binutils-gdb/opcodes/s390-dis.c

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2001-02-10 01:58:38 +01:00
/* s390-dis.c -- Disassemble S390 instructions
Copyright 2000, 2001 Free Software Foundation, Inc.
2001-02-10 01:58:38 +01:00
Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
This file is part of GDB, GAS and the GNU binutils.
This program 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 2 of the License, or
(at your option) any later version.
This program 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 program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
#include <stdio.h>
#include "ansidecl.h"
#include "sysdep.h"
#include "dis-asm.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(info)
struct disassemble_info *info ATTRIBUTE_UNUSED;
{
const struct s390_opcode *opcode;
const struct s390_opcode *opcode_end;
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++;
}
switch (info->mach) {
case bfd_mach_s390_esa:
current_arch_mask = 1 << S390_OPCODE_ESA;
break;
case bfd_mach_s390_esame:
current_arch_mask = 1 << S390_OPCODE_ESAME;
break;
default:
abort();
}
init_flag = 1;
}
/* Extracts an operand value from an instruction. */
static inline unsigned int
s390_extract_operand (insn, 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;
/* 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;
/* double value if the operand is pc relative */
if (operand->flags & S390_OPERAND_PCREL)
val <<= 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 (memaddr, info)
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) {
/* 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->architecture & 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;
/* 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++) {
unsigned int value;
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, info);
else if (operand->flags & S390_OPERAND_SIGNED)
(*info->fprintf_func) (info->stream, "%i", (int) value);
else
(*info->fprintf_func) (info->stream, "%i", 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;
}
}