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nasm/asm/assemble.c
H. Peter Anvin 86142b00e1 assemble: limit-check operand references 
Don't do an out-of-range check for the operands, even
temporarily. Setting the operand pointer to NULL will help catch
errors when accessing non-operands, too.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2024-08-04 23:45:20 -07:00

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/* ----------------------------------------------------------------------- *
*
* Copyright 1996-2024 The NASM Authors - All Rights Reserved
* See the file AUTHORS included with the NASM distribution for
* the specific copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* ----------------------------------------------------------------------- */
/*
* assemble.c code generation for the Netwide Assembler
*
*/
#include "compiler.h"
#include "nasm.h"
#include "nasmlib.h"
#include "error.h"
#include "assemble.h"
#include "insns.h"
#include "tables.h"
#include "disp8.h"
#include "listing.h"
#include "dbginfo.h"
enum match_result {
/*
* Matching errors. These should be sorted so that more specific
* errors come later in the sequence.
*/
MERR_INVALOP,
MERR_OPSIZEMISSING,
MERR_OPSIZEMISMATCH,
MERR_BRNOTHERE,
MERR_BRNUMMISMATCH,
MERR_MASKNOTHERE,
MERR_DECONOTHERE,
MERR_BADCPU,
MERR_BADMODE,
MERR_BADHLE,
MERR_ENCMISMATCH,
MERR_BADBND,
MERR_BADREPNE,
MERR_REGSETSIZE,
MERR_REGSET,
/*
* Matching success; the conditional ones first
*/
MOK_JUMP, /* Matching OK but needs jmp_match() */
MOK_GOOD /* Matching unconditionally OK */
};
typedef struct {
enum ea_type type; /* what kind of EA is this? */
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 */
int8_t disp8; /* compressed displacement for EVEX */
} ea;
#define GEN_SIB(scale, index, base) \
(((scale) << 6) | ((index) << 3) | ((base)))
#define GEN_MODRM(mod, reg, rm) \
(((mod) << 6) | (((reg) & 7) << 3) | ((rm) & 7))
static int64_t calcsize(int32_t, int64_t, int, insn *,
const struct itemplate *);
static int emit_prefix(struct out_data *data, const int bits, insn *ins);
static void gencode(struct out_data *data, insn *ins);
static enum match_result find_match(const struct itemplate **tempp,
insn *instruction,
int32_t segment, int64_t offset, int bits);
static enum match_result matches(const struct itemplate *, insn *, int bits);
static opflags_t regflag(const operand *);
static int32_t regval(const operand *);
static int rexflags(int, opflags_t, int);
static int op_rexflags(const operand *, int);
static int op_evexflags(const operand *, int, uint8_t);
static void add_asp(insn *, int);
static int process_ea(operand *, ea *, int, int, opflags_t,
insn *, enum ea_type, const char **);
/* Get the pointer to an operand if it exits */
static inline struct operand *get_operand(insn *ins, unsigned int n)
{
if (n >= (unsigned int)ins->operands)
return NULL;
else
return &ins->oprs[n];
}
static inline bool absolute_op(const struct operand *o)
{
return o && o->segment == NO_SEG && o->wrt == NO_SEG &&
!(o->opflags & OPFLAG_RELATIVE);
}
static int has_prefix(insn * ins, enum prefix_pos pos, int prefix)
{
return ins->prefixes[pos] == prefix;
}
static void assert_no_prefix(insn * ins, enum prefix_pos pos)
{
if (ins->prefixes[pos])
nasm_nonfatal("invalid %s prefix", prefix_name(ins->prefixes[pos]));
}
static const char *size_name(int size)
{
switch (size) {
case 1:
return "byte";
case 2:
return "word";
case 4:
return "dword";
case 8:
return "qword";
case 10:
return "tword";
case 16:
return "oword";
case 32:
return "yword";
case 64:
return "zword";
default:
return "???";
}
}
static void warn_overflow(int size)
{
nasm_warn(ERR_PASS2 | WARN_NUMBER_OVERFLOW, "%s data exceeds bounds",
size_name(size));
}
static void warn_overflow_const(int64_t data, int size)
{
if (overflow_general(data, size))
warn_overflow(size);
}
static void warn_overflow_out(int64_t data, int size, enum out_flags flags)
{
bool err;
if (flags & OUT_SIGNED)
err = overflow_signed(data, size);
else if (flags & OUT_UNSIGNED)
err = overflow_unsigned(data, size);
else
err = overflow_general(data, size);
if (err)
warn_overflow(size);
}
/*
* Collect macro-related debug information, if applicable.
*/
static void debug_macro_out(const struct out_data *data)
{
struct debug_macro_addr *addr;
uint64_t start = data->offset;
uint64_t end = start + data->size;
addr = debug_macro_get_addr(data->segment);
while (addr) {
if (!addr->len)
addr->start = start;
addr->len = end - addr->start;
addr = addr->up;
}
}
/*
* 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, flatten unnecessary relocations,
* and verify backend compatibility.
*/
/*
* This warning is currently issued by backends, but in the future
* this code should be centralized.
*
*!zeroing [on] \c{RES}\e{x} in initialized section becomes zero
*! a \c{RES}\e{x} directive was used in a section which contains
*! initialized data, and the output format does not support
*! this. Instead, this will be replaced with explicit zero
*! content, which may produce a large output file.
*/
static void out(struct out_data *data)
{
static struct last_debug_info {
struct src_location where;
int32_t segment;
} dbg;
union {
uint8_t b[8];
uint64_t q;
} xdata;
size_t asize, amax;
uint64_t zeropad = 0;
int64_t addrval;
int32_t fixseg; /* Segment for which to produce fixed data */
if (!data->size)
return; /* Nothing to do */
/*
* Convert addresses to RAWDATA if possible
* XXX: not all backends want this for global symbols!!!!
*/
switch (data->type) {
case OUT_ADDRESS:
addrval = data->toffset;
fixseg = NO_SEG; /* Absolute address is fixed data */
goto address;
case OUT_RELADDR:
addrval = data->toffset - data->relbase;
fixseg = data->segment; /* Our own segment is fixed data */
goto address;
address:
nasm_assert(data->size <= 8);
asize = data->size;
amax = ofmt->maxbits >> 3; /* Maximum address size in bytes */
if (data->tsegment == fixseg && data->twrt == NO_SEG) {
if (!(ofmt->flags & OFMT_KEEP_ADDR)) {
if (asize >= (size_t)(data->bits >> 3)) {
/* Support address space wrapping for low-bit modes */
data->flags &= ~OUT_SIGNMASK;
}
warn_overflow_out(addrval, asize, data->flags);
xdata.q = cpu_to_le64(addrval);
data->data = xdata.b;
data->type = OUT_RAWDATA;
asize = amax = 0; /* No longer an address */
}
} else {
/*!
*!reloc-abs-byte [off] 8-bit absolute section-crossing relocation
*! warns that an 8-bit absolute relocation that could
*! not be resolved at assembly time was generated in
*! the output format.
*!
*! This is usually normal, but may not be handled by all
*! possible target environments
*/
/*!
*!reloc-abs-word [off] 16-bit absolute section-crossing relocation
*! warns that a 16-bit absolute relocation that could
*! not be resolved at assembly time was generated in
*! the output format.
*!
*! This is usually normal, but may not be handled by all
*! possible target environments
*/
/*!
*!reloc-abs-dword [off] 32-bit absolute section-crossing relocation
*! warns that a 32-bit absolute relocation that could
*! not be resolved at assembly time was generated in
*! the output format.
*!
*! This is usually normal, but may not be handled by all
*! possible target environments
*/
/*!
*!reloc-abs-qword [off] 64-bit absolute section-crossing relocation
*! warns that a 64-bit absolute relocation that could
*! not be resolved at assembly time was generated in
*! the output format.
*!
*! This is usually normal, but may not be handled by all
*! possible target environments
*/
/*!
*!reloc-rel-byte [off] 8-bit relative section-crossing relocation
*! warns that an 8-bit relative relocation that could
*! not be resolved at assembly time was generated in
*! the output format.
*!
*! This is usually normal, but may not be handled by all
*! possible target environments
*/
/*!
*!reloc-rel-word [off] 16-bit relative section-crossing relocation
*! warns that a 16-bit relative relocation that could
*! not be resolved at assembly time was generated in
*! the output format.
*!
*! This is usually normal, but may not be handled by all
*! possible target environments
*/
/*!
*!reloc-rel-dword [off] 32-bit relative section-crossing relocation
*! warns that a 32-bit relative relocation that could
*! not be resolved at assembly time was generated in
*! the output format.
*!
*! This is usually normal, but may not be handled by all
*! possible target environments
*/
/*!
*!reloc-rel-qword [off] 64-bit relative section-crossing relocation
*! warns that an 64-bit relative relocation that could
*! not be resolved at assembly time was generated in
*! the output format.
*!
*! This is usually normal, but may not be handled by all
*! possible target environments
*/
int warn;
const char *type;
switch (data->type) {
case OUT_ADDRESS:
type = "absolute";
switch (asize) {
case 1: warn = WARN_RELOC_ABS_BYTE; break;
case 2: warn = WARN_RELOC_ABS_WORD; break;
case 4: warn = WARN_RELOC_ABS_DWORD; break;
case 8: warn = WARN_RELOC_ABS_QWORD; break;
default: panic();
}
break;
case OUT_RELADDR:
type = "relative";
switch (asize) {
case 1: warn = WARN_RELOC_REL_BYTE; break;
case 2: warn = WARN_RELOC_REL_WORD; break;
case 4: warn = WARN_RELOC_REL_DWORD; break;
case 8: warn = WARN_RELOC_REL_QWORD; break;
default: panic();
}
break;
default:
warn = 0;
}
if (warn) {
nasm_warn(warn, "%u-bit %s section-crossing relocation",
(unsigned int)(asize << 3), type);
}
}
break;
case OUT_SEGMENT:
nasm_assert(data->size <= 8);
asize = data->size;
amax = 2;
break;
default:
asize = amax = 0; /* Not an address */
break;
}
/*
* If the source location or output segment has changed,
* let the debug backend know. Some backends really don't
* like being given a NULL filename as can happen if we
* use -Lb and expand a macro, so filter out that case.
*/
data->where = src_where();
if (data->where.filename &&
(!src_location_same(data->where, dbg.where) |
(data->segment != dbg.segment))) {
dbg.where = data->where;
dbg.segment = data->segment;
dfmt->linenum(dbg.where.filename, dbg.where.lineno, data->segment);
}
if (asize > amax) {
if (data->type == OUT_RELADDR || (data->flags & OUT_SIGNED)) {
nasm_nonfatal("%u-bit signed relocation unsupported by output format %s",
(unsigned int)(asize << 3), ofmt->shortname);
} else {
/*!
*!zext-reloc [on] relocation zero-extended to match output format
*! warns that a relocation has been zero-extended due
*! to limitations in the output format.
*/
nasm_warn(WARN_ZEXT_RELOC,
"%u-bit %s relocation zero-extended from %u bits",
(unsigned int)(asize << 3),
data->type == OUT_SEGMENT ? "segment" : "unsigned",
(unsigned int)(amax << 3));
}
zeropad = data->size - amax;
data->size = amax;
}
lfmt->output(data);
if (likely(data->segment != NO_SEG)) {
/*
* Collect macro-related information for the debugger, if applicable
*/
if (debug_current_macro)
debug_macro_out(data);
ofmt->output(data);
} else {
/* Outputting to ABSOLUTE section - only reserve is permitted */
if (data->type != OUT_RESERVE)
nasm_nonfatal("attempt to assemble code in [ABSOLUTE] space");
/* No need to push to the backend */
}
data->offset += data->size;
data->insoffs += data->size;
if (zeropad) {
data->type = OUT_ZERODATA;
data->size = zeropad;
lfmt->output(data);
ofmt->output(data);
data->offset += zeropad;
data->insoffs += zeropad;
data->size += zeropad; /* Restore original size value */
}
}
static inline void out_rawdata(struct out_data *data, const void *rawdata,
size_t size)
{
data->type = OUT_RAWDATA;
data->data = rawdata;
data->size = size;
out(data);
}
static void out_rawbyte(struct out_data *data, uint8_t byte)
{
data->type = OUT_RAWDATA;
data->data = &byte;
data->size = 1;
out(data);
}
static inline void out_reserve(struct out_data *data, uint64_t size)
{
data->type = OUT_RESERVE;
data->size = size;
out(data);
}
static void out_segment(struct out_data *data, const struct operand *opx)
{
if (opx->opflags & OPFLAG_RELATIVE)
nasm_nonfatal("segment references cannot be relative");
data->type = OUT_SEGMENT;
data->flags = OUT_UNSIGNED;
data->size = 2;
data->toffset = opx->offset;
data->tsegment = ofmt->segbase(opx->segment | 1);
data->twrt = opx->wrt;
out(data);
}
static void out_imm(struct out_data *data, const struct operand *opx,
int size, enum out_flags sign)
{
if (opx->segment != NO_SEG && (opx->segment & 1)) {
/*
* This is actually a segment reference, but eval() has
* already called ofmt->segbase() for us. Sigh.
*/
if (size < 2)
nasm_nonfatal("segment reference must be 16 bits");
data->type = OUT_SEGMENT;
} else {
data->type = (opx->opflags & OPFLAG_RELATIVE)
? OUT_RELADDR : OUT_ADDRESS;
}
data->flags = sign;
data->toffset = opx->offset;
data->tsegment = opx->segment;
data->twrt = opx->wrt;
/*
* XXX: improve this if at some point in the future we can
* distinguish the subtrahend in expressions like [foo - bar]
* where bar is a symbol in the current segment. However, at the
* current point, if OPFLAG_RELATIVE is set that subtraction has
* already occurred.
*/
data->relbase = 0;
data->size = size;
out(data);
}
static void out_reladdr(struct out_data *data, const struct operand *opx,
int size)
{
if (opx->opflags & OPFLAG_RELATIVE)
nasm_nonfatal("invalid use of self-relative expression");
data->type = OUT_RELADDR;
data->flags = OUT_SIGNED;
data->size = size;
data->toffset = opx->offset;
data->tsegment = opx->segment;
data->twrt = opx->wrt;
data->relbase = data->offset + (data->inslen - data->insoffs);
out(data);
}
static bool jmp_match(int32_t segment, int64_t offset, int bits,
insn * ins, const struct itemplate *temp)
{
int64_t isize;
const uint8_t *code = temp->code;
uint8_t c = code[0];
bool is_byte;
const struct operand * const op0 = get_operand(ins, 0);
if (((c & ~1) != 0370) || (op0->type & STRICT))
return false;
if (!optimizing.level || (optimizing.flag & OPTIM_DISABLE_JMP_MATCH))
return false;
if (optimizing.level < 0 && c == 0371)
return false;
isize = calcsize(segment, offset, bits, ins, temp);
if (op0->opflags & OPFLAG_UNKNOWN)
/* Be optimistic in pass 1 */
return true;
if (op0->segment != segment)
return false;
isize = op0->offset - offset - isize; /* isize is delta */
is_byte = (isize >= -128 && isize <= 127); /* is it byte size? */
if (is_byte && c == 0371 && ins->prefixes[PPS_REP] == P_BND) {
/* jmp short (opcode eb) cannot be used with bnd prefix. */
ins->prefixes[PPS_REP] = P_none;
/*!
*!prefix-bnd [on] invalid \c{BND} prefix
*!=bnd
*! warns about ineffective use of the \c{BND} prefix when the
*! \c{JMP} instruction is converted to the \c{SHORT} form.
*! This should be extremely rare since the short \c{JMP} only
*! is applicable to jumps inside the same module, but if
*! it is legitimate, it may be necessary to use
*! \c{bnd jmp dword}.
*/
nasm_warn(WARN_PREFIX_BND|ERR_PASS2 ,
"jmp short does not init bnd regs - bnd prefix dropped");
}
return is_byte;
}
static inline int64_t merge_resb(insn *ins, int64_t isize)
{
int nbytes = resb_bytes(ins->opcode);
if (likely(!nbytes))
return isize;
if (isize != nbytes * ins->oprs[0].offset)
return isize; /* Has prefixes of some sort */
ins->oprs[0].offset *= ins->times;
isize *= ins->times;
ins->times = 1;
return isize;
}
/* This must be handle non-power-of-2 alignment values */
static inline size_t pad_bytes(size_t len, size_t align)
{
size_t partial = len % align;
return partial ? align - partial : 0;
}
static void out_eops(struct out_data *data, const extop *e)
{
while (e) {
size_t dup = e->dup;
switch (e->type) {
case EOT_NOTHING:
break;
case EOT_EXTOP:
while (dup--)
out_eops(data, e->val.subexpr);
break;
case EOT_DB_NUMBER:
if (e->elem > 8) {
nasm_nonfatal("integer supplied as %d-bit data",
e->elem << 3);
} else {
while (dup--) {
data->insoffs = 0;
data->inslen = data->size = e->elem;
data->tsegment = e->val.num.segment;
data->toffset = e->val.num.offset;
data->twrt = e->val.num.wrt;
data->relbase = 0;
if (e->val.num.segment != NO_SEG &&
(e->val.num.segment & 1)) {
data->type = OUT_SEGMENT;
data->flags = OUT_UNSIGNED;
} else {
data->type = e->val.num.relative
? OUT_RELADDR : OUT_ADDRESS;
data->flags = OUT_WRAP;
}
out(data);
}
}
break;
case EOT_DB_FLOAT:
case EOT_DB_STRING:
case EOT_DB_STRING_FREE:
{
size_t pad, len;
pad = pad_bytes(e->val.string.len, e->elem);
len = e->val.string.len + pad;
while (dup--) {
data->insoffs = 0;
data->inslen = len;
out_rawdata(data, e->val.string.data, e->val.string.len);
if (pad)
out_rawdata(data, zero_buffer, pad);
}
break;
}
case EOT_DB_RESERVE:
data->insoffs = 0;
data->inslen = dup * e->elem;
out_reserve(data, data->inslen);
break;
}
e = e->next;
}
}
/* This is totally just a wild guess what is reasonable... */
#define INCBIN_MAX_BUF (ZERO_BUF_SIZE * 16)
int64_t assemble(int32_t segment, int64_t start, int bits, insn *instruction)
{
struct out_data data;
const struct itemplate *temp;
enum match_result m;
if (instruction->opcode == I_none)
return 0;
nasm_zero(data);
data.offset = start;
data.segment = segment;
data.itemp = NULL;
data.bits = bits;
if (opcode_is_db(instruction->opcode)) {
out_eops(&data, instruction->eops);
} else if (instruction->opcode == I_INCBIN) {
const char *fname = instruction->eops->val.string.data;
FILE *fp;
size_t t = instruction->times; /* INCBIN handles TIMES by itself */
off_t base = 0;
off_t len;
const void *map = NULL;
char *buf = NULL;
size_t blk = 0; /* Buffered I/O block size */
size_t m = 0; /* Bytes last read */
if (!t)
goto done;
fp = nasm_open_read(fname, NF_BINARY|NF_FORMAP);
if (!fp) {
nasm_nonfatal("`incbin': unable to open file `%s'",
fname);
goto done;
}
len = nasm_file_size(fp);
if (len == (off_t)-1) {
nasm_nonfatal("`incbin': unable to get length of file `%s'",
fname);
goto close_done;
}
if (instruction->eops->next) {
base = instruction->eops->next->val.num.offset;
if (base >= len) {
len = 0;
} else {
len -= base;
if (instruction->eops->next->next &&
len > (off_t)instruction->eops->next->next->val.num.offset)
len = (off_t)instruction->eops->next->next->val.num.offset;
}
}
lfmt->set_offset(data.offset);
lfmt->uplevel(LIST_INCBIN, len);
if (!len)
goto end_incbin;
/* Try to map file data */
map = nasm_map_file(fp, base, len);
if (!map) {
blk = len < (off_t)INCBIN_MAX_BUF ? (size_t)len : INCBIN_MAX_BUF;
buf = nasm_malloc(blk);
}
while (t--) {
/*
* Consider these irrelevant for INCBIN, since it is fully
* possible that these might be (way) bigger than an int
* can hold; there is, however, no reason to widen these
* types just for INCBIN. data.inslen == 0 signals to the
* backend that these fields are meaningless, if at all
* needed.
*/
data.insoffs = 0;
data.inslen = 0;
if (map) {
out_rawdata(&data, map, len);
} else if ((off_t)m == len) {
out_rawdata(&data, buf, len);
} else {
off_t l = len;
if (fseeko(fp, base, SEEK_SET) < 0 || ferror(fp)) {
nasm_nonfatal("`incbin': unable to seek on file `%s'",
fname);
goto end_incbin;
}
while (l > 0) {
m = fread(buf, 1, l < (off_t)blk ? (size_t)l : blk, fp);
if (!m || feof(fp)) {
/*
* This shouldn't happen unless the file
* actually changes while we are reading
* it.
*/
nasm_nonfatal("`incbin': unexpected EOF while"
" reading file `%s'", fname);
goto end_incbin;
}
out_rawdata(&data, buf, m);
l -= m;
}
}
}
end_incbin:
lfmt->downlevel(LIST_INCBIN);
if (instruction->times > 1) {
lfmt->uplevel(LIST_TIMES, instruction->times);
lfmt->downlevel(LIST_TIMES);
}
if (ferror(fp)) {
nasm_nonfatal("`incbin': error while"
" reading file `%s'", fname);
}
close_done:
if (buf)
nasm_free(buf);
if (map)
nasm_unmap_file(map, len);
fclose(fp);
done:
instruction->times = 1; /* Tell the upper layer not to iterate */
;
} else {
/* "Real" instruction */
/* Check to see if we need an address-size prefix */
add_asp(instruction, bits);
m = find_match(&temp, instruction, data.segment, data.offset, bits);
if (m == MOK_GOOD) {
/* Matches! */
if (unlikely(itemp_has(temp, IF_OBSOLETE))) {
errflags warning;
const char *whathappened;
const char *validity;
bool never = itemp_has(temp, IF_NEVER);
/*
* If IF_OBSOLETE is set, warn the user. Different
* warning classes for "obsolete but valid for this
* specific CPU" and "obsolete and gone."
*
*!obsolete-removed [on] instruction obsolete and removed on the target CPU
*! warns for an instruction which has been removed
*! from the architecture, and is no longer included
*! in the CPU definition given in the \c{[CPU]}
*! directive, for example \c{POP CS}, the opcode for
*! which, \c{0Fh}, instead is an opcode prefix on
*! CPUs newer than the first generation 8086.
*
*!obsolete-nop [on] instruction obsolete and is a noop on the target CPU
*! warns for an instruction which has been removed
*! from the architecture, but has been architecturally
*! defined to be a noop for future CPUs.
*
*!obsolete-valid [on] instruction obsolete but valid on the target CPU
*! warns for an instruction which has been removed
*! from the architecture, but is still valid on the
*! specific CPU given in the \c{CPU} directive. Code
*! using these instructions is most likely not
*! forward compatible.
*/
whathappened = never ? "never implemented" : "obsolete";
if (!never && !iflag_cmp_cpu_level(&insns_flags[temp->iflag_idx], &cpu)) {
warning = WARN_OBSOLETE_VALID;
validity = "but valid on";
} else if (itemp_has(temp, IF_NOP)) {
warning = WARN_OBSOLETE_NOP;
validity = "and is a noop on";
} else {
warning = WARN_OBSOLETE_REMOVED;
validity = never ? "and invalid on" : "and removed from";
}
nasm_warn(warning, "instruction %s %s the target CPU",
whathappened, validity);
}
data.itemp = temp;
data.bits = bits;
data.insoffs = 0;
data.inslen = calcsize(data.segment, data.offset,
bits, instruction, temp);
nasm_assert(data.inslen >= 0);
data.inslen = merge_resb(instruction, data.inslen);
gencode(&data, instruction);
nasm_assert(data.insoffs == data.inslen);
} else {
/* No match */
switch (m) {
case MERR_OPSIZEMISSING:
nasm_nonfatal("operation size not specified");
break;
case MERR_OPSIZEMISMATCH:
nasm_nonfatal("mismatch in operand sizes");
break;
case MERR_BRNOTHERE:
nasm_nonfatal("broadcast not permitted on this operand");
break;
case MERR_BRNUMMISMATCH:
nasm_nonfatal("mismatch in the number of broadcasting elements");
break;
case MERR_MASKNOTHERE:
nasm_nonfatal("mask not permitted on this operand");
break;
case MERR_DECONOTHERE:
nasm_nonfatal("unsupported mode decorator for instruction");
break;
case MERR_BADCPU:
nasm_nonfatal("no instruction for this cpu level");
break;
case MERR_BADMODE:
nasm_nonfatal("instruction not supported in %d-bit mode", bits);
break;
case MERR_ENCMISMATCH:
if (!instruction->prefixes[PPS_REX]) {
nasm_nonfatal("instruction not encodable without explicit prefix");
} else {
nasm_nonfatal("instruction not encodable with %s prefix",
prefix_name(instruction->prefixes[PPS_REX]));
}
break;
case MERR_BADBND:
case MERR_BADREPNE:
nasm_nonfatal("%s prefix is not allowed",
prefix_name(instruction->prefixes[PPS_REP]));
break;
case MERR_REGSETSIZE:
nasm_nonfatal("invalid register set size");
break;
case MERR_REGSET:
nasm_nonfatal("register set not valid for operand");
break;
default:
nasm_nonfatal("invalid combination of opcode and operands");
break;
}
instruction->times = 1; /* Avoid repeated error messages */
}
}
return data.offset - start;
}
static int32_t eops_typeinfo(const extop *e)
{
int32_t typeinfo = 0;
while (e) {
switch (e->type) {
case EOT_NOTHING:
break;
case EOT_EXTOP:
typeinfo |= eops_typeinfo(e->val.subexpr);
break;
case EOT_DB_FLOAT:
switch (e->elem) {
case 1: typeinfo |= TY_BYTE; break;
case 2: typeinfo |= TY_WORD; break;
case 4: typeinfo |= TY_FLOAT; break;
case 8: typeinfo |= TY_QWORD; break; /* double? */
case 10: typeinfo |= TY_TBYTE; break; /* long double? */
case 16: typeinfo |= TY_YWORD; break;
case 32: typeinfo |= TY_ZWORD; break;
default: break;
}
break;
default:
switch (e->elem) {
case 1: typeinfo |= TY_BYTE; break;
case 2: typeinfo |= TY_WORD; break;
case 4: typeinfo |= TY_DWORD; break;
case 8: typeinfo |= TY_QWORD; break;
case 10: typeinfo |= TY_TBYTE; break;
case 16: typeinfo |= TY_YWORD; break;
case 32: typeinfo |= TY_ZWORD; break;
default: break;
}
break;
}
e = e->next;
}
return typeinfo;
}
static inline void debug_set_db_type(insn *instruction)
{
int32_t typeinfo = TYS_ELEMENTS(instruction->operands);
typeinfo |= eops_typeinfo(instruction->eops);
dfmt->debug_typevalue(typeinfo);
}
static void debug_set_type(insn *instruction)
{
int32_t typeinfo;
if (opcode_is_resb(instruction->opcode)) {
typeinfo = TYS_ELEMENTS(instruction->oprs[0].offset);
switch (instruction->opcode) {
case I_RESB:
typeinfo |= TY_BYTE;
break;
case I_RESW:
typeinfo |= TY_WORD;
break;
case I_RESD:
typeinfo |= TY_DWORD;
break;
case I_RESQ:
typeinfo |= TY_QWORD;
break;
case I_REST:
typeinfo |= TY_TBYTE;
break;
case I_RESO:
typeinfo |= TY_OWORD;
break;
case I_RESY:
typeinfo |= TY_YWORD;
break;
case I_RESZ:
typeinfo |= TY_ZWORD;
break;
default:
panic();
}
} else {
typeinfo = TY_LABEL;
}
dfmt->debug_typevalue(typeinfo);
}
/* Proecess an EQU directive */
static void define_equ(insn * instruction)
{
if (!instruction->label) {
nasm_nonfatal("EQU not preceded by label");
} else if (instruction->operands == 1 &&
(instruction->oprs[0].type & IMMEDIATE) &&
instruction->oprs[0].wrt == NO_SEG) {
define_label(instruction->label,
instruction->oprs[0].segment,
instruction->oprs[0].offset, false);
} else if (instruction->operands == 2
&& (instruction->oprs[0].type & IMMEDIATE)
&& (instruction->oprs[0].type & COLON)
&& instruction->oprs[0].segment == NO_SEG
&& instruction->oprs[0].wrt == NO_SEG
&& (instruction->oprs[1].type & IMMEDIATE)
&& instruction->oprs[1].segment == NO_SEG
&& instruction->oprs[1].wrt == NO_SEG) {
define_label(instruction->label,
instruction->oprs[0].offset | SEG_ABS,
instruction->oprs[1].offset, false);
} else {
nasm_nonfatal("bad syntax for EQU");
}
}
static int64_t len_extops(const extop *e)
{
int64_t isize = 0;
size_t pad;
while (e) {
switch (e->type) {
case EOT_NOTHING:
break;
case EOT_EXTOP:
isize += e->dup * len_extops(e->val.subexpr);
break;
case EOT_DB_STRING:
case EOT_DB_STRING_FREE:
case EOT_DB_FLOAT:
pad = pad_bytes(e->val.string.len, e->elem);
isize += e->dup * (e->val.string.len + pad);
break;
case EOT_DB_NUMBER:
warn_overflow_const(e->val.num.offset, e->elem);
isize += e->dup * e->elem;
break;
case EOT_DB_RESERVE:
isize += e->dup * e->elem;
break;
}
e = e->next;
}
return isize;
}
int64_t insn_size(int32_t segment, int64_t offset, int bits, insn *instruction)
{
const struct itemplate *temp;
enum match_result m;
int64_t isize = 0;
if (instruction->opcode == I_none) {
return 0;
} else if (instruction->opcode == I_EQU) {
define_equ(instruction);
return 0;
} else if (opcode_is_db(instruction->opcode)) {
isize = len_extops(instruction->eops);
debug_set_db_type(instruction);
return isize;
} else if (instruction->opcode == I_INCBIN) {
const extop *e = instruction->eops;
const char *fname = e->val.string.data;
off_t len;
len = nasm_file_size_by_path(fname);
if (len == (off_t)-1) {
nasm_nonfatal("`incbin': unable to get length of file `%s'",
fname);
return 0;
}
e = e->next;
if (e) {
if (len <= (off_t)e->val.num.offset) {
len = 0;
} else {
len -= e->val.num.offset;
e = e->next;
if (e && len > (off_t)e->val.num.offset) {
len = (off_t)e->val.num.offset;
}
}
}
len *= instruction->times;
instruction->times = 1; /* Tell the upper layer to not iterate */
return len;
} else {
/* Normal instruction, or RESx */
/* Check to see if we need an address-size prefix */
add_asp(instruction, bits);
m = find_match(&temp, instruction, segment, offset, bits);
if (m != MOK_GOOD)
return -1; /* No match */
isize = calcsize(segment, offset, bits, instruction, temp);
debug_set_type(instruction);
isize = merge_resb(instruction, isize);
return isize;
}
}
static void bad_hle_warn(const insn * ins, uint8_t hleok)
{
enum prefixes rep_pfx = ins->prefixes[PPS_REP];
enum whatwarn { w_none, w_lock, w_inval } ww;
static const enum whatwarn warn[2][4] =
{
{ w_inval, w_inval, w_none, w_lock }, /* XACQUIRE */
{ w_inval, w_none, w_none, w_lock }, /* XRELEASE */
};
unsigned int n;
n = (unsigned int)rep_pfx - P_XACQUIRE;
if (n > 1)
return; /* Not XACQUIRE/XRELEASE */
ww = warn[n][hleok];
if (!is_class(MEMORY, ins->oprs[0].type))
ww = w_inval; /* HLE requires operand 0 to be memory */
/*!
*!prefix-hle [on] invalid HLE prefix
*!=hle
*! warns about invalid use of the HLE \c{XACQUIRE} or \c{XRELEASE}
*! prefixes.
*/
switch (ww) {
case w_none:
break;
case w_lock:
if (ins->prefixes[PPS_LOCK] != P_LOCK) {
nasm_warn(WARN_PREFIX_HLE|ERR_PASS2,
"%s with this instruction requires lock",
prefix_name(rep_pfx));
}
break;
case w_inval:
nasm_warn(WARN_PREFIX_HLE|ERR_PASS2,
"%s invalid with this instruction",
prefix_name(rep_pfx));
break;
}
}
/* Common construct */
#define case3(x) case (x): case (x)+1: case (x)+2
#define case4(x) case3(x): case (x)+3
static int64_t calcsize(int32_t segment, int64_t offset, int bits,
insn * ins, const struct itemplate *temp)
{
const uint8_t *codes = temp->code;
int64_t length = 0;
uint8_t c;
int rex_mask = ~0;
int op1, op2;
struct operand *opx, *opy;
uint8_t opex = 0;
enum ea_type eat;
uint8_t hleok = 0;
bool lockcheck = true;
enum reg_enum mib_index = R_none; /* For a separate index reg form */
const char *errmsg;
ins->rex = 0; /* Ensure REX is reset */
eat = EA_SCALAR; /* Expect a scalar EA */
memset(ins->evex_p, 0, 3); /* Ensure EVEX is reset */
if (ins->prefixes[PPS_OSIZE] == P_O64)
ins->rex |= REX_W;
(void)segment; /* Don't warn that this parameter is unused */
(void)offset; /* Don't warn that this parameter is unused */
while (*codes) {
c = *codes++;
op1 = (c & 3) + ((opex & 1) << 2);
opx = get_operand(ins, op1);
op2 = ((c >> 3) & 3) + ((opex & 2) << 1);
opy = NULL;
opex = 0; /* For the next iteration */
switch (c) {
case4(01):
codes += c, length += c;
break;
case3(05):
opex = c;
break;
case4(010):
ins->rex |=
op_rexflags(opx, REX_B|REX_H|REX_P|REX_W);
codes++, length++;
break;
case4(014):
/* this is an index reg of a split SIB operand */
mib_index = opx->basereg;
break;
case4(020):
case4(024):
length++;
break;
case4(030):
length += 2;
break;
case4(034):
if (opx->type & (BITS16 | BITS32 | BITS64))
length += (opx->type & BITS16) ? 2 : 4;
else
length += (bits == 16) ? 2 : 4;
break;
case4(040):
length += 4;
break;
case4(044):
length += ins->addr_size >> 3;
break;
case4(050):
length++;
break;
case4(054):
length += 8; /* MOV reg64/imm */
break;
case4(060):
length += 2;
break;
case4(064):
if (opx->type & (BITS16 | BITS32 | BITS64))
length += (opx->type & BITS16) ? 2 : 4;
else
length += (bits == 16) ? 2 : 4;
break;
case4(070):
length += 4;
break;
case4(074):
length += 2;
break;
case 0171:
c = *codes++;
op2 = (op2 & ~3) | ((c >> 3) & 3);
opy = get_operand(ins, op2);
ins->rex |= op_rexflags(opy, REX_R|REX_H|REX_P|REX_W);
length++;
break;
case 0172:
case 0173:
codes++;
length++;
break;
case4(0174):
length++;
break;
case4(0240):
ins->rex |= REX_EV;
ins->vexreg = regval(opx);
ins->evex_p[2] |= op_evexflags(opx, EVEX_P2VP, 2); /* High-16 NDS */
ins->vex_cm = *codes++;
ins->vex_wlp = *codes++;
ins->evex_tuple = (*codes++ - 0300);
break;
case 0250:
ins->rex |= REX_EV;
ins->vexreg = 0;
ins->vex_cm = *codes++;
ins->vex_wlp = *codes++;
ins->evex_tuple = (*codes++ - 0300);
break;
case4(0254):
length += 4;
break;
case4(0260):
ins->rex |= REX_V;
ins->vexreg = regval(opx);
ins->vex_cm = *codes++;
ins->vex_wlp = *codes++;
break;
case 0270:
ins->rex |= REX_V;
ins->vexreg = 0;
ins->vex_cm = *codes++;
ins->vex_wlp = *codes++;
break;
case3(0271):
hleok = c & 3;
break;
case4(0274):
length++;
break;
case4(0300):
break;
case 0310:
if (bits == 64)
return -1;
length += (bits != 16) && !has_prefix(ins, PPS_ASIZE, P_A16);
break;
case 0311:
length += (bits != 32) && !has_prefix(ins, PPS_ASIZE, P_A32);
break;
case 0312:
break;
case 0313:
if (bits != 64 || has_prefix(ins, PPS_ASIZE, P_A16) ||
has_prefix(ins, PPS_ASIZE, P_A32))
return -1;
break;
case4(0314):
break;
case 0320:
{
/*! prefix-opsize [on] invalid operand size prefix
*! warns that an operand prefix (\c{o16}, \c{o32}, \c{o64},
*! \c{osp}) invalid for the specified instruction has been specified.
*! The operand prefix will be ignored by the assembler.
*/
enum prefixes pfx = ins->prefixes[PPS_OSIZE];
if (pfx == P_O16)
break;
if (pfx != P_none)
nasm_warn(WARN_PREFIX_OPSIZE|ERR_PASS2,
"invalid operand size prefix, must be o16");
else
ins->prefixes[PPS_OSIZE] = P_O16;
break;
}
case 0321:
{
enum prefixes pfx = ins->prefixes[PPS_OSIZE];
if (pfx == P_O32)
break;
if (pfx != P_none)
nasm_warn(WARN_PREFIX_OPSIZE|ERR_PASS2,
"invalid operand size prefix, must be o32");
else
ins->prefixes[PPS_OSIZE] = P_O32;
break;
}
case 0322:
break;
case 0323:
rex_mask &= ~REX_W;
break;
case 0324:
ins->rex |= REX_W;
break;
case 0325:
ins->rex |= REX_NH;
break;
case 0326:
break;
case 0331:
break;
case 0332:
case 0333:
length++;
break;
case 0334:
ins->rex |= REX_L;
break;
case 0335:
break;
case 0336:
if (!ins->prefixes[PPS_REP])
ins->prefixes[PPS_REP] = P_REP;
break;
case 0337:
if (!ins->prefixes[PPS_REP])
ins->prefixes[PPS_REP] = P_REPNE;
break;
case 0340:
/*!
*!forward [on] forward reference may have unpredictable results
*! warns that a forward reference is used which may have
*! unpredictable results, notably in a \c{RESB}-type
*! pseudo-instruction. These would be \i\e{critical
*! expressions} (see \k{crit}) but are permitted in a
*! handful of cases for compatibility with older
*! versions of NASM. This warning should be treated as a
*! severe programming error as the code could break at
*! any time for any number of reasons.
*/
/* The bytecode ends in 0, so opx points to operand 0 */
if (!absolute_op(opx))
nasm_nonfatal("attempt to reserve non-constant"
" quantity of BSS space");
else if (opx->opflags & OPFLAG_FORWARD)
nasm_warn(WARN_FORWARD, "forward reference in RESx "
"can have unpredictable results");
else
length += opx->offset * resb_bytes(ins->opcode);
break;
case 0341:
if (!ins->prefixes[PPS_WAIT])
ins->prefixes[PPS_WAIT] = P_WAIT;
break;
case 0360:
break;
case 0361:
length++;
break;
case 0364:
case 0365:
break;
case 0366:
case 0367:
length++;
break;
case 0370:
case 0371:
break;
case 0373:
length++;
break;
case 0374:
eat = EA_XMMVSIB;
break;
case 0375:
eat = EA_YMMVSIB;
break;
case 0376:
eat = EA_ZMMVSIB;
break;
case4(0100):
case4(0110):
case4(0120):
case4(0130):
case4(0200):
case4(0204):
case4(0210):
case4(0214):
case4(0220):
case4(0224):
case4(0230):
case4(0234):
{
ea ea_data;
int rfield;
opflags_t rflags;
const struct operand *op_er_sae;
opy = get_operand(ins, op2);
ea_data.rex = 0; /* Ensure ea.REX is initially 0 */
if (c <= 0177) {
/* pick rfield from operand b (opx) */
rflags = regflag(opx);
rfield = nasm_regvals[opx->basereg];
} else {
rflags = 0;
rfield = c & 7;
opx = NULL;
}
/* EVEX.b1 : evex_brerop contains the operand position */
op_er_sae = ins->evex_brerop;
if (op_er_sae && (op_er_sae->decoflags & (ER | SAE))) {
/* set EVEX.b */
ins->evex_p[2] |= EVEX_P2B;
if (op_er_sae->decoflags & ER) {
/* set EVEX.RC (rounding control) */
ins->evex_p[2] |= ((ins->evex_rm - BRC_RN) << 5)
& EVEX_P2RC;
}
} else {
/* set EVEX.L'L (vector length) */
ins->evex_p[2] |= ((ins->vex_wlp << (5 - 2)) & EVEX_P2LL);
ins->evex_p[1] |= ((ins->vex_wlp << (7 - 4)) & EVEX_P1W);
if (opy->decoflags & BRDCAST_MASK) {
/* set EVEX.b */
ins->evex_p[2] |= EVEX_P2B;
}
}
if (itemp_has(temp, IF_MIB)) {
opy->eaflags |= EAF_MIB;
/*
* if a separate form of MIB (ICC style) is used,
* the index reg info is merged into mem operand
*/
if (mib_index != R_none) {
opy->indexreg = mib_index;
opy->scale = 1;
opy->hintbase = mib_index;
opy->hinttype = EAH_NOTBASE;
}
}
/* SIB encoding required */
if (itemp_has(temp, IF_SIB))
opy->eaflags |= EAF_SIB;
if (process_ea(opy, &ea_data, bits,
rfield, rflags, ins, eat, &errmsg)) {
nasm_nonfatal("%s", errmsg);
return -1;
} else {
ins->rex |= ea_data.rex;
length += ea_data.size;
}
}
break;
default:
nasm_panic("internal instruction table corrupt"
": instruction code \\%o (0x%02X) given", c, c);
break;
}
}
ins->rex &= rex_mask;
if (ins->rex & REX_NH) {
if (ins->rex & REX_H) {
nasm_nonfatal("instruction cannot use high registers");
return -1;
}
ins->rex &= ~REX_P; /* Don't force REX prefix due to high reg */
}
switch (ins->prefixes[PPS_REX]) {
case P_EVEX:
if (!(ins->rex & REX_EV))
return -1;
break;
case P_VEX:
case P_VEX3:
case P_VEX2:
if (!(ins->rex & REX_V))
return -1;
break;
case P_REX:
if (ins->rex & (REX_V|REX_EV))
return -1;
ins->rex |= REX_P; /* Force REX prefix */
break;
default:
break;
}
if (ins->rex & (REX_V | REX_EV)) {
int bad32 = REX_R|REX_W|REX_X|REX_B;
if (ins->rex & REX_H) {
nasm_nonfatal("cannot use high register in AVX instruction");
return -1;
}
switch (ins->vex_wlp & 060) {
case 000:
case 040:
ins->rex &= ~REX_W;
break;
case 020:
ins->rex |= REX_W;
bad32 &= ~REX_W;
break;
case 060:
/* Follow REX_W */
break;
}
if (bits != 64 && ((ins->rex & bad32) || ins->vexreg > 7)) {
nasm_nonfatal("invalid operands in non-64-bit mode");
return -1;
} else if (!(ins->rex & REX_EV) &&
((ins->vexreg > 15) || (ins->evex_p[0] & 0xf0))) {
nasm_nonfatal("invalid high-16 register in non-AVX-512");
return -1;
}
if (ins->rex & REX_EV) {
length += 4;
} else if (ins->vex_cm != 1 || (ins->rex & (REX_W|REX_X|REX_B)) ||
ins->prefixes[PPS_REX] == P_VEX3) {
if (ins->prefixes[PPS_REX] == P_VEX2)
nasm_nonfatal("instruction not encodable with {vex2} prefix");
length += 3;
} else {
length += 2;
}
} else if (ins->rex & REX_MASK) {
if (ins->rex & REX_H) {
nasm_nonfatal("cannot use high byte register in rex instruction");
return -1;
} else if (bits == 64) {
length++;
} else if ((ins->rex & REX_L) &&
!(ins->rex & (REX_P|REX_W|REX_X|REX_B)) &&
iflag_cpu_level_ok(&cpu, IF_X86_64)) {
/* LOCK-as-REX.R */
assert_no_prefix(ins, PPS_LOCK);
lockcheck = false; /* Already errored, no need for warning */
length++;
} else {
nasm_nonfatal("invalid operands in non-64-bit mode");
return -1;
}
}
if (lockcheck && has_prefix(ins, PPS_LOCK, P_LOCK)) {
if ((!itemp_has(temp,IF_LOCK) || !is_class(MEMORY, ins->oprs[0].type)) &&
(!itemp_has(temp,IF_LOCK1) || !is_class(MEMORY, ins->oprs[1].type))) {
/*!
*!prefix-lock-error [on] \c{LOCK} prefix on unlockable instruction
*!=lock
*! warns about \c{LOCK} prefixes on unlockable instructions.
*/
nasm_warn(WARN_PREFIX_LOCK_ERROR|ERR_PASS2 , "instruction is not lockable");
} else if (temp->opcode == I_XCHG) {
/*!
*!prefix-lock-xchg [on] superfluous \c{LOCK} prefix on \c{XCHG} instruction
*! warns about a \c{LOCK} prefix added to an \c{XCHG} instruction.
*! The \c{XCHG} instruction is \e{always} locking, and so this
*! prefix is not necessary; however, NASM will generate it if
*! explicitly provided by the user, so this warning indicates that
*! suboptimal code is being generated.
*/
nasm_warn(WARN_PREFIX_LOCK_XCHG|ERR_PASS2,
"superfluous LOCK prefix on XCHG instruction");
}
}
bad_hle_warn(ins, hleok);
/*
* when BND prefix is set by DEFAULT directive,
* BND prefix is added to every appropriate instruction line
* unless it is overridden by NOBND prefix.
*/
if (globalbnd &&
(itemp_has(temp, IF_BND) && !has_prefix(ins, PPS_REP, P_NOBND)))
ins->prefixes[PPS_REP] = P_BND;
/*
* Add length of legacy prefixes
*/
length += emit_prefix(NULL, bits, ins);
return length;
}
static inline void emit_rex(struct out_data *data, insn *ins)
{
if (data->bits == 64) {
if ((ins->rex & REX_MASK) &&
!(ins->rex & (REX_V | REX_EV)) &&
!ins->rex_done) {
uint8_t rex = (ins->rex & REX_MASK) | REX_P;
out_rawbyte(data, rex);
ins->rex_done = true;
}
}
}
static int emit_prefix(struct out_data *data, const int bits, insn *ins)
{
int bytes = 0;
int j;
for (j = 0; j < MAXPREFIX; j++) {
uint8_t c = 0;
switch (ins->prefixes[j]) {
case P_WAIT:
c = 0x9B;
break;
case P_LOCK:
c = 0xF0;
break;
case P_REPNE:
case P_REPNZ:
case P_XACQUIRE:
case P_BND:
c = 0xF2;
break;
case P_REPE:
case P_REPZ:
case P_REP:
case P_XRELEASE:
c = 0xF3;
break;
case R_CS:
/*!
*!prefix-seg [on] segment prefix ignored in 64-bit mode
*! warns that an \c{es}, \c{cs}, \c{ss} or \c{ds} segment override
*! prefix has no effect in 64-bit mode. The prefix will still be
*! generated as requested.
*/
if (bits == 64)
nasm_warn(WARN_PREFIX_SEG|ERR_PASS2, "cs segment base generated, "
"but will be ignored in 64-bit mode");
c = 0x2E;
break;
case R_DS:
if (bits == 64)
nasm_warn(WARN_PREFIX_SEG|ERR_PASS2, "ds segment base generated, "
"but will be ignored in 64-bit mode");
c = 0x3E;
break;
case R_ES:
if (bits == 64)
nasm_warn(WARN_PREFIX_SEG|ERR_PASS2, "es segment base generated, "
"but will be 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) {
nasm_warn(WARN_PREFIX_SEG|ERR_PASS2, "ss segment base generated, "
"but will be ignored in 64-bit mode");
}
c = 0x36;
break;
case R_SEGR6:
case R_SEGR7:
nasm_nonfatal("segr6 and segr7 cannot be used as prefixes");
break;
case P_A16:
if (bits == 64) {
nasm_nonfatal("16-bit addressing is not supported "
"in 64-bit mode");
} else if (bits != 16)
c = 0x67;
break;
case P_A32:
if (bits != 32)
c = 0x67;
break;
case P_A64:
if (bits != 64) {
nasm_nonfatal("64-bit addressing is only supported "
"in 64-bit mode");
}
break;
case P_ASP:
c = 0x67;
break;
case P_O16:
if (bits != 16)
c = 0x66;
break;
case P_O32:
if (bits == 16)
c = 0x66;
break;
case P_O64:
/* REX.W */
break;
case P_OSP:
c = 0x66;
break;
case P_REX:
case P_VEX:
case P_EVEX:
case P_VEX3:
case P_VEX2:
case P_NOBND:
case P_none:
break;
default:
nasm_panic("invalid instruction prefix");
}
if (c) {
if (data)
out_rawbyte(data, c);
bytes++;
}
}
return bytes;
}
static void gencode(struct out_data *data, insn *ins)
{
uint8_t c;
uint8_t bytes[4];
int64_t size;
int op1, op2;
struct operand *opx, *opy;
const uint8_t *codes = data->itemp->code;
uint8_t opex = 0;
enum ea_type eat = EA_SCALAR;
int r;
const int bits = data->bits;
const char *errmsg;
ins->rex_done = false;
emit_prefix(data, bits, ins);
while (*codes) {
c = *codes++;
op1 = (c & 3) + ((opex & 1) << 2);
opx = get_operand(ins, op1);
op2 = ((c >> 3) & 3) + ((opex & 2) << 1);
opy = NULL;
opex = 0; /* For the next iteration */
switch (c) {
case 01:
case 02:
case 03:
case 04:
emit_rex(data, ins);
out_rawdata(data, codes, c);
codes += c;
break;
case 05:
case 06:
case 07:
opex = c;
break;
case4(010):
emit_rex(data, ins);
out_rawbyte(data, *codes++ + (regval(opx) & 7));
break;
case4(014):
break;
case4(020):
out_imm(data, opx, 1, OUT_WRAP);
break;
case4(024):
out_imm(data, opx, 1, OUT_UNSIGNED);
break;
case4(030):
out_imm(data, opx, 2, OUT_WRAP);
break;
case4(034):
if (opx->type & (BITS16 | BITS32))
size = (opx->type & BITS16) ? 2 : 4;
else
size = (bits == 16) ? 2 : 4;
out_imm(data, opx, size, OUT_WRAP);
break;
case4(040):
out_imm(data, opx, 4, OUT_WRAP);
break;
case4(044):
size = ins->addr_size >> 3;
out_imm(data, opx, size, OUT_WRAP);
break;
case4(050):
if (opx->segment == data->segment) {
int64_t delta = opx->offset - data->offset
- (data->inslen - data->insoffs);
if (delta > 127 || delta < -128)
nasm_nonfatal("short jump is out of range");
}
out_reladdr(data, opx, 1);
break;
case4(054):
out_imm(data, opx, 8, OUT_WRAP);
break;
case4(060):
out_reladdr(data, opx, 2);
break;
case4(064):
if (opx->type & (BITS16 | BITS32 | BITS64))
size = (opx->type & BITS16) ? 2 : 4;
else
size = (bits == 16) ? 2 : 4;
out_reladdr(data, opx, size);
break;
case4(070):
out_reladdr(data, opx, 4);
break;
case4(074):
if (opx->segment == NO_SEG)
nasm_nonfatal("value referenced by FAR is not relocatable");
out_segment(data, opx);
break;
case 0171:
c = *codes++;
op2 = (op2 & ~3) | ((c >> 3) & 3);
opx = &ins->oprs[op2];
r = nasm_regvals[opx->basereg];
c = (c & ~070) | ((r & 7) << 3);
out_rawbyte(data, c);
break;
case 0172:
{
int mask = ins->prefixes[PPS_REX] == P_EVEX ? 7 : 15;
const struct operand *opy;
c = *codes++;
opx = get_operand(ins, op1 = (c >> 3) & 7);
opy = get_operand(ins, op2 = c & 7);
if (!absolute_op(opy))
nasm_nonfatal("non-absolute expression not permitted "
"as argument %d", op2);
else if (opy->offset & ~mask)
nasm_warn(ERR_PASS2|WARN_NUMBER_OVERFLOW,
"is4 argument exceeds bounds");
c = opy->offset & mask;
goto emit_is4;
}
case 0173:
c = *codes++;
opx = get_operand(ins, op1 = c >> 4);
c &= 15;
goto emit_is4;
case4(0174):
c = 0;
emit_is4:
r = nasm_regvals[opx->basereg];
out_rawbyte(data, (r << 4) | ((r & 0x10) >> 1) | c);
break;
case4(0254):
if (absolute_op(opx) &&
(int32_t)opx->offset != (int64_t)opx->offset) {
nasm_warn(ERR_PASS2|WARN_NUMBER_OVERFLOW,
"signed dword immediate exceeds bounds");
}
out_imm(data, opx, 4, OUT_SIGNED);
break;
case4(0240):
case 0250:
codes += 3;
ins->evex_p[2] |= op_evexflags(&ins->oprs[0],
EVEX_P2Z | EVEX_P2AAA, 2);
ins->evex_p[2] ^= EVEX_P2VP; /* 1's complement */
bytes[0] = 0x62;
/* EVEX.X can be set by either REX or EVEX for different reasons */
bytes[1] = ((((ins->rex & 7) << 5) |
(ins->evex_p[0] & (EVEX_P0X | EVEX_P0RP))) ^ 0xf0) |
(ins->vex_cm & EVEX_P0MM);
bytes[2] = ((ins->rex & REX_W) << (7 - 3)) |
((~ins->vexreg & 15) << 3) |
(1 << 2) | (ins->vex_wlp & 3);
bytes[3] = ins->evex_p[2];
out_rawdata(data, bytes, 4);
break;
case4(0260):
case 0270:
codes += 2;
if (ins->vex_cm != 1 || (ins->rex & (REX_W|REX_X|REX_B)) ||
ins->prefixes[PPS_REX] == P_VEX3) {
bytes[0] = (ins->vex_cm >> 6) ? 0x8f : 0xc4;
bytes[1] = (ins->vex_cm & 31) | ((~ins->rex & 7) << 5);
bytes[2] = ((ins->rex & REX_W) << (7-3)) |
((~ins->vexreg & 15)<< 3) | (ins->vex_wlp & 07);
out_rawdata(data, bytes, 3);
} else {
bytes[0] = 0xc5;
bytes[1] = ((~ins->rex & REX_R) << (7-2)) |
((~ins->vexreg & 15) << 3) | (ins->vex_wlp & 07);
out_rawdata(data, bytes, 2);
}
break;
case 0271:
case 0272:
case 0273:
break;
case4(0274):
{
uint64_t uv, um;
int s;
if (absolute_op(opx)) {
if (ins->rex & REX_W)
s = 64;
else if (ins->prefixes[PPS_OSIZE] == P_O16)
s = 16;
else if (ins->prefixes[PPS_OSIZE] == P_O32)
s = 32;
else
s = bits;
um = (uint64_t)2 << (s-1);
uv = opx->offset;
if (uv > 127 && uv < (uint64_t)-128 &&
(uv < um-128 || uv > um-1)) {
/* If this wasn't explicitly byte-sized, warn as though we
* had fallen through to the imm16/32/64 case.
*/
nasm_warn(ERR_PASS2|WARN_NUMBER_OVERFLOW,
"%s value exceeds bounds",
(opx->type & BITS8) ? "signed byte" :
s == 16 ? "word" :
s == 32 ? "dword" :
"signed dword");
}
/* Output as a raw byte to avoid byte overflow check */
out_rawbyte(data, (uint8_t)uv);
} else {
out_imm(data, opx, 1, OUT_WRAP); /* XXX: OUT_SIGNED? */
}
break;
}
case4(0300):
break;
case 0310:
if (bits == 32 && !has_prefix(ins, PPS_ASIZE, P_A16))
out_rawbyte(data, 0x67);
break;
case 0311:
if (bits != 32 && !has_prefix(ins, PPS_ASIZE, P_A32))
out_rawbyte(data, 0x67);
break;
case 0312:
break;
case 0313:
break;
case4(0314):
break;
case 0320:
case 0321:
break;
case 0322:
case 0323:
break;
case 0324:
ins->rex |= REX_W;
break;
case 0325:
break;
case 0326:
break;
case 0331:
break;
case 0332:
case 0333:
out_rawbyte(data, c - 0332 + 0xF2);
break;
case 0334:
if (ins->rex & REX_R)
out_rawbyte(data, 0xF0);
ins->rex &= ~(REX_L|REX_R);
break;
case 0335:
break;
case 0336:
case 0337:
break;
case 0340:
if (ins->oprs[0].segment != NO_SEG)
nasm_panic("non-constant BSS size in pass two");
out_reserve(data, ins->oprs[0].offset * resb_bytes(ins->opcode));
break;
case 0341:
break;
case 0360:
break;
case 0361:
out_rawbyte(data, 0x66);
break;
case 0364:
case 0365:
break;
case 0366:
case 0367:
out_rawbyte(data, c - 0366 + 0x66);
break;
case3(0370):
break;
case 0373:
out_rawbyte(data, bits == 16 ? 3 : 5);
break;
case 0374:
eat = EA_XMMVSIB;
break;
case 0375:
eat = EA_YMMVSIB;
break;
case 0376:
eat = EA_ZMMVSIB;
break;
case4(0100):
case4(0110):
case4(0120):
case4(0130):
case4(0200):
case4(0204):
case4(0210):
case4(0214):
case4(0220):
case4(0224):
case4(0230):
case4(0234):
{
ea ea_data;
int rfield;
opflags_t rflags;
uint8_t *p;
opy = get_operand(ins, op2);
if (c <= 0177) {
/* pick rfield from operand b (opx) */
rflags = regflag(opx);
rfield = nasm_regvals[opx->basereg];
} else {
/* rfield is constant */
rflags = 0;
rfield = c & 7;
opx = NULL;
}
if (process_ea(opy, &ea_data, bits,
rfield, rflags, ins, eat, &errmsg))
nasm_nonfatal("%s", errmsg);
p = bytes;
*p++ = ea_data.modrm;
if (ea_data.sib_present)
*p++ = ea_data.sib;
out_rawdata(data, bytes, p - bytes);
/*
* Make sure the address gets the right offset in case
* the line breaks in the .lst file (BR 1197827)
*/
if (ea_data.bytes) {
/* use compressed displacement, if available */
if (ea_data.disp8) {
out_rawbyte(data, ea_data.disp8);
} else if (ea_data.rip) {
out_reladdr(data, opy, ea_data.bytes);
} else {
int asize = ins->addr_size >> 3;
if (overflow_general(opy->offset, asize) ||
signed_bits(opy->offset, ins->addr_size) !=
signed_bits(opy->offset, ea_data.bytes << 3))
warn_overflow(ea_data.bytes);
out_imm(data, opy, ea_data.bytes,
(asize > ea_data.bytes)
? OUT_SIGNED : OUT_WRAP);
}
}
}
break;
default:
nasm_panic("internal instruction table corrupt"
": instruction code \\%o (0x%02X) given", c, c);
break;
}
}
}
static opflags_t regflag(const operand * o)
{
if (!is_register(o->basereg))
nasm_panic("invalid operand passed to regflag()");
return nasm_reg_flags[o->basereg];
}
static int32_t regval(const operand * o)
{
if (!is_register(o->basereg))
nasm_panic("invalid operand passed to regval()");
return nasm_regvals[o->basereg];
}
static int op_rexflags(const operand * o, int mask)
{
opflags_t flags;
int val;
if (!is_register(o->basereg))
nasm_panic("invalid operand passed to op_rexflags()");
flags = nasm_reg_flags[o->basereg];
val = nasm_regvals[o->basereg];
return rexflags(val, flags, mask);
}
static int rexflags(int val, opflags_t flags, int mask)
{
int rex = 0;
if (val >= 0 && (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 evexflags(int val, decoflags_t deco,
int mask, uint8_t byte)
{
int evex = 0;
switch (byte) {
case 0:
if (val >= 0 && (val & 16))
evex |= (EVEX_P0RP | EVEX_P0X);
break;
case 2:
if (val >= 0 && (val & 16))
evex |= EVEX_P2VP;
if (deco & Z)
evex |= EVEX_P2Z;
if (deco & OPMASK_MASK)
evex |= deco & EVEX_P2AAA;
break;
}
return evex & mask;
}
static int op_evexflags(const operand * o, int mask, uint8_t byte)
{
int val;
val = nasm_regvals[o->basereg];
return evexflags(val, o->decoflags, mask, byte);
}
static enum match_result find_match(const struct itemplate **tempp,
insn *instruction,
int32_t segment, int64_t offset, int bits)
{
const struct itemplate *temp;
enum match_result m, merr;
opflags_t xsizeflags[MAX_OPERANDS];
bool opsizemissing = false;
int i;
for (i = 0; i < instruction->operands; i++)
xsizeflags[i] = instruction->oprs[i].xsize;
merr = MERR_INVALOP;
for (temp = nasm_instructions[instruction->opcode];
temp->opcode != I_none; temp++) {
m = matches(temp, instruction, bits);
if (m == MOK_JUMP) {
if (jmp_match(segment, offset, bits, instruction, temp))
m = MOK_GOOD;
else
m = MERR_INVALOP;
} else if (m == MERR_OPSIZEMISSING && !itemp_has(temp, IF_SX)) {
/*
* Missing operand size and a candidate for fuzzy matching...
*/
for (i = 0; i < temp->operands; i++) {
if (instruction->oprs[i].bcast)
xsizeflags[i] |= temp->deco[i] & BRSIZE_MASK;
else
xsizeflags[i] |= temp->opd[i] & SIZE_MASK;
}
opsizemissing = true;
}
if (m > merr)
merr = m;
if (merr == MOK_GOOD)
goto done;
}
/* No match, but see if we can get a fuzzy operand size match... */
if (!opsizemissing)
goto done;
for (i = 0; i < instruction->operands; i++) {
struct operand *op = &instruction->oprs[i];
/*
* We ignore extrinsic operand sizes on registers, so we should
* never try to fuzzy-match on them. This also resolves the case
* when we have e.g. "xmmrm128" in two different positions.
*/
if (is_class(REGISTER, op->type))
continue;
/* This tests if xsizeflags[i] has more than one bit set */
if ((xsizeflags[i] & (xsizeflags[i]-1)))
goto done; /* No luck */
if (op->bcast) {
op->decoflags |= xsizeflags[i];
op->type |= brsize_to_size(xsizeflags[i]);
} else {
op->type |= xsizeflags[i]; /* Set the size */
}
}
/* Try matching again... */
for (temp = nasm_instructions[instruction->opcode];
temp->opcode != I_none; temp++) {
m = matches(temp, instruction, bits);
if (m == MOK_JUMP) {
if (jmp_match(segment, offset, bits, instruction, temp))
m = MOK_GOOD;
else
m = MERR_INVALOP;
}
if (m > merr)
merr = m;
if (merr == MOK_GOOD)
goto done;
}
done:
*tempp = temp;
return merr;
}
static uint8_t get_broadcast_num(opflags_t opflags, opflags_t brsize)
{
unsigned int opsize = (opflags & SIZE_MASK) >> SIZE_SHIFT;
uint8_t brcast_num;
if (brsize > BITS64)
nasm_fatal("size of broadcasting element is greater than 64 bits");
/*
* The shift term is to take care of the extra BITS80 inserted
* between BITS64 and BITS128.
*/
brcast_num = ((opsize / (BITS64 >> SIZE_SHIFT)) * (BITS64 / brsize))
>> (opsize > (BITS64 >> SIZE_SHIFT));
return brcast_num;
}
static enum match_result matches(const struct itemplate *itemp,
insn *instruction, int bits)
{
opflags_t size[MAX_OPERANDS], asize;
bool opsizemissing = false;
int i, oprs;
/*
* Check the opcode
*/
if (itemp->opcode != instruction->opcode)
return MERR_INVALOP;
/*
* Count the operands
*/
if (itemp->operands != instruction->operands)
return MERR_INVALOP;
/*
* Is it legal?
*/
if (!(optimizing.level > 0) && itemp_has(itemp, IF_OPT))
return MERR_INVALOP;
/*
* {rex/vexn/evex} available?
*/
switch (instruction->prefixes[PPS_REX]) {
case P_EVEX:
if (!itemp_has(itemp, IF_EVEX))
return MERR_ENCMISMATCH;
break;
case P_VEX:
case P_VEX3:
case P_VEX2:
if (!itemp_has(itemp, IF_VEX))
return MERR_ENCMISMATCH;
break;
case P_REX:
if (itemp_has(itemp, IF_VEX) || itemp_has(itemp, IF_EVEX) ||
bits != 64)
return MERR_ENCMISMATCH;
break;
default:
if (itemp_has(itemp, IF_EVEX)) {
if (!iflag_test(&cpu, IF_EVEX))
return MERR_ENCMISMATCH;
} else if (itemp_has(itemp, IF_VEX)) {
if (!iflag_test(&cpu, IF_VEX)) {
return MERR_ENCMISMATCH;
} else if (itemp_has(itemp, IF_LATEVEX)) {
if (!iflag_test(&cpu, IF_LATEVEX) && iflag_test(&cpu, IF_EVEX))
return MERR_ENCMISMATCH;
}
}
break;
}
/*
* 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 MERR_INVALOP;
/*
* Process size flags
*/
switch (itemp_smask(itemp)) {
case IF_GENBIT(IF_SB):
asize = BITS8;
break;
case IF_GENBIT(IF_SW):
asize = BITS16;
break;
case IF_GENBIT(IF_SD):
asize = BITS32;
break;
case IF_GENBIT(IF_SQ):
asize = BITS64;
break;
case IF_GENBIT(IF_SO):
asize = BITS128;
break;
case IF_GENBIT(IF_SY):
asize = BITS256;
break;
case IF_GENBIT(IF_SZ):
asize = BITS512;
break;
case IF_GENBIT(IF_ANYSIZE):
asize = SIZE_MASK;
break;
case IF_GENBIT(IF_SIZE):
switch (bits) {
case 16:
asize = BITS16;
break;
case 32:
asize = BITS32;
break;
case 64:
asize = BITS64;
break;
default:
asize = 0;
break;
}
break;
default:
asize = 0;
break;
}
if (itemp_armask(itemp)) {
/* S- flags only apply to a specific operand */
i = itemp_arg(itemp);
memset(size, 0, sizeof size);
size[i] = asize;
} else {
/* S- flags apply to all operands */
for (i = 0; i < MAX_OPERANDS; i++)
size[i] = asize;
}
/*
* Check that the operand flags all match up,
* it's a bit tricky so lets be verbose:
*
* 1) Find out the size of operand. If instruction
* doesn't have one specified -- we're trying to
* guess it either from template (IF_S* flag) or
* from code bits.
*
* 2) If template operand do not match the instruction OR
* template has an operand size specified AND this size differ
* from which instruction has (perhaps we got it from code bits)
* we are:
* a) Check that only size of instruction and operand is differ
* other characteristics do match
* b) Perhaps it's a register specified in instruction so
* for such a case we just mark that operand as "size
* missing" and this will turn on fuzzy operand size
* logic facility (handled by a caller)
*/
for (i = 0; i < itemp->operands; i++) {
opflags_t type = instruction->oprs[i].type;
decoflags_t deco = instruction->oprs[i].decoflags;
decoflags_t ideco = itemp->deco[i];
bool is_broadcast = deco & BRDCAST_MASK;
uint8_t brcast_num = 0;
opflags_t template_opsize, insn_opsize;
if (!(type & SIZE_MASK))
type |= size[i];
insn_opsize = type & SIZE_MASK;
if (!is_broadcast) {
template_opsize = itemp->opd[i] & SIZE_MASK;
} else {
decoflags_t deco_brsize = ideco & BRSIZE_MASK;
if (~ideco & BRDCAST_MASK)
return MERR_BRNOTHERE;
/*
* when broadcasting, the element size depends on
* the instruction type. decorator flag should match.
*/
if (deco_brsize) {
template_opsize = brsize_to_size(deco_brsize);
/* calculate the proper number : {1to<brcast_num>} */
brcast_num = get_broadcast_num(itemp->opd[i], template_opsize);
} else {
template_opsize = 0;
}
}
if (~ideco & deco & OPMASK_MASK)
return MERR_MASKNOTHERE;
if (~ideco & deco & (Z_MASK|STATICRND_MASK|SAE_MASK))
return MERR_DECONOTHERE;
if (itemp->opd[i] & ~type & ~(SIZE_MASK|REGSET_MASK))
return MERR_INVALOP;
if (~itemp->opd[i] & type & REGSET_MASK)
return (itemp->opd[i] & REGSET_MASK)
? MERR_REGSETSIZE : MERR_REGSET;
if (template_opsize) {
if (template_opsize != insn_opsize) {
if (insn_opsize) {
return MERR_INVALOP;
} else if (!is_class(REGISTER, type)) {
/*
* Note: we don't honor extrinsic operand sizes for registers,
* so "missing operand size" for a register should be
* considered a wildcard match rather than an error.
*/
opsizemissing = true;
} else if (is_class(REG_HIGH, type) &&
instruction->prefixes[PPS_REX]) {
return MERR_ENCMISMATCH;
}
} else if (is_broadcast &&
(brcast_num !=
(2U << ((deco & BRNUM_MASK) >> BRNUM_SHIFT)))) {
/*
* broadcasting opsize matches but the number of repeated memory
* element does not match.
* if 64b double precision float is broadcasted to ymm (256b),
* broadcasting decorator must be {1to4}.
*/
return MERR_BRNUMMISMATCH;
}
}
}
if (opsizemissing)
return MERR_OPSIZEMISSING;
/*
* Check operand sizes
*/
if (itemp_has(itemp, IF_SM) || itemp_has(itemp, IF_SM2)) {
oprs = (itemp_has(itemp, IF_SM2) ? 2 : itemp->operands);
for (i = 0; i < oprs; i++) {
asize = itemp->opd[i] & SIZE_MASK;
if (asize) {
for (i = 0; i < oprs; i++)
size[i] = 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 MERR_OPSIZEMISMATCH;
}
/*
* Check template is okay at the set cpu level
*/
if (iflag_cmp_cpu_level(&insns_flags[itemp->iflag_idx], &cpu) > 0)
return MERR_BADCPU;
/*
* Verify the appropriate long mode flag.
*/
if (itemp_has(itemp, (bits == 64 ? IF_NOLONG : IF_LONG)))
return MERR_BADMODE;
/*
* If we have a HLE prefix, look for the NOHLE flag
*/
if (itemp_has(itemp, IF_NOHLE) &&
(has_prefix(instruction, PPS_REP, P_XACQUIRE) ||
has_prefix(instruction, PPS_REP, P_XRELEASE)))
return MERR_BADHLE;
/*
* Check if special handling needed for Jumps
*/
if ((itemp->code[0] & ~1) == 0370)
return MOK_JUMP;
/*
* Check if BND prefix is allowed.
* Other 0xF2 (REPNE/REPNZ) prefix is prohibited.
*/
if (!itemp_has(itemp, IF_BND) &&
(has_prefix(instruction, PPS_REP, P_BND) ||
has_prefix(instruction, PPS_REP, P_NOBND)))
return MERR_BADBND;
else if (itemp_has(itemp, IF_BND) &&
(has_prefix(instruction, PPS_REP, P_REPNE) ||
has_prefix(instruction, PPS_REP, P_REPNZ)))
return MERR_BADREPNE;
return MOK_GOOD;
}
/*
* Check if ModR/M.mod should/can be 01.
* - EAF_BYTEOFFS is set
* - offset can fit in a byte when EVEX is not used
* - offset can be compressed when EVEX is used
*/
#define IS_MOD_01() (!(input->eaflags & EAF_WORDOFFS) && \
(ins->rex & REX_EV ? seg == NO_SEG && !forw_ref && \
is_disp8n(input, ins, &output->disp8) : \
input->eaflags & EAF_BYTEOFFS || (o >= -128 && \
o <= 127 && seg == NO_SEG && !forw_ref)))
static int process_ea(operand *input, ea *output, int bits,
int rfield, opflags_t rflags, insn *ins,
enum ea_type expected, const char **errmsgp)
{
bool forw_ref = !!(input->opflags & OPFLAG_UNKNOWN);
const int addrbits = ins->addr_size;
const int eaflags = input->eaflags;
const char *errmsg = NULL;
errmsg = NULL;
output->type = EA_SCALAR;
output->rip = false;
output->disp8 = 0;
/* REX flags for the rfield operand */
output->rex |= rexflags(rfield, rflags, REX_R | REX_P | REX_W | REX_H);
/* EVEX.R' flag for the REG operand */
ins->evex_p[0] |= evexflags(rfield, 0, EVEX_P0RP, 0);
if (is_class(REGISTER, input->type)) {
/*
* It's a direct register.
*/
if (!is_register(input->basereg))
goto err;
if (!is_reg_class(REG_EA, input->basereg))
goto err;
/* broadcasting is not available with a direct register operand. */
if (input->decoflags & BRDCAST_MASK) {
errmsg = "broadcast not allowed with register operand";
goto err;
}
output->rex |= op_rexflags(input, REX_B | REX_P | REX_W | REX_H);
ins->evex_p[0] |= op_evexflags(input, EVEX_P0X, 0);
output->sib_present = false; /* no SIB necessary */
output->bytes = 0; /* no offset necessary either */
output->modrm = GEN_MODRM(3, rfield, nasm_regvals[input->basereg]);
} else {
/*
* It's a memory reference.
*/
/* Embedded rounding or SAE is not available with a mem ref operand. */
if (input->decoflags & (ER | SAE)) {
errmsg = "embedded rounding is available only with "
"register-register operations";
goto err;
}
if (input->basereg == -1 &&
(input->indexreg == -1 || input->scale == 0)) {
/*
* It's a pure offset. If it is an IMMEDIATE, it is a pattern
* in insns.dat which allows an immediate to be used as a memory
* address, in which case apply the default REL/ABS.
*/
if (bits == 64) {
if (is_class(IMMEDIATE, input->type)) {
if (!(input->eaflags & EAF_ABS) &&
((input->eaflags & EAF_REL) || globalrel))
input->type |= IP_REL;
}
if ((input->type & IP_REL) == IP_REL) {
/*!
*!ea-absolute [on] absolute address cannot be RIP-relative
*! warns that an address that is inherently absolute cannot
*! be generated with RIP-relative encoding using \c{REL},
*! see \k{REL & ABS}.
*/
if (input->segment == NO_SEG ||
(input->opflags & OPFLAG_RELATIVE)) {
nasm_warn(WARN_EA_ABSOLUTE|ERR_PASS2,
"absolute address can not be RIP-relative");
input->type &= ~IP_REL;
input->type |= MEMORY;
}
}
}
if (bits == 64 && !(IP_REL & ~input->type) && (eaflags & EAF_SIB)) {
errmsg = "instruction requires SIB encoding, cannot be RIP-relative";
goto err;
}
if (eaflags & EAF_BYTEOFFS ||
(eaflags & EAF_WORDOFFS &&
input->disp_size != (addrbits != 16 ? 32 : 16))) {
/*!
*!ea-dispsize [on] displacement size ignored on absolute address
*! warns that NASM does not support generating displacements for
*! inherently absolute addresses that do not match the address size
*! of the instruction.
*/
nasm_warn(WARN_EA_DISPSIZE, "displacement size ignored on absolute address");
}
if ((eaflags & EAF_SIB) || (bits == 64 && (~input->type & IP_REL))) {
output->sib_present = true;
output->sib = GEN_SIB(0, 4, 5);
output->bytes = 4;
output->modrm = GEN_MODRM(0, rfield, 4);
output->rip = false;
} else {
output->sib_present = false;
output->bytes = (addrbits != 16 ? 4 : 2);
output->modrm = GEN_MODRM(0, rfield,
(addrbits != 16 ? 5 : 6));
output->rip = bits == 64;
}
} else {
/*
* It's an indirection.
*/
int i = input->indexreg, b = input->basereg, s = input->scale;
int32_t seg = input->segment;
int hb = input->hintbase, ht = input->hinttype;
int t, it, bt; /* register numbers */
opflags_t x, ix, bx; /* register flags */
if (s == 0)
i = -1; /* make this easy, at least */
if (is_register(i)) {
it = nasm_regvals[i];
ix = nasm_reg_flags[i];
} else {
it = -1;
ix = 0;
}
if (is_register(b)) {
bt = nasm_regvals[b];
bx = nasm_reg_flags[b];
} else {
bt = -1;
bx = 0;
}
/* if either one are a vector register... */
if ((ix|bx) & (XMMREG|YMMREG|ZMMREG) & ~REG_EA) {
opflags_t sok = BITS32 | BITS64;
int32_t o = input->offset;
int mod, scale, index, base;
/*
* For a vector SIB, one has to be a vector and the other,
* if present, a GPR. The vector must be the index operand.
*/
if (it == -1 || (bx & (XMMREG|YMMREG|ZMMREG) & ~REG_EA)) {
if (s == 0)
s = 1;
else if (s != 1)
goto err;
t = bt, bt = it, it = t;
x = bx, bx = ix, ix = x;
}
if (bt != -1) {
if (REG_GPR & ~bx)
goto err;
if (!(REG64 & ~bx) || !(REG32 & ~bx))
sok &= bx;
else
goto err;
}
/*
* While we're here, ensure the user didn't specify
* WORD or QWORD
*/
if (input->disp_size == 16 || input->disp_size == 64)
goto err;
if (addrbits == 16 ||
(addrbits == 32 && !(sok & BITS32)) ||
(addrbits == 64 && !(sok & BITS64)))
goto err;
output->type = ((ix & ZMMREG & ~REG_EA) ? EA_ZMMVSIB
: ((ix & YMMREG & ~REG_EA)
? EA_YMMVSIB : EA_XMMVSIB));
output->rex |= rexflags(it, ix, REX_X);
output->rex |= rexflags(bt, bx, REX_B);
ins->evex_p[2] |= evexflags(it, 0, EVEX_P2VP, 2);
index = it & 7; /* it is known to be != -1 */
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? */
goto err; /* panic */
}
if (bt == -1) {
base = 5;
mod = 0;
} else {
base = (bt & 7);
if (base != REG_NUM_EBP && o == 0 &&
seg == NO_SEG && !forw_ref &&
!(eaflags & (EAF_BYTEOFFS | EAF_WORDOFFS)))
mod = 0;
else if (IS_MOD_01())
mod = 1;
else
mod = 2;
}
output->sib_present = true;
output->bytes = (bt == -1 || mod == 2 ? 4 : mod);
output->modrm = GEN_MODRM(mod, rfield, 4);
output->sib = GEN_SIB(scale, index, base);
} else 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.
*/
opflags_t sok = BITS32 | BITS64;
int32_t o = input->offset;
if (it != -1) {
if (!(REG64 & ~ix) || !(REG32 & ~ix))
sok &= ix;
else
goto err;
}
if (bt != -1) {
if (REG_GPR & ~bx)
goto err; /* Invalid register */
if (~sok & bx & SIZE_MASK)
goto err; /* Invalid size */
sok &= bx;
}
/*
* While we're here, ensure the user didn't specify
* WORD or QWORD
*/
if (input->disp_size == 16 || input->disp_size == 64)
goto err;
if (addrbits == 16 ||
(addrbits == 32 && !(sok & BITS32)) ||
(addrbits == 64 && !(sok & BITS64)))
goto err;
/* 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;
x = bx, bx = ix, ix = x;
}
if (bt == -1 && s == 1 && !(hb == i && ht == EAH_NOTBASE)) {
/* make single reg base, unless hint */
bt = it, bx = ix, it = -1, ix = 0;
}
if (eaflags & EAF_MIB) {
/* MIB/split-SIB encoding */
if (it == -1 && (hb == b && ht == EAH_NOTBASE)) {
/*
* make a single reg index [reg*1].
* gas uses this form for an explicit index register.
*/
it = bt, ix = bx, bt = -1, bx = 0, s = 1;
}
if ((ht == EAH_SUMMED) && bt == -1) {
/* separate once summed index into [base, index] */
bt = it, bx = ix, s--;
}
} else {
if (((s == 2 && it != REG_NUM_ESP &&
(!(eaflags & EAF_TIMESTWO) || (ht == EAH_SUMMED))) ||
s == 3 || s == 5 || s == 9) && bt == -1) {
/* convert 3*EAX to EAX+2*EAX */
bt = it, bx = ix, s--;
}
if (it == -1 && (bt & 7) != REG_NUM_ESP &&
(eaflags & EAF_TIMESTWO) &&
(hb == b && ht == EAH_NOTBASE)) {
/*
* convert [NOSPLIT EAX*1]
* to sib format with 0x0 displacement - [EAX*1+0].
*/
it = bt, ix = bx, bt = -1, bx = 0, s = 1;
}
}
if (s == 1 && it == REG_NUM_ESP) {
/* swap ESP into base if scale is 1 */
t = it, it = bt, bt = t;
x = ix, ix = bx, bx = x;
}
if (it == REG_NUM_ESP ||
(s != 1 && s != 2 && s != 4 && s != 8 && it != -1))
goto err; /* 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 && !(eaflags & EAF_SIB)) {
/* no SIB needed */
int mod, rm;
if (bt == -1) {
rm = 5;
mod = 0;
} else {
rm = (bt & 7);
if (rm != REG_NUM_EBP && o == 0 &&
seg == NO_SEG && !forw_ref &&
!(eaflags & (EAF_BYTEOFFS | EAF_WORDOFFS)))
mod = 0;
else if (IS_MOD_01())
mod = 1;
else
mod = 2;
}
output->sib_present = false;
output->bytes = (bt == -1 || mod == 2 ? 4 : mod);
output->modrm = GEN_MODRM(mod, rfield, 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? */
goto err; /* panic */
}
if (bt == -1) {
base = 5;
mod = 0;
} else {
base = (bt & 7);
if (base != REG_NUM_EBP && o == 0 &&
seg == NO_SEG && !forw_ref &&
!(eaflags & (EAF_BYTEOFFS | EAF_WORDOFFS)))
mod = 0;
else if (IS_MOD_01())
mod = 1;
else
mod = 2;
}
output->sib_present = true;
output->bytes = (bt == -1 || mod == 2 ? 4 : mod);
output->modrm = GEN_MODRM(mod, rfield, 4);
output->sib = GEN_SIB(scale, index, base);
}
} else { /* it's 16-bit */
int mod, rm;
int16_t o = input->offset;
/* check for 64-bit long mode */
if (addrbits == 64)
goto err;
/* 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))
goto err;
/* ensure the user didn't specify DWORD/QWORD */
if (input->disp_size == 32 || input->disp_size == 64)
goto err;
if (s != 1 && i != -1)
goto err; /* 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)
goto err; /* shouldn't ever happen, in theory */
if (i != -1 && b != -1 &&
(i == R_BP || i == R_BX || b == R_SI || b == R_DI))
goto err; /* invalid combinations */
if (b == -1) /* pure offset: handled above */
goto err; /* 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 */
goto err; /* so panic if it does */
if (o == 0 && seg == NO_SEG && !forw_ref && rm != 6 &&
!(eaflags & (EAF_BYTEOFFS | EAF_WORDOFFS)))
mod = 0;
else if (IS_MOD_01())
mod = 1;
else
mod = 2;
output->sib_present = false; /* no SIB - it's 16-bit */
output->bytes = mod; /* bytes of offset needed */
output->modrm = GEN_MODRM(mod, rfield, rm);
}
if (eaflags & EAF_REL) {
/* Explicit REL reference with indirect memory */
nasm_warn(WARN_OTHER,
"indirect address displacements cannot be RIP-relative");
}
}
}
output->size = 1 + output->sib_present + output->bytes;
/*
* The type parsed might not match one supplied by
* a caller. In this case exit with error and let
* the caller to decide how critical it is.
*/
if (output->type != expected)
goto err_set_msg;
return 0;
err_set_msg:
if (!errmsg) {
/* Default error message */
static char invalid_address_msg[40];
snprintf(invalid_address_msg, sizeof invalid_address_msg,
"invalid %d-bit effective address", bits);
errmsg = invalid_address_msg;
}
*errmsgp = errmsg;
return -1;
err:
output->type = EA_INVALID;
goto err_set_msg;
}
static void add_asp(insn *ins, int addrbits)
{
int j, valid;
int defdisp;
valid = (addrbits == 64) ? 64|32 : 32|16;
switch (ins->prefixes[PPS_ASIZE]) {
case P_A16:
valid &= 16;
break;
case P_A32:
valid &= 32;
break;
case P_A64:
valid &= 64;
break;
case P_ASP:
valid &= (addrbits == 32) ? 16 : 32;
break;
default:
break;
}
for (j = 0; j < ins->operands; j++) {
if (is_class(MEMORY, ins->oprs[j].type)) {
opflags_t i, b;
/* Verify as Register */
if (!is_register(ins->oprs[j].indexreg))
i = 0;
else
i = nasm_reg_flags[ins->oprs[j].indexreg];
/* Verify as Register */
if (!is_register(ins->oprs[j].basereg))
b = 0;
else
b = nasm_reg_flags[ins->oprs[j].basereg];
if (ins->oprs[j].scale == 0)
i = 0;
if (!i && !b) {
int ds = ins->oprs[j].disp_size;
if ((addrbits != 64 && ds > 8) ||
(addrbits == 64 && ds == 16))
valid &= ds;
} else {
if (!(REG16 & ~b))
valid &= 16;
if (!(REG32 & ~b))
valid &= 32;
if (!(REG64 & ~b))
valid &= 64;
if (!(REG16 & ~i))
valid &= 16;
if (!(REG32 & ~i))
valid &= 32;
if (!(REG64 & ~i))
valid &= 64;
}
}
}
if (valid & addrbits) {
ins->addr_size = addrbits;
} else if (valid & ((addrbits == 32) ? 16 : 32)) {
/* Add an address size prefix */
ins->prefixes[PPS_ASIZE] = (addrbits == 32) ? P_A16 : P_A32;;
ins->addr_size = (addrbits == 32) ? 16 : 32;
} else {
/* Impossible... */
nasm_nonfatal("impossible combination of address sizes");
ins->addr_size = addrbits; /* Error recovery */
}
defdisp = ins->addr_size == 16 ? 16 : 32;
for (j = 0; j < ins->operands; j++) {
if (!(MEM_OFFS & ~ins->oprs[j].type) &&
(ins->oprs[j].disp_size ? ins->oprs[j].disp_size : defdisp) != ins->addr_size) {
/*
* mem_offs sizes must match the address size; if not,
* strip the MEM_OFFS bit and match only EA instructions
*/
ins->oprs[j].type &= ~(MEM_OFFS & ~MEMORY);
}
}
}
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