In this dialog, the assembler reader and writer options can be set:

Assembler reader
This permits setting the style of the assembler blocks in the sources:
AT&T assembler
The assembler is written in AT&T style assembler (-Ratt on the command line).
Intel style assembler
The assembler is written in Intel style assembler blocks (-Rintel on the command line).

remark that this option is global, but locally the assembler style can be changed with compiler directives.

Assembler info
When writing assembler files, this option decides which extra information is written to the assembler file in comments:
List source
The source lines are written to the assembler files together with the generated assembler (-al on the command line).
List register allocation
The compiler’s internal register allocation/deallocation information is written to the assembler file (-ar on the command line).
List temp allocation
The temporary register allocation/deallocation is written to the assembler file. (-at on the command line).
List node allocation
The node allocation/deallocation is written to the assembler file. (-an on the command line).
use pipe with assembler
use a pipe on unix systems when feeding the assembler code to an external assembler.

The latter three of these options are mainly useful for debugging the compiler itself, it should rarely be necessary to use these.

Assembler output
This option tells the compiler what assembler output should be generated.
Use default output
This depends on the target.
Use GNU as
Assemble using gnu as (-Aas on the command line).
Use NASM coff
Produce NASM coff assembler (go32v2, -Anasmcoff on the command line)
Use NASM elf
Produce NASM elf assembler (linux, -Anasmelf on the command line).
Use NASM obj
Produce NASM obj assembler (-Anasmobj on the command line).
Use MASM
Produce MASM (Microsoft assembler) assembler (-Amasm on the command line).
Use TASM
Produce TASM (Turbo Assembler) assembler (-Atasm on the command line).
Use coff
Write binary coff files directly using the internal assembler (go32v2, -Acoff on the command line).
Use pecoff
Write binary pecoff files files directly using the internal writer. (Win32)