The Netwide Assembler: NASM

Previous Chapter | Contents | Index

Appendix C: NASM Version History

C.1 NASM 2 Series

The NASM 2 series supports x86-64, and is the production version of NASM since 2007.

C.1.1 Version 2.12.01

Portability fixes for some platforms.
Fix error when not specifying a list file.
Correct the handling of macro-local labels in the Codeview debugging format.
Add CLZERO, MONITORX and MWAITX instructions.

C.1.2 Version 2.12

Major fixes to the macho backend (section 7.8); earlier versions would produce invalid symbols and relocations on a regular basis.
Support for thread-local storage in Mach-O.
Support for arbitrary sections in Mach-O.
Fix wrong negative size treated as a big positive value passed into backend causing NASM to crash.
Fix handling of zero-extending unsigned relocations, we have been printing wrong message and forgot to assign segment with predefined value before passing it into output format.
Fix potential write of oversized (with size greater than allowed in output format) relative relocations.
Portability fixes for building NASM with LLVM compiler.
Add support of Codeview version 8 (cv8) debug format for win32 and win64 formats in the COFF backend, see section 7.5.3.
Allow 64-bit outputs in 16/32-bit only backends. Unsigned 64-bit relocations are zero-extended from 32-bits with a warning (suppressible via -w-zext-reloc); signed 64-bit relocations are an arror.
Line numbers in list files now correspond to the lines in the source files, instead of simply being sequential.
There is now an official 64-bit (x64 a.k.a. x86-64) build for Windows.

C.1.3 Version 2.11.09

Fix potential stack overwrite in macho32 backend.
Fix relocation records in macho64 backend.
Fix symbol lookup computation in macho64 backend.
Adjust .symtab and .rela.text sections alignments to 8 bytes in elf64 backed.
Fix section length computation in bin backend which leaded in incorrect relocation records.

C.1.4 Version 2.11.08

Fix section length computation in bin backend which leaded in incorrect relocation records.
Add a warning for numeric preprocessor definitions passed via command line which might have unexpected results otherwise.
Add ability to specify a module name record in rdoff linker with -mn option.
Increase label length capacity up to 256 bytes in rdoff backend for FreePascal sake, which tends to generate very long labels for procedures.
Fix segmentation failure when rip addressing is used in macho64 backend.
Fix access on out of memory when handling strings with a single grave. We have sixed similar problem in previous release but not all cases were covered.
Fix NULL dereference in disassembled on BND instruction.

C.1.5 Version 2.11.07

Fix 256 bit VMOVNTPS instruction.
Fix -MD option handling, which was rather broken in previous release changing command line api.
Fix access to unitialized space when handling strings with a single grave.
Fix nil dereference in handling memory reference parsing.

C.1.6 Version 2.11.06

Update AVX512 instructions based on the Extension Reference (319433-021 Sept 2014).
Fix the behavior of -MF and -MD options (Bugzilla 3392280)
Updated Win32 Makefile to fix issue with build

C.1.7 Version 2.11.05

Add --v as an alias for -v (see section 2.1.25), for command-line compatibility with Yasm.
Fix a bug introduced in 2.11.03 whereby certain instructions would contain multiple REX prefixes, and thus be corrupt.

C.1.8 Version 2.11.04

Removed an invalid error checking code. Sometimes a memref only with a displacement can also set an evex flag. For example:

      vmovdqu32 [0xabcd]{k1}, zmm0

Fixed a bug in disassembler that EVEX.L'L vector length was not matched when EVEX.b was set because it was simply considered as EVEC.RC. Separated EVEX.L'L case from EVEX.RC which is ignored in matching.

C.1.9 Version 2.11.03

Fix a bug there REX prefixes were missing on instructions inside a TIMES statement.

C.1.10 Version 2.11.02

Add the XSAVEC, XSAVES and XRSTORS family instructions.
Add the CLFLUSHOPT instruction.

C.1.11 Version 2.11.01

Allow instructions which implicitly uses XMM0 (VBLENDVPD, VBLENDVPS, PBLENDVB and SHA256RNDS2) to be specified without an explicit xmm0 on the assembly line. In other words, the following two lines produce the same output:

     vblendvpd xmm2,xmm1,xmm0      ; Last operand is fixed xmm0 
     vblendvpd xmm2,xmm1           ; Implicit xmm0 omitted

In the ELF backends, don't crash the assembler if section align is specified without a value.

C.1.12 Version 2.11

Add support for the Intel AVX-512 instruction set:
16 new, 512-bit SIMD registers. Total 32 (ZMM0 ~ ZMM31)
8 new opmask registers (K0 ~ K7). One of 7 registers (K1 ~ K7) can be used as an opmask for conditional execution.
A new EVEX encoding prefix. EVEX is based on VEX and provides more capabilities: opmasks, broadcasting, embedded rounding and compressed displacements.

 - opmask 
     VDIVPD zmm0{k1}{z}, zmm1, zmm3  ; conditional vector operation 
                                     ; using opmask k1. 
                                     ; {z} is for zero-masking 
 - broadcasting 
     VDIVPS zmm4, zmm5, [rbx]{1to16} ; load single-precision float and 
                                     ; replicate it 16 times. 32 * 16 = 512 
 - embedded rounding 
     VCVTSI2SD xmm6, xmm7, {rz-sae}, rax ; round toward zero. note that it 
                                      ; is used as if a separate operand. 
                                      ; it comes after the last SIMD operand

Add support for ZWORD (512 bits), DZ and RESZ.
Add support for the MPX and SHA instruction sets.
Better handling of section redefinition.
Generate manpages when running 'make dist'.
Handle all token chains in mmacro params range.
Support split [base,index] effective address:

     mov eax,[eax+8,ecx*4]   ; eax=base, ecx=index, 4=scale, 8=disp

This is expected to be most useful for the MPX instructions.

Support BND prefix for branch instructions (for MPX).
The DEFAULT directive can now take BND and NOBND options to indicate whether all relevant branches should be getting BND prefixes. This is expected to be the normal for use in MPX code.
Add {evex}, {vex3} and {vex2} instruction prefixes to have NASM encode the corresponding instruction, if possible, with an EVEX, 3-byte VEX, or 2-byte VEX prefix, respectively.
Support for section names longer than 8 bytes in Win32/Win64 COFF.
The NOSPLIT directive by itself no longer forces a single register to become an index register, unless it has an explicit multiplier.

     mov eax,[nosplit eax]       ; eax as base register 
     mov eax,[nosplit eax*1]     ; eax as index register

C.1.14 Version 2.10.08

Fix VMOVNTDQA, MOVNTDQA and MOVLPD instructions.
Fix collision for VGATHERQPS, VPGATHERQD instructions.
Fix VPMOVSXBQ, VGATHERQPD, VSPLLW instructions.
Add a bunch of AMD TBM instructions.
Fix potential stack overwrite in numbers conversion.
Allow byte size in PREFETCHTx instructions.
Make manual pages up to date.
Make F3 and F2 SSE prefixes to override 66.
Support of AMD SVM instructions in 32 bit mode.
Fix near offsets code generation for JMP, CALL instrictions in long mode.
Fix preprocessor parse regression when id is expanding to a whitespace.

C.1.15 Version 2.10.07

Fix line continuation parsing being broken in previous version.

C.1.16 Version 2.10.06

Always quote the dependency source names when using the automatic dependency generation options.
If no dependency target name is specified via the -MT or -MQ options, quote the default output name.
Fix assembly of shift operations in CPU 8086 mode.
Fix incorrect generation of explicit immediate byte for shift by 1 under certain circumstances.
Fix assembly of the VPCMPGTQ instruction.
Fix RIP-relative relocations in the macho64 backend.

C.1.18 Version 2.10.04

Add back the inadvertently deleted 256-bit version of the VORPD instruction.
Correct disassembly of instructions starting with byte 82 hex.
Fix corner cases in token pasting, for example:

   %define N 1e%++%+ 5 
           dd N, 1e+5

C.1.19 Version 2.10.03

Correct the assembly of the instruction:

XRELEASE MOV [absolute],AL

Previous versions would incorrectly generate F3 A2 for this instruction and issue a warning; correct behavior is to emit F3 88 05.

C.1.20 Version 2.10.02

Add the ifunc macro package with integer functions, currently only integer logarithms. See section 5.4.
Add the RDSEED, ADCX and ADOX instructions.

C.1.21 Version 2.10.01

Add missing VPMOVMSKB instruction with reg32, ymmreg operands.

C.1.22 Version 2.10

When optimization is enabled, mov r64,imm now optimizes to the shortest form possible between:

     mov r32,imm32                   ;  5 bytes 
     mov r64,imm32                   ;  7 bytes 
     mov r64,imm64                   ; 10 bytes

To force a specific form, use the STRICT keyword, see section 3.7.

Add support for the Intel AVX2 instruction set.
Add support for Bit Manipulation Instructions 1 and 2.
Add support for Intel Transactional Synchronization Extensions (TSX).
Add support for x32 ELF (32-bit ELF with the CPU in 64-bit mode.) See section 7.9.
Add support for bigendian UTF-16 and UTF-32. See section 3.4.5.

C.1.23 Version 2.09.10

Fix up NSIS script to protect uninstaller against registry keys absence or corruption. It brings in a few additional questions to a user during deinstallation procedure but still it is better than unpredictable file removal.

C.1.24 Version 2.09.09

Fix initialization of section attributes of bin output format.
Fix mach64 output format bug that crashes NASM due to NULL symbols.

C.1.25 Version 2.09.08

Fix __OUTPUT_FORMAT__ assignment when output driver alias is used. For example when -f elf is used __OUTPUT_FORMAT__ must be set to elf, if -f elf32 is used __OUTPUT_FORMAT__ must be assigned accordingly, i.e. to elf32. The rule applies to all output driver aliases. See section 4.11.6.

C.1.26 Version 2.09.07

Fix attempts to close same file several times when -a option is used.
Fixes for VEXTRACTF128, VMASKMOVPS encoding.

C.1.27 Version 2.09.06

Fix missed section attribute initialization in bin output target.

C.1.28 Version 2.09.05

Fix arguments encoding for VPEXTRW instruction.
Remove invalid form of VPEXTRW instruction.
Add VLDDQU as alias for VLDQQU to match specification.

C.1.29 Version 2.09.04

Fix incorrect labels offset for VEX intructions.
Eliminate bogus warning on implicit operand size override.
%if term could not handle 64 bit numbers.
The COFF backend was limiting relocations number to 16 bits even if in real there were a way more relocations.

C.1.30 Version 2.09.03

Print %macro name inside %rep blocks on error.
Fix preprocessor expansion behaviour. It happened sometime too early and sometime simply wrong. Move behaviour back to the origins (down to NASM 2.05.01).
Fix unitialized data dereference on OMF output format.
Issue warning on unterminated %{ construct.
Fix for documentation typo.

C.1.31 Version 2.09.02

Fix reversed tokens when %deftok produces more than one output token.
Fix segmentation fault on disassembling some VEX instructions.
Missing %endif did not always cause error.
Fix typo in documentation.
Compound context local preprocessor single line macro identifiers were not expanded early enough and as result lead to unresolved symbols.

C.1.32 Version 2.09.01

Fix NULL dereference on missed %deftok second parameter.
Fix NULL dereference on invalid %substr parameters.

C.1.33 Version 2.09

Fixed assignment the magnitude of %rep counter. It is limited to 62 bits now.
Fixed NULL dereference if argument of %strlen resolves to whitespace. For example if nonexistent macro parameter is used.
%ifenv, %elifenv, %ifnenv, and %elifnenv directives introduced. See section 4.4.9.
Fixed NULL dereference if environment variable is missed.
Updates of new AVX v7 Intel instructions.
PUSH imm32 is now officially documented.
Fix for encoding the LFS, LGS and LSS in 64-bit mode.
Fixes for compatibility with OpenWatcom compiler and DOS 8.3 file format limitation.
Macros parameters range expansion introduced. See section 4.3.4.
Backward compatibility on expanging of local sigle macros restored.
8 bit relocations for elf and bin output formats are introduced.
Short intersegment jumps are permitted now.
An alignment more than 64 bytes are allowed for win32, win64 output formats.
SECTALIGN directive introduced. See section 4.11.13.
nojmp option introduced in smartalign package. See section 5.2.
Short aliases win, elf and macho for output formats are introduced. Each stands for win32, elf32 and macho32 accordingly.
Faster handling of missing directives implemented.
Various small improvements in documentation.
No hang anymore if unable to open malloc.log file.
The environments without vsnprintf function are able to build nasm again.
AMD LWP instructions updated.
Tighten EA checks. We warn a user if there overflow in EA addressing.
Make -Ox the default optimization level. For the legacy behavior, specify -O0 explicitly. See section 2.1.22.
Environment variables read with %! or tested with %ifenv can now contain non-identifier characters if surrounded by quotes. See section 4.10.2.
Add a new standard macro package %use fp for floating-point convenience macros. See section 5.3.

C.1.34 Version 2.08.02

Fix crash under certain circumstances when using the %+ operator.

C.1.35 Version 2.08.01

Fix the %use statement, which was broken in 2.08.

C.1.36 Version 2.08

A number of enhancements/fixes in macros area.
Support for converting strings to tokens. See section 4.1.9.
Fuzzy operand size logic introduced.
Fix COFF stack overrun on too long export identifiers.
Fix Macho-O alignment bug.
Fix crashes with -fwin32 on file with many exports.
Fix stack overrun for too long [DEBUG id].
Fix incorrect sbyte usage in IMUL (hit only if optimization flag passed).
Append ending token for .stabs records in the ELF output format.
New NSIS script which uses ModernUI and MultiUser approach.
Visual Studio 2008 NASM integration (rules file).
Warn a user if a constant is too long (and as result will be stripped).
The obsoleted pre-XOP AMD SSE5 instruction set which was never actualized was removed.
Fix stack overrun on too long error file name passed from the command line.
Bind symbols to the .text section by default (ie in case if SECTION directive was omitted) in the ELF output format.
Fix sync points array index wrapping.
A few fixes for FMA4 and XOP instruction templates.
Add AMD Lightweight Profiling (LWP) instructions.
Fix the offset for %arg in 64-bit mode.
An undefined local macro (%$) no longer matches a global macro with the same name.
Fix NULL dereference on too long local labels.

C.1.37 Version 2.07

NASM is now under the 2-clause BSD license. See section 1.1.2.
Fix the section type for the .strtab section in the elf64 output format.
Fix the handling of COMMON directives in the obj output format.
New ith and srec output formats; these are variants of the bin output format which output Intel hex and Motorola S-records, respectively. See section 7.2 and section 7.3.
rdf2ihx replaced with an enhanced rdf2bin, which can output binary, COM, Intel hex or Motorola S-records.
The Windows installer now puts the NASM directory first in the PATH of the "NASM Shell".
Revert the early expansion behavior of %+ to pre-2.06 behavior: %+ is only expanded late.
Yet another Mach-O alignment fix.
Don't delete the list file on errors. Also, include error and warning information in the list file.
Support for 64-bit Mach-O output, see section 7.8.
Fix assert failure on certain operations that involve strings with high-bit bytes.

C.1.38 Version 2.06

This release is dedicated to the memory of Charles A. Crayne, long time NASM developer as well as moderator of comp.lang.asm.x86 and author of the book Serious Assembler. We miss you, Chuck.
Support for indirect macro expansion (%[...]). See section 4.1.3.
%pop can now take an argument, see section 4.7.1.
The argument to %use is no longer macro-expanded. Use %[...] if macro expansion is desired.
Support for thread-local storage in ELF32 and ELF64. See section 7.9.4.
Fix crash on %ifmacro without an argument.
Correct the arguments to the POPCNT instruction.
Fix section alignment in the Mach-O format.
Update AVX support to version 5 of the Intel specification.
Fix the handling of accesses to context-local macros from higher levels in the context stack.
Treat WAIT as a prefix rather than as an instruction, thereby allowing constructs like O16 FSAVE to work correctly.
Support for structures with a non-zero base offset. See section 4.11.10.
Correctly handle preprocessor token concatenation (see section 4.3.9) involving floating-point numbers.
The PINSR series of instructions have been corrected and rationalized.
Removed AMD SSE5, replaced with the new XOP/FMA4/CVT16 (rev 3.03) spec.
The ELF backends no longer automatically generate a .comment section.
Add additional "well-known" ELF sections with default attributes. See section 7.9.2.

C.1.39 Version 2.05.01

Fix the -w/-W option parsing, which was broken in NASM 2.05.

C.1.40 Version 2.05

Fix redundant REX.W prefix on JMP reg64.
Make the behaviour of -O0 match NASM 0.98 legacy behavior. See section 2.1.22.
-w-user can be used to suppress the output of %warning directives. See section 2.1.24.
Fix bug where ALIGN would issue a full alignment datum instead of zero bytes.
Fix offsets in list files.
Fix %include inside multi-line macros or loops.
Fix error where NASM would generate a spurious warning on valid optimizations of immediate values.
Fix arguments to a number of the CVT SSE instructions.
Fix RIP-relative offsets when the instruction carries an immediate.
Massive overhaul of the ELF64 backend for spec compliance.
Fix the Geode PFRCPV and PFRSQRTV instruction.
Fix the SSE 4.2 CRC32 instruction.

C.1.41 Version 2.04

Sanitize macro handing in the %error directive.
New %warning directive to issue user-controlled warnings.
%error directives are now deferred to the final assembly phase.
New %fatal directive to immediately terminate assembly.
New %strcat directive to join quoted strings together.
New %use macro directive to support standard macro directives. See section 4.6.4.
Excess default parameters to %macro now issues a warning by default. See section 4.3.
Fix %ifn and %elifn.
Fix nested %else clauses.
Correct the handling of nested %reps.
New %unmacro directive to undeclare a multi-line macro. See section 4.3.12.
Builtin macro __PASS__ which expands to the current assembly pass. See section 4.11.9.
__utf16__ and __utf32__ operators to generate UTF-16 and UTF-32 strings. See section 3.4.5.
Fix bug in case-insensitive matching when compiled on platforms that don't use the configure script. Of the official release binaries, that only affected the OS/2 binary.
Support for x87 packed BCD constants. See section 3.4.7.
Correct the LTR and SLDT instructions in 64-bit mode.
Fix unnecessary REX.W prefix on indirect jumps in 64-bit mode.
Add AVX versions of the AES instructions (VAES...).
Fix the 256-bit FMA instructions.
Add 256-bit AVX stores per the latest AVX spec.
VIA XCRYPT instructions can now be written either with or without REP, apparently different versions of the VIA spec wrote them differently.
Add missing 64-bit MOVNTI instruction.
Fix the operand size of VMREAD and VMWRITE.
Numerous bug fixes, especially to the AES, AVX and VTX instructions.
The optimizer now always runs until it converges. It also runs even when disabled, but doesn't optimize. This allows most forward references to be resolved properly.
%push no longer needs a context identifier; omitting the context identifier results in an anonymous context.

C.1.42 Version 2.03.01

Fix buffer overflow in the listing module.
Fix the handling of hexadecimal escape codes in `...` strings.
The Postscript/PDF documentation has been reformatted.
The -F option now implies -g.

C.1.43 Version 2.03

Add support for Intel AVX, CLMUL and FMA instructions, including YMM registers.
dy, resy and yword for 32-byte operands.
Fix some SSE5 instructions.
Intel INVEPT, INVVPID and MOVBE instructions.
Fix checking for critical expressions when the optimizer is enabled.
Support the DWARF debugging format for ELF targets.
Fix optimizations of signed bytes.
Fix operation on bigendian machines.
Fix buffer overflow in the preprocessor.
SAFESEH support for Win32, IMAGEREL for Win64 (SEH).
%? and %?? to refer to the name of a macro itself. In particular, %idefine keyword $%? can be used to make a keyword "disappear".
New options for dependency generation: -MD, -MF, -MP, -MT, -MQ.
New preprocessor directives %pathsearch and %depend; INCBIN reimplemented as a macro.
%include now resolves macros in a sane manner.
%substr can now be used to get other than one-character substrings.
New type of character/string constants, using backquotes (`...`), which support C-style escape sequences.
%defstr and %idefstr to stringize macro definitions before creation.
Fix forward references used in EQU statements.

C.1.44 Version 2.02

Additional fixes for MMX operands with explicit qword, as well as (hopefully) SSE operands with oword.
Fix handling of truncated strings with DO.
Fix segfaults due to memory overwrites when floating-point constants were used.
Fix segfaults due to missing include files.
Fix OpenWatcom Makefiles for DOS and OS/2.
Add autogenerated instruction list back into the documentation.
ELF: Fix segfault when generating stabs, and no symbols have been defined.
ELF: Experimental support for DWARF debugging information.
New compile date and time standard macros.
%ifnum now returns true for negative numbers.
New %iftoken test for a single token.
New %ifempty test for empty expansion.
Add support for the XSAVE instruction group.
Makefile for Netware/gcc.
Fix issue with some warnings getting emitted way too many times.
Autogenerated instruction list added to the documentation.

C.1.45 Version 2.01

Fix the handling of MMX registers with explicit qword tags on memory (broken in 2.00 due to 64-bit changes.)
Fix the PREFETCH instructions.
Fix the documentation.
Fix debugging info when using -f elf (backwards compatibility alias for -f elf32).
Man pages for rdoff tools (from the Debian project.)
ELF: handle large numbers of sections.
Fix corrupt output when the optimizer runs out of passes.

C.1.46 Version 2.00

Added c99 data-type compliance.
Added general x86-64 support.
Added win64 (x86-64 COFF) output format.
Added __BITS__ standard macro.
Renamed the elf output format to elf32 for clarity.
Added elf64 and macho (MacOS X) output formats.
Added Numeric constants in dq directive.
Added oword, do and reso pseudo operands.
Allow underscores in numbers.
Added 8-, 16- and 128-bit floating-point formats.
Added binary, octal and hexadecimal floating-point.
Correct the generation of floating-point constants.
Added floating-point option control.
Added Infinity and NaN floating point support.
Added ELF Symbol Visibility support.
Added setting OSABI value in ELF header directive.
Added Generate Makefile Dependencies option.
Added Unlimited Optimization Passes option.
Added %IFN and %ELIFN support.
Added Logical Negation Operator.
Enhanced Stack Relative Preprocessor Directives.
Enhanced ELF Debug Formats.
Enhanced Send Errors to a File option.
Added SSSE3, SSE4.1, SSE4.2, SSE5 support.
Added a large number of additional instructions.
Significant performance improvements.
-w+warning and -w-warning can now be written as -Wwarning and -Wno-warning, respectively. See section 2.1.24.
Add -w+error to treat warnings as errors. See section 2.1.24.
Add -w+all and -w-all to enable or disable all suppressible warnings. See section 2.1.24.

C.2 NASM 0.98 Series

The 0.98 series was the production versions of NASM from 1999 to 2007.

C.2.1 Version 0.98.39

fix buffer overflow
fix outas86's .bss handling
"make spotless" no longer deletes config.h.in.
%(el)if(n)idn insensitivity to string quotes difference (#809300).
(nasm.c)__OUTPUT_FORMAT__ changed to string value instead of symbol.

C.2.2 Version 0.98.38

Add Makefile for 16-bit DOS binaries under OpenWatcom, and modify mkdep.pl to be able to generate completely pathless dependencies, as required by OpenWatcom wmake (it supports path searches, but not explicit paths.)
Fix the STR instruction.
Fix the ELF output format, which was broken under certain circumstances due to the addition of stabs support.
Quick-fix Borland format debug-info for -f obj
Fix for %rep with no arguments (#560568)
Fix concatenation of preprocessor function call (#794686)
Fix long label causes coredump (#677841)
Use autoheader as well as autoconf to keep configure from generating ridiculously long command lines.
Make sure that all of the formats which support debugging output actually will suppress debugging output when -g not specified.

C.2.3 Version 0.98.37

Paths given in -I switch searched for incbin-ed as well as %include-ed files.
Added stabs debugging for the ELF output format, patch from Martin Wawro.
Fix output/outbin.c to allow origin > 80000000h.
Make -U switch work.
Fix the use of relative offsets with explicit prefixes, e.g. a32 loop foo.
Remove backslash().
Fix the SMSW and SLDT instructions.
-O2 and -O3 are no longer aliases for -O10 and -O15. If you mean the latter, please say so! :)

C.2.4 Version 0.98.36

Update rdoff - librarian/archiver - common rec - docs!
Fix signed/unsigned problems.
Fix JMP FAR label and CALL FAR label.
Add new multisection support - map files - fix align bug
Fix sysexit, movhps/movlps reg,reg bugs in insns.dat
Q or O suffixes indicate octal
Support Prescott new instructions (PNI).
Cyrix XSTORE instruction.

C.2.5 Version 0.98.35

Fix build failure on 16-bit DOS (Makefile.bc3 workaround for compiler bug.)
Fix dependencies and compiler warnings.
Add "const" in a number of places.
Add -X option to specify error reporting format (use -Xvc to integrate with Microsoft Visual Studio.)
Minor changes for code legibility.
Drop use of tmpnam() in rdoff (security fix.)

C.2.6 Version 0.98.34

Correct additional address-size vs. operand-size confusions.
Generate dependencies for all Makefiles automatically.
Add support for unimplemented (but theoretically available) registers such as tr0 and cr5. Segment registers 6 and 7 are called segr6 and segr7 for the operations which they can be represented.
Correct some disassembler bugs related to redundant address-size prefixes. Some work still remains in this area.
Correctly generate an error for things like "SEG eax".
Add the JMPE instruction, enabled by "CPU IA64".
Correct compilation on newer gcc/glibc platforms.
Issue an error on things like "jmp far eax".

C.2.7 Version 0.98.33

New __NASM_PATCHLEVEL__ and __NASM_VERSION_ID__ standard macros to round out the version-query macros. version.pl now understands X.YYplWW or X.YY.ZZplWW as a version number, equivalent to X.YY.ZZ.WW (or X.YY.0.WW, as appropriate).
New keyword "strict" to disable the optimization of specific operands.
Fix the handing of size overrides with JMP instructions (instructions such as "jmp dword foo".)
Fix the handling of "ABSOLUTE label", where "label" points into a relocatable segment.
Fix OBJ output format with lots of externs.
More documentation updates.
Add -Ov option to get verbose information about optimizations.
Undo a braindead change which broke %elif directives.
Makefile updates.

C.2.8 Version 0.98.32

Fix NASM crashing when %macro directives were left unterminated.
Lots of documentation updates.
Complete rewrite of the PostScript/PDF documentation generator.
The MS Visual C++ Makefile was updated and corrected.
Recognize .rodata as a standard section name in ELF.
Fix some obsolete Perl4-isms in Perl scripts.
Fix configure.in to work with autoconf 2.5x.
Fix a couple of "make cleaner" misses.
Make the normal "./configure && make" work with Cygwin.

C.2.9 Version 0.98.31

Correctly build in a separate object directory again.
Derive all references to the version number from the version file.
New standard macros __NASM_SUBMINOR__ and __NASM_VER__ macros.
Lots of Makefile updates and bug fixes.
New %ifmacro directive to test for multiline macros.
Documentation updates.
Fixes for 16-bit OBJ format output.
Changed the NASM environment variable to NASMENV.

C.2.10 Version 0.98.30

Changed doc files a lot: completely removed old READMExx and Wishlist files, incorporating all information in CHANGES and TODO.
I waited a long time to rename zoutieee.c to (original) outieee.c
moved all output modules to output/ subdirectory.
Added 'make strip' target to strip debug info from nasm & ndisasm.
Added INSTALL file with installation instructions.
Added -v option description to nasm man.
Added dist makefile target to produce source distributions.
16-bit support for ELF output format (GNU extension, but useful.)

C.2.11 Version 0.98.28

Fastcooked this for Debian's Woody release: Frank applied the INCBIN bug patch to 0.98.25alt and called it 0.98.28 to not confuse poor little apt-get.

C.2.12 Version 0.98.26

Reorganised files even better from 0.98.25alt

C.2.13 Version 0.98.25alt

Prettified the source tree. Moved files to more reasonable places.
Added findleak.pl script to misc/ directory.
Attempted to fix doc.

C.2.14 Version 0.98.25

Line continuation character \.
Docs inadvertantly reverted - "dos packaging".

C.2.16 Version 0.98.24

Documentation - Ndisasm doc added to Nasm.doc.

C.2.17 Version 0.98.23

Attempted to remove rdoff version1
Lino Mastrodomenico's patches to preproc.c (%$$ bug?).

C.2.23 Version 0.98.17

H. J. Lu's "bogus elf" patch. (Red Hat problem?)

C.2.24 Version 0.98.16

Fix whitespace before "[section ..." bug.

C.2.25 Version 0.98.15

Rdoff changes (?).
Fix fixes to memory leaks.

C.2.28 Version 0.98.12

Update optimization (new function of "-O1")
Changes to test/bintest.asm (?).

C.2.31 Version 0.98.09

Add multiple sections support to "-f bin".
Changed GLOBAL_TEMP_BASE in outelf.c from 6 to 15.
Add "-v" as an alias to the "-r" switch.
Remove "#ifdef" from Tasm compatibility options.
Remove redundant size-overrides on "mov ds, ex", etc.
Fixes to SSE2, other insns.dat (?).
Enable uppercase "I" and "P" switches.
Case insinsitive "seg" and "wrt".
Update install.sh (?).
Allocate tokens in blocks.
Improve "invalid effective address" messages.

C.2.32 Version 0.98.08

Add "%strlen" and "%substr" macro operators
Fixed broken c16.mac.
Unterminated string error reported.
Fixed bugs as per 0.98bf

C.2.33 Version 0.98.09b with John Coffman patches released 28-Oct-2001

Changes from 0.98.07 release to 98.09b as of 28-Oct-2001

More closely compatible with 0.98 when -O0 is implied or specified. Not strictly identical, since backward branches in range of short offsets are recognized, and signed byte values with no explicit size specification will be assembled as a single byte.
More forgiving with the PUSH instruction. 0.98 requires a size to be specified always. 0.98.09b will imply the size from the current BITS setting (16 or 32).
Changed definition of the optimization flag:

-O0 strict two-pass assembly, JMP and Jcc are handled more like 0.98, except that back- ward JMPs are short, if possible.

-O1 strict two-pass assembly, but forward branches are assembled with code guaranteed to reach; may produce larger code than -O0, but will produce successful assembly more often if branch offset sizes are not specified.

-O2 multi-pass optimization, minimize branch offsets; also will minimize signed immed- iate bytes, overriding size specification.

-O3 like -O2, but more passes taken, if needed

C.2.34 Version 0.98.07 released 01/28/01

Added Stepane Denis' SSE2 instructions to a *working* version of the code - some earlier versions were based on broken code - sorry 'bout that. version "0.98.07"

01/28/01

Cosmetic modifications to nasm.c, nasm.h, AUTHORS, MODIFIED

C.2.35 Version 0.98.06f released 01/18/01

- Add "metalbrain"s jecxz bug fix in insns.dat - alter nasmdoc.src to match - version "0.98.06f"

C.2.36 Version 0.98.06e released 01/09/01

Removed the "outforms.h" file - it appears to be someone's old backup of "outform.h". version "0.98.06e"

01/09/01

fbk - finally added the fix for the "multiple %includes bug", known since 7/27/99 - reported originally (?) and sent to us by Austin Lunnen - he reports that John Fine had a fix within the day. Here it is...
Nelson Rush resigns from the group. Big thanks to Nelson for his leadership and enthusiasm in getting these changes incorporated into Nasm!
fbk - [list +], [list -] directives - ineptly implemented, should be re-written or removed, perhaps.
Brian Raiter / fbk - "elfso bug" fix - applied to aoutb format as well - testing might be desirable...

08/07/00

James Seter - -postfix, -prefix command line switches.
Yuri Zaporozhets - rdoff utility changes.

C.2.37 Version 0.98p1

GAS-like palign (Panos Minos)
FIXME: Someone, fill this in with details

C.2.38 Version 0.98bf (bug-fixed)

Fixed - elf and aoutb bug - shared libraries - multiple "%include" bug in "-f obj" - jcxz, jecxz bug - unrecognized option bug in ndisasm

C.2.39 Version 0.98.03 with John Coffman's changes released 27-Jul-2000

Added signed byte optimizations for the 0x81/0x83 class of instructions: ADC, ADD, AND, CMP, OR, SBB, SUB, XOR: when used as 'ADD reg16,imm' or 'ADD reg32,imm.' Also optimization of signed byte form of 'PUSH imm' and 'IMUL reg,imm'/'IMUL reg,reg,imm.' No size specification is needed.
Added multi-pass JMP and Jcc offset optimization. Offsets on forward references will preferentially use the short form, without the need to code a specific size (short or near) for the branch. Added instructions for 'Jcc label' to use the form 'Jnotcc $+3/JMP label', in cases where a short offset is out of bounds. If compiling for a 386 or higher CPU, then the 386 form of Jcc will be used instead.

This feature is controlled by a new command-line switch: "O", (upper case letter O). "-O0" reverts the assembler to no extra optimization passes, "-O1" allows up to 5 extra passes, and "-O2"(default), allows up to 10 extra optimization passes.

Added a new directive: 'cpu XXX', where XXX is any of: 8086, 186, 286, 386, 486, 586, pentium, 686, PPro, P2, P3 or Katmai. All are case insensitive. All instructions will be selected only if they apply to the selected cpu or lower. Corrected a couple of bugs in cpu-dependence in 'insns.dat'.
Added to 'standard.mac', the "use16" and "use32" forms of the "bits 16/32" directive. This is nothing new, just conforms to a lot of other assemblers. (minor)
Changed label allocation from 320/32 (10000 labels @ 200K+) to 32/37 (1000 labels); makes running under DOS much easier. Since additional label space is allocated dynamically, this should have no effect on large programs with lots of labels. The 37 is a prime, believed to be better for hashing. (minor)

C.2.40 Version 0.98.03

"Integrated patchfile 0.98-0.98.01. I call this version 0.98.03 for historical reasons: 0.98.02 was trashed." --John Coffman <johninsd@san.rr.com>, 27-Jul-2000

Kendall Bennett's SciTech MGL changes
Note that you must define "TASM_COMPAT" at compile-time to get the Tasm Ideal Mode compatibility.
All changes can be compiled in and out using the TASM_COMPAT macros, and when compiled without TASM_COMPAT defined we get the exact same binary as the unmodified 0.98 sources.
standard.mac, macros.c: Added macros to ignore TASM directives before first include
nasm.h: Added extern declaration for tasm_compatible_mode
nasm.c: Added global variable tasm_compatible_mode
Added command line switch for TASM compatible mode (-t)
Changed version command line to reflect when compiled with TASM additions
Added response file processing to allow all arguments on a single line (response file is @resp rather than -@resp for NASM format).
labels.c: Changes islocal() macro to support TASM style @@local labels.
Added islocalchar() macro to support TASM style @@local labels.
parser.c: Added support for TASM style memory references (ie: mov [DWORD eax],10 rather than the NASM style mov DWORD [eax],10).
preproc.c: Added new directives, %arg, %local, %stacksize to directives table
Added support for TASM style directives without a leading % symbol.
Integrated a block of changes from Andrew Zabolotny <bit@eltech.ru>:
A new keyword %xdefine and its case-insensitive counterpart %ixdefine. They work almost the same way as %define and %idefine but expand the definition immediately, not on the invocation. Something like a cross between %define and %assign. The "x" suffix stands for "eXpand", so "xdefine" can be deciphered as "expand-and-define". Thus you can do things like this:

     %assign ofs     0 

     %macro  arg     1 
             %xdefine %1 dword [esp+ofs] 
             %assign ofs ofs+4 
     %endmacro

Changed the place where the expansion of %$name macros are expanded. Now they are converted into ..@ctxnum.name form when detokenizing, so there are no quirks as before when using %$name arguments to macros, in macros etc. For example:

     %macro  abc     1 
             %define %1 hello 
     %endm 

     abc     %$here 
     %$here

Now last line will be expanded into "hello" as expected. This also allows for lots of goodies, a good example are extended "proc" macros included in this archive.

Added a check for "cstk" in smacro_defined() before calling get_ctx() - this allows for things like:

     %ifdef %$abc 
     %endif

to work without warnings even in no context.

Added a check for "cstk" in %if*ctx and %elif*ctx directives - this allows to use %ifctx w