#define THUMB2_INSN_SIZE_BYTES 4
+/* Position of the bit within a 32-bit ARM instruction
+ that defines whether the instruction is a load or store. */
#define INSN_S_L_BIT_NUM 20
#define REG_ALLOC(REGS, LENGTH, RECORD_BUF) \
return 0;
}
-/* Handling opcode 010 insns. */
+/* Handle ARM mode instructions with opcode 010. */
static int
arm_record_ld_st_imm_offset (insn_decode_record *arm_insn_r)
{
struct regcache *reg_cache = arm_insn_r->regcache;
- uint32_t reg_src1 = 0 , reg_dest = 0;
- uint32_t offset_12 = 0, tgt_mem_addr = 0;
+ uint32_t reg_base , reg_dest;
+ uint32_t offset_12, tgt_mem_addr;
uint32_t record_buf[8], record_buf_mem[8];
+ unsigned char wback;
+ ULONGEST u_regval;
- ULONGEST u_regval = 0;
+ /* Calculate wback. */
+ wback = (bit (arm_insn_r->arm_insn, 24) == 0)
+ || (bit (arm_insn_r->arm_insn, 21) == 1);
- arm_insn_r->opcode = bits (arm_insn_r->arm_insn, 21, 24);
- arm_insn_r->decode = bits (arm_insn_r->arm_insn, 4, 7);
+ arm_insn_r->reg_rec_count = 0;
+ reg_base = bits (arm_insn_r->arm_insn, 16, 19);
if (bit (arm_insn_r->arm_insn, INSN_S_L_BIT_NUM))
{
+ /* LDR (immediate), LDR (literal), LDRB (immediate), LDRB (literal), LDRBT
+ and LDRT. */
+
reg_dest = bits (arm_insn_r->arm_insn, 12, 15);
- /* LDR insn has a capability to do branching, if
- MOV LR, PC is precedded by LDR insn having Rn as R15
- in that case, it emulates branch and link insn, and hence we
- need to save CSPR and PC as well. */
- if (ARM_PC_REGNUM != reg_dest)
- {
- record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15);
- arm_insn_r->reg_rec_count = 1;
- }
- else
- {
- record_buf[0] = reg_dest;
- record_buf[1] = ARM_PS_REGNUM;
- arm_insn_r->reg_rec_count = 2;
- }
+ record_buf[arm_insn_r->reg_rec_count++] = reg_dest;
+
+ /* The LDR instruction is capable of doing branching. If MOV LR, PC
+ preceeds a LDR instruction having R15 as reg_base, it
+ emulates a branch and link instruction, and hence we need to save
+ CPSR and PC as well. */
+ if (ARM_PC_REGNUM == reg_dest)
+ record_buf[arm_insn_r->reg_rec_count++] = ARM_PS_REGNUM;
+
+ /* If wback is true, also save the base register, which is going to be
+ written to. */
+ if (wback)
+ record_buf[arm_insn_r->reg_rec_count++] = reg_base;
}
else
{
- /* Store, immediate offset, immediate pre-indexed,
- immediate post-indexed. */
- reg_src1 = bits (arm_insn_r->arm_insn, 16, 19);
+ /* STR (immediate), STRB (immediate), STRBT and STRT. */
+
offset_12 = bits (arm_insn_r->arm_insn, 0, 11);
- regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval);
- /* U == 1 */
+ regcache_raw_read_unsigned (reg_cache, reg_base, &u_regval);
+
+ /* Handle bit U. */
if (bit (arm_insn_r->arm_insn, 23))
- {
- tgt_mem_addr = u_regval + offset_12;
- }
+ {
+ /* U == 1: Add the offset. */
+ tgt_mem_addr = (uint32_t) u_regval + offset_12;
+ }
else
- {
- tgt_mem_addr = u_regval - offset_12;
- }
+ {
+ /* U == 0: subtract the offset. */
+ tgt_mem_addr = (uint32_t) u_regval - offset_12;
+ }
+
+ /* Bit 22 tells us whether the store instruction writes 1 byte or 4
+ bytes. */
+ if (bit (arm_insn_r->arm_insn, 22))
+ {
+ /* STRB and STRBT: 1 byte. */
+ record_buf_mem[0] = 1;
+ }
+ else
+ {
+ /* STR and STRT: 4 bytes. */
+ record_buf_mem[0] = 4;
+ }
+
+ /* Handle bit P. */
+ if (bit (arm_insn_r->arm_insn, 24))
+ record_buf_mem[1] = tgt_mem_addr;
+ else
+ record_buf_mem[1] = (uint32_t) u_regval;
- switch (arm_insn_r->opcode)
- {
- /* STR. */
- case 8:
- case 12:
- /* STR. */
- case 9:
- case 13:
- /* STRT. */
- case 1:
- case 5:
- /* STR. */
- case 4:
- case 0:
- record_buf_mem[0] = 4;
- break;
-
- /* STRB. */
- case 10:
- case 14:
- /* STRB. */
- case 11:
- case 15:
- /* STRBT. */
- case 3:
- case 7:
- /* STRB. */
- case 2:
- case 6:
- record_buf_mem[0] = 1;
- break;
-
- default:
- gdb_assert_not_reached ("no decoding pattern found");
- break;
- }
- record_buf_mem[1] = tgt_mem_addr;
arm_insn_r->mem_rec_count = 1;
- if (9 == arm_insn_r->opcode || 11 == arm_insn_r->opcode
- || 13 == arm_insn_r->opcode || 15 == arm_insn_r->opcode
- || 0 == arm_insn_r->opcode || 2 == arm_insn_r->opcode
- || 4 == arm_insn_r->opcode || 6 == arm_insn_r->opcode
- || 1 == arm_insn_r->opcode || 3 == arm_insn_r->opcode
- || 5 == arm_insn_r->opcode || 7 == arm_insn_r->opcode
- )
- {
- /* We are handling pre-indexed mode; post-indexed mode;
- where Rn is going to be changed. */
- record_buf[0] = reg_src1;
- arm_insn_r->reg_rec_count = 1;
- }
+ /* If wback is true, also save the base register, which is going to be
+ written to. */
+ if (wback)
+ record_buf[arm_insn_r->reg_rec_count++] = reg_base;
}
REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf);
return 0;
}
-/* Handling opcode 100 insns. */
+/* Handle ARM mode instructions with opcode 100. */
static int
arm_record_ld_st_multiple (insn_decode_record *arm_insn_r)
{
struct regcache *reg_cache = arm_insn_r->regcache;
-
- uint32_t register_list[16] = {0}, register_count = 0, register_bits = 0;
- uint32_t reg_src1 = 0, addr_mode = 0, no_of_regs = 0;
- uint32_t start_address = 0, index = 0;
+ uint32_t register_count = 0, register_bits;
+ uint32_t reg_base, addr_mode;
uint32_t record_buf[24], record_buf_mem[48];
+ uint32_t wback;
+ ULONGEST u_regval;
- ULONGEST u_regval[2] = {0};
+ /* Fetch the list of registers. */
+ register_bits = bits (arm_insn_r->arm_insn, 0, 15);
+ arm_insn_r->reg_rec_count = 0;
+
+ /* Fetch the base register that contains the address we are loading data
+ to. */
+ reg_base = bits (arm_insn_r->arm_insn, 16, 19);
- /* This mode is exclusively for load and store multiple. */
- /* Handle incremenrt after/before and decrment after.before mode;
- Rn is changing depending on W bit, but as of now we store Rn too
- without optimization. */
+ /* Calculate wback. */
+ wback = (bit (arm_insn_r->arm_insn, 21) == 1);
if (bit (arm_insn_r->arm_insn, INSN_S_L_BIT_NUM))
{
- /* LDM (1,2,3) where LDM (3) changes CPSR too. */
+ /* LDM/LDMIA/LDMFD, LDMDA/LDMFA, LDMDB and LDMIB. */
- if (bit (arm_insn_r->arm_insn, 20) && !bit (arm_insn_r->arm_insn, 22))
- {
- register_bits = bits (arm_insn_r->arm_insn, 0, 15);
- no_of_regs = 15;
- }
- else
- {
- register_bits = bits (arm_insn_r->arm_insn, 0, 14);
- no_of_regs = 14;
- }
- /* Get Rn. */
- reg_src1 = bits (arm_insn_r->arm_insn, 16, 19);
+ /* Find out which registers are going to be loaded from memory. */
while (register_bits)
- {
- if (register_bits & 0x00000001)
- record_buf[index++] = register_count;
- register_bits = register_bits >> 1;
- register_count++;
- }
+ {
+ if (register_bits & 0x00000001)
+ record_buf[arm_insn_r->reg_rec_count++] = register_count;
+ register_bits = register_bits >> 1;
+ register_count++;
+ }
- /* Extra space for Base Register and CPSR; wihtout optimization. */
- record_buf[index++] = reg_src1;
- record_buf[index++] = ARM_PS_REGNUM;
- arm_insn_r->reg_rec_count = index;
+
+ /* If wback is true, also save the base register, which is going to be
+ written to. */
+ if (wback)
+ record_buf[arm_insn_r->reg_rec_count++] = reg_base;
+
+ /* Save the CPSR register. */
+ record_buf[arm_insn_r->reg_rec_count++] = ARM_PS_REGNUM;
}
else
{
- /* It handles both STM(1) and STM(2). */
- addr_mode = bits (arm_insn_r->arm_insn, 23, 24);
+ /* STM (STMIA, STMEA), STMDA (STMED), STMDB (STMFD) and STMIB (STMFA). */
- register_bits = bits (arm_insn_r->arm_insn, 0, 15);
- /* Get Rn. */
- reg_src1 = bits (arm_insn_r->arm_insn, 16, 19);
- regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval[0]);
+ addr_mode = bits (arm_insn_r->arm_insn, 23, 24);
+
+ regcache_raw_read_unsigned (reg_cache, reg_base, &u_regval);
+
+ /* Find out how many registers are going to be stored to memory. */
while (register_bits)
- {
- if (register_bits & 0x00000001)
- register_count++;
- register_bits = register_bits >> 1;
- }
+ {
+ if (register_bits & 0x00000001)
+ register_count++;
+ register_bits = register_bits >> 1;
+ }
switch (addr_mode)
- {
- /* Decrement after. */
- case 0:
- start_address = (u_regval[0]) - (register_count * 4) + 4;
- arm_insn_r->mem_rec_count = register_count;
- while (register_count)
- {
- record_buf_mem[(register_count * 2) - 1] = start_address;
- record_buf_mem[(register_count * 2) - 2] = 4;
- start_address = start_address + 4;
- register_count--;
- }
- break;
-
- /* Increment after. */
- case 1:
- start_address = u_regval[0];
- arm_insn_r->mem_rec_count = register_count;
- while (register_count)
- {
- record_buf_mem[(register_count * 2) - 1] = start_address;
- record_buf_mem[(register_count * 2) - 2] = 4;
- start_address = start_address + 4;
- register_count--;
- }
- break;
-
- /* Decrement before. */
- case 2:
-
- start_address = (u_regval[0]) - (register_count * 4);
- arm_insn_r->mem_rec_count = register_count;
- while (register_count)
- {
- record_buf_mem[(register_count * 2) - 1] = start_address;
- record_buf_mem[(register_count * 2) - 2] = 4;
- start_address = start_address + 4;
- register_count--;
- }
- break;
-
- /* Increment before. */
- case 3:
- start_address = u_regval[0] + 4;
- arm_insn_r->mem_rec_count = register_count;
- while (register_count)
- {
- record_buf_mem[(register_count * 2) - 1] = start_address;
- record_buf_mem[(register_count * 2) - 2] = 4;
- start_address = start_address + 4;
- register_count--;
- }
- break;
-
- default:
- gdb_assert_not_reached ("no decoding pattern found");
- break;
- }
+ {
+ /* STMDA (STMED): Decrement after. */
+ case 0:
+ record_buf_mem[1] = (uint32_t) u_regval
+ - register_count * INT_REGISTER_SIZE + 4;
+ break;
+ /* STM (STMIA, STMEA): Increment after. */
+ case 1:
+ record_buf_mem[1] = (uint32_t) u_regval;
+ break;
+ /* STMDB (STMFD): Decrement before. */
+ case 2:
+ record_buf_mem[1] = (uint32_t) u_regval
+ - register_count * INT_REGISTER_SIZE;
+ break;
+ /* STMIB (STMFA): Increment before. */
+ case 3:
+ record_buf_mem[1] = (uint32_t) u_regval + INT_REGISTER_SIZE;
+ break;
+ default:
+ gdb_assert_not_reached ("no decoding pattern found");
+ break;
+ }
- /* Base register also changes; based on condition and W bit. */
- /* We save it anyway without optimization. */
- record_buf[0] = reg_src1;
- arm_insn_r->reg_rec_count = 1;
+ record_buf_mem[0] = register_count * INT_REGISTER_SIZE;
+ arm_insn_r->mem_rec_count = 1;
+
+ /* If wback is true, also save the base register, which is going to be
+ written to. */
+ if (wback)
+ record_buf[arm_insn_r->reg_rec_count++] = reg_base;
}
REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf);
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