This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] Fix i386 tablejump problem


On Wed, Dec 19, 2001 at 10:18:51AM -0800, Richard Henderson wrote:
> On Wed, Dec 19, 2001 at 06:44:15PM +0100, Jakub Jelinek wrote:
> > The documentation isn't very clear on whether JUMP_INSN with JUMP_LABEL
> > and REG_LABEL note counts as 2 uses of the label or just one and what
> > happens if one insn have 2 or more REG_LABEL notes.
> 
> Err, the documentation is quite clear that REG_LABEL is
> used by non-JUMP_INSNs.  A JUMP_INSN should never have one,
> with or without JUMP_LABEL.

That used to be the case.
Since Alex's patch from January this is no longer true:
@findex REG_LABEL
@item REG_LABEL
This insn uses @var{op}, a @code{code_label} or a @code{note} of type
@code{NOTE_INSN_DELETED_LABEL}, but is not a
@code{jump_insn}, or it is a @code{jump_insn} that required the label to
be held in a register.  The presence of this note allows jump
optimization to be aware that @var{op} is, in fact, being used, and flow
optimization to build an accurate flow graph.

	Jakub


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]