Re: [PATCH][GCC] Simplification of 1U << (31 - x)

Christophe Lyon wrote: > This causes my builds (all arm and aarch64 targets) to fail: Richard Biener already committed a fix in r254498 (thanks). It seems constants in match.pd now need wi::to_wide. Wilco

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

Hi Wilco On 7 November 2017 at 13:28, Wilco Dijkstra wrote: > Sudi Das wrote: > >> Thanks, I have made the changes to the patch. >> Also can someone please apply it for me. I do not have commit access. >> >> 2017-10-10 Sudakshina Das >> >>PR

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

Sudi Das wrote: > Thanks, I have made the changes to the patch. > Also can someone please apply it for me. I do not have commit access. > > 2017-10-10  Sudakshina Das  > >    PR middle-end/80131 >    * match.pd: Simplify 1 << (C - x) where C = precision (x) - 1. > >

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

ick it up. Thanks Sudi From: Wilco Dijkstra Sent: Monday, October 9, 2017 2:02 PM To: Richard Biener; Sudi Das Cc: Jakub Jelinek; GCC Patches; nd; Richard Earnshaw; James Greenhalgh Subject: Re: [PATCH][GCC] Simplification of 1U << (31 - x)   Richard Biener wrote: > I think the pat

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

Richard Biener wrote: > I think the patch is ok with these changes but obviously we should try > to address > the code-generation issue on x86 at RTL expansion time.  They are sort-of > existing missing optimizations. Note the only x64 specific issue is the backend expansion of 64-bit immediates

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

> To: Sudi Das > Cc: Wilco Dijkstra; Jakub Jelinek; GCC Patches; nd; Richard Earnshaw; James > Greenhalgh > Subject: Re: [PATCH][GCC] Simplification of 1U << (31 - x) > > On Tue, Aug 1, 2017 at 11:14 AM, Sudi Das <sudi@arm.com> wrote: >> >> >>

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

; Richard Earnshaw; James Greenhalgh Subject: Re: [PATCH][GCC] Simplification of 1U << (31 - x)   Jakub Jelinek wrote: > Well, we don't want to regress performance wise on one of the most important > primary targets.  I don't care that much if the RTL/backend work is done > together

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

Jakub Jelinek wrote: > Well, we don't want to regress performance wise on one of the most important > primary targets.  I don't care that much if the RTL/backend work is done > together with the patch, or as a follow-up during stage1/3, but it should be > done, the testcases I've posted can be

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

On Tue, Sep 26, 2017 at 12:44:10PM +, Sudi Das wrote: > > Still waiting on Jakub's comment on whether there are more things needed > at the backend. But I have updated the patch according to Richard's > comments. Well, we don't want to regress performance wise on one of the most important

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

Jakub Jelinek; GCC Patches; nd; Richard Earnshaw; James Greenhalgh Subject: Re: [PATCH][GCC] Simplification of 1U << (31 - x)   On Tue, Aug 1, 2017 at 11:14 AM, Sudi Das <sudi@arm.com> wrote: > > > > > Sorry about the delayed response but looking at the above

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

> ret > .sizef4, .-f4 > > > Thanks > > Sudi > > > > > From: Wilco Dijkstra > Sent: Thursday, April 13, 2017 1:01 PM > To: Richard Biener; Jakub Jelinek > Cc: Sudi Das; GCC Patches; nd; Richard Earnshaw; James Greenhalgh > Subj

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

, w0      add    sp, sp, 16      ret      .size    f4, .-f4 Thanks Sudi From: Wilco Dijkstra Sent: Thursday, April 13, 2017 1:01 PM To: Richard Biener; Jakub Jelinek Cc: Sudi Das; GCC Patches; nd; Richard Earnshaw; James Greenhalgh Subject: Re: [PATCH][GCC] Simplification of 1U << (

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

Richard Biener wrote: > It is IMHO a valid GIMPLE optimization / canonicalization. > >    movabsq $-9223372036854775808, %rax > > so this should then have been generated as 1<<63? > > At some point variable shifts were quite expensive as well.. Yes I don't see a major difference between

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

On Thu, Apr 13, 2017 at 01:49:01PM +0200, Richard Biener wrote: > It is IMHO a valid GIMPLE optimization / canonicalization. As I said, we can do it as GIMPLE canonicalization, but we should have code to undo it if beneficial at RTL level. And the patch has not included that. > > movabsq

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

On Thu, Apr 13, 2017 at 1:41 PM, Jakub Jelinek wrote: > On Thu, Apr 13, 2017 at 11:33:12AM +, Wilco Dijkstra wrote: >> Jakub Jelinek wrote: >> >> > No. Some constants sometimes even 7 instructions (e.g. sparc64; not >> > talking >> > in particular about 1ULL << 63

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

On Thu, Apr 13, 2017 at 11:33:12AM +, Wilco Dijkstra wrote: > Jakub Jelinek wrote: >   > > No.  Some constants sometimes even 7 instructions (e.g. sparc64; not talking > > in particular about 1ULL << 63 constant), or have one instruction > > that is more expensive than normal small constant

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

Jakub Jelinek wrote:   > No.  Some constants sometimes even 7 instructions (e.g. sparc64; not talking > in particular about 1ULL << 63 constant), or have one instruction > that is more expensive than normal small constant load.  Compare say x86_64 > movl/movq vs. movabsq, I think the latter has

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

On Thu, Apr 13, 2017 at 11:16:08AM +, Wilco Dijkstra wrote: > >On Wed, Apr 12, 2017 at 09:29:55AM +, Sudi Das wrote: > > > Hi all > > > > > > This is a fix for PR 80131 > > > Currently the code A << (B - C) is not simplified. > >> However at least a more specific case of 1U << (C -x)

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

>On Wed, Apr 12, 2017 at 09:29:55AM +, Sudi Das wrote: > > Hi all > > > > This is a fix for PR 80131 > > Currently the code A << (B - C) is not simplified. >> However at least a more specific case of 1U << (C -x) where C = >> precision(type) - 1 can be simplified to (1 << C) >> x. > > Is

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

On Wed, Apr 12, 2017 at 08:59:34PM +0200, Jakub Jelinek wrote: > On Wed, Apr 12, 2017 at 01:15:56PM -0500, Segher Boessenkool wrote: > > On Wed, Apr 12, 2017 at 07:06:38PM +0200, Jakub Jelinek wrote: > > > On Wed, Apr 12, 2017 at 09:29:55AM +, Sudi Das wrote: > > > > This is a fix for PR 80131

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

On Wed, Apr 12, 2017 at 01:15:56PM -0500, Segher Boessenkool wrote: > Hi, > > On Wed, Apr 12, 2017 at 07:06:38PM +0200, Jakub Jelinek wrote: > > On Wed, Apr 12, 2017 at 09:29:55AM +, Sudi Das wrote: > > > This is a fix for PR 80131 > > > Currently the code A << (B - C) is not simplified. > >

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

Hi, On Wed, Apr 12, 2017 at 07:06:38PM +0200, Jakub Jelinek wrote: > On Wed, Apr 12, 2017 at 09:29:55AM +, Sudi Das wrote: > > This is a fix for PR 80131 > > Currently the code A << (B - C) is not simplified. > > However at least a more specific case of 1U << (C -x) where C = > >

Re: [PATCH][GCC] Simplification of 1U << (31 - x)

On Wed, Apr 12, 2017 at 09:29:55AM +, Sudi Das wrote: > Hi all > > This is a fix for PR 80131 > Currently the code A << (B - C) is not simplified. > However at least a more specific case of 1U << (C -x) where C = > precision(type) - 1 can be simplified to (1 << C) >> x. Is that always a