What are '1B' variables ?

[Emmanuel Fleury]

Hi all,

I'm playing with -fdump-tree-final_cleanup-blocks and I find from time
to time '1B' used as a variable or a numerical value, e.g.:

  # BLOCK 14 freq:1053
  # PRED: 12 [99.0%]  (false,exec)
<L16>:;
  *D.5198 = (char) __c;
  stdout.10->_IO_write_ptr = D.5198 + 1B;
  goto <bb 16> (<L11>);
  # SUCC: 16 [100.0%]  (fallthru,exec)

What does exactly does mean '1B' in this case ?

PS: I did try to Google and to browse the source code but I was
unsuccessful in both...

Regards
-- 
Emmanuel Fleury

My major preoccupation is the question, 'What is reality?'
  -- Philip K. Dick (1975)