include/simplev_cpp.h

   1 // SPDX-License-Identifier: LGPL-2.1-or-later
   2 // See Notices.txt for copyright information
   3 #pragma once
   4
   5 #ifndef __cplusplus
   6 #error to use SimpleV Cpp with C, include "simplev_c.h"
   7 #endif
   8
   9 #include <cstddef>
  10 #include <cstdint>
  11 #include <type_traits>
  12
  13 template <typename ElementType, std::size_t MAX_VL, typename = void>
  14 struct SVVecTypeStruct;
  15
  16 template <typename ElementType, std::size_t MAX_VL>
  17 using SVVecType = typename SVVecTypeStruct<ElementType, MAX_VL>::Type;
  18
  19
  20 #define MAKE_VEC_TYPE(size)                                                          \
  21     template <typename ElementType, std::size_t MAX_VL>                              \
  22     struct SVVecTypeStruct<ElementType,                                              \
  23                            MAX_VL,                                                   \
  24                            std::enable_if_t<sizeof(ElementType) * MAX_VL == (size)>> \
  25         final                                                                        \
  26     {                                                                                \
  27         typedef ElementType Type __attribute__((vector_size(size)));                 \
  28     };
  29
  30 MAKE_VEC_TYPE(1)
  31 MAKE_VEC_TYPE(2)
  32 MAKE_VEC_TYPE(3)
  33 MAKE_VEC_TYPE(4)
  34 MAKE_VEC_TYPE(5)
  35 MAKE_VEC_TYPE(6)
  36 MAKE_VEC_TYPE(7)
  37 MAKE_VEC_TYPE(8)
  38
  39 #undef MAKE_VEC_TYPE
  40
  41 template <typename ElementType, std::size_t MAX_VL>
  42 struct SVVec final
  43 {
  44     using Type = SVVecType<ElementType, MAX_VL>;
  45     Type value;
  46 };
  47
  48 struct Mask final
  49 {
  50     std::uint64_t value = ~0ULL;
  51 };
  52
  53 template <size_t MAX_VL = 64>
  54 struct VL final
  55 {
  56     std::size_t value = MAX_VL;
  57 };
  58
  59 namespace opcodes
  60 {
  61 inline constexpr std::size_t PRIMARY_OPCODE_SHIFT = 32 - 6;
  62 /// unofficial value. see https://libre-soc.org/openpower/sv/setvl/
  63 /// FIXME: incorrect extended opcode value
  64 inline constexpr std::uint32_t SETVL_OPCODE = (19 << PRIMARY_OPCODE_SHIFT) | (0 << 1);
  65 inline constexpr std::size_t SETVL_IMMEDIATE_SHIFT = 32 - 7 - 16;
  66 inline constexpr std::size_t REG_FIELD_WIDTH = 5;
  67 inline constexpr std::size_t XL_FORM_RT_SHIFT = 32 - REG_FIELD_WIDTH - 6;
  68 inline constexpr std::size_t XL_FORM_RA_SHIFT = 32 - REG_FIELD_WIDTH - 11;
  69 } // namespace opcodes
  70
  71 #define SETVL_ASM(retval, vl)                                            \
  72     "# setvl " retval ", " vl                                            \
  73     ", MVL=%[max_vl]\n\t"                                                \
  74     ".long %[setvl_opcode] | (" retval " << %[xl_form_rt_shift]) | (" vl \
  75     " << %[xl_form_ra_shift]) | ((%[max_vl] - 1) << %[setvl_immediate_shift])"
  76
  77 #define SETVL_ASM_INPUT_ARGS()                                       \
  78     [setvl_opcode] "n"(opcodes::SETVL_OPCODE),                       \
  79         [setvl_immediate_shift] "n"(opcodes::SETVL_IMMEDIATE_SHIFT), \
  80         [xl_form_rt_shift] "n"(opcodes::XL_FORM_RT_SHIFT),           \
  81         [xl_form_ra_shift] "n"(opcodes::XL_FORM_RA_SHIFT)
  82
  83 template <std::size_t MAX_VL>
  84 inline __attribute__((always_inline)) VL<MAX_VL> sv_setvl(std::size_t vl)
  85 {
  86     static_assert(MAX_VL > 0 && MAX_VL < 64);
  87     VL<MAX_VL> retval;
  88     asm(SETVL_ASM("%[retval]", "%[vl]")
  89         : [retval] "=b"(retval.value)
  90         : [vl] "b"(vl), [max_vl] "n"(MAX_VL), SETVL_ASM_INPUT_ARGS());
  91     return retval;
  92 }