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Re: Reload generate invalid instruction on ppc64
- From: Segher Boessenkool <segher at kernel dot crashing dot org>
- To: Carrot Wei <carrot at google dot com>, vmakarov at redhat dot com, David Edelsohn <dje dot gcc at gmail dot com>, GCC Development <gcc at gcc dot gnu dot org>
- Date: Tue, 5 Aug 2014 15:38:43 -0500
- Subject: Re: Reload generate invalid instruction on ppc64
- Authentication-results: sourceware.org; auth=none
- References: <CAEe8uEDftFtsBzhrj5Ab2yj+-uqzAXF8bKZDjjFm8UG-KL24Uw at mail dot gmail dot com> <CAEe8uEB8ZntdO5uHQN-zSCE3fiVC=VyQ2pr_JF+01Jt+X0jVZg at mail dot gmail dot com> <20140805040200 dot GM8921 at bubble dot grove dot modra dot org>
On Tue, Aug 05, 2014 at 01:32:00PM +0930, Alan Modra wrote:
> On Mon, Aug 04, 2014 at 05:54:04PM -0700, Carrot Wei wrote:
> > Another problem is in the definition of insn pattern "*movdi_internal64".
> > (define_insn "*movdi_internal64"
> > [(set (match_operand:DI 0 "nonimmediate_operand"
> > "=Y,r,r,r,r,r,?m,?*d,?*d,r,*h,*h,r,?*wg,r,?*wm")
> > (match_operand:DI 1 "input_operand"
> > "r,Y,r,I,L,nF,d,m,d,*h,r,0,*wg,r,*wm,r"))]
> > "TARGET_POWERPC64
> > && (gpc_reg_operand (operands, DImode)
> > || gpc_reg_operand (operands, DImode))"
> > The predicates of this insn pattern allow the moving of an integer to
> > VSX register, but there is no constraint allow this case. Can this
> > cause problem in reload?
> Probably, just as you found with fprs. The underlying issue is that
> the operand predicates don't match the operand constraints. What's
> more, you can't make them match without breaking up the insn, or
> adding a whole lot of extra alternatives.
Can you disallow this in the condition of the pattern, just like it
already requires at least one of the operands to be gpc_reg_operand?