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[avr-gcc-list] Re: bugfix for cselib_invalidate_regno
From: |
Denis Chertykov |
Subject: |
[avr-gcc-list] Re: bugfix for cselib_invalidate_regno |
Date: |
22 May 2003 22:28:21 +0400 |
User-agent: |
Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 |
Richard Earnshaw <address@hidden> writes:
> > Denis Chertykov <address@hidden> writes:
> >
> > > I have founded a bug in cselib.c:cselib_invalidate_regno.
> > > The avr port triggers this bug.
> > > Current version of cselib_invalidate_regno didn't invalidate lower
> > > register numbers if they contain values that overlap REGNO in case
> > > that (regno < FIRST_PSEUDO_REGISTER && mode == VOIDmode). This happens
> > > if cselib_invalidate_regno called from cselib_process_insn which
> > > handle CALL_INSN.
> > > IE
> > >
> > > /* If this is a call instruction, forget anything stored in a
> > > call clobbered register, or, if this is not a const call, in
> > > memory. */
> > > if (GET_CODE (insn) == CALL_INSN)
> > > {
> > > for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
> > > if (call_used_regs[i])
> > > cselib_invalidate_regno (i, VOIDmode);
> > >
> > >
> > > Can I apply the following patch to mainline and 3.3 branches ?
> > >
> > > Denis.
> > >
> > >
> > > Index: cselib.c
> > > ===================================================================
> > > RCS file: /cvsroot/gcc/egcs/gcc/cselib.c,v
> > > retrieving revision 1.27
> > > diff -c -3 -p -r1.27 cselib.c
> > > *** cselib.c 17 Apr 2003 01:07:12 -0000 1.27
> > > --- cselib.c 19 May 2003 11:09:38 -0000
> > > *************** cselib_invalidate_regno (regno, mode)
> > > *** 1019,1032 ****
> > > pseudos, only REGNO is affected. For hard regs, we must take MODE
> > > into account, and we must also invalidate lower register numbers
> > > if they contain values that overlap REGNO. */
> > > ! if (regno < FIRST_PSEUDO_REGISTER && mode != VOIDmode)
> > > {
> > > if (regno < max_value_regs)
> > > i = 0;
> > > else
> > > i = regno - max_value_regs;
> > >
> > > ! endregno = regno + HARD_REGNO_NREGS (regno, mode);
> > > }
> > > else
> > > {
> > > --- 1019,1033 ----
> > > pseudos, only REGNO is affected. For hard regs, we must take MODE
> > > into account, and we must also invalidate lower register numbers
> > > if they contain values that overlap REGNO. */
> > > ! if (regno < FIRST_PSEUDO_REGISTER)
> > > {
> > > if (regno < max_value_regs)
> > > i = 0;
> > > else
> > > i = regno - max_value_regs;
> > >
> > > ! endregno = regno
> > > ! + (mode != VOIDmode ? HARD_REGNO_NREGS (regno, mode) : 1);
> > > }
> > > else
> > > {
> >
> > Anybody, please, review my tiny patch.
> >
> > Denis.
> >
>
> Why not change the caller to pass reg_raw_mode[regno]. That seems much
> cleaner to me than pretending a hard register can have no mode.
Because my patch make cselib_invalidate_regno more universal.
Your example will work with my patch too.
cselib_invalidate_regno have only two callers, are you sure that the
second always pass the mode != VOIDmode ?
Denis.