Defer the "operand size missing" error until we know all the other
operands have the correct type. Otherwise we'll end up with false
positives, which result in noise entered into the xsizeflags array,
thus causing fuzzy matching to fail.
It's possible we should defer it even further.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This allows automatic fuzzy matching of operand sizes. If an operand
size is not specified, but there is exactly one possible size for the
instruction, select that instruction size. This requires a second
pass through the instruction patterns, and so is slightly slower, but
should be a lot easier to get right than the S- flags, and works even
when there is more than one instruction.
The new SX (Size eXact) flag can be used to prevent fuzzy matching
completely.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Move the instruction-matching loop into a common function. This gives
us a single point to adjust the instruction-selection algorithm.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
*To the best of my knowledge*, we now have authorization from everyone
who has significantly contributed to NASM in the past. As such,
change the license to the 2-clause BSD license.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Add copyright headers to the *.c/*.h files in the main directory. For
files where I'm sure enough that we have all the approvals, I have
given them the 2-BSD license, the others have been given the "LGPL for
now" license header. Most of them can probably be changed after
auditing.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Fix the disassembly of JRCXZ; in 64-bit mode, we should only accept
JECXZ for disassembly with 32-bit address size override.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Add a byte code to explicitly support instructions which only uses the
low 8-bit registers (as if a REX prefix always was present.) This is
usable for instructions which are officially documented as using "the
low byte of a 32-bit register" and so on.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Handle AMD's XOP prefixes; they use basically the same encoding as VEX
prefixes, so treat them simply as a variant of VEX.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Optimize displacements, don't pessimize them. When running in the
optimizer, we always keep track of when a reference is forward. That
doesn't mean it is unknown.
Only be optimistic about the reachability of a symbol with NO_SEG if
we are truly in pass 1, i.e. it could possibly be just a forward
reference. After we have done a single pass, if it is still NO_SEG,
then it is an absolute symbol and need to be treated as such.
WAIT is technically an instruction, but from an assembler standpoint
it behaves as if it had been a prefix. In particular, it has to be
ordered *before* any real hardware prefixes.
We have a number of all-zero buffers in the code. Put a single
all-zero buffer in nasmlib.c. Additionally, add fwritezero()
which can be used to write an arbitrary number of all-zero bytes;
this prevents the situation where the all-zero buffer is simply
too small.
Fix op2 references not yet converted to accessing op2; add an opy
pointer similar to the opx pointer instead of multiple references.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
The bytecode format assumes max 4 operands pretty strictly, but we
already have one instruction with 5 operands, and it's likely to get
more. Support them via extension prefixes (similar to REX prefixes).
For bytecodes which use argument bytes we encode the number directly,
however.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
When issuing warnings for EA displacements during address generation,
actually look a the proper operand!
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Not all backends can handle being handled an intrasegment OUT_REL*ADR,
and we don't fix them up in common code either (which would be the
logical thing to do -- right now we fix them up in a bunch of
individual places.)
For now, just fix up the one in address generation.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
For OUT_REL*ADR, the "size" argument is actually the offset inside the
instruction; that is in fact why we encode the real size in the
instruction itself. Thus, emit the offsets properly using this
mechanism when generating relative EAs.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Use the case4() macros as we already do in disasm.c. It helps reduce
visual clutter, and more clearly demonstrates that groups of four
belong together. Furthermore, it makes the text compact enough that
we can now use case statements to mask down the EA patterns correctly.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Reshuffle the bytecodes for segment register push/pop to make more
sense, and move them from \4 to \344, thus freeing up the single-digit
bytecodes \4..\7 for future use. It doesn't really make sense to use
single-digit bytecodes for this very oddball use.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Add a new opcode for 32->64 bit sign-extended immediate, with warning
on the number not matching.
This unfortunately calls for an audit of all the \4[0123] opcodes, if
they should be replaced by \25[4567]. This only replaces one
instruction (MOV reg64,imm32); other instructions need to be
considered.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
is_sbyte64() was equivalent to is_sbyte32() plus the warning; however,
the warning is only used in one place (and conflicts with another
warning there), so remove the function.
Furthermore, add back the test for pure immediates in
possible_sbyte(); they had been broken out but never folded back in --
and are essential.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
New opcodes to deal with 8-bit immediates which are then sign-extended
to the operand size. These allow us to warn appropriately.
Not sure I'm using these in all the proper places; need audit of all
uses of the \14..\17 opcodes.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
When there is an immediate in the instruction, a RIP-relative offset
may not be relative to the end of the offset itself, since it is
relative to the end of the *instruction*, not the end of the *offset*.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Issue better warnings for out-of-range values. This is not yet
complete.
In particular, note we may have out-of-range for values that end up
being subject to optimization. That is because the optimization takes
place on the *truncated* value, not the pre-truncated value.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Do not warn on valid SBYTE optimizations. If we are optimizing and
match one of the SBYTE conditions, do not error out.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
-O0: JMP default to NEAR, Jcc/LOOP/JCXZ default to SHORT.
In other words, this is reverting to full-blown 0.98 behavior, not
0.98.39.
-O1: JMP and Jcc default to NEAR, LOOP/JCXZ default to SHORT (only
possible form).
Users who wish to control the level of optimization can
continue to specify -O0, -O1, or -Ox,
where x can be the letter itself, or any number > 1.
However, even with optimization turned off,
NASM will always make enough passes to resolve
forward references. As a result, INCBIN is now the only
item left in the critical expressions list, although TIMES
still has its own constant value check.
We added the length of VEX prefixes twice in calcsize(); this resulted
in the wrong symbol addresses when compiling without the optimizer.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Any use of ins->forw_ref that isn't related to control of the
optimizer is fundamentally broken. Use
operand->opflags & OPERAND_FORWARD instead. This even has the nice
side benefit of simplifying the code.
Introduce new preprocessor directives %depend and %pathsearch, and
make incbin a standard macro using these filenames. This lets us
remove the code that makes incbin search the path.
Support is4 bytes without meaningful information in the bottom bits.
This is equivalent to /is4=0 for the assembler, but makes the bottom
bits don't care for the disassembler.
