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] Sent: 03 March 2015 16:19

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 Patches

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, enables

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 expansion

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 compare and

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 wdijk...@arm.com wrote: Maxim Kuvyrkov wrote: On Mar 4, 2015, at 3:30 PM, Wilco Dijkstra wdijk...@arm.com 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 Maxim Kuvyrkov
On Mar 3, 2015, at 7:19 PM, Wilco Dijkstra wdijk...@arm.com 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.

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, given that

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 wdijk...@arm.com 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 fact

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 wdijk...@arm.com 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