18.104.22.168 Instruction Set Syntax
Two slightly different syntaxes are support for ARM and THUMB
instructions. The default,
divided, uses the old style where
ARM and THUMB instructions had their own, separate syntaxes. The new,
unified syntax, which can be selected via the
directive, and has the following main features:
- Immediate operands do not require a
ITinstruction may appear, and if it does it is validated against subsequent conditional affixes. In ARM mode it does not generate machine code, in THUMB mode it does.
- For ARM instructions the conditional affixes always appear at the end
of the instruction. For THUMB instructions conditional affixes can be
used, but only inside the scope of an
- All of the instructions new to the V6T2 architecture (and later) are
available. (Only a few such instructions can be written in the
.Wsuffixes are recognized and honored.
- All instructions set the flags if and only if they have an