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Re: extend fwprop optimization


On Thu, Mar 28, 2013 at 5:34 AM, Wei Mi <wmi@google.com> wrote:
> I am not familiar how to use define_subst, so I write a patch that
> changes define_insn_and_split to define_insn. bootstrapped and
> regression tested on x86_64-unknown-linux-gnu.
>
> A question is: after that change, Is there anyway I can make
> targetm.rtx_costs() aware about the truncation, .i.e the cost is only
> a "shift" instead of "shift + and".

Please also change all operand 2 predicates to "register_operand".

2013-03-27  Wei Mi  <wmi@google.com>

	* config/i386/i386.md: Do shift truncation in define_insn
	instead of define_insn_and_split.

Please write ChangeLog as:

	* config/i386/i386.md (*ashl<mode>3_mask): Rewrite as define_insn.
	Truncate operand 2 using %b asm operand modifier.
	(*<shift_insn><mode>3_mask): Ditto.
	(*<rotate_insn><mode>3_mask): Ditto.

OK for mainline and all release branches with these changes.

Thanks,
Uros.


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