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Re: [RTL]Access rtx oprands

From: Jim Wilson <wilson at specifixinc dot com>
To: 王逸 <cnnjuwy at hotmail dot com>
Cc: gcc at gcc dot gnu dot org
Date: Fri, 25 Jun 2004 18:32:23 -0700
Subject: Re: [RTL]Access rtx oprands
References: <NUTMEGlwRhD54wG8nls000004e9@NUTMEG.CAM.ARTIMI.COM> <Sea1-DAV45BPo2oqsKa0003dd2a@hotmail.com>

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

References:
- RE: [RTL]Access rtx oprands
  - From: Dave Korn
- Re: [RTL]Access rtx oprands
  - From: 王逸

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