DOS ain't dead - NASM 3.01

NASM 3.01 (Announce)

posted by rr , Berlin, Germany, 28.10.2025, 15:36

> > > NASM 3.00 was released on 3 October 2025.
>
> For what it's worth, sometimes it's tiring to upgrade every single point
> release, especially for minor versions released in quick succession.
>
> Having said that, 3.01 was released two weeks ago. See the
> Release Notes for more
> detailed info.

Release Notes (for convenience):

* A new obj2 version of the obj output format, intended for use on OS/2. See section 9.5.
* The condition after %if or %elif would be evaluated while output is suppressed after %exitrep or %exitmacro. Although no output would be generated in either case, assembly would fail if evaluating the expression triggered an error.
* Fix encoding of TCVTROWPS2PHL, correct multiple AVX512-BF16 instructions' operand formats and typoed mnemonics.
* The unofficial but obvious alternate form TEST reg,mem was not accepted by NASM 3.00; corrected.
* For the obj output format, multiple GROUP directives can now be specified for the same group; the resulting group includes all sections specified in all GROUP directives for the group.
* A new %selbits() preprocessor function. See section 5.4.19.
* A new --bits option as convenience shorthand for --before "BITS ...". See section 2.1.31.
* The options and pragmas for configuring external label mangling were inconsistent, the former using the spelling postfix and the latter suffix. Furthermore, these were also documented as directives in addition to pragmas. Implement the already documented directives (bracketed forms only) and allow both postfix and suffix in all cases. See section 2.1.28 and section 8.10.
* Define additional permissive patterns and fix several opcode bugs.
* Fix parsing of two-operand forms of x87 instructions.
* Fix bogus "absolute address can not be RIP-relative" warning.
* Hopefully fix building with OpenWatcom.
* Generate a warning, promoted to error by default, on the use of o64 prefixes in 16- or 32-bit mode. If demoted to a warning or suppressed the prefix is ignored, but likely will trigger subsequent, harder to debug, error messages.
* More consistent handling of jump and call instructions with specified operand sizes.
* Fix an operand size handling bug in the CMPXCHG instruction.

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Complete thread:

NASM 3.00 - Rugxulo, 10.10.2025, 05:52 (Announce)
- NASM 3.00 - mceric, 10.10.2025, 09:09
  - NASM 3.01 - Rugxulo, 27.10.2025, 23:05
    - NASM 3.01 - rr, 28.10.2025, 15:36