This is the mail archive of the gcc-help@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: V_MUST_DEF vs V_MAY_DEF ?

From: Ian Lance Taylor <iant at google dot com>
To: QiangHuang <qianghuang87 at gmail dot com>
Cc: gcc-help <gcc-help at gcc dot gnu dot org>
Date: Fri, 28 Mar 2008 23:15:10 -0700
Subject: Re: V_MUST_DEF vs V_MAY_DEF ?
References: <1807a3db0803282115u5a825d65k7c0c2bb252d8b178@mail.gmail.com>

QiangHuang <qianghuang87@gmail.com> writes:

>     "V_MUST_DEF" and "V_MAY_DEF" , The two tags appear in the IL of
> SSA in GCC.I know they have something to do with the virtual
> operand,however,I wonder that what the exact distinction between them
> is.

See doc/tree-ssa.texi.  But note that in gcc 4.3 the distinction was
removed.  Now there is only one kind of def.

http://gcc.gnu.org/ml/gcc-patches/2006-12/msg00780.html

>     Corresponding to the 2 tags, is there  "V_MUST_USE" or "V_MAY_USE"?

No.

Ian

References:
- V_MUST_DEF vs V_MAY_DEF ?
  - From: QiangHuang

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