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Re: PATCH: Support -mmovbe


On Thu, May 21, 2009 at 6:32 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
> On Wed, May 20, 2009 at 10:16 PM, H.J. Lu <hongjiu.lu@intel.com> wrote:
>
>> Intel Atom has movbe instruction. It can be used to implement
>> __builtin_bswap32 and __builtin_bswap64. ?OK for trunk?
>>
>> Thanks.
>
>> +(define_insn "*movbesi2"
>> + ?[(set (match_operand:SI 0 "nonimmediate_operand" "=r,m")
>> + ? ? ? (bswap:SI (match_operand:SI 1 "nonimmediate_operand" "m,r")))]
>> + ?"TARGET_MOVBE"
>> + ?"movbe\t{%1, %0|%0, %1}"
>> + ?[(set_attr "type" "imov")
>> + ? (set_attr "modrm" "1")
>> + ? (set_attr "prefix_0f" "1")
>> + ? (set_attr "prefix_extra" "1")
>> + ? (set_attr "mode" "SI")])
>> +
>
> The pattern above should be integrated with bswapsi2 insn, so bswap
> insn will be emitted for reg-reg case.
>
>> +(define_insn "*movbedi2"
>> + ?[(set (match_operand:DI 0 "nonimmediate_operand" "=r,m")
>> + ? ? ? (bswap:DI (match_operand:DI 1 "nonimmediate_operand" "m,r")))]
>> + ?"TARGET_MOVBE && TARGET_64BIT"
>> + ?"movbe\t{%1, %0|%0, %1}"
>> + ?[(set_attr "type" "imov")
>> + ? (set_attr "modrm" "1")
>> + ? (set_attr "prefix_0f" "1")
>> + ? (set_attr "prefix_extra" "1")
>> + ? (set_attr "mode" "DI")])
>
> Also the pattern above; it should be integrated with existing bswapdi2.

movbe doesn't support "movbe reg, reg".

> Unfortunatelly, we will have a bit of mess with TARGET_BSWAP,
> TARGET_MOVBE and TARGET_64BIT.
>


-- 
H.J.


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