[Zlib-devel] infnew-5 available for testing

[Mark Adler]

On Thursday, January 9, 2003, at 10:03  PM, Chris Anderson wrote:
> Moreover, POSTINC improved times with both -O3 and -O3 -prof_use:
...
> But, the times are better with POSTINC!

I will take this as sufficient evidence to change the comment in 
inffast.c to suggest that Intel processor compilations use POSTINC.  
Though it appears to be more compiler related than processor related.

> icc7 -O3 -DPOSTINC (13 instructions, w/o POSTINC it was 15)
>
> ..B1.37:                        # Preds ..B1.37 ..B1.36         # 
> Infreq
>         movb      (%edx), %bl                                   #231.36
>         movb      %bl, (%ebp)                                   #231.25
>         movb      1(%edx), %cl                                  #232.36
>         lea       1(%edx), %edi                                 #231.36
>         lea       1(%ebp), %ebx                                 #231.25
>         movb      %cl, 1(%ebp)                                  #232.25
>         movb      2(%edx), %cl                                  #233.36
>         movb      %cl, 2(%ebp)                                  #233.25
>         addl      $-3, %eax                                     #234.25
>         addl      $3, %edx                                      #233.36
>         addl      $3, %ebp                                      #233.25
>         cmpl      $2, %eax                                      #235.30
>         ja        ..B1.37       # Prob 90%                      #235.30

That's certainly an improvement to keep the counter in a register, 
though I'm a little perplexed about what the

>         lea       1(%edx), %edi                                 #231.36
>         lea       1(%ebp), %ebx                                 #231.25

instructions are for.

mark