5f661e0397
For a fix I intend to submit, I would need a function that counts the number of set bits in a word. There is __builtin_popcount that is supported by gcc and clang, but there is also a gnulib module that wraps that and provides a fallback for other compilers, so I think it would be good to use it. I also noticed that there is a bitcount function in arch/arm.c, so I thought that as a first step I would replace that one with the gnulib count-one-bits module. This is what this patch does. The gnulib module provides multiple functions, with various parameter length (unsigned int, unsigned long int, unsigned long long int), I chose the one that made sense for each call site based on the argument type. gnulib/ChangeLog: * update-gnulib.sh (IMPORTED_GNULIB_MODULES): Import count-one-bits module. * configure: Re-generate. * aclocal.m4: Re-generate. * Makefile.in: Re-generate. * import/count-one-bits.c: New file. * import/count-one-bits.h: New file. * import/Makefile.am: Re-generate. * import/Makefile.in: Re-generate. * import/m4/gnulib-cache.m4: Re-generate. * import/m4/gnulib-comp.m4: Re-generate. * import/m4/count-one-bits.m4: New file. gdb/ChangeLog: * arm-tdep.c: Include count-one-bits.h. (cleanup_block_store_pc): Use count_one_bits. (cleanup_block_load_pc): Use count_one_bits. (arm_copy_block_xfer): Use count_one_bits. (thumb2_copy_block_xfer): Use count_one_bits. (thumb_copy_pop_pc_16bit): Use count_one_bits. * arch/arm-get-next-pcs.c: Include count-one-bits.h. (thumb_get_next_pcs_raw): Use count_one_bits. (arm_get_next_pcs_raw): Use count_one_bits_l. * arch/arm.c (bitcount): Remove. * arch/arm.h (bitcount): Remove.
938 lines
27 KiB
C
938 lines
27 KiB
C
/* Common code for ARM software single stepping support.
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Copyright (C) 1988-2020 Free Software Foundation, 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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#include "gdbsupport/common-defs.h"
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#include "gdbsupport/gdb_vecs.h"
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#include "gdbsupport/common-regcache.h"
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#include "arm.h"
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#include "arm-get-next-pcs.h"
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#include "count-one-bits.h"
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/* See arm-get-next-pcs.h. */
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void
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arm_get_next_pcs_ctor (struct arm_get_next_pcs *self,
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struct arm_get_next_pcs_ops *ops,
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int byte_order,
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int byte_order_for_code,
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int has_thumb2_breakpoint,
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struct regcache *regcache)
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{
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self->ops = ops;
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self->byte_order = byte_order;
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self->byte_order_for_code = byte_order_for_code;
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self->has_thumb2_breakpoint = has_thumb2_breakpoint;
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self->regcache = regcache;
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}
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/* Checks for an atomic sequence of instructions beginning with a LDREX{,B,H,D}
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instruction and ending with a STREX{,B,H,D} instruction. If such a sequence
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is found, attempt to step through it. The end of the sequence address is
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added to the next_pcs list. */
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static std::vector<CORE_ADDR>
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thumb_deal_with_atomic_sequence_raw (struct arm_get_next_pcs *self)
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{
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int byte_order_for_code = self->byte_order_for_code;
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CORE_ADDR breaks[2] = {CORE_ADDR_MAX, CORE_ADDR_MAX};
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CORE_ADDR pc = regcache_read_pc (self->regcache);
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CORE_ADDR loc = pc;
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unsigned short insn1, insn2;
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int insn_count;
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int index;
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int last_breakpoint = 0; /* Defaults to 0 (no breakpoints placed). */
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const int atomic_sequence_length = 16; /* Instruction sequence length. */
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ULONGEST status, itstate;
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/* We currently do not support atomic sequences within an IT block. */
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status = regcache_raw_get_unsigned (self->regcache, ARM_PS_REGNUM);
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itstate = ((status >> 8) & 0xfc) | ((status >> 25) & 0x3);
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if (itstate & 0x0f)
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return {};
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/* Assume all atomic sequences start with a ldrex{,b,h,d} instruction. */
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insn1 = self->ops->read_mem_uint (loc, 2, byte_order_for_code);
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loc += 2;
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if (thumb_insn_size (insn1) != 4)
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return {};
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insn2 = self->ops->read_mem_uint (loc, 2, byte_order_for_code);
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loc += 2;
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if (!((insn1 & 0xfff0) == 0xe850
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|| ((insn1 & 0xfff0) == 0xe8d0 && (insn2 & 0x00c0) == 0x0040)))
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return {};
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/* Assume that no atomic sequence is longer than "atomic_sequence_length"
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instructions. */
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for (insn_count = 0; insn_count < atomic_sequence_length; ++insn_count)
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{
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insn1 = self->ops->read_mem_uint (loc, 2,byte_order_for_code);
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loc += 2;
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if (thumb_insn_size (insn1) != 4)
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{
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/* Assume that there is at most one conditional branch in the
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atomic sequence. If a conditional branch is found, put a
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breakpoint in its destination address. */
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if ((insn1 & 0xf000) == 0xd000 && bits (insn1, 8, 11) != 0x0f)
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{
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if (last_breakpoint > 0)
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return {}; /* More than one conditional branch found,
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fallback to the standard code. */
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breaks[1] = loc + 2 + (sbits (insn1, 0, 7) << 1);
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last_breakpoint++;
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}
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/* We do not support atomic sequences that use any *other*
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instructions but conditional branches to change the PC.
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Fall back to standard code to avoid losing control of
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execution. */
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else if (thumb_instruction_changes_pc (insn1))
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return {};
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}
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else
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{
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insn2 = self->ops->read_mem_uint (loc, 2, byte_order_for_code);
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loc += 2;
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/* Assume that there is at most one conditional branch in the
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atomic sequence. If a conditional branch is found, put a
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breakpoint in its destination address. */
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if ((insn1 & 0xf800) == 0xf000
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&& (insn2 & 0xd000) == 0x8000
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&& (insn1 & 0x0380) != 0x0380)
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{
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int sign, j1, j2, imm1, imm2;
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unsigned int offset;
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sign = sbits (insn1, 10, 10);
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imm1 = bits (insn1, 0, 5);
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imm2 = bits (insn2, 0, 10);
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j1 = bit (insn2, 13);
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j2 = bit (insn2, 11);
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offset = (sign << 20) + (j2 << 19) + (j1 << 18);
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offset += (imm1 << 12) + (imm2 << 1);
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if (last_breakpoint > 0)
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return {}; /* More than one conditional branch found,
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fallback to the standard code. */
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breaks[1] = loc + offset;
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last_breakpoint++;
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}
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/* We do not support atomic sequences that use any *other*
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instructions but conditional branches to change the PC.
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Fall back to standard code to avoid losing control of
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execution. */
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else if (thumb2_instruction_changes_pc (insn1, insn2))
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return {};
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/* If we find a strex{,b,h,d}, we're done. */
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if ((insn1 & 0xfff0) == 0xe840
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|| ((insn1 & 0xfff0) == 0xe8c0 && (insn2 & 0x00c0) == 0x0040))
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break;
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}
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}
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/* If we didn't find the strex{,b,h,d}, we cannot handle the sequence. */
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if (insn_count == atomic_sequence_length)
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return {};
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/* Insert a breakpoint right after the end of the atomic sequence. */
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breaks[0] = loc;
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/* Check for duplicated breakpoints. Check also for a breakpoint
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placed (branch instruction's destination) anywhere in sequence. */
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if (last_breakpoint
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&& (breaks[1] == breaks[0]
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|| (breaks[1] >= pc && breaks[1] < loc)))
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last_breakpoint = 0;
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std::vector<CORE_ADDR> next_pcs;
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/* Adds the breakpoints to the list to be inserted. */
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for (index = 0; index <= last_breakpoint; index++)
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next_pcs.push_back (MAKE_THUMB_ADDR (breaks[index]));
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return next_pcs;
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}
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/* Checks for an atomic sequence of instructions beginning with a LDREX{,B,H,D}
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instruction and ending with a STREX{,B,H,D} instruction. If such a sequence
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is found, attempt to step through it. The end of the sequence address is
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added to the next_pcs list. */
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static std::vector<CORE_ADDR>
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arm_deal_with_atomic_sequence_raw (struct arm_get_next_pcs *self)
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{
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int byte_order_for_code = self->byte_order_for_code;
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CORE_ADDR breaks[2] = {CORE_ADDR_MAX, CORE_ADDR_MAX};
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CORE_ADDR pc = regcache_read_pc (self->regcache);
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CORE_ADDR loc = pc;
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unsigned int insn;
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int insn_count;
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int index;
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int last_breakpoint = 0; /* Defaults to 0 (no breakpoints placed). */
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const int atomic_sequence_length = 16; /* Instruction sequence length. */
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/* Assume all atomic sequences start with a ldrex{,b,h,d} instruction.
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Note that we do not currently support conditionally executed atomic
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instructions. */
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insn = self->ops->read_mem_uint (loc, 4, byte_order_for_code);
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loc += 4;
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if ((insn & 0xff9000f0) != 0xe1900090)
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return {};
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/* Assume that no atomic sequence is longer than "atomic_sequence_length"
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instructions. */
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for (insn_count = 0; insn_count < atomic_sequence_length; ++insn_count)
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{
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insn = self->ops->read_mem_uint (loc, 4, byte_order_for_code);
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loc += 4;
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/* Assume that there is at most one conditional branch in the atomic
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sequence. If a conditional branch is found, put a breakpoint in
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its destination address. */
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if (bits (insn, 24, 27) == 0xa)
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{
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if (last_breakpoint > 0)
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return {}; /* More than one conditional branch found, fallback
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to the standard single-step code. */
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breaks[1] = BranchDest (loc - 4, insn);
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last_breakpoint++;
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}
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/* We do not support atomic sequences that use any *other* instructions
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but conditional branches to change the PC. Fall back to standard
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code to avoid losing control of execution. */
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else if (arm_instruction_changes_pc (insn))
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return {};
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/* If we find a strex{,b,h,d}, we're done. */
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if ((insn & 0xff9000f0) == 0xe1800090)
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break;
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}
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/* If we didn't find the strex{,b,h,d}, we cannot handle the sequence. */
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if (insn_count == atomic_sequence_length)
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return {};
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/* Insert a breakpoint right after the end of the atomic sequence. */
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breaks[0] = loc;
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/* Check for duplicated breakpoints. Check also for a breakpoint
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placed (branch instruction's destination) anywhere in sequence. */
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if (last_breakpoint
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&& (breaks[1] == breaks[0]
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|| (breaks[1] >= pc && breaks[1] < loc)))
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last_breakpoint = 0;
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std::vector<CORE_ADDR> next_pcs;
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/* Adds the breakpoints to the list to be inserted. */
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for (index = 0; index <= last_breakpoint; index++)
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next_pcs.push_back (breaks[index]);
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return next_pcs;
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}
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/* Find the next possible PCs for thumb mode. */
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static std::vector<CORE_ADDR>
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thumb_get_next_pcs_raw (struct arm_get_next_pcs *self)
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{
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int byte_order = self->byte_order;
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int byte_order_for_code = self->byte_order_for_code;
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CORE_ADDR pc = regcache_read_pc (self->regcache);
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unsigned long pc_val = ((unsigned long) pc) + 4; /* PC after prefetch */
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unsigned short inst1;
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CORE_ADDR nextpc = pc + 2; /* Default is next instruction. */
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ULONGEST status, itstate;
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struct regcache *regcache = self->regcache;
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std::vector<CORE_ADDR> next_pcs;
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nextpc = MAKE_THUMB_ADDR (nextpc);
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pc_val = MAKE_THUMB_ADDR (pc_val);
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inst1 = self->ops->read_mem_uint (pc, 2, byte_order_for_code);
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/* Thumb-2 conditional execution support. There are eight bits in
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the CPSR which describe conditional execution state. Once
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reconstructed (they're in a funny order), the low five bits
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describe the low bit of the condition for each instruction and
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how many instructions remain. The high three bits describe the
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base condition. One of the low four bits will be set if an IT
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block is active. These bits read as zero on earlier
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processors. */
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status = regcache_raw_get_unsigned (regcache, ARM_PS_REGNUM);
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itstate = ((status >> 8) & 0xfc) | ((status >> 25) & 0x3);
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/* If-Then handling. On GNU/Linux, where this routine is used, we
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use an undefined instruction as a breakpoint. Unlike BKPT, IT
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can disable execution of the undefined instruction. So we might
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miss the breakpoint if we set it on a skipped conditional
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instruction. Because conditional instructions can change the
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flags, affecting the execution of further instructions, we may
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need to set two breakpoints. */
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if (self->has_thumb2_breakpoint)
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{
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if ((inst1 & 0xff00) == 0xbf00 && (inst1 & 0x000f) != 0)
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{
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/* An IT instruction. Because this instruction does not
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modify the flags, we can accurately predict the next
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executed instruction. */
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itstate = inst1 & 0x00ff;
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pc += thumb_insn_size (inst1);
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while (itstate != 0 && ! condition_true (itstate >> 4, status))
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{
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inst1 = self->ops->read_mem_uint (pc, 2,byte_order_for_code);
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pc += thumb_insn_size (inst1);
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itstate = thumb_advance_itstate (itstate);
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}
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next_pcs.push_back (MAKE_THUMB_ADDR (pc));
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return next_pcs;
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}
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else if (itstate != 0)
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{
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/* We are in a conditional block. Check the condition. */
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if (! condition_true (itstate >> 4, status))
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{
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/* Advance to the next executed instruction. */
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pc += thumb_insn_size (inst1);
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itstate = thumb_advance_itstate (itstate);
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while (itstate != 0 && ! condition_true (itstate >> 4, status))
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{
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inst1 = self->ops->read_mem_uint (pc, 2, byte_order_for_code);
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pc += thumb_insn_size (inst1);
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itstate = thumb_advance_itstate (itstate);
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}
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next_pcs.push_back (MAKE_THUMB_ADDR (pc));
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return next_pcs;
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}
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else if ((itstate & 0x0f) == 0x08)
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{
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/* This is the last instruction of the conditional
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block, and it is executed. We can handle it normally
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because the following instruction is not conditional,
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and we must handle it normally because it is
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permitted to branch. Fall through. */
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}
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else
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{
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int cond_negated;
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/* There are conditional instructions after this one.
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If this instruction modifies the flags, then we can
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not predict what the next executed instruction will
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be. Fortunately, this instruction is architecturally
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forbidden to branch; we know it will fall through.
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Start by skipping past it. */
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pc += thumb_insn_size (inst1);
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itstate = thumb_advance_itstate (itstate);
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/* Set a breakpoint on the following instruction. */
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gdb_assert ((itstate & 0x0f) != 0);
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next_pcs.push_back (MAKE_THUMB_ADDR (pc));
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cond_negated = (itstate >> 4) & 1;
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/* Skip all following instructions with the same
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condition. If there is a later instruction in the IT
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block with the opposite condition, set the other
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breakpoint there. If not, then set a breakpoint on
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the instruction after the IT block. */
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do
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{
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inst1 = self->ops->read_mem_uint (pc, 2, byte_order_for_code);
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pc += thumb_insn_size (inst1);
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itstate = thumb_advance_itstate (itstate);
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}
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while (itstate != 0 && ((itstate >> 4) & 1) == cond_negated);
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next_pcs.push_back (MAKE_THUMB_ADDR (pc));
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return next_pcs;
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}
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}
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}
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else if (itstate & 0x0f)
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{
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/* We are in a conditional block. Check the condition. */
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int cond = itstate >> 4;
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if (! condition_true (cond, status))
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{
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/* Advance to the next instruction. All the 32-bit
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instructions share a common prefix. */
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next_pcs.push_back (MAKE_THUMB_ADDR (pc + thumb_insn_size (inst1)));
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}
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return next_pcs;
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/* Otherwise, handle the instruction normally. */
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}
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if ((inst1 & 0xff00) == 0xbd00) /* pop {rlist, pc} */
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{
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CORE_ADDR sp;
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/* Fetch the saved PC from the stack. It's stored above
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all of the other registers. */
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unsigned long offset
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= count_one_bits (bits (inst1, 0, 7)) * ARM_INT_REGISTER_SIZE;
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sp = regcache_raw_get_unsigned (regcache, ARM_SP_REGNUM);
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nextpc = self->ops->read_mem_uint (sp + offset, 4, byte_order);
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}
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else if ((inst1 & 0xf000) == 0xd000) /* conditional branch */
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{
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unsigned long cond = bits (inst1, 8, 11);
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if (cond == 0x0f) /* 0x0f = SWI */
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{
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nextpc = self->ops->syscall_next_pc (self);
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}
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else if (cond != 0x0f && condition_true (cond, status))
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nextpc = pc_val + (sbits (inst1, 0, 7) << 1);
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}
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else if ((inst1 & 0xf800) == 0xe000) /* unconditional branch */
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{
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nextpc = pc_val + (sbits (inst1, 0, 10) << 1);
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}
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else if (thumb_insn_size (inst1) == 4) /* 32-bit instruction */
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{
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unsigned short inst2;
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inst2 = self->ops->read_mem_uint (pc + 2, 2, byte_order_for_code);
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/* Default to the next instruction. */
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nextpc = pc + 4;
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nextpc = MAKE_THUMB_ADDR (nextpc);
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if ((inst1 & 0xf800) == 0xf000 && (inst2 & 0x8000) == 0x8000)
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{
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/* Branches and miscellaneous control instructions. */
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if ((inst2 & 0x1000) != 0 || (inst2 & 0xd001) == 0xc000)
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{
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/* B, BL, BLX. */
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int j1, j2, imm1, imm2;
|
|
|
|
imm1 = sbits (inst1, 0, 10);
|
|
imm2 = bits (inst2, 0, 10);
|
|
j1 = bit (inst2, 13);
|
|
j2 = bit (inst2, 11);
|
|
|
|
unsigned long offset = ((imm1 << 12) + (imm2 << 1));
|
|
offset ^= ((!j2) << 22) | ((!j1) << 23);
|
|
|
|
nextpc = pc_val + offset;
|
|
/* For BLX make sure to clear the low bits. */
|
|
if (bit (inst2, 12) == 0)
|
|
nextpc = nextpc & 0xfffffffc;
|
|
}
|
|
else if (inst1 == 0xf3de && (inst2 & 0xff00) == 0x3f00)
|
|
{
|
|
/* SUBS PC, LR, #imm8. */
|
|
nextpc = regcache_raw_get_unsigned (regcache, ARM_LR_REGNUM);
|
|
nextpc -= inst2 & 0x00ff;
|
|
}
|
|
else if ((inst2 & 0xd000) == 0x8000 && (inst1 & 0x0380) != 0x0380)
|
|
{
|
|
/* Conditional branch. */
|
|
if (condition_true (bits (inst1, 6, 9), status))
|
|
{
|
|
int sign, j1, j2, imm1, imm2;
|
|
|
|
sign = sbits (inst1, 10, 10);
|
|
imm1 = bits (inst1, 0, 5);
|
|
imm2 = bits (inst2, 0, 10);
|
|
j1 = bit (inst2, 13);
|
|
j2 = bit (inst2, 11);
|
|
|
|
unsigned long offset
|
|
= (sign << 20) + (j2 << 19) + (j1 << 18);
|
|
offset += (imm1 << 12) + (imm2 << 1);
|
|
|
|
nextpc = pc_val + offset;
|
|
}
|
|
}
|
|
}
|
|
else if ((inst1 & 0xfe50) == 0xe810)
|
|
{
|
|
/* Load multiple or RFE. */
|
|
int rn, offset, load_pc = 1;
|
|
|
|
rn = bits (inst1, 0, 3);
|
|
if (bit (inst1, 7) && !bit (inst1, 8))
|
|
{
|
|
/* LDMIA or POP */
|
|
if (!bit (inst2, 15))
|
|
load_pc = 0;
|
|
offset = count_one_bits (inst2) * 4 - 4;
|
|
}
|
|
else if (!bit (inst1, 7) && bit (inst1, 8))
|
|
{
|
|
/* LDMDB */
|
|
if (!bit (inst2, 15))
|
|
load_pc = 0;
|
|
offset = -4;
|
|
}
|
|
else if (bit (inst1, 7) && bit (inst1, 8))
|
|
{
|
|
/* RFEIA */
|
|
offset = 0;
|
|
}
|
|
else if (!bit (inst1, 7) && !bit (inst1, 8))
|
|
{
|
|
/* RFEDB */
|
|
offset = -8;
|
|
}
|
|
else
|
|
load_pc = 0;
|
|
|
|
if (load_pc)
|
|
{
|
|
CORE_ADDR addr = regcache_raw_get_unsigned (regcache, rn);
|
|
nextpc = self->ops->read_mem_uint (addr + offset, 4, byte_order);
|
|
}
|
|
}
|
|
else if ((inst1 & 0xffef) == 0xea4f && (inst2 & 0xfff0) == 0x0f00)
|
|
{
|
|
/* MOV PC or MOVS PC. */
|
|
nextpc = regcache_raw_get_unsigned (regcache, bits (inst2, 0, 3));
|
|
nextpc = MAKE_THUMB_ADDR (nextpc);
|
|
}
|
|
else if ((inst1 & 0xff70) == 0xf850 && (inst2 & 0xf000) == 0xf000)
|
|
{
|
|
/* LDR PC. */
|
|
CORE_ADDR base;
|
|
int rn, load_pc = 1;
|
|
|
|
rn = bits (inst1, 0, 3);
|
|
base = regcache_raw_get_unsigned (regcache, rn);
|
|
if (rn == ARM_PC_REGNUM)
|
|
{
|
|
base = (base + 4) & ~(CORE_ADDR) 0x3;
|
|
if (bit (inst1, 7))
|
|
base += bits (inst2, 0, 11);
|
|
else
|
|
base -= bits (inst2, 0, 11);
|
|
}
|
|
else if (bit (inst1, 7))
|
|
base += bits (inst2, 0, 11);
|
|
else if (bit (inst2, 11))
|
|
{
|
|
if (bit (inst2, 10))
|
|
{
|
|
if (bit (inst2, 9))
|
|
base += bits (inst2, 0, 7);
|
|
else
|
|
base -= bits (inst2, 0, 7);
|
|
}
|
|
}
|
|
else if ((inst2 & 0x0fc0) == 0x0000)
|
|
{
|
|
int shift = bits (inst2, 4, 5), rm = bits (inst2, 0, 3);
|
|
base += regcache_raw_get_unsigned (regcache, rm) << shift;
|
|
}
|
|
else
|
|
/* Reserved. */
|
|
load_pc = 0;
|
|
|
|
if (load_pc)
|
|
nextpc
|
|
= self->ops->read_mem_uint (base, 4, byte_order);
|
|
}
|
|
else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf000)
|
|
{
|
|
/* TBB. */
|
|
CORE_ADDR tbl_reg, table, offset, length;
|
|
|
|
tbl_reg = bits (inst1, 0, 3);
|
|
if (tbl_reg == 0x0f)
|
|
table = pc + 4; /* Regcache copy of PC isn't right yet. */
|
|
else
|
|
table = regcache_raw_get_unsigned (regcache, tbl_reg);
|
|
|
|
offset = regcache_raw_get_unsigned (regcache, bits (inst2, 0, 3));
|
|
length = 2 * self->ops->read_mem_uint (table + offset, 1, byte_order);
|
|
nextpc = pc_val + length;
|
|
}
|
|
else if ((inst1 & 0xfff0) == 0xe8d0 && (inst2 & 0xfff0) == 0xf010)
|
|
{
|
|
/* TBH. */
|
|
CORE_ADDR tbl_reg, table, offset, length;
|
|
|
|
tbl_reg = bits (inst1, 0, 3);
|
|
if (tbl_reg == 0x0f)
|
|
table = pc + 4; /* Regcache copy of PC isn't right yet. */
|
|
else
|
|
table = regcache_raw_get_unsigned (regcache, tbl_reg);
|
|
|
|
offset = 2 * regcache_raw_get_unsigned (regcache, bits (inst2, 0, 3));
|
|
length = 2 * self->ops->read_mem_uint (table + offset, 2, byte_order);
|
|
nextpc = pc_val + length;
|
|
}
|
|
}
|
|
else if ((inst1 & 0xff00) == 0x4700) /* bx REG, blx REG */
|
|
{
|
|
if (bits (inst1, 3, 6) == 0x0f)
|
|
nextpc = UNMAKE_THUMB_ADDR (pc_val);
|
|
else
|
|
nextpc = regcache_raw_get_unsigned (regcache, bits (inst1, 3, 6));
|
|
}
|
|
else if ((inst1 & 0xff87) == 0x4687) /* mov pc, REG */
|
|
{
|
|
if (bits (inst1, 3, 6) == 0x0f)
|
|
nextpc = pc_val;
|
|
else
|
|
nextpc = regcache_raw_get_unsigned (regcache, bits (inst1, 3, 6));
|
|
|
|
nextpc = MAKE_THUMB_ADDR (nextpc);
|
|
}
|
|
else if ((inst1 & 0xf500) == 0xb100)
|
|
{
|
|
/* CBNZ or CBZ. */
|
|
int imm = (bit (inst1, 9) << 6) + (bits (inst1, 3, 7) << 1);
|
|
ULONGEST reg = regcache_raw_get_unsigned (regcache, bits (inst1, 0, 2));
|
|
|
|
if (bit (inst1, 11) && reg != 0)
|
|
nextpc = pc_val + imm;
|
|
else if (!bit (inst1, 11) && reg == 0)
|
|
nextpc = pc_val + imm;
|
|
}
|
|
|
|
next_pcs.push_back (nextpc);
|
|
|
|
return next_pcs;
|
|
}
|
|
|
|
/* Get the raw next possible addresses. PC in next_pcs is the current program
|
|
counter, which is assumed to be executing in ARM mode.
|
|
|
|
The values returned have the execution state of the next instruction
|
|
encoded in it. Use IS_THUMB_ADDR () to see whether the instruction is
|
|
in Thumb-State, and gdbarch_addr_bits_remove () to get the plain memory
|
|
address in GDB and arm_addr_bits_remove in GDBServer. */
|
|
|
|
static std::vector<CORE_ADDR>
|
|
arm_get_next_pcs_raw (struct arm_get_next_pcs *self)
|
|
{
|
|
int byte_order = self->byte_order;
|
|
int byte_order_for_code = self->byte_order_for_code;
|
|
unsigned long pc_val;
|
|
unsigned long this_instr = 0;
|
|
unsigned long status;
|
|
CORE_ADDR nextpc;
|
|
struct regcache *regcache = self->regcache;
|
|
CORE_ADDR pc = regcache_read_pc (self->regcache);
|
|
std::vector<CORE_ADDR> next_pcs;
|
|
|
|
pc_val = (unsigned long) pc;
|
|
this_instr = self->ops->read_mem_uint (pc, 4, byte_order_for_code);
|
|
|
|
status = regcache_raw_get_unsigned (regcache, ARM_PS_REGNUM);
|
|
nextpc = (CORE_ADDR) (pc_val + 4); /* Default case */
|
|
|
|
if (bits (this_instr, 28, 31) == INST_NV)
|
|
switch (bits (this_instr, 24, 27))
|
|
{
|
|
case 0xa:
|
|
case 0xb:
|
|
{
|
|
/* Branch with Link and change to Thumb. */
|
|
nextpc = BranchDest (pc, this_instr);
|
|
nextpc |= bit (this_instr, 24) << 1;
|
|
nextpc = MAKE_THUMB_ADDR (nextpc);
|
|
break;
|
|
}
|
|
case 0xc:
|
|
case 0xd:
|
|
case 0xe:
|
|
/* Coprocessor register transfer. */
|
|
if (bits (this_instr, 12, 15) == 15)
|
|
error (_("Invalid update to pc in instruction"));
|
|
break;
|
|
}
|
|
else if (condition_true (bits (this_instr, 28, 31), status))
|
|
{
|
|
switch (bits (this_instr, 24, 27))
|
|
{
|
|
case 0x0:
|
|
case 0x1: /* data processing */
|
|
case 0x2:
|
|
case 0x3:
|
|
{
|
|
unsigned long operand1, operand2, result = 0;
|
|
unsigned long rn;
|
|
int c;
|
|
|
|
if (bits (this_instr, 12, 15) != 15)
|
|
break;
|
|
|
|
if (bits (this_instr, 22, 25) == 0
|
|
&& bits (this_instr, 4, 7) == 9) /* multiply */
|
|
error (_("Invalid update to pc in instruction"));
|
|
|
|
/* BX <reg>, BLX <reg> */
|
|
if (bits (this_instr, 4, 27) == 0x12fff1
|
|
|| bits (this_instr, 4, 27) == 0x12fff3)
|
|
{
|
|
rn = bits (this_instr, 0, 3);
|
|
nextpc = ((rn == ARM_PC_REGNUM)
|
|
? (pc_val + 8)
|
|
: regcache_raw_get_unsigned (regcache, rn));
|
|
|
|
next_pcs.push_back (nextpc);
|
|
return next_pcs;
|
|
}
|
|
|
|
/* Multiply into PC. */
|
|
c = (status & FLAG_C) ? 1 : 0;
|
|
rn = bits (this_instr, 16, 19);
|
|
operand1 = ((rn == ARM_PC_REGNUM)
|
|
? (pc_val + 8)
|
|
: regcache_raw_get_unsigned (regcache, rn));
|
|
|
|
if (bit (this_instr, 25))
|
|
{
|
|
unsigned long immval = bits (this_instr, 0, 7);
|
|
unsigned long rotate = 2 * bits (this_instr, 8, 11);
|
|
operand2 = ((immval >> rotate) | (immval << (32 - rotate)))
|
|
& 0xffffffff;
|
|
}
|
|
else /* operand 2 is a shifted register. */
|
|
operand2 = shifted_reg_val (regcache, this_instr, c,
|
|
pc_val, status);
|
|
|
|
switch (bits (this_instr, 21, 24))
|
|
{
|
|
case 0x0: /*and */
|
|
result = operand1 & operand2;
|
|
break;
|
|
|
|
case 0x1: /*eor */
|
|
result = operand1 ^ operand2;
|
|
break;
|
|
|
|
case 0x2: /*sub */
|
|
result = operand1 - operand2;
|
|
break;
|
|
|
|
case 0x3: /*rsb */
|
|
result = operand2 - operand1;
|
|
break;
|
|
|
|
case 0x4: /*add */
|
|
result = operand1 + operand2;
|
|
break;
|
|
|
|
case 0x5: /*adc */
|
|
result = operand1 + operand2 + c;
|
|
break;
|
|
|
|
case 0x6: /*sbc */
|
|
result = operand1 - operand2 + c;
|
|
break;
|
|
|
|
case 0x7: /*rsc */
|
|
result = operand2 - operand1 + c;
|
|
break;
|
|
|
|
case 0x8:
|
|
case 0x9:
|
|
case 0xa:
|
|
case 0xb: /* tst, teq, cmp, cmn */
|
|
result = (unsigned long) nextpc;
|
|
break;
|
|
|
|
case 0xc: /*orr */
|
|
result = operand1 | operand2;
|
|
break;
|
|
|
|
case 0xd: /*mov */
|
|
/* Always step into a function. */
|
|
result = operand2;
|
|
break;
|
|
|
|
case 0xe: /*bic */
|
|
result = operand1 & ~operand2;
|
|
break;
|
|
|
|
case 0xf: /*mvn */
|
|
result = ~operand2;
|
|
break;
|
|
}
|
|
nextpc = self->ops->addr_bits_remove (self, result);
|
|
break;
|
|
}
|
|
|
|
case 0x4:
|
|
case 0x5: /* data transfer */
|
|
case 0x6:
|
|
case 0x7:
|
|
if (bits (this_instr, 25, 27) == 0x3 && bit (this_instr, 4) == 1)
|
|
{
|
|
/* Media instructions and architecturally undefined
|
|
instructions. */
|
|
break;
|
|
}
|
|
|
|
if (bit (this_instr, 20))
|
|
{
|
|
/* load */
|
|
if (bits (this_instr, 12, 15) == 15)
|
|
{
|
|
/* rd == pc */
|
|
unsigned long rn;
|
|
unsigned long base;
|
|
|
|
if (bit (this_instr, 22))
|
|
error (_("Invalid update to pc in instruction"));
|
|
|
|
/* byte write to PC */
|
|
rn = bits (this_instr, 16, 19);
|
|
base = ((rn == ARM_PC_REGNUM)
|
|
? (pc_val + 8)
|
|
: regcache_raw_get_unsigned (regcache, rn));
|
|
|
|
if (bit (this_instr, 24))
|
|
{
|
|
/* pre-indexed */
|
|
int c = (status & FLAG_C) ? 1 : 0;
|
|
unsigned long offset =
|
|
(bit (this_instr, 25)
|
|
? shifted_reg_val (regcache, this_instr, c,
|
|
pc_val, status)
|
|
: bits (this_instr, 0, 11));
|
|
|
|
if (bit (this_instr, 23))
|
|
base += offset;
|
|
else
|
|
base -= offset;
|
|
}
|
|
nextpc
|
|
= (CORE_ADDR) self->ops->read_mem_uint ((CORE_ADDR) base,
|
|
4, byte_order);
|
|
}
|
|
}
|
|
break;
|
|
|
|
case 0x8:
|
|
case 0x9: /* block transfer */
|
|
if (bit (this_instr, 20))
|
|
{
|
|
/* LDM */
|
|
if (bit (this_instr, 15))
|
|
{
|
|
/* loading pc */
|
|
int offset = 0;
|
|
CORE_ADDR rn_val_offset = 0;
|
|
unsigned long rn_val
|
|
= regcache_raw_get_unsigned (regcache,
|
|
bits (this_instr, 16, 19));
|
|
|
|
if (bit (this_instr, 23))
|
|
{
|
|
/* up */
|
|
unsigned long reglist = bits (this_instr, 0, 14);
|
|
offset = count_one_bits_l (reglist) * 4;
|
|
if (bit (this_instr, 24)) /* pre */
|
|
offset += 4;
|
|
}
|
|
else if (bit (this_instr, 24))
|
|
offset = -4;
|
|
|
|
rn_val_offset = rn_val + offset;
|
|
nextpc = (CORE_ADDR) self->ops->read_mem_uint (rn_val_offset,
|
|
4, byte_order);
|
|
}
|
|
}
|
|
break;
|
|
|
|
case 0xb: /* branch & link */
|
|
case 0xa: /* branch */
|
|
{
|
|
nextpc = BranchDest (pc, this_instr);
|
|
break;
|
|
}
|
|
|
|
case 0xc:
|
|
case 0xd:
|
|
case 0xe: /* coproc ops */
|
|
break;
|
|
case 0xf: /* SWI */
|
|
{
|
|
nextpc = self->ops->syscall_next_pc (self);
|
|
}
|
|
break;
|
|
|
|
default:
|
|
error (_("Bad bit-field extraction"));
|
|
return next_pcs;
|
|
}
|
|
}
|
|
|
|
next_pcs.push_back (nextpc);
|
|
|
|
return next_pcs;
|
|
}
|
|
|
|
/* See arm-get-next-pcs.h. */
|
|
|
|
std::vector<CORE_ADDR>
|
|
arm_get_next_pcs (struct arm_get_next_pcs *self)
|
|
{
|
|
std::vector<CORE_ADDR> next_pcs;
|
|
|
|
if (self->ops->is_thumb (self))
|
|
{
|
|
next_pcs = thumb_deal_with_atomic_sequence_raw (self);
|
|
if (next_pcs.empty ())
|
|
next_pcs = thumb_get_next_pcs_raw (self);
|
|
}
|
|
else
|
|
{
|
|
next_pcs = arm_deal_with_atomic_sequence_raw (self);
|
|
if (next_pcs.empty ())
|
|
next_pcs = arm_get_next_pcs_raw (self);
|
|
}
|
|
|
|
if (self->ops->fixup != NULL)
|
|
{
|
|
for (CORE_ADDR &pc_ref : next_pcs)
|
|
pc_ref = self->ops->fixup (self, pc_ref);
|
|
}
|
|
|
|
return next_pcs;
|
|
}
|