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nasm/assemble.c

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/* assemble.c code generation for the Netwide Assembler
*
* The Netwide Assembler is copyright (C) 1996 Simon Tatham and
* Julian Hall. All rights reserved. The software is
* redistributable under the licence given in the file "Licence"
* distributed in the NASM archive.
*
* the actual codes (C syntax, i.e. octal):
* \0 - terminates the code. (Unless it's a literal of course.)
* \1, \2, \3 - that many literal bytes follow in the code stream
* \4, \6 - the POP/PUSH (respectively) codes for CS, DS, ES, SS
* (POP is never used for CS) depending on operand 0
* \5, \7 - the second byte of POP/PUSH codes for FS, GS, depending
* on operand 0
* \10, \11, \12 - a literal byte follows in the code stream, to be added
* to the register value of operand 0, 1 or 2
* \17 - encodes the literal byte 0. (Some compilers don't take
* kindly to a zero byte in the _middle_ of a compile time
* string constant, so I had to put this hack in.)
* \14, \15, \16 - a signed byte immediate operand, from operand 0, 1 or 2
* \20, \21, \22 - a byte immediate operand, from operand 0, 1 or 2
* \24, \25, \26 - an unsigned byte immediate operand, from operand 0, 1 or 2
* \30, \31, \32 - a word immediate operand, from operand 0, 1 or 2
* \34, \35, \36 - select between \3[012] and \4[012] depending on 16/32 bit
* assembly mode or the operand-size override on the operand
* \37 - a word constant, from the _segment_ part of operand 0
* \40, \41, \42 - a long immediate operand, from operand 0, 1 or 2
* \44, \45, \46 - select between \3[012], \4[012] and \5[456]
* depending on assembly mode or the address-size override
* on the operand.
* \50, \51, \52 - a byte relative operand, from operand 0, 1 or 2
* \54, \55, \56 - a qword immediate operand, from operand 0, 1 or 2
* \60, \61, \62 - a word relative operand, from operand 0, 1 or 2
* \64, \65, \66 - select between \6[012] and \7[012] depending on 16/32 bit
* assembly mode or the operand-size override on the operand
* \70, \71, \72 - a long relative operand, from operand 0, 1 or 2
* \1ab - a ModRM, calculated on EA in operand a, with the spare
* field the register value of operand b.
* \130,\131,\132 - an immediate word or signed byte for operand 0, 1, or 2
* \133,\134,\135 - or 2 (s-field) into next opcode byte if operand 0, 1, or 2
* is a signed byte rather than a word.
* \140,\141,\142 - an immediate dword or signed byte for operand 0, 1, or 2
* \143,\144,\145 - or 2 (s-field) into next opcode byte if operand 0, 1, or 2
* is a signed byte rather than a dword.
* \150,\151,\152 - an immediate qword or signed byte for operand 0, 1, or 2
* \153,\154,\155 - or 2 (s-field) into next opcode byte if operand 0, 1, or 2
* is a signed byte rather than a qword.
* \2ab - a ModRM, calculated on EA in operand a, with the spare
* field equal to digit b.
* \30x - might be an 0x67 byte, depending on the address size of
* the memory reference in operand x.
* \310 - indicates fixed 16-bit address size, i.e. optional 0x67.
* \311 - indicates fixed 32-bit address size, i.e. optional 0x67.
* \312 - (disassembler only) marker on LOOP, LOOPxx instructions.
* \313 - indicates fixed 64-bit address size, 0x67 invalid.
* \320 - indicates fixed 16-bit operand size, i.e. optional 0x66.
* \321 - indicates fixed 32-bit operand size, i.e. optional 0x66.
* \322 - indicates that this instruction is only valid when the
* operand size is the default (instruction to disassembler,
* generates no code in the assembler)
* \323 - indicates fixed 64-bit operand size, REX on extensions only.
* \324 - indicates 64-bit operand size requiring REX prefix.
* \330 - a literal byte follows in the code stream, to be added
* to the condition code value of the instruction.
* \331 - instruction not valid with REP prefix. Hint for
* disassembler only; for SSE instructions.
* \332 - disassemble a rep (0xF3 byte) prefix as repe not rep.
* \333 - REP prefix (0xF3 byte); for SSE instructions. Not encoded
* as a literal byte in order to aid the disassembler.
* \334 - LOCK prefix used instead of REX.R
* \340 - reserve <operand 0> bytes of uninitialized storage.
* Operand 0 had better be a segmentless constant.
* \370,\371,\372 - match only if operand 0 meets byte jump criteria.
* 370 is used for Jcc, 371 is used for JMP.
* \373 - assemble 0x03 if bits==16, 0x05 if bits==32;
* used for conditional jump over longer jump
*/
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include "nasm.h"
#include "nasmlib.h"
#include "assemble.h"
#include "insns.h"
#include "preproc.h"
#include "regflags.c"
#include "regvals.c"
extern struct itemplate *nasm_instructions[];
typedef struct {
int sib_present; /* is a SIB byte necessary? */
int bytes; /* # of bytes of offset needed */
int size; /* lazy - this is sib+bytes+1 */
uint8_t modrm, sib, rex, rip; /* the bytes themselves */
} ea;
static uint32_t cpu; /* cpu level received from nasm.c */
static efunc errfunc;
static struct ofmt *outfmt;
static ListGen *list;
static int32_t calcsize(int32_t, int32_t, int, insn *, const char *);
static void gencode(int32_t, int32_t, int, insn *, const char *, int32_t);
static int matches(struct itemplate *, insn *, int bits);
static int32_t regflag(const operand *);
static int32_t regval(const operand *);
static int rexflags(int, int32_t, int);
static int op_rexflags(const operand *, int);
static ea *process_ea(operand *, ea *, int, int, int, int);
static int chsize(operand *, int);
static void assert_no_prefix(insn * ins, int prefix)
{
int j;
for (j = 0; j < ins->nprefix; j++) {
if (ins->prefixes[j] == prefix) {
errfunc(ERR_NONFATAL, "invalid %s prefix", prefix_name(prefix));
break;
}
}
}
/*
* This routine wrappers the real output format's output routine,
* in order to pass a copy of the data off to the listing file
* generator at the same time.
*/
static void out(int32_t offset, int32_t segto, const void *data,
uint32_t type, int32_t segment, int32_t wrt)
{
static int32_t lineno = 0; /* static!!! */
static char *lnfname = NULL;
if ((type & OUT_TYPMASK) == OUT_ADDRESS) {
if (segment != NO_SEG || wrt != NO_SEG) {
/*
* This address is relocated. We must write it as
* OUT_ADDRESS, so there's no work to be done here.
*/
list->output(offset, data, type);
} else {
uint8_t p[8], *q = p;
/*
* This is a non-relocated address, and we're going to
* convert it into RAWDATA format.
*/
if ((type & OUT_SIZMASK) == 4) {
WRITELONG(q, *(int32_t *)data);
list->output(offset, p, OUT_RAWDATA + 4);
} else if ((type & OUT_SIZMASK) == 8) {
WRITEDLONG(q, *(int64_t *)data);
list->output(offset, p, OUT_RAWDATA + 8);
} else {
WRITESHORT(q, *(int32_t *)data);
list->output(offset, p, OUT_RAWDATA + 2);
}
}
} else if ((type & OUT_TYPMASK) == OUT_RAWDATA) {
list->output(offset, data, type);
} else if ((type & OUT_TYPMASK) == OUT_RESERVE) {
list->output(offset, NULL, type);
} else if ((type & OUT_TYPMASK) == OUT_REL2ADR ||
(type & OUT_TYPMASK) == OUT_REL4ADR) {
list->output(offset, data, type);
}
/*
* this call to src_get determines when we call the
* debug-format-specific "linenum" function
* it updates lineno and lnfname to the current values
* returning 0 if "same as last time", -2 if lnfname
* changed, and the amount by which lineno changed,
* if it did. thus, these variables must be static
*/
if (src_get(&lineno, &lnfname)) {
outfmt->current_dfmt->linenum(lnfname, lineno, segto);
}
outfmt->output(segto, data, type, segment, wrt);
}
static int jmp_match(int32_t segment, int32_t offset, int bits,
insn * ins, const char *code)
{
int32_t isize;
uint8_t c = code[0];
if (c != 0370 && c != 0371)
return 0;
if (ins->oprs[0].opflags & OPFLAG_FORWARD) {
if ((optimizing < 0 || (ins->oprs[0].type & STRICT))
&& c == 0370)
return 1;
else
return (pass0 == 0); /* match a forward reference */
}
isize = calcsize(segment, offset, bits, ins, code);
if (ins->oprs[0].segment != segment)
return 0;
isize = ins->oprs[0].offset - offset - isize; /* isize is now the delta */
if (isize >= -128L && isize <= 127L)
return 1; /* it is byte size */
return 0;
}
int32_t assemble(int32_t segment, int32_t offset, int bits, uint32_t cp,
insn * instruction, struct ofmt *output, efunc error,
ListGen * listgen)
{
struct itemplate *temp;
int j;
int size_prob;
int32_t insn_end;
int32_t itimes;
int32_t start = offset;
int32_t wsize = 0; /* size for DB etc. */
errfunc = error; /* to pass to other functions */
cpu = cp;
outfmt = output; /* likewise */
list = listgen; /* and again */
switch (instruction->opcode) {
case -1:
return 0;
case I_DB:
wsize = 1;
break;
case I_DW:
wsize = 2;
break;
case I_DD:
wsize = 4;
break;
case I_DQ:
wsize = 8;
break;
case I_DT:
wsize = 10;
break;
}
if (wsize) {
extop *e;
int32_t t = instruction->times;
if (t < 0)
errfunc(ERR_PANIC,
"instruction->times < 0 (%ld) in assemble()", t);
while (t--) { /* repeat TIMES times */
for (e = instruction->eops; e; e = e->next) {
if (e->type == EOT_DB_NUMBER) {
if (wsize == 1) {
if (e->segment != NO_SEG)
errfunc(ERR_NONFATAL,
"one-byte relocation attempted");
else {
uint8_t out_byte = e->offset;
out(offset, segment, &out_byte,
OUT_RAWDATA + 1, NO_SEG, NO_SEG);
}
} else if (wsize > 8) {
errfunc(ERR_NONFATAL, "integer supplied to a DT"
" instruction");
} else
out(offset, segment, &e->offset,
OUT_ADDRESS + wsize, e->segment, e->wrt);
offset += wsize;
} else if (e->type == EOT_DB_STRING) {
int align;
out(offset, segment, e->stringval,
OUT_RAWDATA + e->stringlen, NO_SEG, NO_SEG);
align = e->stringlen % wsize;
if (align) {
align = wsize - align;
out(offset, segment, "\0\0\0\0\0\0\0\0",
OUT_RAWDATA + align, NO_SEG, NO_SEG);
}
offset += e->stringlen + align;
}
}
if (t > 0 && t == instruction->times - 1) {
/*
* Dummy call to list->output to give the offset to the
* listing module.
*/
list->output(offset, NULL, OUT_RAWDATA);
list->uplevel(LIST_TIMES);
}
}
if (instruction->times > 1)
list->downlevel(LIST_TIMES);
return offset - start;
}
if (instruction->opcode == I_INCBIN) {
static char fname[FILENAME_MAX];
FILE *fp;
int32_t len;
char *prefix = "", *combine;
char **pPrevPath = NULL;
len = FILENAME_MAX - 1;
if (len > instruction->eops->stringlen)
len = instruction->eops->stringlen;
strncpy(fname, instruction->eops->stringval, len);
fname[len] = '\0';
while (1) { /* added by alexfru: 'incbin' uses include paths */
combine = nasm_malloc(strlen(prefix) + len + 1);
strcpy(combine, prefix);
strcat(combine, fname);
if ((fp = fopen(combine, "rb")) != NULL) {
nasm_free(combine);
break;
}
nasm_free(combine);
pPrevPath = pp_get_include_path_ptr(pPrevPath);
if (pPrevPath == NULL)
break;
prefix = *pPrevPath;
}
if (fp == NULL)
error(ERR_NONFATAL, "`incbin': unable to open file `%s'",
fname);
else if (fseek(fp, 0L, SEEK_END) < 0)
error(ERR_NONFATAL, "`incbin': unable to seek on file `%s'",
fname);
else {
static char buf[2048];
int32_t t = instruction->times;
int32_t base = 0;
len = ftell(fp);
if (instruction->eops->next) {
base = instruction->eops->next->offset;
len -= base;
if (instruction->eops->next->next &&
len > instruction->eops->next->next->offset)
len = instruction->eops->next->next->offset;
}
/*
* Dummy call to list->output to give the offset to the
* listing module.
*/
list->output(offset, NULL, OUT_RAWDATA);
list->uplevel(LIST_INCBIN);
while (t--) {
int32_t l;
fseek(fp, base, SEEK_SET);
l = len;
while (l > 0) {
int32_t m =
fread(buf, 1, (l > sizeof(buf) ? sizeof(buf) : l),
fp);
if (!m) {
/*
* This shouldn't happen unless the file
* actually changes while we are reading
* it.
*/
error(ERR_NONFATAL,
"`incbin': unexpected EOF while"
" reading file `%s'", fname);
t = 0; /* Try to exit cleanly */
break;
}
out(offset, segment, buf, OUT_RAWDATA + m,
NO_SEG, NO_SEG);
l -= m;
}
}
list->downlevel(LIST_INCBIN);
if (instruction->times > 1) {
/*
* Dummy call to list->output to give the offset to the
* listing module.
*/
list->output(offset, NULL, OUT_RAWDATA);
list->uplevel(LIST_TIMES);
list->downlevel(LIST_TIMES);
}
fclose(fp);
return instruction->times * len;
}
return 0; /* if we're here, there's an error */
}
size_prob = FALSE;
for (temp = nasm_instructions[instruction->opcode]; temp->opcode != -1; temp++){
int m = matches(temp, instruction, bits);
if (m == 99)
m += jmp_match(segment, offset, bits, instruction, temp->code);
if (m == 100) { /* matches! */
const char *codes = temp->code;
int32_t insn_size = calcsize(segment, offset, bits,
instruction, codes);
itimes = instruction->times;
if (insn_size < 0) /* shouldn't be, on pass two */
error(ERR_PANIC, "errors made it through from pass one");
else
while (itimes--) {
for (j = 0; j < instruction->nprefix; j++) {
uint8_t c = 0;
switch (instruction->prefixes[j]) {
case P_LOCK:
c = 0xF0;
break;
case P_REPNE:
case P_REPNZ:
c = 0xF2;
break;
case P_REPE:
case P_REPZ:
case P_REP:
c = 0xF3;
break;
case R_CS:
if (bits == 64) {
error(ERR_WARNING,
"cs segment base ignored in 64-bit mode");
}
c = 0x2E;
break;
case R_DS:
if (bits == 64) {
error(ERR_WARNING,
"ds segment base ignored in 64-bit mode");
}
c = 0x3E;
break;
case R_ES:
if (bits == 64) {
error(ERR_WARNING,
"es segment base ignored in 64-bit mode");
}
c = 0x26;
break;
case R_FS:
c = 0x64;
break;
case R_GS:
c = 0x65;
break;
case R_SS:
if (bits == 64) {
error(ERR_WARNING,
"ss segment base ignored in 64-bit mode");
}
c = 0x36;
break;
case R_SEGR6:
case R_SEGR7:
error(ERR_NONFATAL,
"segr6 and segr7 cannot be used as prefixes");
break;
case P_A16:
if (bits == 64) {
error(ERR_NONFATAL,
"16-bit addressing is not supported "
"in 64-bit mode");
break;
}
if (bits != 16)
c = 0x67;
break;
case P_A32:
if (bits != 32)
c = 0x67;
break;
case P_O16:
if (bits != 16)
c = 0x66;
break;
case P_O32:
if (bits == 16)
c = 0x66;
break;
default:
error(ERR_PANIC, "invalid instruction prefix");
}
if (c != 0) {
out(offset, segment, &c, OUT_RAWDATA + 1,
NO_SEG, NO_SEG);
offset++;
}
}
insn_end = offset + insn_size;
gencode(segment, offset, bits, instruction, codes,
insn_end);
offset += insn_size;
if (itimes > 0 && itimes == instruction->times - 1) {
/*
* Dummy call to list->output to give the offset to the
* listing module.
*/
list->output(offset, NULL, OUT_RAWDATA);
list->uplevel(LIST_TIMES);
}
}
if (instruction->times > 1)
list->downlevel(LIST_TIMES);
return offset - start;
} else if (m > 0 && m > size_prob) {
size_prob = m;
}
// temp++;
}
if (temp->opcode == -1) { /* didn't match any instruction */
switch (size_prob) {
case 1:
error(ERR_NONFATAL, "operation size not specified");
break;
case 2:
error(ERR_NONFATAL, "mismatch in operand sizes");
break;
case 3:
error(ERR_NONFATAL, "no instruction for this cpu level");
break;
case 4:
error(ERR_NONFATAL, "instruction not supported in 64-bit mode");
break;
default:
error(ERR_NONFATAL,
"invalid combination of opcode and operands");
break;
}
}
return 0;
}
int32_t insn_size(int32_t segment, int32_t offset, int bits, uint32_t cp,
insn * instruction, efunc error)
{
struct itemplate *temp;
errfunc = error; /* to pass to other functions */
cpu = cp;
if (instruction->opcode == -1)
return 0;
if (instruction->opcode == I_DB ||
instruction->opcode == I_DW ||
instruction->opcode == I_DD ||
instruction->opcode == I_DQ || instruction->opcode == I_DT) {
extop *e;
int32_t isize, osize, wsize = 0; /* placate gcc */
isize = 0;
switch (instruction->opcode) {
case I_DB:
wsize = 1;
break;
case I_DW:
wsize = 2;
break;
case I_DD:
wsize = 4;
break;
case I_DQ:
wsize = 8;
break;
case I_DT:
wsize = 10;
break;
}
for (e = instruction->eops; e; e = e->next) {
int32_t align;
osize = 0;
if (e->type == EOT_DB_NUMBER)
osize = 1;
else if (e->type == EOT_DB_STRING)
osize = e->stringlen;
align = (-osize) % wsize;
if (align < 0)
align += wsize;
isize += osize + align;
}
return isize * instruction->times;
}
if (instruction->opcode == I_INCBIN) {
char fname[FILENAME_MAX];
FILE *fp;
int32_t len;
char *prefix = "", *combine;
char **pPrevPath = NULL;
len = FILENAME_MAX - 1;
if (len > instruction->eops->stringlen)
len = instruction->eops->stringlen;
strncpy(fname, instruction->eops->stringval, len);
fname[len] = '\0';
while (1) { /* added by alexfru: 'incbin' uses include paths */
combine = nasm_malloc(strlen(prefix) + len + 1);
strcpy(combine, prefix);
strcat(combine, fname);
if ((fp = fopen(combine, "rb")) != NULL) {
nasm_free(combine);
break;
}
nasm_free(combine);
pPrevPath = pp_get_include_path_ptr(pPrevPath);
if (pPrevPath == NULL)
break;
prefix = *pPrevPath;
}
if (fp == NULL)
error(ERR_NONFATAL, "`incbin': unable to open file `%s'",
fname);
else if (fseek(fp, 0L, SEEK_END) < 0)
error(ERR_NONFATAL, "`incbin': unable to seek on file `%s'",
fname);
else {
len = ftell(fp);
fclose(fp);
if (instruction->eops->next) {
len -= instruction->eops->next->offset;
if (instruction->eops->next->next &&
len > instruction->eops->next->next->offset) {
len = instruction->eops->next->next->offset;
}
}
return instruction->times * len;
}
return 0; /* if we're here, there's an error */
}
for (temp = nasm_instructions[instruction->opcode]; temp->opcode != -1; temp++) {
int m = matches(temp, instruction, bits);
if (m == 99)
m += jmp_match(segment, offset, bits, instruction, temp->code);
if (m == 100) {
/* we've matched an instruction. */
int32_t isize;
const char *codes = temp->code;
int j;
isize = calcsize(segment, offset, bits, instruction, codes);
if (isize < 0)
return -1;
for (j = 0; j < instruction->nprefix; j++) {
if ((instruction->prefixes[j] != P_A16 &&
instruction->prefixes[j] != P_O16 && bits == 16) ||
(instruction->prefixes[j] != P_A32 &&
instruction->prefixes[j] != P_O32 && bits >= 32)) {
isize++;
}
}
return isize * instruction->times;
}
}
return -1; /* didn't match any instruction */
}
/* check that opn[op] is a signed byte of size 16 or 32,
and return the signed value*/
static int is_sbyte(insn * ins, int op, int size)
{
int32_t v;
int ret;
ret = !(ins->forw_ref && ins->oprs[op].opflags) && /* dead in the water on forward reference or External */
optimizing >= 0 &&
!(ins->oprs[op].type & STRICT) &&
ins->oprs[op].wrt == NO_SEG && ins->oprs[op].segment == NO_SEG;
v = ins->oprs[op].offset;
if (size == 16)
v = (int16_t)v; /* sign extend if 16 bits */
return ret && v >= -128L && v <= 127L;
}
static int32_t calcsize(int32_t segment, int32_t offset, int bits,
insn * ins, const char *codes)
{
int32_t length = 0;
uint8_t c;
int rex_mask = ~0;
ins->rex = 0; /* Ensure REX is reset */
(void)segment; /* Don't warn that this parameter is unused */
(void)offset; /* Don't warn that this parameter is unused */
while (*codes)
switch (c = *codes++) {
case 01:
case 02:
case 03:
codes += c, length += c;
break;
case 04:
case 05:
case 06:
case 07:
length++;
break;
case 010:
case 011:
case 012:
ins->rex |=
op_rexflags(&ins->oprs[c - 010], REX_B|REX_H|REX_P|REX_W);
codes++, length++;
break;
case 017:
length++;
break;
case 014:
case 015:
case 016:
length++;
break;
case 020:
case 021:
case 022:
length++;
break;
case 024:
case 025:
case 026:
length++;
break;
case 030:
case 031:
case 032:
length += 2;
break;
case 034:
case 035:
case 036:
if (ins->oprs[c - 034].type & (BITS16 | BITS32 | BITS64))
length += (ins->oprs[c - 034].type & BITS16) ? 2 : 4;
else
length += (bits == 16) ? 2 : 4;
break;
case 037:
length += 2;
break;
case 040:
case 041:
case 042:
length += 4;
break;
case 044:
case 045:
case 046:
length += ((ins->oprs[c - 044].addr_size ?
ins->oprs[c - 044].addr_size : bits) >> 3);
break;
case 050:
case 051:
case 052:
length++;
break;
case 054:
case 055:
case 056:
length += 8; /* MOV reg64/imm */
break;
case 060:
case 061:
case 062:
length += 2;
break;
case 064:
case 065:
case 066:
if (ins->oprs[c - 064].type & (BITS16 | BITS32 | BITS64))
length += (ins->oprs[c - 064].type & BITS16) ? 2 : 4;
else
length += (bits == 16) ? 2 : 4;
break;
case 070:
case 071:
case 072:
length += 4;
break;
case 0130:
case 0131:
case 0132:
length += is_sbyte(ins, c - 0130, 16) ? 1 : 2;
break;
case 0133:
case 0134:
case 0135:
codes += 2;
length++;
break;
case 0140:
case 0141:
case 0142:
length += is_sbyte(ins, c - 0140, 32) ? 1 : 4;
break;
case 0143:
case 0144:
case 0145:
codes += 2;
length++;
break;
case 0300:
case 0301:
case 0302:
length += chsize(&ins->oprs[c - 0300], bits);
break;
case 0310:
length += (bits != 16);
break;
case 0311:
length += (bits != 32);
break;
case 0312:
break;
case 0313:
break;
case 0320:
length += (bits != 16);
break;
case 0321:
length += (bits == 16);
break;
case 0322:
break;
case 0323:
rex_mask &= ~REX_W;
break;
case 0324:
ins->rex |= REX_W;
break;
case 0330:
codes++, length++;
break;
case 0331:
case 0332:
break;
case 0333:
length++;
break;
case 0334:
assert_no_prefix(ins, P_LOCK);
ins->rex |= REX_L;
break;
case 0340:
case 0341:
case 0342:
if (ins->oprs[0].segment != NO_SEG)
errfunc(ERR_NONFATAL, "attempt to reserve non-constant"
" quantity of BSS space");
else
length += ins->oprs[0].offset << (c - 0340);
break;
case 0370:
case 0371:
case 0372:
break;
case 0373:
length++;
break;
default: /* can't do it by 'case' statements */
if (c >= 0100 && c <= 0277) { /* it's an EA */
ea ea_data;
int rfield;
int32_t rflags;
ea_data.rex = 0; /* Ensure ea.REX is initially 0 */
if (c <= 0177) {
/* pick rfield from operand b */
rflags = regflag(&ins->oprs[c & 7]);
rfield = regvals[ins->oprs[c & 7].basereg];
} else {
rflags = 0;
rfield = c & 7;
}
if (!process_ea
(&ins->oprs[(c >> 3) & 7], &ea_data, bits,
rfield, rflags, ins->forw_ref)) {
errfunc(ERR_NONFATAL, "invalid effective address");
return -1;
} else {
ins->rex |= ea_data.rex;
length += ea_data.size;
}
} else
errfunc(ERR_PANIC, "internal instruction table corrupt"
": instruction code 0x%02X given", c);
}
ins->rex &= rex_mask;
if (ins->rex & REX_REAL) {
if (ins->rex & REX_H) {
errfunc(ERR_NONFATAL, "cannot use high register in rex instruction");
return -1;
} else if (bits == 64 ||
((ins->rex & REX_L) &&
!(ins->rex & (REX_P|REX_W|REX_X|REX_B)) &&
cpu >= IF_X86_64)) {
length++;
} else {
errfunc(ERR_NONFATAL, "invalid operands in non-64-bit mode");
return -1;
}
}
return length;
}
#define EMIT_REX() \
if((ins->rex & REX_REAL) && (bits == 64)) { \
ins->rex = (ins->rex & REX_REAL)|REX_P; \
out(offset, segment, &ins->rex, OUT_RAWDATA+1, NO_SEG, NO_SEG); \
ins->rex = 0; \
offset += 1; \
}
static void gencode(int32_t segment, int32_t offset, int bits,
insn * ins, const char *codes, int32_t insn_end)
{
static char condval[] = { /* conditional opcodes */
0x7, 0x3, 0x2, 0x6, 0x2, 0x4, 0xF, 0xD, 0xC, 0xE, 0x6, 0x2,
0x3, 0x7, 0x3, 0x5, 0xE, 0xC, 0xD, 0xF, 0x1, 0xB, 0x9, 0x5,
0x0, 0xA, 0xA, 0xB, 0x8, 0x4
};
uint8_t c;
uint8_t bytes[4];
int32_t size;
int64_t data;
while (*codes)
switch (c = *codes++) {
case 01:
case 02:
case 03:
EMIT_REX();
out(offset, segment, codes, OUT_RAWDATA + c, NO_SEG, NO_SEG);
codes += c;
offset += c;
break;
case 04:
case 06:
switch (ins->oprs[0].basereg) {
case R_CS:
bytes[0] = 0x0E + (c == 0x04 ? 1 : 0);
break;
case R_DS:
bytes[0] = 0x1E + (c == 0x04 ? 1 : 0);
break;
case R_ES:
bytes[0] = 0x06 + (c == 0x04 ? 1 : 0);
break;
case R_SS:
bytes[0] = 0x16 + (c == 0x04 ? 1 : 0);
break;
default:
errfunc(ERR_PANIC,
"bizarre 8086 segment register received");
}
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset++;
break;
case 05:
case 07:
switch (ins->oprs[0].basereg) {
case R_FS:
bytes[0] = 0xA0 + (c == 0x05 ? 1 : 0);
break;
case R_GS:
bytes[0] = 0xA8 + (c == 0x05 ? 1 : 0);
break;
default:
errfunc(ERR_PANIC,
"bizarre 386 segment register received");
}
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset++;
break;
case 010:
case 011:
case 012:
EMIT_REX();
bytes[0] = *codes++ + ((regval(&ins->oprs[c - 010])) & 7);
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset += 1;
break;
case 017:
bytes[0] = 0;
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset += 1;
break;
case 014:
case 015:
case 016:
if (ins->oprs[c - 014].offset < -128
|| ins->oprs[c - 014].offset > 127) {
errfunc(ERR_WARNING, "signed byte value exceeds bounds");
}
if (ins->oprs[c - 014].segment != NO_SEG) {
data = ins->oprs[c - 014].offset;
out(offset, segment, &data, OUT_ADDRESS + 1,
ins->oprs[c - 014].segment, ins->oprs[c - 014].wrt);
} else {
bytes[0] = ins->oprs[c - 014].offset;
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG,
NO_SEG);
}
offset += 1;
break;
case 020:
case 021:
case 022:
if (ins->oprs[c - 020].offset < -256
|| ins->oprs[c - 020].offset > 255) {
errfunc(ERR_WARNING, "byte value exceeds bounds");
}
if (ins->oprs[c - 020].segment != NO_SEG) {
data = ins->oprs[c - 020].offset;
out(offset, segment, &data, OUT_ADDRESS + 1,
ins->oprs[c - 020].segment, ins->oprs[c - 020].wrt);
} else {
bytes[0] = ins->oprs[c - 020].offset;
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG,
NO_SEG);
}
offset += 1;
break;
case 024:
case 025:
case 026:
if (ins->oprs[c - 024].offset < 0
|| ins->oprs[c - 024].offset > 255)
errfunc(ERR_WARNING, "unsigned byte value exceeds bounds");
if (ins->oprs[c - 024].segment != NO_SEG) {
data = ins->oprs[c - 024].offset;
out(offset, segment, &data, OUT_ADDRESS + 1,
ins->oprs[c - 024].segment, ins->oprs[c - 024].wrt);
} else {
bytes[0] = ins->oprs[c - 024].offset;
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG,
NO_SEG);
}
offset += 1;
break;
case 030:
case 031:
case 032:
if (ins->oprs[c - 030].segment == NO_SEG &&
ins->oprs[c - 030].wrt == NO_SEG &&
(ins->oprs[c - 030].offset < -65536L ||
ins->oprs[c - 030].offset > 65535L)) {
errfunc(ERR_WARNING, "word value exceeds bounds");
}
data = ins->oprs[c - 030].offset;
out(offset, segment, &data, OUT_ADDRESS + 2,
ins->oprs[c - 030].segment, ins->oprs[c - 030].wrt);
offset += 2;
break;
case 034:
case 035:
case 036:
if (ins->oprs[c - 034].type & (BITS16 | BITS32))
size = (ins->oprs[c - 034].type & BITS16) ? 2 : 4;
else
size = (bits == 16) ? 2 : 4;
data = ins->oprs[c - 034].offset;
if (size == 2 && (data < -65536L || data > 65535L))
errfunc(ERR_WARNING, "word value exceeds bounds");
out(offset, segment, &data, OUT_ADDRESS + size,
ins->oprs[c - 034].segment, ins->oprs[c - 034].wrt);
offset += size;
break;
case 037:
if (ins->oprs[0].segment == NO_SEG)
errfunc(ERR_NONFATAL, "value referenced by FAR is not"
" relocatable");
data = 0L;
out(offset, segment, &data, OUT_ADDRESS + 2,
outfmt->segbase(1 + ins->oprs[0].segment),
ins->oprs[0].wrt);
offset += 2;
break;
case 040:
case 041:
case 042:
data = ins->oprs[c - 040].offset;
out(offset, segment, &data, OUT_ADDRESS + 4,
ins->oprs[c - 040].segment, ins->oprs[c - 040].wrt);
offset += 4;
break;
case 044:
case 045:
case 046:
data = ins->oprs[c - 044].offset;
size = ((ins->oprs[c - 044].addr_size ?
ins->oprs[c - 044].addr_size : bits) >> 3);
if (size == 2 && (data < -65536L || data > 65535L))
errfunc(ERR_WARNING, "word value exceeds bounds");
out(offset, segment, &data, OUT_ADDRESS + size,
ins->oprs[c - 044].segment, ins->oprs[c - 044].wrt);
offset += size;
break;
case 050:
case 051:
case 052:
if (ins->oprs[c - 050].segment != segment)
errfunc(ERR_NONFATAL,
"short relative jump outside segment");
data = ins->oprs[c - 050].offset - insn_end;
if (data > 127 || data < -128)
errfunc(ERR_NONFATAL, "short jump is out of range");
bytes[0] = data;
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset += 1;
break;
case 054:
case 055:
case 056:
data = (int64_t)ins->oprs[c - 054].offset;
out(offset, segment, &data, OUT_ADDRESS + 8,
ins->oprs[c - 054].segment, ins->oprs[c - 054].wrt);
offset += 8;
break;
case 060:
case 061:
case 062:
if (ins->oprs[c - 060].segment != segment) {
data = ins->oprs[c - 060].offset;
out(offset, segment, &data,
OUT_REL2ADR + insn_end - offset,
ins->oprs[c - 060].segment, ins->oprs[c - 060].wrt);
} else {
data = ins->oprs[c - 060].offset - insn_end;
out(offset, segment, &data,
OUT_ADDRESS + 2, NO_SEG, NO_SEG);
}
offset += 2;
break;
case 064:
case 065:
case 066:
if (ins->oprs[c - 064].type & (BITS16 | BITS32 | BITS64))
size = (ins->oprs[c - 064].type & BITS16) ? 2 : 4;
else
size = (bits == 16) ? 2 : 4;
if (ins->oprs[c - 064].segment != segment) {
int32_t reltype = (size == 2 ? OUT_REL2ADR : OUT_REL4ADR);
data = ins->oprs[c - 064].offset;
out(offset, segment, &data, reltype + insn_end - offset,
ins->oprs[c - 064].segment, ins->oprs[c - 064].wrt);
} else {
data = ins->oprs[c - 064].offset - insn_end;
out(offset, segment, &data,
OUT_ADDRESS + size, NO_SEG, NO_SEG);
}
offset += size;
break;
case 070:
case 071:
case 072:
if (ins->oprs[c - 070].segment != segment) {
data = ins->oprs[c - 070].offset;
out(offset, segment, &data,
OUT_REL4ADR + insn_end - offset,
ins->oprs[c - 070].segment, ins->oprs[c - 070].wrt);
} else {
data = ins->oprs[c - 070].offset - insn_end;
out(offset, segment, &data,
OUT_ADDRESS + 4, NO_SEG, NO_SEG);
}
offset += 4;
break;
case 0130:
case 0131:
case 0132:
data = ins->oprs[c - 0130].offset;
if (is_sbyte(ins, c - 0130, 16)) {
bytes[0] = data;
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG,
NO_SEG);
offset++;
} else {
if (ins->oprs[c - 0130].segment == NO_SEG &&
ins->oprs[c - 0130].wrt == NO_SEG &&
(data < -65536L || data > 65535L)) {
errfunc(ERR_WARNING, "word value exceeds bounds");
}
out(offset, segment, &data, OUT_ADDRESS + 2,
ins->oprs[c - 0130].segment, ins->oprs[c - 0130].wrt);
offset += 2;
}
break;
case 0133:
case 0134:
case 0135:
EMIT_REX();
codes++;
bytes[0] = *codes++;
if (is_sbyte(ins, c - 0133, 16))
bytes[0] |= 2; /* s-bit */
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset++;
break;
case 0140:
case 0141:
case 0142:
data = ins->oprs[c - 0140].offset;
if (is_sbyte(ins, c - 0140, 32)) {
bytes[0] = data;
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG,
NO_SEG);
offset++;
} else {
out(offset, segment, &data, OUT_ADDRESS + 4,
ins->oprs[c - 0140].segment, ins->oprs[c - 0140].wrt);
offset += 4;
}
break;
case 0143:
case 0144:
case 0145:
EMIT_REX();
codes++;
bytes[0] = *codes++;
if (is_sbyte(ins, c - 0143, 32))
bytes[0] |= 2; /* s-bit */
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset++;
break;
case 0300:
case 0301:
case 0302:
if (chsize(&ins->oprs[c - 0300], bits)) {
*bytes = 0x67;
out(offset, segment, bytes,
OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset += 1;
} else
offset += 0;
break;
case 0310:
if (bits != 16) {
*bytes = 0x67;
out(offset, segment, bytes,
OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset += 1;
} else
offset += 0;
break;
case 0311:
if (bits != 32) {
*bytes = 0x67;
out(offset, segment, bytes,
OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset += 1;
} else
offset += 0;
break;
case 0312:
break;
case 0313:
ins->rex = 0;
break;
case 0320:
if (bits != 16) {
*bytes = 0x66;
out(offset, segment, bytes,
OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset += 1;
} else
offset += 0;
break;
case 0321:
if (bits == 16) {
*bytes = 0x66;
out(offset, segment, bytes,
OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset += 1;
} else
offset += 0;
break;
case 0322:
case 0323:
break;
case 0324:
ins->rex |= REX_W;
break;
case 0330:
*bytes = *codes++ ^ condval[ins->condition];
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset += 1;
break;
case 0331:
case 0332:
break;
case 0333:
*bytes = 0xF3;
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset += 1;
break;
case 0334:
if (ins->rex & REX_R) {
*bytes = 0xF0;
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset += 1;
}
ins->rex &= ~(REX_L|REX_R);
break;
case 0340:
case 0341:
case 0342:
if (ins->oprs[0].segment != NO_SEG)
errfunc(ERR_PANIC, "non-constant BSS size in pass two");
else {
int32_t size = ins->oprs[0].offset << (c - 0340);
if (size > 0)
out(offset, segment, NULL,
OUT_RESERVE + size, NO_SEG, NO_SEG);
offset += size;
}
break;
case 0370:
case 0371:
case 0372:
break;
case 0373:
*bytes = bits == 16 ? 3 : 5;
out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG);
offset += 1;
break;
default: /* can't do it by 'case' statements */
if (c >= 0100 && c <= 0277) { /* it's an EA */
ea ea_data;
int rfield;
int32_t rflags;
uint8_t *p;
int32_t s;
if (c <= 0177) {
/* pick rfield from operand b */
rflags = regflag(&ins->oprs[c & 7]);
rfield = regvals[ins->oprs[c & 7].basereg];
} else {
/* rfield is constant */
rflags = 0;
rfield = c & 7;
}
if (!process_ea
(&ins->oprs[(c >> 3) & 7], &ea_data, bits,
rfield, rflags, ins->forw_ref)) {
errfunc(ERR_NONFATAL, "invalid effective address");
}
p = bytes;
*p++ = ea_data.modrm;
if (ea_data.sib_present)
*p++ = ea_data.sib;
s = p - bytes;
out(offset, segment, bytes, OUT_RAWDATA + s,
NO_SEG, NO_SEG);
switch (ea_data.bytes) {
case 0:
break;
case 1:
if (ins->oprs[(c >> 3) & 7].segment != NO_SEG) {
data = ins->oprs[(c >> 3) & 7].offset;
out(offset, segment, &data, OUT_ADDRESS + 1,
ins->oprs[(c >> 3) & 7].segment,
ins->oprs[(c >> 3) & 7].wrt);
} else {
*bytes = ins->oprs[(c >> 3) & 7].offset;
out(offset, segment, bytes, OUT_RAWDATA + 1,
NO_SEG, NO_SEG);
}
s++;
break;
case 8:
case 2:
case 4:
data = ins->oprs[(c >> 3) & 7].offset;
if (ea_data.rip && (ins->oprs[(c >> 3) & 7].segment == 0xFFFFFFFF))
ea_data.rip = 0; /* Make distinction between Symbols and Immediates */
out(offset, segment, &data, /* RIP = Relative, not Absolute */
(ea_data.rip ? OUT_REL4ADR : OUT_ADDRESS) + ea_data.bytes,
ins->oprs[(c >> 3) & 7].segment,
ins->oprs[(c >> 3) & 7].wrt);
s += ea_data.bytes;
break;
}
offset += s;
} else
errfunc(ERR_PANIC, "internal instruction table corrupt"
": instruction code 0x%02X given", c);
}
}
static int regflag(const operand * o)
{
if (o->basereg < EXPR_REG_START || o->basereg >= REG_ENUM_LIMIT) {
errfunc(ERR_PANIC, "invalid operand passed to regflag()");
}
return reg_flags[o->basereg];
}
static int regval(const operand * o)
{
if (o->basereg < EXPR_REG_START || o->basereg >= REG_ENUM_LIMIT) {
errfunc(ERR_PANIC, "invalid operand passed to regval()");
}
return regvals[o->basereg];
}
static int op_rexflags(const operand * o, int mask)
{
int32_t flags;
int val;
if (o->basereg < EXPR_REG_START || o->basereg >= REG_ENUM_LIMIT) {
errfunc(ERR_PANIC, "invalid operand passed to op_rexflags()");
}
flags = reg_flags[o->basereg];
val = regvals[o->basereg];
return rexflags(val, flags, mask);
}
static int rexflags(int val, int32_t flags, int mask)
{
int rex = 0;
if (val >= 8)
rex |= REX_B|REX_X|REX_R;
if (flags & BITS64)
rex |= REX_W;
if (!(REG_HIGH & ~flags)) /* AH, CH, DH, BH */
rex |= REX_H;
else if (!(REG8 & ~flags) && val >= 4) /* SPL, BPL, SIL, DIL */
rex |= REX_P;
return rex & mask;
}
static int matches(struct itemplate *itemp, insn * instruction, int bits)
{
int i, size[3], asize, oprs, ret;
ret = 100;
/*
* Check the opcode
*/
if (itemp->opcode != instruction->opcode)
return 0;
/*
* Count the operands
*/
if (itemp->operands != instruction->operands)
return 0;
/*
* Check that no spurious colons or TOs are present
*/
for (i = 0; i < itemp->operands; i++)
if (instruction->oprs[i].type & ~itemp->opd[i] & (COLON | TO))
return 0;
/*
* Check that the operand flags all match up
*/
for (i = 0; i < itemp->operands; i++)
if (itemp->opd[i] & ~instruction->oprs[i].type ||
((itemp->opd[i] & SIZE_MASK) &&
((itemp->opd[i] ^ instruction->oprs[i].type) & SIZE_MASK))) {
if ((itemp->opd[i] & ~instruction->oprs[i].type & ~SIZE_MASK) ||
(instruction->oprs[i].type & SIZE_MASK))
return 0;
else
return 1;
}
/*
* Check operand sizes
*/
if (itemp->flags & IF_ARMASK) {
size[0] = size[1] = size[2] = 0;
switch (itemp->flags & IF_ARMASK) {
case IF_AR0:
i = 0;
break;
case IF_AR1:
i = 1;
break;
case IF_AR2:
i = 2;
break;
default:
break; /* Shouldn't happen */
}
if (itemp->flags & IF_SB) {
size[i] = BITS8;
} else if (itemp->flags & IF_SW) {
size[i] = BITS16;
} else if (itemp->flags & IF_SD) {
size[i] = BITS32;
} else if (itemp->flags & IF_SQ) {
size[i] = BITS64;
}
} else {
asize = 0;
if (itemp->flags & IF_SB) {
asize = BITS8;
oprs = itemp->operands;
} else if (itemp->flags & IF_SW) {
asize = BITS16;
oprs = itemp->operands;
} else if (itemp->flags & IF_SD) {
asize = BITS32;
oprs = itemp->operands;
} else if (itemp->flags & IF_SQ) {
asize = BITS64;
oprs = itemp->operands;
}
size[0] = size[1] = size[2] = asize;
}
if (itemp->flags & (IF_SM | IF_SM2)) {
oprs = (itemp->flags & IF_SM2 ? 2 : itemp->operands);
asize = 0;
for (i = 0; i < oprs; i++) {
if ((asize = itemp->opd[i] & SIZE_MASK) != 0) {
int j;
for (j = 0; j < oprs; j++)
size[j] = asize;
break;
}
}
} else {
oprs = itemp->operands;
}
for (i = 0; i < itemp->operands; i++) {
if (!(itemp->opd[i] & SIZE_MASK) &&
(instruction->oprs[i].type & SIZE_MASK & ~size[i]))
return 2;
}
/*
* Check template is okay at the set cpu level
*/
if (((itemp->flags & IF_PLEVEL) > cpu))
return 3;
/*
* Check if instruction is available in long mode
*/
if ((itemp->flags & IF_NOLONG) && (bits == 64))
return 4;
/*
* Check if special handling needed for Jumps
*/
if ((uint8_t)(itemp->code[0]) >= 0370)
return 99;
return ret;
}
static ea *process_ea(operand * input, ea * output, int addrbits,
int rfield, int32_t rflags, int forw_ref)
{
int rip = FALSE; /* Used for RIP-relative addressing */
/* REX flags for the rfield operand */
output->rex |= rexflags(rfield, rflags, REX_R|REX_P|REX_W|REX_H);
if (!(REGISTER & ~input->type)) { /* register direct */
int i;
int32_t f;
if (input->basereg < EXPR_REG_START /* Verify as Register */
|| input->basereg >= REG_ENUM_LIMIT)
return NULL;
f = regflag(input);
i = regvals[input->basereg];
if (REG_EA & ~f)
return NULL; /* Invalid EA register */
output->rex |= op_rexflags(input, REX_B|REX_P|REX_W|REX_H);
output->sib_present = FALSE; /* no SIB necessary */
output->bytes = 0; /* no offset necessary either */
output->modrm = 0xC0 | ((rfield & 7) << 3) | (i & 7);
} else { /* it's a memory reference */
if (input->basereg == -1
&& (input->indexreg == -1 || input->scale == 0)) {
/* it's a pure offset */
if (input->addr_size)
addrbits = input->addr_size;
if (addrbits == 64) {
int scale, index, base;
output->sib_present = TRUE;
scale = 0;
index = 4;
base = 5;
output->sib = (scale << 6) | (index << 3) | base;
output->bytes = 4;
output->modrm = 4 | ((rfield & 7) << 3);
} else {
output->sib_present = FALSE;
output->bytes = (addrbits != 16 ? 4 : 2);
output->modrm = (addrbits != 16 ? 5 : 6) | ((rfield & 7) << 3);
}
} else { /* it's an indirection */
int i = input->indexreg, b = input->basereg, s = input->scale;
int32_t o = input->offset, seg = input->segment;
int hb = input->hintbase, ht = input->hinttype;
int t;
int it, bt;
int32_t ix, bx; /* register flags */
if (s == 0)
i = -1; /* make this easy, at least */
if (i >= EXPR_REG_START && i < REG_ENUM_LIMIT) {
it = regvals[i];
ix = reg_flags[i];
} else {
it = -1;
ix = 0;
}
if (b != -1 && b >= EXPR_REG_START && b < REG_ENUM_LIMIT) {
bt = regvals[b];
bx = reg_flags[b];
} else {
bt = -1;
bx = 0;
}
/* check for a 32/64-bit memory reference... */
if ((ix|bx) & (BITS32|BITS64)) {
/* it must be a 32/64-bit memory reference. Firstly we have
* to check that all registers involved are type E/Rxx. */
int32_t sok = BITS32|BITS64;
if (it != -1) {
if (!(REG64 & ~ix) || !(REG32 & ~ix))
sok &= ix;
else
return NULL;
}
if (bt != -1) {
if ((REG_GPR & ~bx) && (IP_REG & ~bx))
return NULL; /* Invalid register */
if (~sok & bx & SIZE_MASK)
return NULL; /* Invalid size */
sok &= ~bx;
if (!(IP_REG & ~bx)) {
bt = b = -1;
rip = TRUE;
}
}
/* While we're here, ensure the user didn't specify WORD. */
if (input->addr_size == 16 ||
(input->addr_size == 32 && !(sok & BITS32)) ||
(input->addr_size == 64 && !(sok & BITS64)))
return NULL;
/* now reorganize base/index */
if (s == 1 && bt != it && bt != -1 && it != -1 &&
((hb == b && ht == EAH_NOTBASE)
|| (hb == i && ht == EAH_MAKEBASE))) {
/* swap if hints say so */
t = bt, bt = it, it = t;
t = bx, bx = ix, ix = t;
}
if (bt == it) /* convert EAX+2*EAX to 3*EAX */
bt = -1, bx = 0, s++;
if (bt == -1 && s == 1 && !(hb == it && ht == EAH_NOTBASE)) {
/* make single reg base, unless hint */
bt = it, bx = ix, it = -1, ix = 0;
}
if (((s == 2 && (it & 7) != (REG_NUM_ESP & 7)
&& !(input->eaflags & EAF_TIMESTWO)) || s == 3
|| s == 5 || s == 9) && bt == -1)
bt = it, bx = ix, s--; /* convert 3*EAX to EAX+2*EAX */
if (it == -1 && (bt & 7) != (REG_NUM_ESP & 7)
&& (input->eaflags & EAF_TIMESTWO))
it = bt, ix = bx, bt = -1, bx = 0, s = 1;
/* convert [NOSPLIT EAX] to sib format with 0x0 displacement */
if (s == 1 && (it & 7) == (REG_NUM_ESP & 7)) {
/* swap ESP into base if scale is 1 */
t = it, it = bt, bt = t;
t = ix, ix = bx, bx = t;
}
if ((it & 7) == (REG_NUM_ESP & 7)
|| (s != 1 && s != 2 && s != 4 && s != 8 && it != -1))
return NULL; /* wrong, for various reasons */
output->rex |= rexflags(it, ix, REX_X);
output->rex |= rexflags(bt, bx, REX_B);
if (it == -1 && (bt & 7) != (REG_NUM_ESP & 7)) {
/* no SIB needed */
int mod, rm;
if (bt == -1) {
rm = 5;
mod = 0;
} else {
rm = (bt & 7);
if (rm != (REG_NUM_EBP & 7) && o == 0 &&
seg == NO_SEG && !forw_ref &&
!(input->eaflags &
(EAF_BYTEOFFS | EAF_WORDOFFS)))
mod = 0;
else if (input->eaflags & EAF_BYTEOFFS ||
(o >= -128 && o <= 127 && seg == NO_SEG
&& !forw_ref
&& !(input->eaflags & EAF_WORDOFFS)))
mod = 1;
else
mod = 2;
}
output->sib_present = FALSE;
output->bytes = (bt == -1 || mod == 2 ? 4 : mod);
output->modrm = (mod << 6) | ((rfield & 7) << 3) | rm;
} else {
/* we need a SIB */
int mod, scale, index, base;
if (it == -1)
index = 4, s = 1;
else
index = (it & 7);
switch (s) {
case 1:
scale = 0;
break;
case 2:
scale = 1;
break;
case 4:
scale = 2;
break;
case 8:
scale = 3;
break;
default: /* then what the smeg is it? */
return NULL; /* panic */
}
if (bt == -1) {
base = 5;
mod = 0;
} else {
base = (bt & 7);
if (base != (REG_NUM_EBP & 7) && o == 0 &&
seg == NO_SEG && !forw_ref &&
!(input->eaflags &
(EAF_BYTEOFFS | EAF_WORDOFFS)))
mod = 0;
else if (input->eaflags & EAF_BYTEOFFS ||
(o >= -128 && o <= 127 && seg == NO_SEG
&& !forw_ref
&& !(input->eaflags & EAF_WORDOFFS)))
mod = 1;
else
mod = 2;
}
output->sib_present = TRUE;
output->bytes = (bt == -1 || mod == 2 ? 4 : mod);
output->modrm = (mod << 6) | ((rfield & 7) << 3) | 4;
output->sib = (scale << 6) | (index << 3) | base;
}
/* Process RIP-relative Addressing */
if (rip) {
if (globalbits != 64 ||
(output->modrm & 0xC7) != 0x05)
return NULL;
output->rip = TRUE;
} else {
output->rip = FALSE;
/* Actual Disp32 needs blank SIB on x64 */
if (globalbits == 64 &&
!(output->sib_present) &&
((output->modrm & 0xC7) == 0x05)) {
output->sib_present = TRUE;
/* RM Field = 4 (forward to Base of SIB) */
output->modrm--;
/* Index = 4 (none), Base = 5 */
output->sib = (4 << 3) | 5;
}
}
} else { /* it's 16-bit */
int mod, rm;
/* check for 64-bit long mode */
if (addrbits == 64)
return NULL;
/* check all registers are BX, BP, SI or DI */
if ((b != -1 && b != R_BP && b != R_BX && b != R_SI
&& b != R_DI) || (i != -1 && i != R_BP && i != R_BX
&& i != R_SI && i != R_DI))
return NULL;
/* ensure the user didn't specify DWORD/QWORD */
if (input->addr_size == 32 || input->addr_size == 64)
return NULL;
if (s != 1 && i != -1)
return NULL; /* no can do, in 16-bit EA */
if (b == -1 && i != -1) {
int tmp = b;
b = i;
i = tmp;
} /* swap */
if ((b == R_SI || b == R_DI) && i != -1) {
int tmp = b;
b = i;
i = tmp;
}
/* have BX/BP as base, SI/DI index */
if (b == i)
return NULL; /* shouldn't ever happen, in theory */
if (i != -1 && b != -1 &&
(i == R_BP || i == R_BX || b == R_SI || b == R_DI))
return NULL; /* invalid combinations */
if (b == -1) /* pure offset: handled above */
return NULL; /* so if it gets to here, panic! */
rm = -1;
if (i != -1)
switch (i * 256 + b) {
case R_SI * 256 + R_BX:
rm = 0;
break;
case R_DI * 256 + R_BX:
rm = 1;
break;
case R_SI * 256 + R_BP:
rm = 2;
break;
case R_DI * 256 + R_BP:
rm = 3;
break;
} else
switch (b) {
case R_SI:
rm = 4;
break;
case R_DI:
rm = 5;
break;
case R_BP:
rm = 6;
break;
case R_BX:
rm = 7;
break;
}
if (rm == -1) /* can't happen, in theory */
return NULL; /* so panic if it does */
if (o == 0 && seg == NO_SEG && !forw_ref && rm != 6 &&
!(input->eaflags & (EAF_BYTEOFFS | EAF_WORDOFFS)))
mod = 0;
else if (input->eaflags & EAF_BYTEOFFS ||
(o >= -128 && o <= 127 && seg == NO_SEG
&& !forw_ref
&& !(input->eaflags & EAF_WORDOFFS)))
mod = 1;
else
mod = 2;
output->sib_present = FALSE; /* no SIB - it's 16-bit */
output->bytes = mod; /* bytes of offset needed */
output->modrm = (mod << 6) | ((rfield & 7) << 3) | rm;
}
}
}
output->size = 1 + output->sib_present + output->bytes;
return output;
}
static int chsize(operand * input, int addrbits)
{
if (!(MEMORY & ~input->type)) {
int32_t i, b;
if (input->indexreg < EXPR_REG_START /* Verify as Register */
|| input->indexreg >= REG_ENUM_LIMIT)
i = 0;
else
i = reg_flags[input->indexreg];
if (input->basereg < EXPR_REG_START /* Verify as Register */
|| input->basereg >= REG_ENUM_LIMIT)
b = 0;
else
b = reg_flags[input->basereg];
if (input->scale == 0)
i = 0;
if (!i && !b) /* pure offset */
return (input->addr_size != 0 && input->addr_size != addrbits);
if (!(REG32 & ~i) || !(REG32 & ~b))
return (addrbits != 32);
else
return (addrbits == 32);
} else {
return 0;
}
}
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