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version 1.73.34 (Nov 25, 2025)

[+] Added AMX instructions.


version 1.73.33 (Nov 23, 2025)

[+] Added UINTR, SERIALIZE, TSXLDTRK, HRESET, SGX, ENQCMD instruction sets.

[-] Corrected encoding of "umonitor" instruction.


version 1.73.32 (Dec 04, 2023)

[-] Corrected encoding of "rdpid" instruction operand.


version 1.73.31 (Jul 12, 2023)

[+] Handling multiple sign characters before a floating-point value.

[-] Corrected an issue with negative offsets for some relocatable addresses.

[-] Fixed a potential crash in external stub processor for PE.


version 1.73.30 (Feb 21, 2022)

[-] No longer signal an error when there is no line to concatenate with "\".


version 1.73.29 (Dec 18, 2021)

[-] Corrected an issue in external use of expression calculator.


version 1.73.28 (Sep 16, 2021)

[+] Added special preprocessing of symbols "__file__" and "__line__"
    (backported from flat assembler g).


version 1.73.27 (Jan 27, 2021)

[-] The assembler should no longer prematurely abort when sign-extended 32-bit
    value in 64-bit instruction overflows during intermediate passes.


version 1.73.26 (Jan 26, 2021)

[-] Corrected assembly of some "mov" variants when "use32" setting is used
    with 64-bit relocatable formats.


version 1.73.25 (Aug 20, 2020)

[-] Corrected operand size handling for "vldmxcsr"/"vstmxcsr" instructions.


version 1.73.24 (Apr 29, 2020)

[+] Added "invlpgb" and "tlbsync" instructions.

[-] Upper bits of default entry point of ELF64 executable were not correctly
    stored in the header.


version 1.73.23 (Apr 09, 2020)

[+] Added "psmash", "pvalidate", "rmpadjust" and "rmpupdate" instructions.

[-] No longer allowing "mov" to/from CR9-CR15 outside of long mode.


version 1.73.22 (Feb 09, 2020)

[-] Removed a trick from preprocessor's implementation that caused
    the x64 version to crash when replacing symbolic constant in a label.


version 1.73.21 (Dec 05, 2019)

[+] Added "$%" and "$%%" symbols, and output offset addressing with "load"
    and "store" directives (backported from flat assembler g).
    It can be used only with binary output format.

[+] Added VAES and VPCMULQDQ instruction set extensions.

[+] Added "pconfig" instruction.


version 1.73.20 (Nov 29, 2019)

[-] Fixed a bug in "cmpxchg" and "xadd" introduced by previous version.


version 1.73.19 (Nov 27, 2019)

[+] Added AVX512_BITALG, AVX512_VPOPCNTDQ, AVX512_VBMI2, AVX512_VNNI
    and AVX512_4VNNIW instruction sets.

[+] Added CET_SS and CET_IBT instruction sets.

[+] Added "ptwrite" instruction.


version 1.73.18 (Nov 13, 2019)

[-] Addresses prefixed with "fs:" or "gs:" are no longer RIP-relative by default.


version 1.73.17 (Nov 10, 2019)

[+] Added "mcommit" instruction.


version 1.73.16 (Aug 04, 2019)

[-] Corrected a mistake in AVX-512 mask parsing that led to "{k0}" mask being
    erroneously accepted.


version 1.73.15 (Aug 01, 2019)

[+] Added "movdiri", "movdir64b" instructions and GFNI instruction set.


version 1.73.14 (Jul 30, 2019)

[+] Added "rdpru" and "wbnoinvd" instructions.


version 1.73.13 (Jul 14, 2019)

[-] Corrections in 64-bit Linux interface.


version 1.73.12 (May 19, 2019)

[-] Implied memory size allowed for 16-bit "movzx"/"movsx".


version 1.73.11 (Apr 19, 2019)

[+] Added "definite" operator.


version 1.73.10 (Apr 05, 2019)

[+] Added "cldemote", "tpause", "umonitor" and "umwait" instructions.


version 1.73.09 (Feb 17, 2019)

[-] Fixed a bug in AVX-512 instruction encoding with "{sae}" modifier.


version 1.73.08 (Jan 31, 2019)

[-] Fixed a bug in "align" directive for "dynamic" variant of ELF executable.


version 1.73.07 (Jan 30, 2019)

[+] Added "dynamic" variant of ELF executable.

[+] Added "gnurelro" segment type for ELF executable.


version 1.73.06 (Jan 04, 2019)

[+] Added "ud0" and "ud1" instruction.

[-] Fixed a minor bug in ELF formatter.


version 1.73.05 (Jan 03, 2019)

[-] Segments in ELF executable format automatically expanded to cover headers
    and dynamic linking information.


version 1.73.04 (Apr 30, 2018)

[-] Fixed a bug in "bndstx"/"bndldx" special address syntax processing.


version 1.73.03 (Apr 15, 2018)

[+] Added "rdpid", "xsavec", "xsaves", "xrstors", "clzero", "monitorx" and "mwaitx"
    instructions.


version 1.73.02 (Dec 16, 2017)

[-] Fixed a bug in the storage of "virtual as" blocks.


version 1.73.01 (Nov 25, 2017)

[+] Added virtual block continuation syntax (backported from flat assembler g).

[+] Documentation update.

[-] Fixed a bug in addressing data of the "virtual as" block.


version 1.73.00 (Nov 24, 2017)

[+] Added "virtual as" syntax (backported from flat assembler g).


version 1.72 (Oct 10, 2017)

[+] Support for Intel AVX-512, SHA, CLFLUSHOPT, CLWB, PCOMMIT, ADX, RDSEED, SMAP
    and MPX instruction sets.

[+] Added "irpv" and "postpone" directives.

[+] Added ability to define a special kind of label identifying the
    addressing space. This label can the be used with "load" or "store"
    directives to allow operations on bytes in any addressing space,
    not just the current one. This special label is defined by following
    its name with double colon, and can only be used with "load" and
    "store" directive, where address can now be specified in two parts,
    first the adressing space label, then the colon and then the
    address inside that addressing space.

[+] In the definition of macroinstruction the last argument can now be followed by
    "&" character to indicate that this argument can be filled with all the remaining
    contents of line that called the macro. This feature cannot be combined with a
    multi-value arguments.

[+] Default value for macroinstruction parameter can now be defined with ":"
    character as an alternative to "=".

[+] Added a 64-bit ELF executable version of flat assembler for Linux. It has
    no extended capabilities compared to regular versions, it just simulates
    the 32-bit environment to allow running the assembler on systems that
    support only 64-bit executables.

[+] Added "gnustack" and "gnuehframe" segment types to ELF executable formatter.

[+] Console versions now display preprocessed instruction that caused an error
    (previously only displayed by Windows GUI interface).

[+] Brought back the "-d" switch for command line.

[-] Removed dependence on size context for expression operators like NOT and XOR.

[+] Added "bsf" and "bsr" operators to numerical expressions.

[+] Allowed underscore character to be put inside a number value.

[+] Allowed octal numbers ending with "q".

[-] Removed the restriction that disallowed numerical constant to
    forward-reference its own value.


version 1.70 (Apr 17, 2012)

[+] Added support for AVX, AVX2, AES, CLMUL, FMA, RDRAND, FSGSBASE, F16C,
    FMA4, XOP, MOVBE, BMI, TBM, INVPCID, HLE and RTM instruction sets.

[+] Added half-precision floating point values support.

[+] Extended the syntax of "rept" directive to allow numerical expressions
    to be calculated by preprocessor in its arguments.

[+] Added "large" and "NX" settings for PE format.

[+] Allowed PE fixups to be resolved anywhere in the generated executable.

[+] Allowed to specify branding value (use 3 for Linux) after the
    "format ELF executable" setting.

[+] Added "intepreter", "dynamic" and "note" keywords for creation of
    special segments in ELF executables.

[-] Fixed long mode opcode generator to allow absolute addresses to be
    generated with "qword" keyword inside square brackets.

[-] Disallowed negative immediates with "int", "enter", "ret" instructions.

[+] Allowed symbolic information dump file to be created even in case of error.
    In such case it contains only the preprocessed source that can be extracted
    with PREPSRC tool. If error occured during preprocessing, only the source up
    to the point of error is provided.

[+] Added symbol references table to symbolic dump file.

[-] Corrected the "defined" and "used" flags in the symbols dump to reflect the
    state from the final assembly pass.

[+] Added "assert" directive.

[-] Formatter symbols like "PE" or "readable" are now recognized only in the
    context of formatter directives, and thus are no longer disallowed as
    labels.

[+] Macroinstruction argument now can have default value, defined with "="
    symbol followed by value after the argument name in definition.

[+] Added "relativeto" operator, which can be used in logical expressions
    to test whether two values differ only by a constant and not relocatable
    amount.

[-] Revised the expression calculator, it now is able to correctly perform
    calculations in signed and unsigned ranges in full 64-bit. This fixes
    a number of issues - the overflow will now be correctly detected for
    64-bit values in cases, where previous versions could not distinguish
    whether it was an overflow or not. The effect of these corrections is
    that "dq" directive will now behave consistently with behavior of the
    data directives for smaller sizes, and the same applies to all the
    places where "qword" size for value is used.


version 1.68 (Jun 13, 2009)

[+] Added SSSE3 (Supplemental SSE3), SSE4.1, SSE4.2 and SSE4a instructions.

[+] Added the AMD SVM and Intel SMX instructions.

[+] Added "rdmsrq", "wrmsrq", "sysexitq" and "sysretq" mnemonics for the
    64-bit variants of respective instructions.

[+] Added "fstenvw", "fstenvd", "fsavew", "fsaved", "frstorw" and "frstord"
    mnemonics to allow choosing between 16-bit and 32-bit variants of
    structures used by the "fstenv", "fsave" and "frstor" instructions.

[+] Added "plt" operator for the ELF output format.

[+] Allowed "rva" operator to be used in MS COFF object format, and also
    added "static" keyword for the "public" directive.

[+] Added Intel-style aliases for the additional long mode 8-bit registers.

[-] The PE formatter now automatically detects whether relocatable labels
    should be used, depending on whether the fixups directory is placed
    somewhere into executable by programer, or not. This makes possible the
    more flexible use of the addressing symbols in case of PE executable fixed
    at some position.

[-] Added support for outputting the 32-bit address relocations in case of
    64-bit object formats and PE executable. This makes some specific
    instructions compilable, but it also forces linker to put such
    generated code into the low 2 gigabytes of addressing space.

[+] Added "EFI", "EFIboot" and "EFIruntime" subsystem keywords for PE format.

[-] Corrected the precedence of operators of macroinstruction line maker.
    The symbol escaping now has always the higher priority than symbol conversion,
    and both have higher precedence than concatenation.

[+] Allowed to check "@b" and "@f" symbols with "defined" operator.

[+] Allowed "as" operator to specify the output file extension when
    placed at the end of the "format" directive line.

[-] Definition of macro with the same name as one of the preprocessor's directives
    is no longer allowed.

[+] Allowed single quote character to be put inside the number value,
    to help improve long numbers readability.

[+] Added optional symbolic information output, and a set of tools that extract
    various kinds of information from it.

[+] Added "err" directive that allows to signalize error from the source.


version 1.66 (May 7, 2006)

[+] Added "define" directive to preprocessor, which defines symbolic constants,
    the same kind as "equ" directive, however there's an important difference
    that "define" doesn't process symbolic constants in the value before
    assigning it. For example:

        a equ 1
        a equ a+a

        define b 1
        define b b+b

    defines the "a" constant with value "1+1", but the "b" is defined with
    value "b+b". This directive may be useful in some advanced
    macroinstructions.

[-] Moved part of the conditional expression processing into parser,
    for slightly better performance and lesser memory usage by assembler.
    The logical values defined with "eq", "eqtype" and "in" operators are now
    evaluated by the parser and if they are enough to determine the condition,
    the whole block is processed accordingly. Thus this block:

        if eax eq EAX | 0/0
                nop
        end if

    is parsed into just "nop" instruction, since parser is able to determine
    that the condition is true, even though one of the logical values makes no
    sense - but since this is none of the "eq", "eqtype" and "in" expressions,
    the parser doesn't investigate.

[-] Also the assembler is now calculating only as many logical values as it
    needs to determine the condition. So this block:

        if defined alpha & alpha

        end if

    will not cause error when "alpha" is not defined, as it would with previous
    versions. This is because after checking that "defined alpha" is false
    condition it doesn't need to know the second logical value to determine the
    value of conjunction.

[+] Added "short" keyword for specifying jump type, the "jmp byte" form is now
    obsolete and no longer correct - use "jmp short" instead.

[-] The size operator applied to jump no longer applies to the size of relative
    displacement - now it applies to the size of target address.

[-] The "ret" instruction with 0 parameter is now assembled into short form,
    unless you force using the 16-bit immediate with "word" operator.

[+] Added missing extended registers for the 32-bit addressing in long mode.

[+] Added "linkremove" and "linkinfo" section flags for MS COFF output.

[+] Added support for GOT offsets in ELF object formatter, which can be useful
    when making position-independent code for shared libraries. For any label
    you can get its offset relative to GOT by preceding it with "rva" operator
    (the same keyword as for PE format is used, to avoid adding a new one,
    while this one has very similar meaning).

[-] Changed ELF executable to use "segment" directive in place of "section",
    to make the distinction between the run-time segments and linkable
    sections. If you had a "section" directive in your ELF executables and they
    no longer assemble, replace it with "segment".

[-] The PE formatter now always creates the fixups directory when told to -
    even when there are no fixups to be put there (in such case it creates the
    directory with one empty block).

[-] Some of the internal structures have been extended to provide the
    possibility of making extensive symbol dumps.

[-] Corrected "fix" directive to keep the value intact before assigning it to the
    prioritized constant.

[+] The ` operator now works with any kind of symbol; when used with quoted
    string it simply does nothing. Thus the sequence of ` operators applied to
    one symbol work the same as if there was just one. In similar manner, the
    sequence of # operators now works as if it was a single one - using such a
    sequence instead of escaping, which was kept for some backward
    compatibility, is now deprecated.

[-] Corrected order of identifying assembler directives ("if db eq db" was
    incorrectly interpreted as data definition).

[-] Many other small bugs fixed.


version 1.64 (Aug 8, 2005)

[+] Output of PE executables for Win64 architecture (with "format PE64"
    setting).

[+] Added "while" and "break" directives.

[+] Added "irp" and "irps" directives.

[+] The macro arguments can be marked as required with the "*" character.

[-] Fixed checking for overflow when multiplying 64-bit values - the result
    must always fit in the range of signed 64 integer now.

[-] Segment prefixes were generated incorrectly in 16-bit mode when BP was used
    as a second addressing register - fixed.

[-] The "local" directive was not creating unique labels in some cases - fixed.

[-] The "not encodable with long immediate" error in 64-bit mode was sometimes
    wrongly signaled - fixed.

[-] Other minor fixes and corrections.


version 1.62 (Jun 14, 2005)

[+] Escaping of symbols inside macroinstructions with backslash.

[+] Ability of outputting the COFF object files for Win64 architecture
    (with "format MS64 COFF" setting).

[+] New preprocessor directives: "restruc", "rept" and "match"

[+] VMX instructions support (not documented).

[+] Extended data directives to allow use of the "dup" operator.

[+] Extended "struc" features to allow custom definitions of main structure's
    label.

[-] When building resources from the the .RES file that contained more
    than one resource of the same string name, the separate resource
    directories were created with the same names - fixed.

[-] Several bugs in the ELF64 object output has been fixed.

[-] Corrected behavior of "fix" directive to more straightforward.

[-] Fixed bug in "include" directive, which caused files included from within
    macros to be processed the wrong way.
