src/gallium/drivers/llvmpipe/lp_bld_type.h

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  27
  28 /**
  29  * @file
  30  * Convenient representation of SIMD types.
  31  *
  32  * @author Jose Fonseca <jfonseca@vmware.com>
  33  */
  34
  35
  36 #ifndef LP_BLD_TYPE_H
  37 #define LP_BLD_TYPE_H
  38
  39
  40 #include <llvm-c/Core.h>
  41
  42 #include <pipe/p_compiler.h>
  43
  44
  45 /**
  46  * Several functions can only cope with vectors of length up to this value.
  47  * You may need to increase that value if you want to represent bigger vectors.
  48  */
  49 #define LP_MAX_VECTOR_LENGTH 16
  50
  51
  52 /**
  53  * The LLVM type system can't conveniently express all the things we care about
  54  * on the types used for intermediate computations, such as signed vs unsigned,
  55  * normalized values, or fixed point.
  56  */
  57 union lp_type {
  58    struct {
  59       /**
  60        * Floating-point. Cannot be used with fixed. Integer numbers are
  61        * represented by this zero.
  62        */
  63       unsigned floating:1;
  64
  65       /**
  66        * Fixed-point. Cannot be used with floating. Integer numbers are
  67        * represented by this zero.
  68        */
  69       unsigned fixed:1;
  70
  71       /**
  72        * Whether it can represent negative values or not.
  73        *
  74        * Floating point values should always have this bit set.
  75        */
  76       unsigned sign:1;
  77
  78       /**
  79        * Whether values are normalized to fit [0, 1] interval, or [-1, 1]
  80        * interval for signed types.
  81        *
  82        * For integer types it means the representable integer range should be
  83        * interpreted as the interval above.
  84        *
  85        * For floating and fixed point formats it means the values should be
  86        * clamped to the interval above.
  87        */
  88       unsigned norm:1;
  89
  90       /**
  91        * Element width.
  92        *
  93        * For fixed point values, the fixed point is assumed to be at half the
  94        * width.
  95        */
  96       unsigned width:14;
  97
  98       /**
  99        * Vector length.
 100        *
 101        * width*length should be a power of two greater or equal to eight.
 102        *
 103        * @sa LP_MAX_VECTOR_LENGTH
 104        */
 105       unsigned length:14;
 106    };
 107    uint32_t value;
 108 };
 109
 110
 111 /**
 112  * We need most of the information here in order to correctly and efficiently
 113  * translate an arithmetic operation into LLVM IR. Putting it here avoids the
 114  * trouble of passing it as parameters.
 115  */
 116 struct lp_build_context
 117 {
 118    LLVMBuilderRef builder;
 119
 120    /**
 121     * This not only describes the input/output LLVM types, but also whether
 122     * to normalize/clamp the results.
 123     */
 124    union lp_type type;
 125
 126    /** Same as lp_build_undef(type) */
 127    LLVMValueRef undef;
 128
 129    /** Same as lp_build_zero(type) */
 130    LLVMValueRef zero;
 131
 132    /** Same as lp_build_one(type) */
 133    LLVMValueRef one;
 134 };
 135
 136
 137 LLVMTypeRef
 138 lp_build_elem_type(union lp_type type);
 139
 140
 141 LLVMTypeRef
 142 lp_build_vec_type(union lp_type type);
 143
 144
 145 boolean
 146 lp_check_elem_type(union lp_type type, LLVMTypeRef elem_type);
 147
 148
 149 boolean
 150 lp_check_vec_type(union lp_type type, LLVMTypeRef vec_type);
 151
 152
 153 boolean
 154 lp_check_value(union lp_type type, LLVMValueRef val);
 155
 156
 157 #endif /* !LP_BLD_TYPE_H */