Info Catalog as: Xtensa Relaxation as: Xtensa Call Relaxation

as: Xtensa Branch Relaxation

 
 9.54.4.1 Conditional Branch Relaxation
 ......................................
 
 When the target of a branch is too far away from the branch itself,
 i.e., when the offset from the branch to the target is too large to fit
 in the immediate field of the branch instruction, it may be necessary to
 replace the branch with a branch around a jump.  For example,
 
          beqz    a2, L
 
    may result in:
 
          bnez.n  a2, M
          j L
      M:
 
    (The 'BNEZ.N' instruction would be used in this example only if the
 density option is available.  Otherwise, 'BNEZ' would be used.)
 
    This relaxation works well because the unconditional jump instruction
 has a much larger offset range than the various conditional branches.
 However, an error will occur if a branch target is beyond the range of a
 jump instruction.  'as' cannot relax unconditional jumps.  Similarly, an
 error will occur if the original input contains an unconditional jump to
 a target that is out of range.
 
    Branch relaxation is enabled by default.  It can be disabled by using
 underscore prefixes (Opcode Names Xtensa Opcodes.), the
DONTPRINTYET  '--no-transform' command-line option (Command-line Options Xtensa
 Options.), or the 'no-transform' directive (*notetransform: Transform
DONTPRINTYET  '--no-transform' command-line option (Command-line Options Xtensa
 Options.), or the 'no-transform' directive (transform Transform

 Directive.).
 

Info Catalog as: Xtensa Relaxation as: Xtensa Call Relaxation