    sampler->base.destroy = lp_llvm_sampler_soa_destroy;
 215    sampler->base.emit_fetch_texel = lp_llvm_sampler_soa_emit_fetch_texel;
 216    sampler->dynamic_state.base.width = lp_llvm_texture_width;
 217    sampler->dynamic_state.base.height = lp_llvm_texture_height;
 218    sampler->dynamic_state.base.depth = lp_llvm_texture_depth;
 219    sampler->dynamic_state.base.last_level = lp_llvm_texture_last_level;
 220    sampler->dynamic_state.base.row_stride = lp_llvm_texture_row_stride;
 221    sampler->dynamic_state.base.img_stride = lp_llvm_texture_img_stride;
 222    sampler->dynamic_state.base.data_ptr = lp_llvm_texture_data_ptr;
 223    sampler->dynamic_state.base.min_lod = lp_llvm_texture_min_lod;
 224    sampler->dynamic_state.base.max_lod = lp_llvm_texture_max_lod;
 225    sampler->dynamic_state.base.lod_bias = lp_llvm_texture_lod_bias;
 226
 227    sampler->dynamic_state.static_state = static_state;
 228    sampler->dynamic_state.context_ptr = context_ptr;
 229
 230    return &sampler->base;
 231 }
 232