RE: [PATCH][AArch64] Use conditional negate for abs expansion

2015-05-14 Thread Wilco Dijkstra
> James Greenhalgh wrote: > On Mon, Apr 27, 2015 at 05:57:26PM +0100, Wilco Dijkstra wrote: > > > James Greenhalgh wrote: > > > On Mon, Apr 27, 2015 at 02:42:36PM +0100, Wilco Dijkstra wrote: > > > > > -Original Message- > > > > > From: Wilco Dijkstra [mailto:wdijk...@arm.com] > > > > > Sen

Re: [PATCH][AArch64] Use conditional negate for abs expansion

2015-05-14 Thread James Greenhalgh
On Mon, Apr 27, 2015 at 05:57:26PM +0100, Wilco Dijkstra wrote: > > James Greenhalgh wrote: > > On Mon, Apr 27, 2015 at 02:42:36PM +0100, Wilco Dijkstra wrote: > > > > -Original Message- > > > > From: Wilco Dijkstra [mailto:wdijk...@arm.com] > > > > Sent: 03 March 2015 16:19 > > > > To: GCC

RE: [PATCH][AArch64] Use conditional negate for abs expansion

2015-04-27 Thread Wilco Dijkstra
> James Greenhalgh wrote: > On Mon, Apr 27, 2015 at 02:42:36PM +0100, Wilco Dijkstra wrote: > > > -Original Message- > > > From: Wilco Dijkstra [mailto:wdijk...@arm.com] > > > Sent: 03 March 2015 16:19 > > > To: GCC Patches > > > Subject: [PATCH][AArch64] Use conditional negate for abs expa

Re: [PATCH][AArch64] Use conditional negate for abs expansion

2015-04-27 Thread James Greenhalgh
On Mon, Apr 27, 2015 at 02:42:36PM +0100, Wilco Dijkstra wrote: > > -Original Message- > > From: Wilco Dijkstra [mailto:wdijk...@arm.com] > > Sent: 03 March 2015 16:19 > > To: GCC Patches > > Subject: [PATCH][AArch64] Use conditional negate for abs expansion > > > > Expand abs into a compa

RE: [PATCH][AArch64] Use conditional negate for abs expansion

2015-04-27 Thread Wilco Dijkstra
ping > -Original Message- > From: Wilco Dijkstra [mailto:wdijk...@arm.com] > Sent: 03 March 2015 16:19 > To: GCC Patches > Subject: [PATCH][AArch64] Use conditional negate for abs expansion > > Expand abs into a compare and conditional negate. This is the most obvious > expansion, enable

Re: [PATCH][AArch64] Use conditional negate for abs expansion

2015-03-04 Thread Maxim Kuvyrkov
On Mar 4, 2015, at 6:00 PM, Wilco Dijkstra wrote: > >> Maxim Kuvyrkov wrote: >>> On Mar 4, 2015, at 3:30 PM, Wilco Dijkstra wrote: >>> Maxim Kuvyrkov wrote: You are removing the 2nd alternative that generates "abs" with your patch. While I agree >> that using "csneg"

RE: [PATCH][AArch64] Use conditional negate for abs expansion

2015-03-04 Thread Wilco Dijkstra
> Maxim Kuvyrkov wrote: > > On Mar 4, 2015, at 3:30 PM, Wilco Dijkstra wrote: > > > >> Maxim Kuvyrkov wrote: > >> > >> You are removing the 2nd alternative that generates "abs" with your patch. > >> While I agree > that > >> using "csneg" is faster on all implementations, can you say the same fo

Re: [PATCH][AArch64] Use conditional negate for abs expansion

2015-03-04 Thread Maxim Kuvyrkov
> On Mar 4, 2015, at 3:30 PM, Wilco Dijkstra wrote: > >> Maxim Kuvyrkov wrote: >> >> You are removing the 2nd alternative that generates "abs" with your patch. >> While I agree that >> using "csneg" is faster on all implementations, can you say the same for >> "abs"? Especially >> given the

RE: [PATCH][AArch64] Use conditional negate for abs expansion

2015-03-04 Thread Wilco Dijkstra
> Maxim Kuvyrkov wrote: > > You are removing the 2nd alternative that generates "abs" with your patch. > While I agree that > using "csneg" is faster on all implementations, can you say the same for > "abs"? Especially > given the fact that csneg requires 4 operands instead of abs'es 2? Yes, g

Re: [PATCH][AArch64] Use conditional negate for abs expansion

2015-03-04 Thread Maxim Kuvyrkov
> On Mar 3, 2015, at 7:19 PM, Wilco Dijkstra wrote: > > Expand abs into a compare and conditional negate. This is the most obvious > expansion, enables > merging of the comparison into ALU instructions and is faster on all > implementations. > Bootstrapped & > regression tested. > > int f(i