
For ARC there are registers that are not part of a required set in XML target descriptions by default, but are almost always present on ARC targets and are universally exposed by the ptrace interface. Hardware loop registers being one of them. LP_START and LP_END auxiliary registers are hardware loop start and end. Formally, they are optional, but it is hard to find an ARC configuration that doesn't have them. They are always present in processors that can run GNU/Linux. GDB needs to know about those registers to implement proper software single stepping, since they affect what instruction will be next. This commit adds the code to check for the existance of "lp_start" and "lp_end" in XML target descriptions. If they exist, then the function reports that the target supports hardware loops. gdb/ChangeLog: * arc-tdep.c (arc_check_for_hardware_loop): New. * arc-tdep.h (gdbarch_tdep): New field has_hw_loops. gdb/doc/ChangeLog: * gdb.texinfo (Synopsys ARC): Document LP_START, LP_END and BTA.
180 lines
6.1 KiB
C
180 lines
6.1 KiB
C
/* Target dependent code for ARC architecture, for GDB.
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Copyright 2005-2020 Free Software Foundation, Inc.
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Contributed by Synopsys Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#ifndef ARC_TDEP_H
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#define ARC_TDEP_H
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/* Need disassemble_info. */
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#include "dis-asm.h"
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#include "gdbarch.h"
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#include "arch/arc.h"
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/* To simplify GDB code this enum assumes that internal regnums should be same
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as architectural register numbers, i.e. PCL regnum is 63. This allows to
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use internal GDB regnums as architectural numbers when dealing with
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instruction encodings, for example when analyzing what are the registers
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saved in function prologue. */
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enum arc_regnum
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{
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/* Core registers. */
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ARC_R0_REGNUM = 0,
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ARC_R1_REGNUM = 1,
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ARC_R4_REGNUM = 4,
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ARC_R7_REGNUM = 7,
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ARC_R9_REGNUM = 9,
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ARC_R13_REGNUM = 13,
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ARC_R16_REGNUM = 16,
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ARC_R25_REGNUM = 25,
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/* Global data pointer. */
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ARC_GP_REGNUM,
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/* Frame pointer. */
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ARC_FP_REGNUM,
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/* Stack pointer. */
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ARC_SP_REGNUM,
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/* Return address from interrupt. */
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ARC_ILINK_REGNUM,
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ARC_R30_REGNUM,
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/* Return address from function. */
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ARC_BLINK_REGNUM,
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/* Accumulator registers. */
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ARC_R58_REGNUM = 58,
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ARC_R59_REGNUM,
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/* Zero-delay loop counter. */
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ARC_LP_COUNT_REGNUM = 60,
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/* Reserved register number. There should never be a register with such
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number, this name is needed only for a sanity check in
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arc_cannot_(fetch|store)_register. */
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ARC_RESERVED_REGNUM,
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/* Long-immediate value. This is not a physical register - if instruction
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has register 62 as an operand, then this operand is a literal value
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stored in the instruction memory right after the instruction itself.
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This value is required in this enumeration as an architectural number
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for instruction analysis. */
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ARC_LIMM_REGNUM,
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/* Program counter, aligned to 4-bytes, read-only. */
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ARC_PCL_REGNUM,
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ARC_LAST_CORE_REGNUM = ARC_PCL_REGNUM,
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/* AUX registers. */
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/* Actual program counter. */
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ARC_PC_REGNUM,
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ARC_FIRST_AUX_REGNUM = ARC_PC_REGNUM,
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/* Status register. */
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ARC_STATUS32_REGNUM,
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/* Zero-delay loop start instruction. */
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ARC_LP_START_REGNUM,
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/* Zero-delay loop next-after-last instruction. */
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ARC_LP_END_REGNUM,
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/* Branch target address. */
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ARC_BTA_REGNUM,
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ARC_LAST_AUX_REGNUM = ARC_BTA_REGNUM,
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ARC_LAST_REGNUM = ARC_LAST_AUX_REGNUM,
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/* Additional ABI constants. */
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ARC_FIRST_ARG_REGNUM = ARC_R0_REGNUM,
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ARC_LAST_ARG_REGNUM = ARC_R7_REGNUM,
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ARC_FIRST_CALLEE_SAVED_REGNUM = ARC_R13_REGNUM,
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ARC_LAST_CALLEE_SAVED_REGNUM = ARC_R25_REGNUM,
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};
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/* Number of bytes in ARC register. All ARC registers are considered 32-bit.
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Those registers, which are actually shorter has zero-on-read for extra bits.
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Longer registers are represented as pairs of 32-bit registers. */
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#define ARC_REGISTER_SIZE 4
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#define arc_print(fmt, args...) fprintf_unfiltered (gdb_stdlog, fmt, ##args)
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extern int arc_debug;
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/* Target-dependent information. */
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struct gdbarch_tdep
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{
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/* Offset to PC value in jump buffer. If this is negative, longjmp
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support will be disabled. */
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int jb_pc;
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/* Whether target has hardware (aka zero-delay) loops. */
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bool has_hw_loops;
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};
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/* Utility functions used by other ARC-specific modules. */
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static inline int
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arc_mach_is_arc600 (struct gdbarch *gdbarch)
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{
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return (gdbarch_bfd_arch_info (gdbarch)->mach == bfd_mach_arc_arc600
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|| gdbarch_bfd_arch_info (gdbarch)->mach == bfd_mach_arc_arc601);
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}
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static inline int
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arc_mach_is_arc700 (struct gdbarch *gdbarch)
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{
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return gdbarch_bfd_arch_info (gdbarch)->mach == bfd_mach_arc_arc700;
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}
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static inline int
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arc_mach_is_arcv2 (struct gdbarch *gdbarch)
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{
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return gdbarch_bfd_arch_info (gdbarch)->mach == bfd_mach_arc_arcv2;
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}
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/* ARC EM and ARC HS are unique BFD arches, however they share the same machine
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number as "ARCv2". */
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static inline bool
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arc_arch_is_hs (const struct bfd_arch_info* arch)
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{
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return startswith (arch->printable_name, "HS");
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}
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static inline bool
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arc_arch_is_em (const struct bfd_arch_info* arch)
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{
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return startswith (arch->printable_name, "EM");
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}
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/* Function to access ARC disassembler. Underlying opcodes disassembler will
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print an instruction into stream specified in the INFO, so if it is
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undesired, then this stream should be set to some invisible stream, but it
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can't be set to an actual NULL value - that would cause a crash. */
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int arc_delayed_print_insn (bfd_vma addr, struct disassemble_info *info);
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/* Return properly initialized disassemble_info for ARC disassembler - it will
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not print disassembled instructions to stderr. */
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struct disassemble_info arc_disassemble_info (struct gdbarch *gdbarch);
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/* Get branch/jump target address for the INSN. Note that this function
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returns branch target and doesn't evaluate if this branch is taken or not.
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For the indirect jumps value depends in register state, hence can change.
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It is an error to call this function for a non-branch instruction. */
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CORE_ADDR arc_insn_get_branch_target (const struct arc_instruction &insn);
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/* Get address of next instruction after INSN, assuming linear execution (no
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taken branches). If instruction has a delay slot, then returned value will
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point at the instruction in delay slot. That is - "address of instruction +
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instruction length with LIMM". */
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CORE_ADDR arc_insn_get_linear_next_pc (const struct arc_instruction &insn);
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#endif /* ARC_TDEP_H */
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