Re: [PATCH, libcpp] Faster line lexer.

2015-07-10 Thread Uros Bizjak 
Hello!

 As I wrote at

 [PATCH, libcpp]: Use asm flag outputs in search_line_sse42 main loop

 https://www.mail-archive.com/gcc-patches@gcc.gnu.org/msg113610.html

 I wont repeat myself with reasons summary is that current sse4.2 code is
 reduntant as it has same performance as sse2 one.
 This improves sse2 performance by around 10% vs sse4.2 code by
 using better header.

Have you tried new SSE4.2 implementation (the one with asm flags) with
unrolled loop?

Uros.

Re: [PATCH, libcpp] Faster line lexer.

2015-07-10 Thread Jakub Jelinek 
On Fri, Jul 10, 2015 at 11:37:18AM +0200, Uros Bizjak wrote:
 Hello!
 
  As I wrote at
 
  [PATCH, libcpp]: Use asm flag outputs in search_line_sse42 main loop
 
  https://www.mail-archive.com/gcc-patches@gcc.gnu.org/msg113610.html
 
  I wont repeat myself with reasons summary is that current sse4.2 code is
  reduntant as it has same performance as sse2 one.
  This improves sse2 performance by around 10% vs sse4.2 code by
  using better header.
 
 Have you tried new SSE4.2 implementation (the one with asm flags) with
 unrolled loop?

Also, the SSE4.2 implementation looks shorter, so more I-cache friendly,
so I wouldn't really say it is redundant if they are roughly same speed.

Jakub