sparc.c

早期freebsd实现

/*-
 * This code is derived from software copyrighted by the Free Software
 * Foundation.
 *
 * Modified 1993 by Chris Torek at Lawrence Berkeley Laboratory.
 */

#ifndef lint
static char sccsid[] = "@(#)sparc.c	5.2 (Berkeley) 4/12/93";
#endif /* not lint */

/* sparc.c -- Assemble for the SPARC
   Copyright (C) 1989 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA.  */


#include <stdio.h>
#include <ctype.h>

#include "sparc-opcode.h"
#include "as.h"
#include "frags.h"
#include "struc-symbol.h"
#include "flonum.h"
#include "expr.h"
#include "hash.h"
#include "md.h"
#include "sparc.h"
#include "write.h"
#include "read.h"
#include "symbols.h"

void md_begin();
void md_end();
void md_number_to_chars();
void md_assemble();
char *md_atof();
void md_convert_frag();
void md_create_short_jump();
void md_create_long_jump();
int  md_estimate_size_before_relax();
void md_number_to_imm();
void md_number_to_disp();
void md_number_to_field();
void md_ri_to_chars();
void emit_relocations();
static void sparc_ip();

const relax_typeS md_relax_table[] = { 0 };

/* handle of the OPCODE hash table */
static struct hash_control *op_hash = NULL;

static void s_seg(), s_proc(), s_data1(), s_reserve(), s_common();
extern void s_globl(), s_long(), s_short(), s_space(), cons();

const pseudo_typeS
md_pseudo_table[] = {
    { "common",     s_common,   0 },
    { "global",     s_globl,    0 },
    { "half",       cons,       2 },
    { "proc",       s_proc,     0 },
    { "reserve",    s_reserve,  0 },
    { "seg",        s_seg,      0 },
    { "skip",       s_space,    0 },
    { "word",       cons,       4 },
    { NULL,         0,          0 },
};

int md_short_jump_size = 4;
int md_long_jump_size = 4;
int omagic  =  (0x103 << 16) | OMAGIC;  /* Magic number for header */

/* This array holds the chars that always start a comment.  If the
    pre-processor is disabled, these aren't very useful */
char comment_chars[] = "!";	/* JF removed '|' from comment_chars */

/* This array holds the chars that only start a comment at the beginning of
   a line.  If the line seems to have the form '# 123 filename'
   .line and .file directives will appear in the pre-processed output */
/* Note that input_file.c hand checks for '#' at the beginning of the
   first line of the input file.  This is because the compiler outputs
   #NO_APP at the beginning of its output. */
/* Also note that '/*' will always start a comment */
char line_comment_chars[] = "#";

/* Chars that can be used to separate mant from exp in floating point nums */
char EXP_CHARS[] = "eE";

/* Chars that mean this number is a floating point constant */
/* As in 0f12.456 */
/* or    0d1.2345e12 */
char FLT_CHARS[] = "rRsSfFdDxXpP";

/* Also be aware that MAXIMUM_NUMBER_OF_CHARS_FOR_FLOAT may have to be
   changed in read.c .  Ideally it shouldn't have to know about it at all,
   but nothing is ideal around here.
 */
int size_reloc_info = sizeof(struct reloc_info_sparc);

static unsigned char octal[256];
#define isoctal(c)  octal[c]
static unsigned char toHex[256];

/*
 *  anull bit - causes the branch delay slot instructions to not be executed 
 */
#define ANNUL       (1 << 29)

struct sparc_it {
    char    *error;
    unsigned long opcode;
    struct nlist *nlistp;
    expressionS exp;
    int pcrel;
    enum reloc_type reloc;
} the_insn, set_insn;

#ifdef __STDC__
static void print_insn(struct sparc_it *insn);
static int getExpression(char *str);
#else
static void print_insn();
static int getExpression();
#endif
static char *expr_end;
static int special_case;

#define SPECIAL_CASE_SET    1

/*
 * sort of like s_lcomm
 *
 */
static void
s_reserve()
{
    char *name;
    char c;
    char *p;
    int temp;
    symbolS *symbolP;

    name = input_line_pointer;
    c = get_symbol_end();
    p = input_line_pointer;
    *p = c;
    SKIP_WHITESPACE();
    if ( * input_line_pointer != ',' ) {
	as_warn("Expected comma after name");
	ignore_rest_of_line();
	return;
    }
    input_line_pointer ++;
    if ((temp = get_absolute_expression()) < 0) {
	as_warn("BSS length (%d.) <0! Ignored.", temp);
	ignore_rest_of_line();
	return;
    }
    *p = 0;
    symbolP = symbol_find_or_make(name);
    *p = c;
    if (strncmp(input_line_pointer, ",\"bss\"", 6) != 0) {
	as_warn("bad .reserve segment: `%s'", input_line_pointer);
	return;
    }
    input_line_pointer += 6;
    if (symbolP->sy_other == 0 
        && symbolP->sy_desc  == 0
	&& ((symbolP->sy_type  == N_BSS
	&& symbolP->sy_value == local_bss_counter)
	|| ((symbolP->sy_type & N_TYPE) == N_UNDF
	&& symbolP->sy_value == 0))) {
	    symbolP->sy_value = local_bss_counter;
	    symbolP->sy_type  = N_BSS;
	    symbolP->sy_frag  = & bss_address_frag;
	    local_bss_counter += temp;
    } else {
	as_warn( "Ignoring attempt to re-define symbol from %d. to %d.",
	    symbolP->sy_value, local_bss_counter );
    }
    demand_empty_rest_of_line();
    return;
}

static void
s_common()
{
    register char *name;
    register char c;
    register char *p;
    register int temp;
    register symbolS *	symbolP;

    name = input_line_pointer;
    c = get_symbol_end();
    /* just after name is now '\0' */
    p = input_line_pointer;
    *p = c;
    SKIP_WHITESPACE();
    if ( * input_line_pointer != ',' ) {
	as_warn("Expected comma after symbol-name");
	ignore_rest_of_line();
	return;
    }
    input_line_pointer ++; /* skip ',' */
    if ( (temp = get_absolute_expression ()) < 0 ) {
	as_warn(".COMMon length (%d.) <0! Ignored.", temp);
	ignore_rest_of_line();
	return;
    }
    *p = 0;
    symbolP = symbol_find_or_make (name);
    *p = c;
    if (   (symbolP->sy_type & N_TYPE) != N_UNDF ||
        symbolP->sy_other != 0 || symbolP->sy_desc != 0) {
	as_warn( "Ignoring attempt to re-define symbol");
	ignore_rest_of_line();
	return;
    }
    if (symbolP->sy_value) {
	if (symbolP->sy_value != temp) {
	    as_warn( "Length of .comm \"%s\" is already %d. Not changed to %d.",
		symbolP->sy_name, symbolP->sy_value, temp);
	}
    } else {
	symbolP->sy_value = temp;
	symbolP->sy_type |= N_EXT;
    }
    know(symbolP->sy_frag == &zero_address_frag);
    if (strncmp(input_line_pointer, ",\"bss\"", 6) != 0) {
	p=input_line_pointer;
	while(*p && *p!='\n')
		p++;
	c= *p;
	*p='\0';
	as_warn("bad .common segment: `%s'", input_line_pointer);
	*p=c;
	return;
    }
    input_line_pointer += 6;
    demand_empty_rest_of_line();
    return;
}

static void
s_seg()
{

    if (strncmp(input_line_pointer, "\"text\"", 6) == 0) {
	input_line_pointer += 6;
	s_text();
	return;
    }
    if (strncmp(input_line_pointer, "\"data\"", 6) == 0) {
	input_line_pointer += 6;
	s_data();
	return;
    }
    if (strncmp(input_line_pointer, "\"data1\"", 7) == 0) {
	input_line_pointer += 7;
	s_data1();
	return;
    }
    as_warn("Unknown segment type");
    demand_empty_rest_of_line();
    return;
}

static void
s_data1()
{
    subseg_new(SEG_DATA, 1);
    demand_empty_rest_of_line();
    return;
}

static void
s_proc()
{
    extern char is_end_of_line[];

    while (!is_end_of_line[*input_line_pointer]) {
	++input_line_pointer;
    }
    ++input_line_pointer;
    return;
}

/* This function is called once, at assembler startup time.  It should
   set up all the tables, etc. that the MD part of the assembler will need.  */
void
md_begin()
{
  register char *retval = NULL;
  int lose = 0;
  register unsigned int i = 0;

  op_hash = hash_new();
  if (op_hash == NULL)
    as_fatal("Virtual memory exhausted");

  while (i < NUMOPCODES)
    {
      const char *name = sparc_opcodes[i].name;
      retval = hash_insert(op_hash, name, &sparc_opcodes[i]);
      if(retval != NULL && *retval != '\0')
	{
	  fprintf (stderr, "internal error: can't hash `%s': %s\n",
		   sparc_opcodes[i].name, retval);
	  lose = 1;
	}
      do
	{
	  if (sparc_opcodes[i].match & sparc_opcodes[i].lose)
	    {
	      fprintf (stderr, "internal error: losing opcode: `%s' \"%s\"\n",
		       sparc_opcodes[i].name, sparc_opcodes[i].args);
	      lose = 1;
	    }
	  ++i;
	} while (i < NUMOPCODES
		 && !strcmp(sparc_opcodes[i].name, name));
    }

  if (lose)
    as_fatal ("Broken assembler.  No assembly attempted.");

  for (i = '0'; i < '8'; ++i)
    octal[i] = 1;
  for (i = '0'; i <= '9'; ++i)
    toHex[i] = i - '0';
  for (i = 'a'; i <= 'f'; ++i)
    toHex[i] = i + 10 - 'a';
  for (i = 'A'; i <= 'F'; ++i)
    toHex[i] = i + 10 - 'A';
}

void
md_end()
{
    return;
}

void
md_assemble(str)
    char *str;
{
    char *toP;
    int rsd;

    assert(str);
    sparc_ip(str);
    toP = frag_more(4);
    /* put out the opcode */
    md_number_to_chars(toP, the_insn.opcode, 4);

    /* put out the symbol-dependent stuff */
    if (the_insn.reloc != NO_RELOC) {
	fix_new(
	    frag_now,                           /* which frag */
	    (toP - frag_now->fr_literal), /* where */
	    4,                                  /* size */
	    the_insn.exp.X_add_symbol,
	    the_insn.exp.X_subtract_symbol,
	    the_insn.exp.X_add_number,
	    the_insn.pcrel,
	    the_insn.reloc
	);
    }
    switch (special_case) {

    case SPECIAL_CASE_SET:
	special_case = 0;
	assert(the_insn.reloc == RELOC_HI22);
	if (the_insn.exp.X_seg == SEG_ABSOLUTE &&
	    the_insn.exp.X_add_symbol == 0 &&
	    the_insn.exp.X_subtract_symbol == 0 &&
	    (the_insn.exp.X_add_number & 0x3ff) == 0)
		return;
	toP = frag_more(4);
	rsd = (the_insn.opcode >> 25) & 0x1f;
	the_insn.opcode = 0x80102000 | (rsd << 25) | (rsd << 14);
	md_number_to_chars(toP, the_insn.opcode, 4);
	fix_new(
	    frag_now,                           /* which frag */
	    (toP - frag_now->fr_literal),       /* where */
	    4,                                  /* size */
	    the_insn.exp.X_add_symbol,
	    the_insn.exp.X_subtract_symbol,
	    the_insn.exp.X_add_number,
	    the_insn.pcrel,
	    RELOC_LO10
	);
	return;

    case 0:
	return;

    default:
	abort();
    }
}

static void
sparc_ip(str)
    char *str;
{
    char *s;
    const char *args;
    char c;
    unsigned long i;
    struct sparc_opcode *insn;
    char *argsStart;
    unsigned long   opcode;
    unsigned int mask;
    int match = FALSE;
    int comma = 0;

    for (s = str; islower(*s) || (*s >= '0' && *s <= '3'); ++s)
	;
    switch (*s) {

    case '\0':
	break;

    case ',':
	comma = 1;

	/*FALLTHROUGH*/

    case ' ':
	*s++ = '\0';
	break;

    default:
	    as_warn("Unknown opcode: `%s'", str);
	    exit(1);
    }
    if ((insn = (struct sparc_opcode *) hash_find(op_hash, str)) == NULL) {
	as_warn("Unknown opcode: `%s'", str);
	return;
    }
    if (comma) {
	*--s = ',';
    }
    argsStart = s;
    for (;;) {
	opcode = insn->match;
	bzero(&the_insn, sizeof(the_insn));
	the_insn.reloc = NO_RELOC;

	/*
	 * Build the opcode, checking as we go to make
	 * sure that the operands match
	 */
	for (args = insn->args; ; ++args) {
	    switch (*args) {

	    case '\0':  /* end of args */
		if (*s == '\0') {
		    match = TRUE;
		}
		break;

	    case '+':
		if (*s == '+') {
		    ++s;
		    continue;
		}
		if (*s == '-') {
		    continue;
		}
		break;

	    case '[':   /* these must match exactly */
	    case ']':
	    case ',':
	    case ' ':
		if (*s++ == *args)
		    continue;
		break;

	    case '#':   /* must be at least one digit */
		if (isdigit(*s++)) {
		    while (isdigit(*s)) {
			++s;
		    }
		    continue;
		}
		break;

	    case 'C':   /* coprocessor state register */
		if (strncmp(s, "%csr", 4) == 0) {
		    s += 4;
		    continue;
		}
		break;

	    case 'b':    /* next operand is a coprocessor register */
	    case 'c':
	    case 'D':
	        if (*s++ == '%' && *s++ == 'c' && isdigit(*s)) {
		    mask = *s++;
		    if (isdigit(*s)) {
			mask = 10 * (mask - '0') + (*s++ - '0');
			if (mask >= 32) {
			    break;
			}
		    } else {
			mask -= '0';
		    }
		    switch (*args) {

		    case 'b':
			opcode |= mask << 14;
			continue;

		    case 'c':
			opcode |= mask;
			continue;

		    case 'D':
			opcode |= mask << 25;
			continue;
		    }
		}
		break;

	    case 'r':   /* next operand must be a register */
	    case 'R':
	    case '1':
	    case '2':
	    case 'd':
		if (*s++ == '%') {
		    switch (c = *s++) {

		    case 'f':   /* frame pointer */
		        if (*s++ == 'p') {
			    mask = 0x1e;
			    break;
			}
			goto error;

		    case 'g':   /* global register */
			if (isoctal(c = *s++)) {
			    mask = c - '0';
			    break;
			}
			goto error;

		    case 'i':   /* in register */
			if (isoctal(c = *s++)) {
			    mask = c - '0' + 24;
			    break;
			}
			goto error;

		    case 'l':   /* local register */
			if (isoctal(c = *s++)) {
			    mask= (c - '0' + 16) ;
			    break;
			}
			goto error;

		    case 'o':   /* out register */
			if (isoctal(c = *s++)) {
			    mask= (c - '0' + 8) ;
			    break;
			}
			goto error;

		    case 's':   /* stack pointer */
		        if (*s++ == 'p') {
			    mask= 0xe;
			    break;
			}
			goto error;

		    case 'r': /* any register */
		        if (!isdigit(c = *s++)) {
			    goto error;
			}
			/* FALLTHROUGH */
		    case '0': case '1': case '2': case '3': case '4':
		    case '5': case '6': case '7': case '8': case '9':
			if (isdigit(*s)) {
			    if ((c = 10 * (c - '0') + (*s++ - '0')) >= 32) {
				goto error;
			    }
			} else {
			    c -= '0';
			}
			mask= c;
			break;

		    default:
			goto error;
		    }
		    /*
		     * Got the register, now figure out where
		     * it goes in the opcode.
		     */
		    switch (*args) {

		    case '1':
			opcode |= mask << 14;
			continue;

		    case '2':
			opcode |= mask;
			continue;

		    case 'd':
			opcode |= mask << 25;
			continue;

		    case 'r':
			opcode |= (mask << 25) | (mask << 14);
			continue;

		    case 'R':
			opcode |= (mask << 25) | mask;
			continue;
		    }
		}
		break;

	    case 'e':    /* next operand is a floating point register */
	    case 'f':
	    case 'g':
	        if (*s++ == '%' && *s++ == 'f' && isdigit(*s)) {
		    mask = *s++;
		    if (isdigit(*s)) {
			mask = 10 * (mask - '0') + (*s++ - '0');