src/gallium/drivers/llvmpipe/lp_bld_const.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2009 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 /**
  30  * @file
  31  * Helper functions for constant building.
  32  *
  33  * @author Jose Fonseca <jfonseca@vmware.com>
  34  */
  35
  36
  37 #include "util/u_debug.h"
  38
  39 #include "lp_bld_type.h"
  40 #include "lp_bld_const.h"
  41
  42
  43 /**
  44  * Shift of the unity.
  45  *
  46  * Same as lp_const_scale(), but in terms of shifts.
  47  */
  48 unsigned
  49 lp_const_shift(union lp_type type)
  50 {
  51    if(type.floating)
  52       return 0;
  53    else if(type.fixed)
  54       return type.width/2;
  55    else if(type.norm)
  56       return type.sign ? type.width - 1 : type.width;
  57    else
  58       return 0;
  59 }
  60
  61
  62 unsigned
  63 lp_const_offset(union lp_type type)
  64 {
  65    if(type.floating || type.fixed)
  66       return 0;
  67    else if(type.norm)
  68       return 1;
  69    else
  70       return 0;
  71 }
  72
  73
  74 /**
  75  * Scaling factor between the LLVM native value and its interpretation.
  76  *
  77  * This is 1.0 for all floating types and unnormalized integers, and something
  78  * else for the fixed points types and normalized integers.
  79  */
  80 double
  81 lp_const_scale(union lp_type type)
  82 {
  83    unsigned long long llscale;
  84    double dscale;
  85
  86    llscale = (unsigned long long)1 << lp_const_shift(type);
  87    llscale -= lp_const_offset(type);
  88    dscale = (double)llscale;
  89    assert((unsigned long long)dscale == llscale);
  90
  91    return dscale;
  92 }
  93
  94
  95 LLVMValueRef
  96 lp_build_undef(union lp_type type)
  97 {
  98    LLVMTypeRef vec_type = lp_build_vec_type(type);
  99    return LLVMGetUndef(vec_type);
 100 }
 101
 102
 103 LLVMValueRef
 104 lp_build_zero(union lp_type type)
 105 {
 106    LLVMTypeRef vec_type = lp_build_vec_type(type);
 107    return LLVMConstNull(vec_type);
 108 }
 109
 110
 111 LLVMValueRef
 112 lp_build_one(union lp_type type)
 113 {
 114    LLVMTypeRef elem_type;
 115    LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
 116    unsigned i;
 117
 118    assert(type.length <= LP_MAX_VECTOR_LENGTH);
 119
 120    elem_type = lp_build_elem_type(type);
 121
 122    if(type.floating)
 123       elems[0] = LLVMConstReal(elem_type, 1.0);
 124    else if(type.fixed)
 125       elems[0] = LLVMConstInt(elem_type, 1LL << (type.width/2), 0);
 126    else if(!type.norm)
 127       elems[0] = LLVMConstInt(elem_type, 1, 0);
 128    else {
 129       /* special case' -- 1.0 for normalized types is more easily attained if
 130        * we start with a vector consisting of all bits set */
 131       LLVMTypeRef vec_type = LLVMVectorType(elem_type, type.length);
 132       LLVMValueRef vec = LLVMConstAllOnes(vec_type);
 133
 134       if(type.sign)
 135          vec = LLVMConstLShr(vec, LLVMConstInt(LLVMInt32Type(), 1, 0));
 136
 137       return vec;
 138    }
 139
 140    for(i = 1; i < type.length; ++i)
 141       elems[i] = elems[0];
 142
 143    return LLVMConstVector(elems, type.length);
 144 }
 145
 146
 147 LLVMValueRef
 148 lp_build_const_uni(union lp_type type,
 149                    double val)
 150 {
 151    LLVMTypeRef elem_type = lp_build_elem_type(type);
 152    LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
 153    unsigned i;
 154
 155    assert(type.length <= LP_MAX_VECTOR_LENGTH);
 156
 157    if(type.floating) {
 158       elems[0] = LLVMConstReal(elem_type, val);
 159    }
 160    else {
 161       double dscale = lp_const_scale(type);
 162
 163       elems[0] = LLVMConstInt(elem_type, val*dscale + 0.5, 0);
 164    }
 165
 166    for(i = 1; i < type.length; ++i)
 167       elems[i] = elems[0];
 168
 169    return LLVMConstVector(elems, type.length);
 170 }
 171
 172
 173 LLVMValueRef
 174 lp_build_int_const_uni(union lp_type type,
 175                        long long val)
 176 {
 177    LLVMTypeRef elem_type = lp_build_int_elem_type(type);
 178    LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
 179    unsigned i;
 180
 181    assert(type.length <= LP_MAX_VECTOR_LENGTH);
 182
 183    for(i = 0; i < type.length; ++i)
 184       elems[i] = LLVMConstInt(elem_type, val, type.sign ? 1 : 0);
 185
 186    return LLVMConstVector(elems, type.length);
 187 }
 188
 189
 190 LLVMValueRef
 191 lp_build_const_aos(union lp_type type,
 192                    double r, double g, double b, double a,
 193                    const unsigned char *swizzle)
 194 {
 195    const unsigned char default_swizzle[4] = {0, 1, 2, 3};
 196    LLVMTypeRef elem_type;
 197    LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
 198    unsigned i;
 199
 200    assert(type.length % 4 == 0);
 201    assert(type.length <= LP_MAX_VECTOR_LENGTH);
 202
 203    elem_type = lp_build_elem_type(type);
 204
 205    if(swizzle == NULL)
 206       swizzle = default_swizzle;
 207
 208    if(type.floating) {
 209       elems[swizzle[0]] = LLVMConstReal(elem_type, r);
 210       elems[swizzle[1]] = LLVMConstReal(elem_type, g);
 211       elems[swizzle[2]] = LLVMConstReal(elem_type, b);
 212       elems[swizzle[3]] = LLVMConstReal(elem_type, a);
 213    }
 214    else {
 215       double dscale = lp_const_scale(type);
 216
 217       elems[swizzle[0]] = LLVMConstInt(elem_type, r*dscale + 0.5, 0);
 218       elems[swizzle[1]] = LLVMConstInt(elem_type, g*dscale + 0.5, 0);
 219       elems[swizzle[2]] = LLVMConstInt(elem_type, b*dscale + 0.5, 0);
 220       elems[swizzle[3]] = LLVMConstInt(elem_type, a*dscale + 0.5, 0);
 221    }
 222
 223    for(i = 4; i < type.length; ++i)
 224       elems[i] = elems[i % 4];
 225
 226    return LLVMConstVector(elems, type.length);
 227 }
 228
 229
 230 LLVMValueRef
 231 lp_build_const_mask_aos(union lp_type type,
 232                         boolean cond[4])
 233 {
 234    LLVMTypeRef elem_type = LLVMIntType(type.width);
 235    LLVMValueRef masks[LP_MAX_VECTOR_LENGTH];
 236    unsigned i, j;
 237
 238    assert(type.length <= LP_MAX_VECTOR_LENGTH);
 239
 240    for(j = 0; j < type.length; j += 4)
 241       for(i = 0; i < 4; ++i)
 242          masks[j + i] = LLVMConstInt(elem_type, cond[i] ? ~0 : 0, 0);
 243
 244    return LLVMConstVector(masks, type.length);
 245 }