ARMv6T2 defines Thumb-2, a major enhancement of the Thumb instruction set. Thumb-2 provides almost exactly the same functionality as the ARM instruction set. It has both 16-bit and 32-bit instructions, and achieves ARM-like performance with Thumb-like code density.

ARMv6T2 also defines several new instructions in the ARM instruction set.

The assembler supports all the new instructions in both ARM and Thumb-2.

RVCT v2.2 includes support for new ARMv6 architecture extensions:

The RVCT v2.2 assembler enables you to write source code that can be assembled to either ARM or Thumb-2 instructions. You can use the same language to write Thumb instructions for pre-Thumb-2 processors.

However, RVCT v2.2 also supports the old assembly language syntax to enable the assembly of legacy code.

The ARM assembler supports the COMMON directive to allocate a block of memory, of the defined size, at the specified symbol. You can also specify how the memory is aligned:

COMMON symbol{,size{,alignment}}

The ARM assembler provides a new option, --dwarf3,to specify DWARF 3 standard debug tables. DWARF 2 remains the default.

The ARM assembler offers new options to give symbol visibility when building shared objects or DLLs, that is, use:

The ARM assembler can output ELF symbols with a visibility set through the use of new attributes to the IMPORT and EXPORT directives: