#include "defs.h"
#include "frame.h"
#include "gdbcore.h"
static int sign_extend (int value, int bits);
void
_initialize_ns32k_tdep (void)
{
tm_print_insn = print_insn_ns32k;
}
CORE_ADDR
umax_skip_prologue (CORE_ADDR pc)
{
register unsigned char op = read_memory_integer (pc, 1);
if (op == 0x82)
{
op = read_memory_integer (pc + 2, 1);
if ((op & 0x80) == 0)
pc += 3;
else if ((op & 0xc0) == 0x80)
pc += 4;
else
pc += 6;
}
return pc;
}
int
umax_frame_num_args (struct frame_info *fi)
{
int numargs;
CORE_ADDR pc;
CORE_ADDR enter_addr;
unsigned int insn;
unsigned int addr_mode;
int width;
numargs = -1;
enter_addr = ns32k_get_enter_addr ((fi)->pc);
if (enter_addr > 0)
{
pc = ((enter_addr == 1)
? SAVED_PC_AFTER_CALL (fi)
: FRAME_SAVED_PC (fi));
insn = read_memory_integer (pc, 2);
addr_mode = (insn >> 11) & 0x1f;
insn = insn & 0x7ff;
if ((insn & 0x7fc) == 0x57c
&& addr_mode == 0x14)
{
if (insn == 0x57c)
width = 1;
else if (insn == 0x57d)
width = 2;
else if (insn == 0x57f)
width = 4;
else
internal_error (__FILE__, __LINE__, "bad else");
numargs = read_memory_integer (pc + 2, width);
if (width > 1)
flip_bytes (&numargs, width);
numargs = -sign_extend (numargs, width * 8) / 4;
}
}
return numargs;
}
static int
sign_extend (int value, int bits)
{
value = value & ((1 << bits) - 1);
return (value & (1 << (bits - 1))
? value | (~((1 << bits) - 1))
: value);
}
void
flip_bytes (void *p, int count)
{
char tmp;
char *ptr = 0;
while (count > 0)
{
tmp = *ptr;
ptr[0] = ptr[count - 1];
ptr[count - 1] = tmp;
ptr++;
count -= 2;
}
}
int
ns32k_localcount (CORE_ADDR enter_pc)
{
unsigned char localtype;
int localcount;
localtype = read_memory_integer (enter_pc + 2, 1);
if ((localtype & 0x80) == 0)
localcount = localtype;
else if ((localtype & 0xc0) == 0x80)
localcount = (((localtype & 0x3f) << 8)
| (read_memory_integer (enter_pc + 3, 1) & 0xff));
else
localcount = (((localtype & 0x3f) << 24)
| ((read_memory_integer (enter_pc + 3, 1) & 0xff) << 16)
| ((read_memory_integer (enter_pc + 4, 1) & 0xff) << 8)
| (read_memory_integer (enter_pc + 5, 1) & 0xff));
return localcount;
}
static int
ns32k_about_to_return (CORE_ADDR pc)
{
return (read_memory_integer (pc, 1) == 0x12);
}
CORE_ADDR
ns32k_get_enter_addr (CORE_ADDR pc)
{
CORE_ADDR enter_addr;
unsigned char op;
if (pc == 0)
return 0;
if (ns32k_about_to_return (pc))
return 1;
enter_addr = get_pc_function_start (pc);
if (pc == enter_addr)
return 1;
op = read_memory_integer (enter_addr, 1);
if (op != 0x82)
return 0;
return enter_addr;
}