contrib/llvm/tools/clang/lib/Headers/cuda_builtin_vars.h

   1 /*===---- cuda_builtin_vars.h - CUDA built-in variables ---------------------===
   2  *
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   5  * in the Software without restriction, including without limitation the rights
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   8  * furnished to do so, subject to the following conditions:
   9  *
  10  * The above copyright notice and this permission notice shall be included in
  11  * all copies or substantial portions of the Software.
  12  *
  13  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  14  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  15  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  16  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  17  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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  19  * THE SOFTWARE.
  20  *
  21  *===-----------------------------------------------------------------------===
  22  */
  23
  24 #ifndef __CUDA_BUILTIN_VARS_H
  25 #define __CUDA_BUILTIN_VARS_H
  26
  27 // The file implements built-in CUDA variables using __declspec(property).
  28 // https://msdn.microsoft.com/en-us/library/yhfk0thd.aspx
  29 // All read accesses of built-in variable fields get converted into calls to a
  30 // getter function which in turn would call appropriate builtin to fetch the
  31 // value.
  32 //
  33 // Example:
  34 //    int x = threadIdx.x;
  35 // IR output:
  36 //  %0 = call i32 @llvm.ptx.read.tid.x() #3
  37 // PTX output:
  38 //  mov.u32     %r2, %tid.x;
  39
  40 #define __CUDA_DEVICE_BUILTIN(FIELD, INTRINSIC)                                \
  41   __declspec(property(get = __fetch_builtin_##FIELD)) unsigned int FIELD;      \
  42   static inline __attribute__((always_inline))                                 \
  43       __attribute__((device)) unsigned int __fetch_builtin_##FIELD(void) {     \
  44     return INTRINSIC;                                                          \
  45   }
  46
  47 #if __cplusplus >= 201103L
  48 #define __DELETE =delete
  49 #else
  50 #define __DELETE
  51 #endif
  52
  53 // Make sure nobody can create instances of the special varible types.  nvcc
  54 // also disallows taking address of special variables, so we disable address-of
  55 // operator as well.
  56 #define __CUDA_DISALLOW_BUILTINVAR_ACCESS(TypeName)                            \
  57   __attribute__((device)) TypeName() __DELETE;                                 \
  58   __attribute__((device)) TypeName(const TypeName &) __DELETE;                 \
  59   __attribute__((device)) void operator=(const TypeName &) const __DELETE;     \
  60   __attribute__((device)) TypeName *operator&() const __DELETE
  61
  62 struct __cuda_builtin_threadIdx_t {
  63   __CUDA_DEVICE_BUILTIN(x,__builtin_ptx_read_tid_x());
  64   __CUDA_DEVICE_BUILTIN(y,__builtin_ptx_read_tid_y());
  65   __CUDA_DEVICE_BUILTIN(z,__builtin_ptx_read_tid_z());
  66 private:
  67   __CUDA_DISALLOW_BUILTINVAR_ACCESS(__cuda_builtin_threadIdx_t);
  68 };
  69
  70 struct __cuda_builtin_blockIdx_t {
  71   __CUDA_DEVICE_BUILTIN(x,__builtin_ptx_read_ctaid_x());
  72   __CUDA_DEVICE_BUILTIN(y,__builtin_ptx_read_ctaid_y());
  73   __CUDA_DEVICE_BUILTIN(z,__builtin_ptx_read_ctaid_z());
  74 private:
  75   __CUDA_DISALLOW_BUILTINVAR_ACCESS(__cuda_builtin_blockIdx_t);
  76 };
  77
  78 struct __cuda_builtin_blockDim_t {
  79   __CUDA_DEVICE_BUILTIN(x,__builtin_ptx_read_ntid_x());
  80   __CUDA_DEVICE_BUILTIN(y,__builtin_ptx_read_ntid_y());
  81   __CUDA_DEVICE_BUILTIN(z,__builtin_ptx_read_ntid_z());
  82 private:
  83   __CUDA_DISALLOW_BUILTINVAR_ACCESS(__cuda_builtin_blockDim_t);
  84 };
  85
  86 struct __cuda_builtin_gridDim_t {
  87   __CUDA_DEVICE_BUILTIN(x,__builtin_ptx_read_nctaid_x());
  88   __CUDA_DEVICE_BUILTIN(y,__builtin_ptx_read_nctaid_y());
  89   __CUDA_DEVICE_BUILTIN(z,__builtin_ptx_read_nctaid_z());
  90 private:
  91   __CUDA_DISALLOW_BUILTINVAR_ACCESS(__cuda_builtin_gridDim_t);
  92 };
  93
  94 #define __CUDA_BUILTIN_VAR                                                     \
  95   extern const __attribute__((device)) __attribute__((weak))
  96 __CUDA_BUILTIN_VAR __cuda_builtin_threadIdx_t threadIdx;
  97 __CUDA_BUILTIN_VAR __cuda_builtin_blockIdx_t blockIdx;
  98 __CUDA_BUILTIN_VAR __cuda_builtin_blockDim_t blockDim;
  99 __CUDA_BUILTIN_VAR __cuda_builtin_gridDim_t gridDim;
 100
 101 // warpSize should translate to read of %WARP_SZ but there's currently no
 102 // builtin to do so. According to PTX v4.2 docs 'to date, all target
 103 // architectures have a WARP_SZ value of 32'.
 104 __attribute__((device)) const int warpSize = 32;
 105
 106 #undef __CUDA_DEVICE_BUILTIN
 107 #undef __CUDA_BUILTIN_VAR
 108 #undef __CUDA_DISALLOW_BUILTINVAR_ACCESS
 109
 110 #endif /* __CUDA_BUILTIN_VARS_H */