binutils-gdb/opcodes/s390-dis.c

297 lines
8.8 KiB
C

/* s390-dis.c -- Disassemble S390 instructions
Copyright (C) 2000-2014 Free Software Foundation, Inc.
Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
This file is part of the GNU opcodes library.
This library is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
It is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
License for more details.
You should have received a copy of the GNU General Public License
along with this file; see the file COPYING. If not, write to the
Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "sysdep.h"
#include <stdio.h>
#include "ansidecl.h"
#include "dis-asm.h"
#include "opintl.h"
#include "opcode/s390.h"
static int init_flag = 0;
static int opc_index[256];
static int current_arch_mask = 0;
/* Set up index table for first opcode byte. */
static void
init_disasm (struct disassemble_info *info)
{
const struct s390_opcode *opcode;
const struct s390_opcode *opcode_end;
const char *p;
memset (opc_index, 0, sizeof (opc_index));
opcode_end = s390_opcodes + s390_num_opcodes;
for (opcode = s390_opcodes; opcode < opcode_end; opcode++)
{
opc_index[(int) opcode->opcode[0]] = opcode - s390_opcodes;
while ((opcode < opcode_end) &&
(opcode[1].opcode[0] == opcode->opcode[0]))
opcode++;
}
for (p = info->disassembler_options; p != NULL; )
{
if (CONST_STRNEQ (p, "esa"))
current_arch_mask = 1 << S390_OPCODE_ESA;
else if (CONST_STRNEQ (p, "zarch"))
current_arch_mask = 1 << S390_OPCODE_ZARCH;
else
fprintf (stderr, "Unknown S/390 disassembler option: %s\n", p);
p = strchr (p, ',');
if (p != NULL)
p++;
}
if (!current_arch_mask)
current_arch_mask = 1 << S390_OPCODE_ZARCH;
init_flag = 1;
}
/* Extracts an operand value from an instruction. */
/* We do not perform the shift operation for larl-type address
operands here since that would lead to an overflow of the 32 bit
integer value. Instead the shift operation is done when printing
the operand in print_insn_s390. */
static inline unsigned int
s390_extract_operand (unsigned char *insn, const struct s390_operand *operand)
{
unsigned int val;
int bits;
/* Extract fragments of the operand byte for byte. */
insn += operand->shift / 8;
bits = (operand->shift & 7) + operand->bits;
val = 0;
do
{
val <<= 8;
val |= (unsigned int) *insn++;
bits -= 8;
}
while (bits > 0);
val >>= -bits;
val &= ((1U << (operand->bits - 1)) << 1) - 1;
/* Check for special long displacement case. */
if (operand->bits == 20 && operand->shift == 20)
val = (val & 0xff) << 12 | (val & 0xfff00) >> 8;
/* Sign extend value if the operand is signed or pc relative. */
if ((operand->flags & (S390_OPERAND_SIGNED | S390_OPERAND_PCREL))
&& (val & (1U << (operand->bits - 1))))
val |= (-1U << (operand->bits - 1)) << 1;
/* Length x in an instructions has real length x + 1. */
if (operand->flags & S390_OPERAND_LENGTH)
val++;
return val;
}
/* Print a S390 instruction. */
int
print_insn_s390 (bfd_vma memaddr, struct disassemble_info *info)
{
bfd_byte buffer[6];
const struct s390_opcode *opcode;
const struct s390_opcode *opcode_end;
unsigned int value;
int status, opsize, bufsize;
char separator;
if (init_flag == 0)
init_disasm (info);
/* The output looks better if we put 6 bytes on a line. */
info->bytes_per_line = 6;
/* Every S390 instruction is max 6 bytes long. */
memset (buffer, 0, 6);
status = (*info->read_memory_func) (memaddr, buffer, 6, info);
if (status != 0)
{
for (bufsize = 0; bufsize < 6; bufsize++)
if ((*info->read_memory_func) (memaddr, buffer, bufsize + 1, info) != 0)
break;
if (bufsize <= 0)
{
(*info->memory_error_func) (status, memaddr, info);
return -1;
}
/* Opsize calculation looks strange but it works
00xxxxxx -> 2 bytes, 01xxxxxx/10xxxxxx -> 4 bytes,
11xxxxxx -> 6 bytes. */
opsize = ((((buffer[0] >> 6) + 1) >> 1) + 1) << 1;
status = opsize > bufsize;
}
else
{
bufsize = 6;
opsize = ((((buffer[0] >> 6) + 1) >> 1) + 1) << 1;
}
if (status == 0)
{
const struct s390_opcode *op;
/* Find the first match in the opcode table. */
opcode_end = s390_opcodes + s390_num_opcodes;
for (opcode = s390_opcodes + opc_index[(int) buffer[0]];
(opcode < opcode_end) && (buffer[0] == opcode->opcode[0]);
opcode++)
{
const struct s390_operand *operand;
const unsigned char *opindex;
/* Check architecture. */
if (!(opcode->modes & current_arch_mask))
continue;
/* Check signature of the opcode. */
if ((buffer[1] & opcode->mask[1]) != opcode->opcode[1]
|| (buffer[2] & opcode->mask[2]) != opcode->opcode[2]
|| (buffer[3] & opcode->mask[3]) != opcode->opcode[3]
|| (buffer[4] & opcode->mask[4]) != opcode->opcode[4]
|| (buffer[5] & opcode->mask[5]) != opcode->opcode[5])
continue;
/* Advance to an opcode with a more specific mask. */
for (op = opcode + 1; op < opcode_end; op++)
{
if ((buffer[0] & op->mask[0]) != op->opcode[0])
break;
if ((buffer[1] & op->mask[1]) != op->opcode[1]
|| (buffer[2] & op->mask[2]) != op->opcode[2]
|| (buffer[3] & op->mask[3]) != op->opcode[3]
|| (buffer[4] & op->mask[4]) != op->opcode[4]
|| (buffer[5] & op->mask[5]) != op->opcode[5])
continue;
if (((int)opcode->mask[0] + opcode->mask[1] +
opcode->mask[2] + opcode->mask[3] +
opcode->mask[4] + opcode->mask[5]) <
((int)op->mask[0] + op->mask[1] +
op->mask[2] + op->mask[3] +
op->mask[4] + op->mask[5]))
opcode = op;
}
/* The instruction is valid. */
if (opcode->operands[0] != 0)
(*info->fprintf_func) (info->stream, "%s\t", opcode->name);
else
(*info->fprintf_func) (info->stream, "%s", opcode->name);
/* Extract the operands. */
separator = 0;
for (opindex = opcode->operands; *opindex != 0; opindex++)
{
operand = s390_operands + *opindex;
value = s390_extract_operand (buffer, operand);
if ((operand->flags & S390_OPERAND_INDEX) && value == 0)
continue;
if ((operand->flags & S390_OPERAND_BASE) &&
value == 0 && separator == '(')
{
separator = ',';
continue;
}
if (separator)
(*info->fprintf_func) (info->stream, "%c", separator);
if (operand->flags & S390_OPERAND_GPR)
(*info->fprintf_func) (info->stream, "%%r%i", value);
else if (operand->flags & S390_OPERAND_FPR)
(*info->fprintf_func) (info->stream, "%%f%i", value);
else if (operand->flags & S390_OPERAND_AR)
(*info->fprintf_func) (info->stream, "%%a%i", value);
else if (operand->flags & S390_OPERAND_CR)
(*info->fprintf_func) (info->stream, "%%c%i", value);
else if (operand->flags & S390_OPERAND_PCREL)
(*info->print_address_func) (memaddr + (int)value + (int)value,
info);
else if (operand->flags & S390_OPERAND_SIGNED)
(*info->fprintf_func) (info->stream, "%i", (int) value);
else
(*info->fprintf_func) (info->stream, "%u", value);
if (operand->flags & S390_OPERAND_DISP)
{
separator = '(';
}
else if (operand->flags & S390_OPERAND_BASE)
{
(*info->fprintf_func) (info->stream, ")");
separator = ',';
}
else
separator = ',';
}
/* Found instruction, printed it, return its size. */
return opsize;
}
/* No matching instruction found, fall through to hex print. */
}
if (bufsize >= 4)
{
value = (unsigned int) buffer[0];
value = (value << 8) + (unsigned int) buffer[1];
value = (value << 8) + (unsigned int) buffer[2];
value = (value << 8) + (unsigned int) buffer[3];
(*info->fprintf_func) (info->stream, ".long\t0x%08x", value);
return 4;
}
else if (bufsize >= 2)
{
value = (unsigned int) buffer[0];
value = (value << 8) + (unsigned int) buffer[1];
(*info->fprintf_func) (info->stream, ".short\t0x%04x", value);
return 2;
}
else
{
value = (unsigned int) buffer[0];
(*info->fprintf_func) (info->stream, ".byte\t0x%02x", value);
return 1;
}
}
void
print_s390_disassembler_options (FILE *stream)
{
fprintf (stream, _("\n\
The following S/390 specific disassembler options are supported for use\n\
with the -M switch (multiple options should be separated by commas):\n"));
fprintf (stream, _(" esa Disassemble in ESA architecture mode\n"));
fprintf (stream, _(" zarch Disassemble in z/Architecture mode\n"));
}