[Bug rtl-optimization/53422] reduce the size of CODE_LABEL rtl

[dann at ics dot uci.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53422

--- Comment #3 from Dan Nicolaescu <dann at ics dot uci.edu> 2012-05-21 16:53:25 UTC ---
(In reply to comment #2)
> The reason for the extra fields in BARRIER and CODE_LABEL is to make it
> possible for a BARRIER or CODE_LABEL to be turned into
> INSN/JUMP_INSN/CALL_INSN.  So you'd need to verify it isn't needed anywhere. 

JUMP_INSN and CALL_INSN have 9 fields, CODE_LABEL/BARRIER have 8.

The patch went through regressions when it was written, years ago, but not
since then.  I won't have time to do anything about it anytime soon.

> Note, your reordering of CODE_LABEL fields doesn't change anything on the
> allocated size, even tail 0 format fields are allocated.

See in the original message: "then it's easy to define CODE_LABEL conditionally
so that it does not use that last entry on the rest of the machines."