[llvm-testresults] Geryon-X86-64 i386 nightly tester results

[Dale Johannesen]

On Apr 8, 2009, at 11:45 AMPDT, Dan Gohman wrote:

>
> On Apr 8, 2009, at 2:39 AM, Apache wrote:
>>
>> multisource/Benchmarks/Trimaran/netbench-url/netbench-url: -22.11%
>> (2.85 => 3.48)
>
> This is reproducible, though it all comes down to this one
> change in one hot 14-instruction loop:
>
> -    movl %r13d, %ecx
> -    addl %ebp, ecx
> +    leal (%rbp,%r13), %ecx
>
> This is exactly what the two-address lowering heuristics
> are designed to do; the change is that they're no longer
> missing this case. Fixing this would require some new
> heuristics that can decide when mov+add is really better
> than lea.

I believe this is replacing a 32-bit add with a 64-bit add.  Would it  
help to write the lea as
    leal (%ebp, %r13d), %ecx
?  We ought to be able to do that when the result is 32 bits.