Certain pseudo opcodes are permitted for branch instructions.
They expand to the shortest branch instruction that reach the
target. Generally these mnemonics are made by prepending j
to
the start of Motorola mnemonic. These pseudo opcodes are not affected
by the --short-branchs
or --force-long-branchs
options.
The following table summarizes the pseudo-operations.
Displacement Width +-------------------------------------------------------------+ | Options | | --short-branchs --force-long-branchs | +--------------------------+----------------------------------+ Pseudo-Op |BYTE WORD | BYTE WORD | +--------------------------+----------------------------------+ bsr | bsr <pc-rel> <error> | jsr <abs> | bra | bra <pc-rel> <error> | jmp <abs> | jbsr | bsr <pc-rel> jsr <abs> | bsr <pc-rel> jsr <abs> | jbra | bra <pc-rel> jmp <abs> | bra <pc-rel> jmp <abs> | bXX | bXX <pc-rel> <error> | bNX +3; jmp <abs> | jbXX | bXX <pc-rel> bNX +3; | bXX <pc-rel> bNX +3; jmp <abs> | | jmp <abs> | | +--------------------------+----------------------------------+ XX: condition NX: negative of condition XX
jbsr
jbra
jb
XX
jb
XX
stands for an entire family of pseudo-operations,
where XX is a conditional branch or condition-code test. The full
list of pseudo-ops in this family is:
jbcc jbeq jbge jbgt jbhi jbvs jbpl jblo jbcs jbne jblt jble jbls jbvc jbmi
For the cases of non-PC relative displacements and long displacements,
as
issues a longer code fragment in terms of
NX, the opposite condition to XX. For example, for the
non-PC relative case:
jbXX foogives
bNXs oof jmp foo oof: