[3/2] Use strspn/strcspn/strpbrk ifunc in internal calls.

  To make a strtok faster and improve performance in general we need to do one
additional change.

A comment:

/* It doesn't make sense to send libc-internal strcspn calls through a PLT.
   The speedup we get from using SSE4.2 instruction is likely eaten away
   by the indirect call in the PLT.  */

Does not make sense at all because nobody bothered to check it. Gap
between these implementations is quite big, when haystack is empty a
sse2 is around 40 cycles slower because it needs to populate a lookup
table and difference only increases with size. That is much bigger than
plt slowdown which is few cycles.

Even benchtest show a gap which also may be reverse by branch
misprediction but my internal benchmark shown.

 simple_strspn stupid_strspn __strspn_sse42  __strspn_sse2
Length    0, alignment  0, acc len  6:  18.6562 35.2344 17.0469 61.6719
Length    6, alignment  0, acc len  6:  59.5469 72.5781 16.4219 73.625

This patch also handles strpbrk which is implemented by including a
x86_64/multiarch/strcspn.S file.

	* sysdeps/x86_64/multiarch/strspn.S: Remove plt indirection.
	* sysdeps/x86_64/multiarch/strcspn.S: Likewise.
  

ping
On Tue, Mar 18, 2014 at 11:01:38AM +0100, Ondřej Bílka wrote:
> To make a strtok faster and improve performance in general we need to do one
> additional change.
> 
> A comment:
> 
> /* It doesn't make sense to send libc-internal strcspn calls through a PLT.
>    The speedup we get from using SSE4.2 instruction is likely eaten away
>    by the indirect call in the PLT.  */
> 
> Does not make sense at all because nobody bothered to check it. Gap
> between these implementations is quite big, when haystack is empty a
> sse2 is around 40 cycles slower because it needs to populate a lookup
> table and difference only increases with size. That is much bigger than
> plt slowdown which is few cycles.
> 
> Even benchtest show a gap which also may be reverse by branch
> misprediction but my internal benchmark shown.
> 
>  simple_strspn stupid_strspn __strspn_sse42  __strspn_sse2
> Length    0, alignment  0, acc len  6:  18.6562 35.2344 17.0469 61.6719
> Length    6, alignment  0, acc len  6:  59.5469 72.5781 16.4219 73.625
> 
> This patch also handles strpbrk which is implemented by including a
> x86_64/multiarch/strcspn.S file.
> 
> 	* sysdeps/x86_64/multiarch/strspn.S: Remove plt indirection.
> 	* sysdeps/x86_64/multiarch/strcspn.S: Likewise.
> 
> diff --git a/sysdeps/x86_64/multiarch/strcspn.S b/sysdeps/x86_64/multiarch/strcspn.S
> index 24f55e9..1b3e1aa 100644
> --- a/sysdeps/x86_64/multiarch/strcspn.S
> +++ b/sysdeps/x86_64/multiarch/strcspn.S
> @@ -65,14 +65,7 @@ END(STRCSPN)
>  # undef END
>  # define END(name) \
>  	cfi_endproc; .size STRCSPN_SSE2, .-STRCSPN_SSE2
> -# undef libc_hidden_builtin_def
> -/* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> -   The speedup we get from using SSE4.2 instruction is likely eaten away
> -   by the indirect call in the PLT.  */
> -# define libc_hidden_builtin_def(name) \
> -	.globl __GI_STRCSPN; __GI_STRCSPN = STRCSPN_SSE2
>  #endif
> -
>  #endif /* HAVE_SSE4_SUPPORT */
>  
>  #ifdef USE_AS_STRPBRK
> diff --git a/sysdeps/x86_64/multiarch/strspn.S b/sysdeps/x86_64/multiarch/strspn.S
> index bf7308e..fde1e1e 100644
> --- a/sysdeps/x86_64/multiarch/strspn.S
> +++ b/sysdeps/x86_64/multiarch/strspn.S
> @@ -50,12 +50,6 @@ END(strspn)
>  # undef END
>  # define END(name) \
>  	cfi_endproc; .size __strspn_sse2, .-__strspn_sse2
> -# undef libc_hidden_builtin_def
> -/* It doesn't make sense to send libc-internal strspn calls through a PLT.
> -   The speedup we get from using SSE4.2 instruction is likely eaten away
> -   by the indirect call in the PLT.  */
> -# define libc_hidden_builtin_def(name) \
> -	.globl __GI_strspn; __GI_strspn = __strspn_sse2
>  #endif
>  
>  #endif /* HAVE_SSE4_SUPPORT */
  

ping
On Thu, Mar 27, 2014 at 10:18:06PM +0100, Ondřej Bílka wrote:
> ping
> On Tue, Mar 18, 2014 at 11:01:38AM +0100, Ondřej Bílka wrote:
> > To make a strtok faster and improve performance in general we need to do one
> > additional change.
> > 
> > A comment:
> > 
> > /* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> >    The speedup we get from using SSE4.2 instruction is likely eaten away
> >    by the indirect call in the PLT.  */
> > 
> > Does not make sense at all because nobody bothered to check it. Gap
> > between these implementations is quite big, when haystack is empty a
> > sse2 is around 40 cycles slower because it needs to populate a lookup
> > table and difference only increases with size. That is much bigger than
> > plt slowdown which is few cycles.
> > 
> > Even benchtest show a gap which also may be reverse by branch
> > misprediction but my internal benchmark shown.
> > 
> >  simple_strspn stupid_strspn __strspn_sse42  __strspn_sse2
> > Length    0, alignment  0, acc len  6:  18.6562 35.2344 17.0469 61.6719
> > Length    6, alignment  0, acc len  6:  59.5469 72.5781 16.4219 73.625
> > 
> > This patch also handles strpbrk which is implemented by including a
> > x86_64/multiarch/strcspn.S file.
> > 
> > 	* sysdeps/x86_64/multiarch/strspn.S: Remove plt indirection.
> > 	* sysdeps/x86_64/multiarch/strcspn.S: Likewise.
> > 
> > diff --git a/sysdeps/x86_64/multiarch/strcspn.S b/sysdeps/x86_64/multiarch/strcspn.S
> > index 24f55e9..1b3e1aa 100644
> > --- a/sysdeps/x86_64/multiarch/strcspn.S
> > +++ b/sysdeps/x86_64/multiarch/strcspn.S
> > @@ -65,14 +65,7 @@ END(STRCSPN)
> >  # undef END
> >  # define END(name) \
> >  	cfi_endproc; .size STRCSPN_SSE2, .-STRCSPN_SSE2
> > -# undef libc_hidden_builtin_def
> > -/* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > -   by the indirect call in the PLT.  */
> > -# define libc_hidden_builtin_def(name) \
> > -	.globl __GI_STRCSPN; __GI_STRCSPN = STRCSPN_SSE2
> >  #endif
> > -
> >  #endif /* HAVE_SSE4_SUPPORT */
> >  
> >  #ifdef USE_AS_STRPBRK
> > diff --git a/sysdeps/x86_64/multiarch/strspn.S b/sysdeps/x86_64/multiarch/strspn.S
> > index bf7308e..fde1e1e 100644
> > --- a/sysdeps/x86_64/multiarch/strspn.S
> > +++ b/sysdeps/x86_64/multiarch/strspn.S
> > @@ -50,12 +50,6 @@ END(strspn)
> >  # undef END
> >  # define END(name) \
> >  	cfi_endproc; .size __strspn_sse2, .-__strspn_sse2
> > -# undef libc_hidden_builtin_def
> > -/* It doesn't make sense to send libc-internal strspn calls through a PLT.
> > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > -   by the indirect call in the PLT.  */
> > -# define libc_hidden_builtin_def(name) \
> > -	.globl __GI_strspn; __GI_strspn = __strspn_sse2
> >  #endif
> >  
> >  #endif /* HAVE_SSE4_SUPPORT */
> 
> -- 
> 
> Too many little pins on CPU confusing it, bend back and forth until 10-20% are neatly removed. Do _not_ leave metal bits visible!
  

On Sat, Apr 05, 2014 at 04:48:41PM +0200, Ondřej Bílka wrote:
> ping
> On Thu, Mar 27, 2014 at 10:18:06PM +0100, Ondřej Bílka wrote:
> > ping
> > On Tue, Mar 18, 2014 at 11:01:38AM +0100, Ondřej Bílka wrote:
> > > To make a strtok faster and improve performance in general we need to do one
> > > additional change.
> > > 
> > > A comment:
> > > 
> > > /* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > >    The speedup we get from using SSE4.2 instruction is likely eaten away
> > >    by the indirect call in the PLT.  */
> > > 
> > > Does not make sense at all because nobody bothered to check it. Gap
> > > between these implementations is quite big, when haystack is empty a
> > > sse2 is around 40 cycles slower because it needs to populate a lookup
> > > table and difference only increases with size. That is much bigger than
> > > plt slowdown which is few cycles.
> > > 
> > > Even benchtest show a gap which also may be reverse by branch
> > > misprediction but my internal benchmark shown.
> > > 
> > >  simple_strspn stupid_strspn __strspn_sse42  __strspn_sse2
> > > Length    0, alignment  0, acc len  6:  18.6562 35.2344 17.0469 61.6719
> > > Length    6, alignment  0, acc len  6:  59.5469 72.5781 16.4219 73.625
> > > 
> > > This patch also handles strpbrk which is implemented by including a
> > > x86_64/multiarch/strcspn.S file.
> > > 
> > > 	* sysdeps/x86_64/multiarch/strspn.S: Remove plt indirection.
> > > 	* sysdeps/x86_64/multiarch/strcspn.S: Likewise.
> > > 
> > > diff --git a/sysdeps/x86_64/multiarch/strcspn.S b/sysdeps/x86_64/multiarch/strcspn.S
> > > index 24f55e9..1b3e1aa 100644
> > > --- a/sysdeps/x86_64/multiarch/strcspn.S
> > > +++ b/sysdeps/x86_64/multiarch/strcspn.S
> > > @@ -65,14 +65,7 @@ END(STRCSPN)
> > >  # undef END
> > >  # define END(name) \
> > >  	cfi_endproc; .size STRCSPN_SSE2, .-STRCSPN_SSE2
> > > -# undef libc_hidden_builtin_def
> > > -/* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > -   by the indirect call in the PLT.  */
> > > -# define libc_hidden_builtin_def(name) \
> > > -	.globl __GI_STRCSPN; __GI_STRCSPN = STRCSPN_SSE2
> > >  #endif
> > > -
> > >  #endif /* HAVE_SSE4_SUPPORT */
> > >  
> > >  #ifdef USE_AS_STRPBRK
> > > diff --git a/sysdeps/x86_64/multiarch/strspn.S b/sysdeps/x86_64/multiarch/strspn.S
> > > index bf7308e..fde1e1e 100644
> > > --- a/sysdeps/x86_64/multiarch/strspn.S
> > > +++ b/sysdeps/x86_64/multiarch/strspn.S
> > > @@ -50,12 +50,6 @@ END(strspn)
> > >  # undef END
> > >  # define END(name) \
> > >  	cfi_endproc; .size __strspn_sse2, .-__strspn_sse2
> > > -# undef libc_hidden_builtin_def
> > > -/* It doesn't make sense to send libc-internal strspn calls through a PLT.
> > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > -   by the indirect call in the PLT.  */
> > > -# define libc_hidden_builtin_def(name) \
> > > -	.globl __GI_strspn; __GI_strspn = __strspn_sse2
> > >  #endif
> > >  
> > >  #endif /* HAVE_SSE4_SUPPORT */
> > 
> > -- 
> > 
> > Too many little pins on CPU confusing it, bend back and forth until 10-20% are neatly removed. Do _not_ leave metal bits visible!
> 
> -- 
> 
> Look, buddy:  Windows 3.1 IS A General Protection Fault.
  

ping
On Sat, Apr 12, 2014 at 09:24:47PM +0200, Ondřej Bílka wrote:
> On Sat, Apr 05, 2014 at 04:48:41PM +0200, Ondřej Bílka wrote:
> > ping
> > On Thu, Mar 27, 2014 at 10:18:06PM +0100, Ondřej Bílka wrote:
> > > ping
> > > On Tue, Mar 18, 2014 at 11:01:38AM +0100, Ondřej Bílka wrote:
> > > > To make a strtok faster and improve performance in general we need to do one
> > > > additional change.
> > > > 
> > > > A comment:
> > > > 
> > > > /* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > >    The speedup we get from using SSE4.2 instruction is likely eaten away
> > > >    by the indirect call in the PLT.  */
> > > > 
> > > > Does not make sense at all because nobody bothered to check it. Gap
> > > > between these implementations is quite big, when haystack is empty a
> > > > sse2 is around 40 cycles slower because it needs to populate a lookup
> > > > table and difference only increases with size. That is much bigger than
> > > > plt slowdown which is few cycles.
> > > > 
> > > > Even benchtest show a gap which also may be reverse by branch
> > > > misprediction but my internal benchmark shown.
> > > > 
> > > >  simple_strspn stupid_strspn __strspn_sse42  __strspn_sse2
> > > > Length    0, alignment  0, acc len  6:  18.6562 35.2344 17.0469 61.6719
> > > > Length    6, alignment  0, acc len  6:  59.5469 72.5781 16.4219 73.625
> > > > 
> > > > This patch also handles strpbrk which is implemented by including a
> > > > x86_64/multiarch/strcspn.S file.
> > > > 
> > > > 	* sysdeps/x86_64/multiarch/strspn.S: Remove plt indirection.
> > > > 	* sysdeps/x86_64/multiarch/strcspn.S: Likewise.
> > > > 
> > > > diff --git a/sysdeps/x86_64/multiarch/strcspn.S b/sysdeps/x86_64/multiarch/strcspn.S
> > > > index 24f55e9..1b3e1aa 100644
> > > > --- a/sysdeps/x86_64/multiarch/strcspn.S
> > > > +++ b/sysdeps/x86_64/multiarch/strcspn.S
> > > > @@ -65,14 +65,7 @@ END(STRCSPN)
> > > >  # undef END
> > > >  # define END(name) \
> > > >  	cfi_endproc; .size STRCSPN_SSE2, .-STRCSPN_SSE2
> > > > -# undef libc_hidden_builtin_def
> > > > -/* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > -   by the indirect call in the PLT.  */
> > > > -# define libc_hidden_builtin_def(name) \
> > > > -	.globl __GI_STRCSPN; __GI_STRCSPN = STRCSPN_SSE2
> > > >  #endif
> > > > -
> > > >  #endif /* HAVE_SSE4_SUPPORT */
> > > >  
> > > >  #ifdef USE_AS_STRPBRK
> > > > diff --git a/sysdeps/x86_64/multiarch/strspn.S b/sysdeps/x86_64/multiarch/strspn.S
> > > > index bf7308e..fde1e1e 100644
> > > > --- a/sysdeps/x86_64/multiarch/strspn.S
> > > > +++ b/sysdeps/x86_64/multiarch/strspn.S
> > > > @@ -50,12 +50,6 @@ END(strspn)
> > > >  # undef END
> > > >  # define END(name) \
> > > >  	cfi_endproc; .size __strspn_sse2, .-__strspn_sse2
> > > > -# undef libc_hidden_builtin_def
> > > > -/* It doesn't make sense to send libc-internal strspn calls through a PLT.
> > > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > -   by the indirect call in the PLT.  */
> > > > -# define libc_hidden_builtin_def(name) \
> > > > -	.globl __GI_strspn; __GI_strspn = __strspn_sse2
> > > >  #endif
> > > >  
> > > >  #endif /* HAVE_SSE4_SUPPORT */
> > > 
> > > -- 
> > > 
> > > Too many little pins on CPU confusing it, bend back and forth until 10-20% are neatly removed. Do _not_ leave metal bits visible!
> > 
> > -- 
> > 
> > Look, buddy:  Windows 3.1 IS A General Protection Fault.
> 
> -- 
> 
> Failure to adjust for daylight savings time.
  

ping
On Mon, May 12, 2014 at 02:00:11PM +0200, Ondřej Bílka wrote:
> ping
> On Sat, Apr 12, 2014 at 09:24:47PM +0200, Ondřej Bílka wrote:
> > On Sat, Apr 05, 2014 at 04:48:41PM +0200, Ondřej Bílka wrote:
> > > ping
> > > On Thu, Mar 27, 2014 at 10:18:06PM +0100, Ondřej Bílka wrote:
> > > > ping
> > > > On Tue, Mar 18, 2014 at 11:01:38AM +0100, Ondřej Bílka wrote:
> > > > > To make a strtok faster and improve performance in general we need to do one
> > > > > additional change.
> > > > > 
> > > > > A comment:
> > > > > 
> > > > > /* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > > >    The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > >    by the indirect call in the PLT.  */
> > > > > 
> > > > > Does not make sense at all because nobody bothered to check it. Gap
> > > > > between these implementations is quite big, when haystack is empty a
> > > > > sse2 is around 40 cycles slower because it needs to populate a lookup
> > > > > table and difference only increases with size. That is much bigger than
> > > > > plt slowdown which is few cycles.
> > > > > 
> > > > > Even benchtest show a gap which also may be reverse by branch
> > > > > misprediction but my internal benchmark shown.
> > > > > 
> > > > >  simple_strspn stupid_strspn __strspn_sse42  __strspn_sse2
> > > > > Length    0, alignment  0, acc len  6:  18.6562 35.2344 17.0469 61.6719
> > > > > Length    6, alignment  0, acc len  6:  59.5469 72.5781 16.4219 73.625
> > > > > 
> > > > > This patch also handles strpbrk which is implemented by including a
> > > > > x86_64/multiarch/strcspn.S file.
> > > > > 
> > > > > 	* sysdeps/x86_64/multiarch/strspn.S: Remove plt indirection.
> > > > > 	* sysdeps/x86_64/multiarch/strcspn.S: Likewise.
> > > > > 
> > > > > diff --git a/sysdeps/x86_64/multiarch/strcspn.S b/sysdeps/x86_64/multiarch/strcspn.S
> > > > > index 24f55e9..1b3e1aa 100644
> > > > > --- a/sysdeps/x86_64/multiarch/strcspn.S
> > > > > +++ b/sysdeps/x86_64/multiarch/strcspn.S
> > > > > @@ -65,14 +65,7 @@ END(STRCSPN)
> > > > >  # undef END
> > > > >  # define END(name) \
> > > > >  	cfi_endproc; .size STRCSPN_SSE2, .-STRCSPN_SSE2
> > > > > -# undef libc_hidden_builtin_def
> > > > > -/* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > -   by the indirect call in the PLT.  */
> > > > > -# define libc_hidden_builtin_def(name) \
> > > > > -	.globl __GI_STRCSPN; __GI_STRCSPN = STRCSPN_SSE2
> > > > >  #endif
> > > > > -
> > > > >  #endif /* HAVE_SSE4_SUPPORT */
> > > > >  
> > > > >  #ifdef USE_AS_STRPBRK
> > > > > diff --git a/sysdeps/x86_64/multiarch/strspn.S b/sysdeps/x86_64/multiarch/strspn.S
> > > > > index bf7308e..fde1e1e 100644
> > > > > --- a/sysdeps/x86_64/multiarch/strspn.S
> > > > > +++ b/sysdeps/x86_64/multiarch/strspn.S
> > > > > @@ -50,12 +50,6 @@ END(strspn)
> > > > >  # undef END
> > > > >  # define END(name) \
> > > > >  	cfi_endproc; .size __strspn_sse2, .-__strspn_sse2
> > > > > -# undef libc_hidden_builtin_def
> > > > > -/* It doesn't make sense to send libc-internal strspn calls through a PLT.
> > > > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > -   by the indirect call in the PLT.  */
> > > > > -# define libc_hidden_builtin_def(name) \
> > > > > -	.globl __GI_strspn; __GI_strspn = __strspn_sse2
> > > > >  #endif
> > > > >  
> > > > >  #endif /* HAVE_SSE4_SUPPORT */
> > > > 
> > > > -- 
> > > > 
> > > > Too many little pins on CPU confusing it, bend back and forth until 10-20% are neatly removed. Do _not_ leave metal bits visible!
> > > 
> > > -- 
> > > 
> > > Look, buddy:  Windows 3.1 IS A General Protection Fault.
> > 
> > -- 
> > 
> > Failure to adjust for daylight savings time.
> 
> -- 
> 
> monitor VLF leakage
  

ping
On Sat, May 24, 2014 at 01:23:13AM +0200, Ondřej Bílka wrote:
> ping
> On Mon, May 12, 2014 at 02:00:11PM +0200, Ondřej Bílka wrote:
> > ping
> > On Sat, Apr 12, 2014 at 09:24:47PM +0200, Ondřej Bílka wrote:
> > > On Sat, Apr 05, 2014 at 04:48:41PM +0200, Ondřej Bílka wrote:
> > > > ping
> > > > On Thu, Mar 27, 2014 at 10:18:06PM +0100, Ondřej Bílka wrote:
> > > > > ping
> > > > > On Tue, Mar 18, 2014 at 11:01:38AM +0100, Ondřej Bílka wrote:
> > > > > > To make a strtok faster and improve performance in general we need to do one
> > > > > > additional change.
> > > > > > 
> > > > > > A comment:
> > > > > > 
> > > > > > /* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > > > >    The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > >    by the indirect call in the PLT.  */
> > > > > > 
> > > > > > Does not make sense at all because nobody bothered to check it. Gap
> > > > > > between these implementations is quite big, when haystack is empty a
> > > > > > sse2 is around 40 cycles slower because it needs to populate a lookup
> > > > > > table and difference only increases with size. That is much bigger than
> > > > > > plt slowdown which is few cycles.
> > > > > > 
> > > > > > Even benchtest show a gap which also may be reverse by branch
> > > > > > misprediction but my internal benchmark shown.
> > > > > > 
> > > > > >  simple_strspn stupid_strspn __strspn_sse42  __strspn_sse2
> > > > > > Length    0, alignment  0, acc len  6:  18.6562 35.2344 17.0469 61.6719
> > > > > > Length    6, alignment  0, acc len  6:  59.5469 72.5781 16.4219 73.625
> > > > > > 
> > > > > > This patch also handles strpbrk which is implemented by including a
> > > > > > x86_64/multiarch/strcspn.S file.
> > > > > > 
> > > > > > 	* sysdeps/x86_64/multiarch/strspn.S: Remove plt indirection.
> > > > > > 	* sysdeps/x86_64/multiarch/strcspn.S: Likewise.
> > > > > > 
> > > > > > diff --git a/sysdeps/x86_64/multiarch/strcspn.S b/sysdeps/x86_64/multiarch/strcspn.S
> > > > > > index 24f55e9..1b3e1aa 100644
> > > > > > --- a/sysdeps/x86_64/multiarch/strcspn.S
> > > > > > +++ b/sysdeps/x86_64/multiarch/strcspn.S
> > > > > > @@ -65,14 +65,7 @@ END(STRCSPN)
> > > > > >  # undef END
> > > > > >  # define END(name) \
> > > > > >  	cfi_endproc; .size STRCSPN_SSE2, .-STRCSPN_SSE2
> > > > > > -# undef libc_hidden_builtin_def
> > > > > > -/* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > > > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > > -   by the indirect call in the PLT.  */
> > > > > > -# define libc_hidden_builtin_def(name) \
> > > > > > -	.globl __GI_STRCSPN; __GI_STRCSPN = STRCSPN_SSE2
> > > > > >  #endif
> > > > > > -
> > > > > >  #endif /* HAVE_SSE4_SUPPORT */
> > > > > >  
> > > > > >  #ifdef USE_AS_STRPBRK
> > > > > > diff --git a/sysdeps/x86_64/multiarch/strspn.S b/sysdeps/x86_64/multiarch/strspn.S
> > > > > > index bf7308e..fde1e1e 100644
> > > > > > --- a/sysdeps/x86_64/multiarch/strspn.S
> > > > > > +++ b/sysdeps/x86_64/multiarch/strspn.S
> > > > > > @@ -50,12 +50,6 @@ END(strspn)
> > > > > >  # undef END
> > > > > >  # define END(name) \
> > > > > >  	cfi_endproc; .size __strspn_sse2, .-__strspn_sse2
> > > > > > -# undef libc_hidden_builtin_def
> > > > > > -/* It doesn't make sense to send libc-internal strspn calls through a PLT.
> > > > > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > > -   by the indirect call in the PLT.  */
> > > > > > -# define libc_hidden_builtin_def(name) \
> > > > > > -	.globl __GI_strspn; __GI_strspn = __strspn_sse2
> > > > > >  #endif
> > > > > >  
> > > > > >  #endif /* HAVE_SSE4_SUPPORT */
> > > > > 
> > > > > -- 
> > > > > 
> > > > > Too many little pins on CPU confusing it, bend back and forth until 10-20% are neatly removed. Do _not_ leave metal bits visible!
> > > > 
> > > > -- 
> > > > 
> > > > Look, buddy:  Windows 3.1 IS A General Protection Fault.
> > > 
> > > -- 
> > > 
> > > Failure to adjust for daylight savings time.
> > 
> > -- 
> > 
> > monitor VLF leakage
> 
> -- 
> 
> Stale file handle (next time use Tupperware(tm)!)
  

ping
On Wed, Jun 04, 2014 at 02:47:54PM +0200, Ondřej Bílka wrote:
> ping
> On Sat, May 24, 2014 at 01:23:13AM +0200, Ondřej Bílka wrote:
> > ping
> > On Mon, May 12, 2014 at 02:00:11PM +0200, Ondřej Bílka wrote:
> > > ping
> > > On Sat, Apr 12, 2014 at 09:24:47PM +0200, Ondřej Bílka wrote:
> > > > On Sat, Apr 05, 2014 at 04:48:41PM +0200, Ondřej Bílka wrote:
> > > > > ping
> > > > > On Thu, Mar 27, 2014 at 10:18:06PM +0100, Ondřej Bílka wrote:
> > > > > > ping
> > > > > > On Tue, Mar 18, 2014 at 11:01:38AM +0100, Ondřej Bílka wrote:
> > > > > > > To make a strtok faster and improve performance in general we need to do one
> > > > > > > additional change.
> > > > > > > 
> > > > > > > A comment:
> > > > > > > 
> > > > > > > /* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > > > > >    The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > > >    by the indirect call in the PLT.  */
> > > > > > > 
> > > > > > > Does not make sense at all because nobody bothered to check it. Gap
> > > > > > > between these implementations is quite big, when haystack is empty a
> > > > > > > sse2 is around 40 cycles slower because it needs to populate a lookup
> > > > > > > table and difference only increases with size. That is much bigger than
> > > > > > > plt slowdown which is few cycles.
> > > > > > > 
> > > > > > > Even benchtest show a gap which also may be reverse by branch
> > > > > > > misprediction but my internal benchmark shown.
> > > > > > > 
> > > > > > >  simple_strspn stupid_strspn __strspn_sse42  __strspn_sse2
> > > > > > > Length    0, alignment  0, acc len  6:  18.6562 35.2344 17.0469 61.6719
> > > > > > > Length    6, alignment  0, acc len  6:  59.5469 72.5781 16.4219 73.625
> > > > > > > 
> > > > > > > This patch also handles strpbrk which is implemented by including a
> > > > > > > x86_64/multiarch/strcspn.S file.
> > > > > > > 
> > > > > > > 	* sysdeps/x86_64/multiarch/strspn.S: Remove plt indirection.
> > > > > > > 	* sysdeps/x86_64/multiarch/strcspn.S: Likewise.
> > > > > > > 
> > > > > > > diff --git a/sysdeps/x86_64/multiarch/strcspn.S b/sysdeps/x86_64/multiarch/strcspn.S
> > > > > > > index 24f55e9..1b3e1aa 100644
> > > > > > > --- a/sysdeps/x86_64/multiarch/strcspn.S
> > > > > > > +++ b/sysdeps/x86_64/multiarch/strcspn.S
> > > > > > > @@ -65,14 +65,7 @@ END(STRCSPN)
> > > > > > >  # undef END
> > > > > > >  # define END(name) \
> > > > > > >  	cfi_endproc; .size STRCSPN_SSE2, .-STRCSPN_SSE2
> > > > > > > -# undef libc_hidden_builtin_def
> > > > > > > -/* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > > > > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > > > -   by the indirect call in the PLT.  */
> > > > > > > -# define libc_hidden_builtin_def(name) \
> > > > > > > -	.globl __GI_STRCSPN; __GI_STRCSPN = STRCSPN_SSE2
> > > > > > >  #endif
> > > > > > > -
> > > > > > >  #endif /* HAVE_SSE4_SUPPORT */
> > > > > > >  
> > > > > > >  #ifdef USE_AS_STRPBRK
> > > > > > > diff --git a/sysdeps/x86_64/multiarch/strspn.S b/sysdeps/x86_64/multiarch/strspn.S
> > > > > > > index bf7308e..fde1e1e 100644
> > > > > > > --- a/sysdeps/x86_64/multiarch/strspn.S
> > > > > > > +++ b/sysdeps/x86_64/multiarch/strspn.S
> > > > > > > @@ -50,12 +50,6 @@ END(strspn)
> > > > > > >  # undef END
> > > > > > >  # define END(name) \
> > > > > > >  	cfi_endproc; .size __strspn_sse2, .-__strspn_sse2
> > > > > > > -# undef libc_hidden_builtin_def
> > > > > > > -/* It doesn't make sense to send libc-internal strspn calls through a PLT.
> > > > > > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > > > -   by the indirect call in the PLT.  */
> > > > > > > -# define libc_hidden_builtin_def(name) \
> > > > > > > -	.globl __GI_strspn; __GI_strspn = __strspn_sse2
> > > > > > >  #endif
> > > > > > >  
> > > > > > >  #endif /* HAVE_SSE4_SUPPORT */
> > > > > > 
> > > > > > -- 
> > > > > > 
> > > > > > Too many little pins on CPU confusing it, bend back and forth until 10-20% are neatly removed. Do _not_ leave metal bits visible!
> > > > > 
> > > > > -- 
> > > > > 
> > > > > Look, buddy:  Windows 3.1 IS A General Protection Fault.
> > > > 
> > > > -- 
> > > > 
> > > > Failure to adjust for daylight savings time.
> > > 
> > > -- 
> > > 
> > > monitor VLF leakage
> > 
> > -- 
> > 
> > Stale file handle (next time use Tupperware(tm)!)
> 
> -- 
> 
> piezo-electric interference
  

ping
On Tue, Jun 24, 2014 at 12:41:52PM +0200, Ondřej Bílka wrote:
> ping
> On Wed, Jun 04, 2014 at 02:47:54PM +0200, Ondřej Bílka wrote:
> > ping
> > On Sat, May 24, 2014 at 01:23:13AM +0200, Ondřej Bílka wrote:
> > > ping
> > > On Mon, May 12, 2014 at 02:00:11PM +0200, Ondřej Bílka wrote:
> > > > ping
> > > > On Sat, Apr 12, 2014 at 09:24:47PM +0200, Ondřej Bílka wrote:
> > > > > On Sat, Apr 05, 2014 at 04:48:41PM +0200, Ondřej Bílka wrote:
> > > > > > ping
> > > > > > On Thu, Mar 27, 2014 at 10:18:06PM +0100, Ondřej Bílka wrote:
> > > > > > > ping
> > > > > > > On Tue, Mar 18, 2014 at 11:01:38AM +0100, Ondřej Bílka wrote:
> > > > > > > > To make a strtok faster and improve performance in general we need to do one
> > > > > > > > additional change.
> > > > > > > > 
> > > > > > > > A comment:
> > > > > > > > 
> > > > > > > > /* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > > > > > >    The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > > > >    by the indirect call in the PLT.  */
> > > > > > > > 
> > > > > > > > Does not make sense at all because nobody bothered to check it. Gap
> > > > > > > > between these implementations is quite big, when haystack is empty a
> > > > > > > > sse2 is around 40 cycles slower because it needs to populate a lookup
> > > > > > > > table and difference only increases with size. That is much bigger than
> > > > > > > > plt slowdown which is few cycles.
> > > > > > > > 
> > > > > > > > Even benchtest show a gap which also may be reverse by branch
> > > > > > > > misprediction but my internal benchmark shown.
> > > > > > > > 
> > > > > > > >  simple_strspn stupid_strspn __strspn_sse42  __strspn_sse2
> > > > > > > > Length    0, alignment  0, acc len  6:  18.6562 35.2344 17.0469 61.6719
> > > > > > > > Length    6, alignment  0, acc len  6:  59.5469 72.5781 16.4219 73.625
> > > > > > > > 
> > > > > > > > This patch also handles strpbrk which is implemented by including a
> > > > > > > > x86_64/multiarch/strcspn.S file.
> > > > > > > > 
> > > > > > > > 	* sysdeps/x86_64/multiarch/strspn.S: Remove plt indirection.
> > > > > > > > 	* sysdeps/x86_64/multiarch/strcspn.S: Likewise.
> > > > > > > > 
> > > > > > > > diff --git a/sysdeps/x86_64/multiarch/strcspn.S b/sysdeps/x86_64/multiarch/strcspn.S
> > > > > > > > index 24f55e9..1b3e1aa 100644
> > > > > > > > --- a/sysdeps/x86_64/multiarch/strcspn.S
> > > > > > > > +++ b/sysdeps/x86_64/multiarch/strcspn.S
> > > > > > > > @@ -65,14 +65,7 @@ END(STRCSPN)
> > > > > > > >  # undef END
> > > > > > > >  # define END(name) \
> > > > > > > >  	cfi_endproc; .size STRCSPN_SSE2, .-STRCSPN_SSE2
> > > > > > > > -# undef libc_hidden_builtin_def
> > > > > > > > -/* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > > > > > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > > > > -   by the indirect call in the PLT.  */
> > > > > > > > -# define libc_hidden_builtin_def(name) \
> > > > > > > > -	.globl __GI_STRCSPN; __GI_STRCSPN = STRCSPN_SSE2
> > > > > > > >  #endif
> > > > > > > > -
> > > > > > > >  #endif /* HAVE_SSE4_SUPPORT */
> > > > > > > >  
> > > > > > > >  #ifdef USE_AS_STRPBRK
> > > > > > > > diff --git a/sysdeps/x86_64/multiarch/strspn.S b/sysdeps/x86_64/multiarch/strspn.S
> > > > > > > > index bf7308e..fde1e1e 100644
> > > > > > > > --- a/sysdeps/x86_64/multiarch/strspn.S
> > > > > > > > +++ b/sysdeps/x86_64/multiarch/strspn.S
> > > > > > > > @@ -50,12 +50,6 @@ END(strspn)
> > > > > > > >  # undef END
> > > > > > > >  # define END(name) \
> > > > > > > >  	cfi_endproc; .size __strspn_sse2, .-__strspn_sse2
> > > > > > > > -# undef libc_hidden_builtin_def
> > > > > > > > -/* It doesn't make sense to send libc-internal strspn calls through a PLT.
> > > > > > > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > > > > -   by the indirect call in the PLT.  */
> > > > > > > > -# define libc_hidden_builtin_def(name) \
> > > > > > > > -	.globl __GI_strspn; __GI_strspn = __strspn_sse2
> > > > > > > >  #endif
> > > > > > > >  
> > > > > > > >  #endif /* HAVE_SSE4_SUPPORT */
> > > > > > > 
> > > > > > > -- 
> > > > > > > 
> > > > > > > Too many little pins on CPU confusing it, bend back and forth until 10-20% are neatly removed. Do _not_ leave metal bits visible!
> > > > > > 
> > > > > > -- 
> > > > > > 
> > > > > > Look, buddy:  Windows 3.1 IS A General Protection Fault.
> > > > > 
> > > > > -- 
> > > > > 
> > > > > Failure to adjust for daylight savings time.
> > > > 
> > > > -- 
> > > > 
> > > > monitor VLF leakage
> > > 
> > > -- 
> > > 
> > > Stale file handle (next time use Tupperware(tm)!)
> > 
> > -- 
> > 
> > piezo-electric interference
> 
> -- 
> 
> Hard drive sleeping. Let it wake up on it's own...
  

ping
On Wed, Dec 10, 2014 at 03:39:31PM +0100, Ondřej Bílka wrote:
> ping
> On Tue, Jun 24, 2014 at 12:41:52PM +0200, Ondřej Bílka wrote:
> > ping
> > On Wed, Jun 04, 2014 at 02:47:54PM +0200, Ondřej Bílka wrote:
> > > ping
> > > On Sat, May 24, 2014 at 01:23:13AM +0200, Ondřej Bílka wrote:
> > > > ping
> > > > On Mon, May 12, 2014 at 02:00:11PM +0200, Ondřej Bílka wrote:
> > > > > ping
> > > > > On Sat, Apr 12, 2014 at 09:24:47PM +0200, Ondřej Bílka wrote:
> > > > > > On Sat, Apr 05, 2014 at 04:48:41PM +0200, Ondřej Bílka wrote:
> > > > > > > ping
> > > > > > > On Thu, Mar 27, 2014 at 10:18:06PM +0100, Ondřej Bílka wrote:
> > > > > > > > ping
> > > > > > > > On Tue, Mar 18, 2014 at 11:01:38AM +0100, Ondřej Bílka wrote:
> > > > > > > > > To make a strtok faster and improve performance in general we need to do one
> > > > > > > > > additional change.
> > > > > > > > > 
> > > > > > > > > A comment:
> > > > > > > > > 
> > > > > > > > > /* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > > > > > > >    The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > > > > >    by the indirect call in the PLT.  */
> > > > > > > > > 
> > > > > > > > > Does not make sense at all because nobody bothered to check it. Gap
> > > > > > > > > between these implementations is quite big, when haystack is empty a
> > > > > > > > > sse2 is around 40 cycles slower because it needs to populate a lookup
> > > > > > > > > table and difference only increases with size. That is much bigger than
> > > > > > > > > plt slowdown which is few cycles.
> > > > > > > > > 
> > > > > > > > > Even benchtest show a gap which also may be reverse by branch
> > > > > > > > > misprediction but my internal benchmark shown.
> > > > > > > > > 
> > > > > > > > >  simple_strspn stupid_strspn __strspn_sse42  __strspn_sse2
> > > > > > > > > Length    0, alignment  0, acc len  6:  18.6562 35.2344 17.0469 61.6719
> > > > > > > > > Length    6, alignment  0, acc len  6:  59.5469 72.5781 16.4219 73.625
> > > > > > > > > 
> > > > > > > > > This patch also handles strpbrk which is implemented by including a
> > > > > > > > > x86_64/multiarch/strcspn.S file.
> > > > > > > > > 
> > > > > > > > > 	* sysdeps/x86_64/multiarch/strspn.S: Remove plt indirection.
> > > > > > > > > 	* sysdeps/x86_64/multiarch/strcspn.S: Likewise.
> > > > > > > > > 
> > > > > > > > > diff --git a/sysdeps/x86_64/multiarch/strcspn.S b/sysdeps/x86_64/multiarch/strcspn.S
> > > > > > > > > index 24f55e9..1b3e1aa 100644
> > > > > > > > > --- a/sysdeps/x86_64/multiarch/strcspn.S
> > > > > > > > > +++ b/sysdeps/x86_64/multiarch/strcspn.S
> > > > > > > > > @@ -65,14 +65,7 @@ END(STRCSPN)
> > > > > > > > >  # undef END
> > > > > > > > >  # define END(name) \
> > > > > > > > >  	cfi_endproc; .size STRCSPN_SSE2, .-STRCSPN_SSE2
> > > > > > > > > -# undef libc_hidden_builtin_def
> > > > > > > > > -/* It doesn't make sense to send libc-internal strcspn calls through a PLT.
> > > > > > > > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > > > > > -   by the indirect call in the PLT.  */
> > > > > > > > > -# define libc_hidden_builtin_def(name) \
> > > > > > > > > -	.globl __GI_STRCSPN; __GI_STRCSPN = STRCSPN_SSE2
> > > > > > > > >  #endif
> > > > > > > > > -
> > > > > > > > >  #endif /* HAVE_SSE4_SUPPORT */
> > > > > > > > >  
> > > > > > > > >  #ifdef USE_AS_STRPBRK
> > > > > > > > > diff --git a/sysdeps/x86_64/multiarch/strspn.S b/sysdeps/x86_64/multiarch/strspn.S
> > > > > > > > > index bf7308e..fde1e1e 100644
> > > > > > > > > --- a/sysdeps/x86_64/multiarch/strspn.S
> > > > > > > > > +++ b/sysdeps/x86_64/multiarch/strspn.S
> > > > > > > > > @@ -50,12 +50,6 @@ END(strspn)
> > > > > > > > >  # undef END
> > > > > > > > >  # define END(name) \
> > > > > > > > >  	cfi_endproc; .size __strspn_sse2, .-__strspn_sse2
> > > > > > > > > -# undef libc_hidden_builtin_def
> > > > > > > > > -/* It doesn't make sense to send libc-internal strspn calls through a PLT.
> > > > > > > > > -   The speedup we get from using SSE4.2 instruction is likely eaten away
> > > > > > > > > -   by the indirect call in the PLT.  */
> > > > > > > > > -# define libc_hidden_builtin_def(name) \
> > > > > > > > > -	.globl __GI_strspn; __GI_strspn = __strspn_sse2
> > > > > > > > >  #endif
> > > > > > > > >  
> > > > > > > > >  #endif /* HAVE_SSE4_SUPPORT */
> > > > > > > > 
> > > > > > > > -- 
> > > > > > > > 
> > > > > > > > Too many little pins on CPU confusing it, bend back and forth until 10-20% are neatly removed. Do _not_ leave metal bits visible!
> > > > > > > 
> > > > > > > -- 
> > > > > > > 
> > > > > > > Look, buddy:  Windows 3.1 IS A General Protection Fault.
> > > > > > 
> > > > > > -- 
> > > > > > 
> > > > > > Failure to adjust for daylight savings time.
> > > > > 
> > > > > -- 
> > > > > 
> > > > > monitor VLF leakage
> > > > 
> > > > -- 
> > > > 
> > > > Stale file handle (next time use Tupperware(tm)!)
> > > 
> > > -- 
> > > 
> > > piezo-electric interference
> > 
> > -- 
> > 
> > Hard drive sleeping. Let it wake up on it's own...
> 
> -- 
> 
> tachyon emissions overloading the system
  

On 18 Mar 2014 11:01, Ondřej Bílka wrote:
> To make a strtok faster and improve performance in general we need to do one
> additional change.
> 
> A comment:
> 
> /* It doesn't make sense to send libc-internal strcspn calls through a PLT.
>    The speedup we get from using SSE4.2 instruction is likely eaten away
>    by the indirect call in the PLT.  */
> 
> Does not make sense at all because nobody bothered to check it. Gap
> between these implementations is quite big, when haystack is empty a
> sse2 is around 40 cycles slower because it needs to populate a lookup
> table and difference only increases with size. That is much bigger than
> plt slowdown which is few cycles.
> 
> Even benchtest show a gap which also may be reverse by branch
> misprediction but my internal benchmark shown.
> 
>  simple_strspn stupid_strspn __strspn_sse42  __strspn_sse2
> Length    0, alignment  0, acc len  6:  18.6562 35.2344 17.0469 61.6719
> Length    6, alignment  0, acc len  6:  59.5469 72.5781 16.4219 73.625
> 
> This patch also handles strpbrk which is implemented by including a
> x86_64/multiarch/strcspn.S file.
> 
> 	* sysdeps/x86_64/multiarch/strspn.S: Remove plt indirection.
> 	* sysdeps/x86_64/multiarch/strcspn.S: Likewise.

since H.J. wrote the code, he probably should be the one approving this change
-mike
  

On Thu, Mar 5, 2015 at 6:03 PM, Mike Frysinger <vapier@gentoo.org> wrote:
> On 18 Mar 2014 11:01, Ondřej Bílka wrote:
>> To make a strtok faster and improve performance in general we need to do one
>> additional change.
>>
>> A comment:
>>
>> /* It doesn't make sense to send libc-internal strcspn calls through a PLT.
>>    The speedup we get from using SSE4.2 instruction is likely eaten away
>>    by the indirect call in the PLT.  */
>>
>> Does not make sense at all because nobody bothered to check it. Gap
>> between these implementations is quite big, when haystack is empty a
>> sse2 is around 40 cycles slower because it needs to populate a lookup
>> table and difference only increases with size. That is much bigger than
>> plt slowdown which is few cycles.
>>
>> Even benchtest show a gap which also may be reverse by branch
>> misprediction but my internal benchmark shown.
>>
>>  simple_strspn stupid_strspn __strspn_sse42  __strspn_sse2
>> Length    0, alignment  0, acc len  6:  18.6562 35.2344 17.0469 61.6719
>> Length    6, alignment  0, acc len  6:  59.5469 72.5781 16.4219 73.625
>>
>> This patch also handles strpbrk which is implemented by including a
>> x86_64/multiarch/strcspn.S file.
>>
>>       * sysdeps/x86_64/multiarch/strspn.S: Remove plt indirection.
>>       * sysdeps/x86_64/multiarch/strcspn.S: Likewise.
>
> since H.J. wrote the code, he probably should be the one approving this change
> -mike

Looks good to me.  Please commit.  Sorry for the long delay.

Thanks.