Request for reviews (S): 6667595
Vladimir Kozlov
Vladimir.Kozlov at Sun.COM
Thu Feb 28 14:31:56 PST 2008
I will suspend the 6667595 changes (see at the bottom) push
for further investigation since it inroduced the regression
in scimark.sparse, jvm98.compress, jvm98.mpegaudio.
Without it the rest of changes are fine.
Thanks,
Vladimir
% rwcompare -r ref.server_5pb0_m11 ref.server_5pb0_6667595
============================================================================
ref.server_5pb0_m11
Benchmark Samples Mean Stdev
jetstream 20 133.45 14.54
Copy 20 107.95 52.44
Parse 20 115.25 0.55
Read 20 18.20 0.52
Write 20 162.55 18.26
scimark 20 628.57 0.75
Sparse 20 491.83 1.19
LU 20 1266.50 2.60
SOR 20 1040.44 1.69
FFT 20 35.32 0.03
Monte 20 308.76 0.08
specjvm98 20 582.67 2.70
javac 20 406.57 3.60
db 20 321.79 2.20
jess 20 626.98 3.41
jack 20 465.16 5.81
compress 20 501.72 8.59
mtrt 20 1596.34 19.49
mpegaudio 20 746.32 1.80
volano25 20 175659.75 2567.56
connections 20 400.00 0.00
time 20 4.56 0.07
============================================================================
ref.server_5pb0_6667595
Benchmark Samples Mean Stdev %Diff P Significant
jetstream 20 132.99 15.36 -0.35 0.923 *
Copy 20 114.20 53.06 -5.79 0.710 *
Parse 20 114.85 0.49 0.35 0.020 *
Read 20 18.00 0.46 1.10 0.207 *
Write 20 157.95 17.77 2.83 0.424 *
scimark 20 627.41 0.54 -0.18 0.000 Yes
Sparse 20 484.32 0.20 -1.53 0.000 Yes
LU 20 1268.91 2.34 0.19 0.004 Yes
SOR 20 1039.75 1.72 -0.07 0.209 *
FFT 20 35.32 0.03 0.00 0.996 *
Monte 20 308.77 0.08 0.00 0.864 *
specjvm98 20 581.29 1.62 -0.24 0.059 *
javac 20 405.99 3.79 -0.14 0.623 *
db 20 321.75 2.31 -0.01 0.956 *
jess 20 628.42 2.32 0.23 0.127 *
jack 20 464.62 5.79 -0.12 0.768 *
compress 20 494.36 1.97 -1.47 0.001 Yes
mtrt 20 1612.23 16.80 0.99 0.009 Yes
mpegaudio 20 737.84 1.82 -1.14 0.000 Yes
volano25 20 175913.16 1695.56 0.14 0.715 *
connections 20 400.00 0.00 0.00 0.000 Yes
time 20 4.55 0.04 0.16 0.697 *
============================================================================
% rwcompare -r ref.server_5pb0_m11 ref.server_5pb0_no_6667595
============================================================================
ref.server_5pb0_m11
Benchmark Samples Mean Stdev
jetstream 20 133.45 14.54
Copy 20 107.95 52.44
Parse 20 115.25 0.55
Read 20 18.20 0.52
Write 20 162.55 18.26
scimark 20 628.57 0.75
Sparse 20 491.83 1.19
LU 20 1266.50 2.60
SOR 20 1040.44 1.69
FFT 20 35.32 0.03
Monte 20 308.76 0.08
specjvm98 20 582.67 2.70
javac 20 406.57 3.60
db 20 321.79 2.20
jess 20 626.98 3.41
jack 20 465.16 5.81
compress 20 501.72 8.59
mtrt 20 1596.34 19.49
mpegaudio 20 746.32 1.80
volano25 20 175659.75 2567.56
connections 20 400.00 0.00
time 20 4.56 0.07
============================================================================
ref.server_5pb0_no_6667595
Benchmark Samples Mean Stdev %Diff P Significant
jetstream 20 131.83 17.43 -1.21 0.751 *
Copy 20 122.80 54.19 -13.76 0.384 *
Parse 20 115.05 0.60 0.17 0.281 *
Read 20 17.95 0.69 1.37 0.203 *
Write 20 152.35 11.45 6.27 0.042 *
scimark 20 628.91 0.63 0.05 0.124 *
Sparse 20 492.13 0.28 0.06 0.277 *
LU 20 1267.55 2.02 0.08 0.162 *
SOR 20 1040.78 1.74 0.03 0.540 *
FFT 20 35.33 0.02 0.02 0.316 *
Monte 20 308.78 0.06 0.01 0.445 *
specjvm98 20 583.30 2.55 0.11 0.454 *
javac 20 406.16 4.43 -0.10 0.749 *
db 20 321.39 2.53 -0.13 0.593 *
jess 20 626.66 2.82 -0.05 0.751 *
jack 20 467.51 4.96 0.50 0.178 *
compress 20 501.30 6.51 -0.08 0.861 *
mtrt 20 1606.65 19.31 0.65 0.101 *
mpegaudio 20 746.07 2.02 -0.03 0.679 *
volano25 20 175220.75 2102.28 -0.25 0.558 *
connections 20 400.00 0.00 0.00 0.000 Yes
time 20 4.57 0.06 -0.24 0.573 *
============================================================================
Tom Rodriguez wrote:
>
> 6667595: looks ok. That seems like it will have a lot of impact on the
> generated code. have you benchmarked that change by itself?
>
> Vladimir Kozlov wrote:
>> --------------------------------------------------------------------------------------------
>>
>> http://webrev.invokedynamic.info/kvn/6667595/index.html
>>
>> Fixed 6667595: Set probability FAIR for pre-, post- loops and ALWAYS
>> for main loop
>>
>> Problem:
>> C2 clone original loop's probability when it constructs pre-, main,
>> post- loops.
>> Then C2 adds zero-trip guard for main loop with probability FAIR.
>> As result a main loop's probability could be half of a pre-loop's
>> probability
>> and RA may generates stack spills in the main loop and not in the
>> pre-loop.
>>
>> Solution:
>> Set probability FAIR for pre-, post- loops and ALWAYS for zero-trip
>> guard for main loop
>> assuming a main loop is executed always.
>>
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