gdb/arch/loongarch.h

   1 /* Common target-dependent functionality for LoongArch
   2
   3    Copyright (C) 2022-2024 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef ARCH_LOONGARCH_H
  21 #define ARCH_LOONGARCH_H
  22
  23 #include "gdbsupport/tdesc.h"
  24
  25 /* Register numbers of various important registers.  */
  26 enum loongarch_regnum
  27 {
  28   LOONGARCH_RA_REGNUM = 1,              /* Return Address.  */
  29   LOONGARCH_SP_REGNUM = 3,              /* Stack Pointer.  */
  30   LOONGARCH_A0_REGNUM = 4,              /* First Argument/Return Value.  */
  31   LOONGARCH_A7_REGNUM = 11,             /* Seventh Argument/Syscall Number.  */
  32   LOONGARCH_FP_REGNUM = 22,             /* Frame Pointer.  */
  33   LOONGARCH_ORIG_A0_REGNUM = 32,        /* Syscall's original arg0.  */
  34   LOONGARCH_PC_REGNUM = 33,             /* Program Counter.  */
  35   LOONGARCH_BADV_REGNUM = 34,           /* Bad Vaddr for Addressing Exception.  */
  36   LOONGARCH_USED_NUM_GREGSET = 35,      /* 32 GPR, ORIG_A0, PC, BADV.  */
  37   LOONGARCH_LINUX_NUM_GREGSET = 45,     /* 32 GPR, ORIG_A0, PC, BADV, RESERVED 10.  */
  38   LOONGARCH_ARG_REGNUM = 8,            /* r4-r11: general-purpose argument registers.
  39                                           f0-f7: floating-point argument registers.  */
  40   LOONGARCH_FIRST_FP_REGNUM = LOONGARCH_USED_NUM_GREGSET,
  41   LOONGARCH_LINUX_NUM_FPREGSET = 32,
  42   LOONGARCH_FIRST_FCC_REGNUM = LOONGARCH_FIRST_FP_REGNUM + LOONGARCH_LINUX_NUM_FPREGSET,
  43   LOONGARCH_LINUX_NUM_FCC = 8,
  44   LOONGARCH_FCSR_REGNUM = LOONGARCH_FIRST_FCC_REGNUM + LOONGARCH_LINUX_NUM_FCC,
  45   LOONGARCH_FIRST_LSX_REGNUM = LOONGARCH_FCSR_REGNUM + 1,
  46   LOONGARCH_LINUX_NUM_LSXREGSET = 32,
  47   LOONGARCH_FIRST_LASX_REGNUM = LOONGARCH_FIRST_LSX_REGNUM + LOONGARCH_LINUX_NUM_LSXREGSET,
  48   LOONGARCH_LINUX_NUM_LASXREGSET = 32,
  49
  50   LOONGARCH_FIRST_SCR_REGNUM = LOONGARCH_FIRST_LASX_REGNUM + LOONGARCH_LINUX_NUM_LASXREGSET,
  51   LOONGARCH_LINUX_NUM_SCR = 4,
  52   LOONGARCH_LAST_SCR_REGNUM = LOONGARCH_FIRST_SCR_REGNUM + LOONGARCH_LINUX_NUM_SCR - 1,
  53   LOONGARCH_EFLAGS_REGNUM = LOONGARCH_LAST_SCR_REGNUM + 1,
  54   LOONGARCH_FTOP_REGNUM = LOONGARCH_EFLAGS_REGNUM + 1,
  55 };
  56
  57 enum loongarch_fputype
  58 {
  59   SINGLE_FLOAT = 1,
  60   DOUBLE_FLOAT = 2,
  61 };
  62
  63  #define LOONGARCH_LBT_REGS_SIZE (8 * LOONGARCH_LINUX_NUM_SCR + 4 + 4)
  64
  65 /* The set of LoongArch architectural features that we track that impact how
  66    we configure the actual gdbarch instance.  We hold one of these in the
  67    gdbarch_tdep structure, and use it to distinguish between different
  68    LoongArch gdbarch instances.
  69
  70    The information in here ideally comes from the target description,
  71    however, if the target doesn't provide a target description then we will
  72    create a default target description by first populating one of these
  73    based on what we know about the binary being executed, and using that to
  74    drive default target description creation.  */
  75
  76 struct loongarch_gdbarch_features
  77 {
  78   /* The size of the x-registers in bytes.  This is either 4 (loongarch32)
  79      or 8 (loongarch64).  No other value is valid.  Initialise to the invalid
  80      0 value so we can spot if one of these is used uninitialised.  */
  81   int xlen = 0;
  82
  83   /* The type of floating-point.  This is either 1 (single float) or 2
  84      (double float).  No other value is valid.  Initialise to the invalid
  85      0 value so we can spot if one of these is used uninitialised.  */
  86   int fputype = 0;
  87
  88   /* Equality operator.  */
  89   bool operator== (const struct loongarch_gdbarch_features &rhs) const
  90   {
  91     return (xlen == rhs.xlen);
  92   }
  93
  94   /* Inequality operator.  */
  95   bool operator!= (const struct loongarch_gdbarch_features &rhs) const
  96   {
  97     return !((*this) == rhs);
  98   }
  99
 100   /* Used by std::unordered_map to hash feature sets.  */
 101   std::size_t hash () const noexcept
 102   {
 103     std::size_t val = (xlen & 0x1f) << 5;
 104     return val;
 105   }
 106 };
 107
 108 #ifdef GDBSERVER
 109
 110 /* Create and return a target description that is compatible with FEATURES.
 111    This is only used directly from the gdbserver where the created target
 112    description is modified after it is return.  */
 113
 114 target_desc_up loongarch_create_target_description
 115         (const struct loongarch_gdbarch_features features);
 116
 117 #else
 118
 119 /* Lookup an already existing target description matching FEATURES, or
 120    create a new target description if this is the first time we have seen
 121    FEATURES.  For the same FEATURES the same target_desc is always
 122    returned.  This is important when trying to lookup gdbarch objects as
 123    GDBARCH_LIST_LOOKUP_BY_INFO performs a pointer comparison on target
 124    descriptions to find candidate gdbarch objects.  */
 125
 126 const target_desc *loongarch_lookup_target_description
 127         (const struct loongarch_gdbarch_features features);
 128
 129 #endif /* GDBSERVER */
 130
 131 #endif /* ARCH_LOONGARCH_H  */