On Thu, Oct 5, 2023 at 1:45 PM Roger Sayle wrote:
>
> Doh! ENOPATCH.
>
> > -Original Message-
> > From: Roger Sayle
> > Sent: 05 October 2023 12:44
> > To: 'gcc-patches@gcc.gnu.org'
> > Cc: 'Uros Bizjak'
> > Subject: [X8
Doh! ENOPATCH.
> -Original Message-
> From: Roger Sayle
> Sent: 05 October 2023 12:44
> To: 'gcc-patches@gcc.gnu.org'
> Cc: 'Uros Bizjak'
> Subject: [X86 PATCH] Implement doubleword shift left by 1 bit using
add+adc.
>
>
> This patc
This patch tweaks the i386 back-end's ix86_split_ashl to implement
doubleword left shifts by 1 bit, using an add followed by an add-with-carry
(i.e. a doubleword x+x) instead of using the x86's shld instruction.
The replacement sequence both requires fewer bytes and is faster on
both Intel and AM
