gdb/arch/loongarch.h

   1 /* Common target-dependent functionality for LoongArch
   2
   3    Copyright (C) 2022-2023 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_LINUX_NUM_GREGSET = 45,     /* 32 GPR, ORIG_A0, PC, BADV, RESERVED 10.  */
  37   LOONGARCH_ARG_REGNUM = 8,            /* r4-r11: general-purpose argument registers.
  38                                           f0-f7: floating-point argument registers.  */
  39   LOONGARCH_FIRST_FP_REGNUM = LOONGARCH_LINUX_NUM_GREGSET,
  40   LOONGARCH_LINUX_NUM_FPREGSET = 32,
  41   LOONGARCH_FIRST_FCC_REGNUM = LOONGARCH_FIRST_FP_REGNUM + LOONGARCH_LINUX_NUM_FPREGSET,
  42   LOONGARCH_LINUX_NUM_FCC = 8,
  43   LOONGARCH_FCSR_REGNUM = LOONGARCH_FIRST_FCC_REGNUM + LOONGARCH_LINUX_NUM_FCC,
  44 };
  45
  46 enum loongarch_fputype
  47 {
  48   SINGLE_FLOAT = 1,
  49   DOUBLE_FLOAT = 2,
  50 };
  51
  52 /* The set of LoongArch architectural features that we track that impact how
  53    we configure the actual gdbarch instance.  We hold one of these in the
  54    gdbarch_tdep structure, and use it to distinguish between different
  55    LoongArch gdbarch instances.
  56
  57    The information in here ideally comes from the target description,
  58    however, if the target doesn't provide a target description then we will
  59    create a default target description by first populating one of these
  60    based on what we know about the binary being executed, and using that to
  61    drive default target description creation.  */
  62
  63 struct loongarch_gdbarch_features
  64 {
  65   /* The size of the x-registers in bytes.  This is either 4 (loongarch32)
  66      or 8 (loongarch64).  No other value is valid.  Initialise to the invalid
  67      0 value so we can spot if one of these is used uninitialised.  */
  68   int xlen = 0;
  69
  70   /* The type of floating-point.  This is either 1 (single float) or 2
  71      (double float).  No other value is valid.  Initialise to the invalid
  72      0 value so we can spot if one of these is used uninitialised.  */
  73   int fputype = 0;
  74
  75   /* Equality operator.  */
  76   bool operator== (const struct loongarch_gdbarch_features &rhs) const
  77   {
  78     return (xlen == rhs.xlen);
  79   }
  80
  81   /* Inequality operator.  */
  82   bool operator!= (const struct loongarch_gdbarch_features &rhs) const
  83   {
  84     return !((*this) == rhs);
  85   }
  86
  87   /* Used by std::unordered_map to hash feature sets.  */
  88   std::size_t hash () const noexcept
  89   {
  90     std::size_t val = (xlen & 0x1f) << 5;
  91     return val;
  92   }
  93 };
  94
  95 #ifdef GDBSERVER
  96
  97 /* Create and return a target description that is compatible with FEATURES.
  98    This is only used directly from the gdbserver where the created target
  99    description is modified after it is return.  */
 100
 101 target_desc_up loongarch_create_target_description
 102         (const struct loongarch_gdbarch_features features);
 103
 104 #else
 105
 106 /* Lookup an already existing target description matching FEATURES, or
 107    create a new target description if this is the first time we have seen
 108    FEATURES.  For the same FEATURES the same target_desc is always
 109    returned.  This is important when trying to lookup gdbarch objects as
 110    GDBARCH_LIST_LOOKUP_BY_INFO performs a pointer comparison on target
 111    descriptions to find candidate gdbarch objects.  */
 112
 113 const target_desc *loongarch_lookup_target_description
 114         (const struct loongarch_gdbarch_features features);
 115
 116 #endif /* GDBSERVER */
 117
 118 #endif /* ARCH_LOONGARCH_H  */