binutils-gdb/gas/config/tc-tic80.c

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/* tc-tic80.c -- Assemble for the TI TMS320C80 (MV)
Copyright 1996, 1997, 2000, 2001, 2002, 2005
Free Software Foundation, Inc.
This file is part of GAS, the GNU Assembler.
GAS 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, or (at your option)
any later version.
GAS 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 GAS; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
#include "as.h"
#include "safe-ctype.h"
#include "opcode/tic80.h"
#define internal_error(what) \
as_fatal (_("internal error:%s:%d: %s\n"), __FILE__, __LINE__, what)
#define internal_error_a(what,arg) \
as_fatal (_("internal error:%s:%d: %s %ld\n"), __FILE__, __LINE__, what, arg)
/* Generic assembler global variables which must be defined by all
targets. */
/* Characters which always start a comment. */
const char comment_chars[] = ";";
/* Characters which start a comment at the beginning of a line. */
const char line_comment_chars[] = ";*#";
/* Characters which may be used to separate multiple commands on a single
line. The semicolon is such a character by default and should not be
explicitly listed. */
const char line_separator_chars[] = "";
/* Characters which are used to indicate an exponent in a floating
point number. */
const char EXP_CHARS[] = "eE";
/* Characters which mean that a number is a floating point constant,
as in 0f1.0. */
const char FLT_CHARS[] = "fF";
/* This table describes all the machine specific pseudo-ops the assembler
has to support. The fields are:
pseudo-op name without dot
function to call to execute this pseudo-op
integer arg to pass to the function */
const pseudo_typeS md_pseudo_table[] =
{
{ "align", s_align_bytes, 4 }, /* Do byte alignment, default is a 4 byte boundary. */
{ "word", cons, 4 }, /* FIXME: Should this be machine independent? */
{ "bss", s_lcomm_bytes, 1 },
{ "sect", obj_coff_section, 0}, /* For compatibility with TI tools. */
{ "section", obj_coff_section, 0}, /* Standard COFF .section pseudo-op. */
{ NULL, NULL, 0 }
};
/* Opcode hash table. */
static struct hash_control *tic80_hash;
/* Replace short PC relative instructions with long form when
necessary. Currently this is off by default or when given the
-no-relax option. Turning it on by using the -relax option forces
all PC relative instructions to use the long form, which is why it
is currently not the default. */
static int tic80_relax = 0;
int
md_estimate_size_before_relax (fragS *fragP ATTRIBUTE_UNUSED,
segT segment_type ATTRIBUTE_UNUSED)
{
internal_error (_("Relaxation is a luxury we can't afford"));
return -1;
}
/* We have no need to default values of symbols. */
symbolS *
md_undefined_symbol (char *name ATTRIBUTE_UNUSED)
{
return NULL;
}
/* Turn a string in input_line_pointer into a floating point constant
of type TYPE, and store the appropriate bytes in *LITP. The number
of LITTLENUMS emitted is stored in *SIZEP. An error message is
returned, or NULL on OK. */
#define MAX_LITTLENUMS 4
char *
md_atof (int type, char *litP, int *sizeP)
{
int prec;
LITTLENUM_TYPE words[MAX_LITTLENUMS];
LITTLENUM_TYPE *wordP;
char *t;
switch (type)
{
case 'f':
case 'F':
case 's':
case 'S':
prec = 2;
break;
case 'd':
case 'D':
case 'r':
case 'R':
prec = 4;
break;
default:
*sizeP = 0;
return _("bad call to md_atof ()");
}
t = atof_ieee (input_line_pointer, type, words);
if (t)
input_line_pointer = t;
*sizeP = prec * sizeof (LITTLENUM_TYPE);
for (wordP = words; prec--;)
{
md_number_to_chars (litP, (valueT) (*wordP++), sizeof (LITTLENUM_TYPE));
litP += sizeof (LITTLENUM_TYPE);
}
return NULL;
}
/* Check to see if the constant value in NUM will fit in a field of
width BITS if it has flags FLAGS. */
static int
const_overflow (unsigned long num, int bits, int flags)
{
long min, max;
int retval = 0;
/* Only need to check fields less than 32 bits wide. */
if (bits >= 32)
return retval;
if (flags & TIC80_OPERAND_SIGNED)
{
max = (1 << (bits - 1)) - 1;
min = - (1 << (bits - 1));
retval = (long) num > max || (long) num < min;
}
else
{
max = (1 << bits) - 1;
retval = num > (unsigned long) max;
}
return retval;
}
/* get_operands () parses a string of operands and fills in a passed
array of expressions in EXP.
Note that we use O_absent expressions to record additional information
about the previous non-O_absent expression, such as ":m" or ":s"
modifiers or register numbers enclosed in parens like "(r10)".
Returns the number of expressions that were placed in EXP. */
static int
get_operands (expressionS exp[])
{
char *p = input_line_pointer;
int numexp = 0;
int parens = 0;
while (*p)
{
/* Skip leading whitespace. */
while (*p == ' ' || *p == '\t' || *p == ',')
p++;
/* Check to see if we have any operands left to parse. */
if (*p == 0 || *p == '\n' || *p == '\r')
break;
/* Notice scaling or direct memory operand modifiers and save them in
an O_absent expression after the expression that they modify. */
if (*p == ':')
{
p++;
exp[numexp].X_op = O_absent;
if (*p == 'm')
{
p++;
/* This is a ":m" modifier. */
exp[numexp].X_add_number = TIC80_OPERAND_M_SI | TIC80_OPERAND_M_LI;
}
else if (*p == 's')
{
p++;
/* This is a ":s" modifier. */
exp[numexp].X_add_number = TIC80_OPERAND_SCALED;
}
else
as_bad (_("':' not followed by 'm' or 's'"));
numexp++;
continue;
}
/* Handle leading '(' on operands that use them, by recording that we
have entered a paren nesting level and then continuing. We complain
about multiple nesting. */
if (*p == '(')
{
if (++parens != 1)
as_bad (_("paren nesting"));
p++;
continue;
}
/* Handle trailing ')' on operands that use them, by reducing the
nesting level and then continuing. We complain if there were too
many closures. */
if (*p == ')')
{
/* Record that we have left a paren group and continue. */
if (--parens < 0)
as_bad (_("mismatched parenthesis"));
p++;
continue;
}
/* Begin operand parsing at the current scan point. */
input_line_pointer = p;
expression (&exp[numexp]);
if (exp[numexp].X_op == O_illegal)
as_bad (_("illegal operand"));
else if (exp[numexp].X_op == O_absent)
as_bad (_("missing operand"));
numexp++;
p = input_line_pointer;
}
if (parens)
{
exp[numexp].X_op = O_absent;
exp[numexp++].X_add_number = TIC80_OPERAND_PARENS;
}
/* Mark the end of the valid operands with an illegal expression. */
exp[numexp].X_op = O_illegal;
return numexp;
}
/* find_opcode() gets a pointer to the entry in the opcode table that
matches the instruction being assembled, or returns NULL if no such match
is found.
First it parses all the operands and save them as expressions. Note that
we use O_absent expressions to record additional information about the
previous non-O_absent expression, such as ":m" or ":s" modifiers or
register numbers enclosed in parens like "(r10)".
It then looks at all opcodes with the same name and uses the operands to
choose the correct opcode. */
static struct tic80_opcode *
find_opcode (struct tic80_opcode *opcode, expressionS myops[])
{
int numexp; /* Number of expressions from parsing operands. */
int expi; /* Index of current expression to match. */
int opi; /* Index of current operand to match. */
int match = 0; /* Set to 1 when an operand match is found. */
struct tic80_opcode *opc = opcode; /* Pointer to current opcode table entry. */
const struct tic80_opcode *end; /* Pointer to end of opcode table. */
/* First parse all the operands so we only have to do it once. There may
be more expressions generated than there are operands. */
numexp = get_operands (myops);
/* For each opcode with the same name, try to match it against the parsed
operands. */
end = tic80_opcodes + tic80_num_opcodes;
while (!match && (opc < end) && (strcmp (opc->name, opcode->name) == 0))
{
/* Start off assuming a match. If we find a mismatch, then this is
reset and the operand/expr matching loop terminates with match
equal to zero, which allows us to try the next opcode. */
match = 1;
/* For each expression, try to match it against the current operand
for the current opcode. Upon any mismatch, we abandon further
matching for the current opcode table entry. */
for (expi = 0, opi = -1; (expi < numexp) && match; expi++)
{
int bits, flags, X_op, num;
X_op = myops[expi].X_op;
num = myops[expi].X_add_number;
/* The O_absent expressions apply to the same operand as the most
recent non O_absent expression. So only increment the operand
index when the current expression is not one of these special
expressions. */
if (X_op != O_absent)
opi++;
flags = tic80_operands[opc->operands[opi]].flags;
bits = tic80_operands[opc->operands[opi]].bits;
switch (X_op)
{
case O_register:
/* Also check that registers that are supposed to be
even actually are even. */
if (((flags & TIC80_OPERAND_GPR) != (num & TIC80_OPERAND_GPR)) ||
((flags & TIC80_OPERAND_FPA) != (num & TIC80_OPERAND_FPA)) ||
((flags & TIC80_OPERAND_CR) != (num & TIC80_OPERAND_CR)) ||
((flags & TIC80_OPERAND_EVEN) && (num & 1)) ||
const_overflow (num & ~TIC80_OPERAND_MASK, bits, flags))
match = 0;
break;
case O_constant:
if ((flags & TIC80_OPERAND_ENDMASK) && (num == 32))
/* Endmask values of 0 and 32 give identical
results. */
num = 0;
if ((flags & (TIC80_OPERAND_FPA | TIC80_OPERAND_GPR)) ||
const_overflow (num, bits, flags))
match = 0;
break;
case O_symbol:
if ((bits < 32) && (flags & TIC80_OPERAND_PCREL)
&& !tic80_relax)
{
/* The default is to prefer the short form of PC
relative relocations. This is the only form that
the TI assembler supports. If the -relax option
is given, we never use the short forms.
FIXME: Should be able to choose "best-fit". */
}
else if ((bits == 32))
{
/* The default is to prefer the long form of base
relative relocations. This is the only form that
the TI assembler supports. If the -no-relax
option is given, we always use the long form of
PC relative relocations.
FIXME: Should be able to choose "best-fit". */
}
else
{
/* Symbols that don't match one of the above cases are
rejected as an operand. */
match = 0;
}
break;
case O_absent:
/* If this is an O_absent expression, then it may be an
expression that supplies additional information about
the operand, such as ":m" or ":s" modifiers. Check to
see that the operand matches this requirement. */
if (!((num & flags & TIC80_OPERAND_M_SI)
|| (num & flags & TIC80_OPERAND_M_LI)
|| (num & flags & TIC80_OPERAND_SCALED)))
match = 0;
break;
case O_big:
if ((num > 0) || !(flags & TIC80_OPERAND_FLOAT))
match = 0;
break;
case O_illegal:
case O_symbol_rva:
case O_uminus:
case O_bit_not:
case O_logical_not:
case O_multiply:
case O_divide:
case O_modulus:
case O_left_shift:
case O_right_shift:
case O_bit_inclusive_or:
case O_bit_or_not:
case O_bit_exclusive_or:
case O_bit_and:
case O_add:
case O_subtract:
case O_eq:
case O_ne:
case O_lt:
case O_le:
case O_ge:
case O_gt:
case O_logical_and:
case O_logical_or:
case O_max:
default:
internal_error_a (_("unhandled expression type"), (long) X_op);
}
}
if (!match)
opc++;
}
return match ? opc : NULL;
}
/* build_insn takes a pointer to the opcode entry in the opcode table
and the array of operand expressions and writes out the instruction.
Note that the opcode word and extended word may be written to different
frags, with the opcode at the end of one frag and the extension at the
beginning of the next. */
static void
build_insn (struct tic80_opcode *opcode, expressionS *opers)
{
int expi; /* Index of current expression to match. */
int opi; /* Index of current operand to match. */
unsigned long insn[2]; /* Instruction and long immediate (if any). */
char *f; /* Pointer to frag location for insn[0]. */
fragS *ffrag; /* Frag containing location f. */
char *fx = NULL; /* Pointer to frag location for insn[1]. */
fragS *fxfrag; /* Frag containing location fx. */
/* Start with the raw opcode bits from the opcode table. */
insn[0] = opcode->opcode;
insn[1] = 0;
/* We are going to insert at least one 32 bit opcode so get the
frag now. */
f = frag_more (4);
ffrag = frag_now;
/* For each operand expression, insert the appropriate bits into the
instruction. */
for (expi = 0, opi = -1; opers[expi].X_op != O_illegal; expi++)
{
int bits, shift, flags, X_op, num;
X_op = opers[expi].X_op;
num = opers[expi].X_add_number;
/* The O_absent expressions apply to the same operand as the most
recent non O_absent expression. So only increment the operand
index when the current expression is not one of these special
expressions. */
if (X_op != O_absent)
opi++;
flags = tic80_operands[opcode->operands[opi]].flags;
bits = tic80_operands[opcode->operands[opi]].bits;
shift = tic80_operands[opcode->operands[opi]].shift;
switch (X_op)
{
case O_register:
num &= ~TIC80_OPERAND_MASK;
insn[0] = insn[0] | (num << shift);
break;
case O_constant:
if ((flags & TIC80_OPERAND_ENDMASK) && (num == 32))
/* Endmask values of 0 and 32 give identical results. */
num = 0;
else if ((flags & TIC80_OPERAND_BITNUM))
/* BITNUM values are stored in one's complement form. */
num = (~num & 0x1F);
/* Mask off upper bits, just it case it is signed and is
negative. */
if (bits < 32)
{
num &= (1 << bits) - 1;
insn[0] = insn[0] | (num << shift);
}
else
{
fx = frag_more (4);
fxfrag = frag_now;
insn[1] = num;
}
break;
case O_symbol:
if (bits == 32)
{
fx = frag_more (4);
fxfrag = frag_now;
insn[1] = 0;
if (flags & TIC80_OPERAND_PCREL)
fix_new_exp (fxfrag, fx - (fxfrag->fr_literal),
4, &opers[expi], 1, R_MPPCR);
else
fix_new_exp (fxfrag, fx - (fxfrag->fr_literal),
4, &opers[expi], 0, R_RELLONGX);
}
else if (flags & TIC80_OPERAND_PCREL)
fix_new_exp (ffrag, f - (ffrag->fr_literal),
4, /* FIXME! how is this used? */
&opers[expi], 1, R_MPPCR15W);
else
internal_error (_("symbol reloc that is not PC relative or 32 bits"));
break;
case O_absent:
/* Each O_absent expression can indicate exactly one
possible modifier. */
if ((num & TIC80_OPERAND_M_SI)
&& (flags & TIC80_OPERAND_M_SI))
insn[0] = insn[0] | (1 << 17);
else if ((num & TIC80_OPERAND_M_LI)
&& (flags & TIC80_OPERAND_M_LI))
insn[0] = insn[0] | (1 << 15);
else if ((num & TIC80_OPERAND_SCALED)
&& (flags & TIC80_OPERAND_SCALED))
insn[0] = insn[0] | (1 << 11);
else if ((num & TIC80_OPERAND_PARENS)
&& (flags & TIC80_OPERAND_PARENS))
/* No code to generate, just accept and discard this
expression. */
;
else
internal_error_a (_("unhandled operand modifier"),
(long) opers[expi].X_add_number);
break;
case O_big:
fx = frag_more (4);
fxfrag = frag_now;
{
int precision = 2;
long exponent_bits = 8L;
LITTLENUM_TYPE words[2];
/* Value is still in generic_floating_point_number. */
gen_to_words (words, precision, exponent_bits);
insn[1] = (words[0] << 16) | words[1];
}
break;
case O_illegal:
case O_symbol_rva:
case O_uminus:
case O_bit_not:
case O_logical_not:
case O_multiply:
case O_divide:
case O_modulus:
case O_left_shift:
case O_right_shift:
case O_bit_inclusive_or:
case O_bit_or_not:
case O_bit_exclusive_or:
case O_bit_and:
case O_add:
case O_subtract:
case O_eq:
case O_ne:
case O_lt:
case O_le:
case O_ge:
case O_gt:
case O_logical_and:
case O_logical_or:
case O_max:
default:
internal_error_a (_("unhandled expression"), (long) X_op);
break;
}
}
/* Write out the instruction, either 4 or 8 bytes. */
md_number_to_chars (f, insn[0], 4);
if (fx != NULL)
md_number_to_chars (fx, insn[1], 4);
}
/* This is the main entry point for the machine-dependent assembler. Gas
calls this function for each input line which does not contain a
pseudoop.
STR points to a NULL terminated machine dependent instruction. This
function is supposed to emit the frags/bytes it assembles to. */
void
md_assemble (char *str)
{
char *scan;
char *input_line_save;
struct tic80_opcode *opcode;
expressionS myops[16];
/* Ensure there is something there to assemble. */
assert (str);
/* Drop any leading whitespace. */
while (ISSPACE (*str))
str++;
/* Isolate the mnemonic from the rest of the string by finding the first
whitespace character and zapping it to a null byte. */
for (scan = str; *scan != '\000' && !ISSPACE (*scan); scan++)
;
if (*scan != '\000')
*scan++ = '\000';
/* Try to find this mnemonic in the hash table. */
if ((opcode = (struct tic80_opcode *) hash_find (tic80_hash, str)) == NULL)
{
as_bad (_("Invalid mnemonic: '%s'"), str);
return;
}
str = scan;
while (ISSPACE (*scan))
scan++;
input_line_save = input_line_pointer;
input_line_pointer = str;
opcode = find_opcode (opcode, myops);
if (opcode == NULL)
as_bad (_("Invalid operands: '%s'"), input_line_save);
input_line_pointer = input_line_save;
build_insn (opcode, myops);
}
/* This function is called once at the start of assembly, after the command
line arguments have been parsed and all the machine independent
initializations have been completed.
It should set up all the tables, etc., that the machine dependent part of
the assembler will need. */
void
md_begin (void)
{
char *prev_name = "";
register const struct tic80_opcode *op;
register const struct tic80_opcode *op_end;
const struct predefined_symbol *pdsp;
extern int coff_flags; /* Defined in obj-coff.c */
/* Set F_AR32WR in coff_flags, which will end up in the file header
f_flags field. */
coff_flags |= F_AR32WR; /* TIc80 is 32 bit little endian. */
/* Insert unique names into hash table. The TIc80 instruction set
has many identical opcode names that have different opcodes based
on the operands. This hash table then provides a quick index to
the first opcode with a particular name in the opcode table. */
tic80_hash = hash_new ();
op_end = tic80_opcodes + tic80_num_opcodes;
for (op = tic80_opcodes; op < op_end; op++)
{
if (strcmp (prev_name, op->name) != 0)
{
prev_name = (char *) op->name;
hash_insert (tic80_hash, op->name, (char *) op);
}
}
/* Insert the predefined symbols into the symbol table. We use
symbol_create rather than symbol_new so that these symbols don't
end up in the object files' symbol table. Note that the values
of the predefined symbols include some upper bits that
distinguish the type of the symbol (register, bitnum, condition
code, etc) and these bits must be masked away before actually
inserting the values into the instruction stream. For registers
we put these bits in the symbol table since we use them later and
there is no question that they aren't part of the register
number. For constants we can't do that since the constant can be
any value, so they are masked off before putting them into the
symbol table. */
pdsp = NULL;
while ((pdsp = tic80_next_predefined_symbol (pdsp)) != NULL)
{
segT segment;
valueT valu;
int symtype;
symtype = PDS_VALUE (pdsp) & TIC80_OPERAND_MASK;
switch (symtype)
{
case TIC80_OPERAND_GPR:
case TIC80_OPERAND_FPA:
case TIC80_OPERAND_CR:
segment = reg_section;
valu = PDS_VALUE (pdsp);
break;
case TIC80_OPERAND_CC:
case TIC80_OPERAND_BITNUM:
segment = absolute_section;
valu = PDS_VALUE (pdsp) & ~TIC80_OPERAND_MASK;
break;
default:
internal_error_a (_("unhandled predefined symbol bits"),
(long) symtype);
break;
}
symbol_table_insert (symbol_create (PDS_NAME (pdsp), segment, valu,
&zero_address_frag));
}
}
/* The assembler adds md_shortopts to the string passed to getopt. */
const char *md_shortopts = "";
/* The assembler adds md_longopts to the machine independent long options
that are passed to getopt. */
struct option md_longopts[] =
{
#define OPTION_RELAX (OPTION_MD_BASE)
{"relax", no_argument, NULL, OPTION_RELAX},
#define OPTION_NO_RELAX (OPTION_RELAX + 1)
{"no-relax", no_argument, NULL, OPTION_NO_RELAX},
{NULL, no_argument, NULL, 0}
};
size_t md_longopts_size = sizeof (md_longopts);
/* The md_parse_option function will be called whenever getopt returns an
unrecognized code, presumably indicating a special code value which
appears in md_longopts for machine specific command line options. */
int
md_parse_option (int c, char *arg ATTRIBUTE_UNUSED)
{
switch (c)
{
case OPTION_RELAX:
tic80_relax = 1;
break;
case OPTION_NO_RELAX:
tic80_relax = 0;
break;
default:
return 0;
}
return 1;
}
/* The md_show_usage function will be called whenever a usage message is
printed. It should print a description of the machine specific options
found in md_longopts. */
void
md_show_usage (FILE *stream)
{
fprintf (stream, "\
TIc80 options:\n\
-relax alter PC relative branch instructions to use long form when needed\n\
-no-relax always use short PC relative branch instructions, error on overflow\n");
}
/* Attempt to simplify or even eliminate a fixup. The return value is
ignored; perhaps it was once meaningful, but now it is historical.
To indicate that a fixup has been eliminated, set fixP->fx_done. */
void
md_apply_fix3 (fixS *fixP, valueT * valP, segT seg ATTRIBUTE_UNUSED)
{
long val = * (long *) valP;
char *dest = fixP->fx_frag->fr_literal + fixP->fx_where;
int overflow;
switch (fixP->fx_r_type)
{
case R_RELLONGX:
md_number_to_chars (dest, (valueT) val, 4);
break;
case R_MPPCR:
val >>= 2;
val += 1; /* Target address computed from inst start. */
md_number_to_chars (dest, (valueT) val, 4);
break;
case R_MPPCR15W:
overflow = (val < -65536L) || (val > 65532L);
if (overflow)
as_bad_where (fixP->fx_file, fixP->fx_line,
_("PC offset 0x%lx outside range 0x%lx-0x%lx"),
val, -65536L, 65532L);
else
{
val >>= 2;
*dest++ = val & 0xFF;
val >>= 8;
*dest = (*dest & 0x80) | (val & 0x7F);
}
break;
case R_ABS:
md_number_to_chars (dest, (valueT) val, fixP->fx_size);
break;
default:
internal_error_a (_("unhandled relocation type in fixup"),
(long) fixP->fx_r_type);
break;
}
if (fixP->fx_addsy == NULL && fixP->fx_pcrel == 0)
fixP->fx_done = 1;
}
/* Functions concerning relocs. */
/* The location from which a PC relative jump should be calculated,
given a PC relative reloc.
For the TIc80, this is the address of the 32 bit opcode containing
the PC relative field. */
long
md_pcrel_from (fixS *fixP)
{
return (fixP->fx_frag->fr_address + fixP->fx_where);
}
/* Called after relax() is finished.
In: Address of frag.
fr_type == rs_machine_dependent.
fr_subtype is what the address relaxed to.
Out: Any fixSs and constants are set up.
Caller will turn frag into a ".space 0". */
void
md_convert_frag (object_headers *headers ATTRIBUTE_UNUSED,
segT seg ATTRIBUTE_UNUSED,
fragS *fragP ATTRIBUTE_UNUSED)
{
internal_error (_("md_convert_frag() not implemented yet"));
abort ();
}
void
tc_coff_symbol_emit_hook (symbolS *ignore ATTRIBUTE_UNUSED)
{
}
#if defined OBJ_COFF
short
tc_coff_fix2rtype (fixS *fixP)
{
return (fixP->fx_r_type);
}
#endif /* OBJ_COFF */