[RTL]Access rtx oprands

[Jim Wilson]

王 逸 wrote:
> #define PATTERN(INSN) XEXP (INSN, 5)
> So I think XEXP(insn, 0) gets the insn_uid while XEXP(insn, 5) gets the call rtx in a call_insn, this right?

Yes, this is right, however, it is unsafe.  You must use PATTERN instead
of XEXP (insn, 5) because we reserve the right to change the numbering
later.  And it has changed.  It used to be XEXP (insn, 3) not long ago.
 Also, this will avoid confusing other gcc hackers, as they know what
PATTERN means, but XEXP (insn, 5) is strange and unfamiliar.
-- 
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com