llvm dev - Feb 2015 - [LLVMdev] [RFC] AArch64: Should we disable GlobalMerge?

Hi all,

I've started looking at the GlobalMerge pass, enabled by default on
ARM and AArch64.  I think we should reconsider that, at least for
AArch64.

As is, the pass just merges all globals together, in groups of 4KB
(AArch64, 128B on ARM).

At the time it was enabled, the general thinking was "it's almost
free, it doesn't affect performance much, we might as well use it".
Now, it's preventing some link-time optimizations (as acknowledged in
one of the FIXMEs).


-- Performance impact
Overall, it isn't that profitable on the test-suite, and actually
degrades performance on a lot of other - "non-benchmark" - projects I
tried (where the main reason to use a global is file- or function-
static variables, only accessed through a single getter function).

Across several runs on the entire test-suite, when disabling the pass,
I measured:
without LTO, a -0.19% geomean improvement
with LTO, a +0.11% geomean regression.

As for just SPEC2006, there are two big regressions: 400.perlbench
(10.6% w/ LTO, 2.7% w/o) and 471.omnetpp (2.3% w/, 3.9% w/o).

Numbers are attached.


-- A way forward
One obvious way to improve it is: look at uses of globals, and try to
form sets of globals commonly used together.  The tricky part is to
define heuristics for "commonly".  Also, the pass then becomes much
more expensive.  I'm currently looking into improving it, and will
report if I come up with a good solution.  But this shouldn't stop us
from disabling it, for now.

Also, the pass seems like a good candidate for
-O3/CodeGenOpt::Aggressive.  However, the latter is implied by LTO,
which IMO shouldn't include these not-always-profitable optimizations.
That's another problem though.



Right now, I think we should disable the pass by default, until it's
deemed profitable enough.

-Ahmed

With the numbers!
-Ahmed


On Wed, Feb 25, 2015 at 4:57 PM, Ahmed Bougacha
<ahmed.bougacha at gmail.com> wrote:
> Hi all,
>
> I've started looking at the GlobalMerge pass, enabled by default on
> ARM and AArch64.  I think we should reconsider that, at least for
> AArch64.
>
> As is, the pass just merges all globals together, in groups of 4KB
> (AArch64, 128B on ARM).
>
> At the time it was enabled, the general thinking was "it's almost
> free, it doesn't affect performance much, we might as well use
it".
> Now, it's preventing some link-time optimizations (as acknowledged in
> one of the FIXMEs).
>
>
> -- Performance impact
> Overall, it isn't that profitable on the test-suite, and actually
> degrades performance on a lot of other - "non-benchmark" -
projects I
> tried (where the main reason to use a global is file- or function-
> static variables, only accessed through a single getter function).
>
> Across several runs on the entire test-suite, when disabling the pass,
> I measured:
> without LTO, a -0.19% geomean improvement
> with LTO, a +0.11% geomean regression.
>
> As for just SPEC2006, there are two big regressions: 400.perlbench
> (10.6% w/ LTO, 2.7% w/o) and 471.omnetpp (2.3% w/, 3.9% w/o).
>
> Numbers are attached.
>
>
> -- A way forward
> One obvious way to improve it is: look at uses of globals, and try to
> form sets of globals commonly used together.  The tricky part is to
> define heuristics for "commonly".  Also, the pass then becomes
much
> more expensive.  I'm currently looking into improving it, and will
> report if I come up with a good solution.  But this shouldn't stop us
> from disabling it, for now.
>
> Also, the pass seems like a good candidate for
> -O3/CodeGenOpt::Aggressive.  However, the latter is implied by LTO,
> which IMO shouldn't include these not-always-profitable optimizations.
> That's another problem though.
>
>
>
> Right now, I think we should disable the pass by default, until it's
> deemed profitable enough.
>
> -Ahmed
-------------- next part --------------
Name                                                                            
Prev      Current   %       σ
Geometric_Mean                                                                  
7.3031    7.3114    0.11%   -
External/SPEC/CINT2006/400_perlbench/400_perlbench                              
13.8190   15.2806   10.58%  0.0295
MultiSource/Benchmarks/nbench/nbench                                            
25.8387   28.1101   8.79%   1.6962
MultiSource/Benchmarks/Ptrdist/yacr2/yacr2                                      
1.5316    1.6158    5.50%   0.0014
External/SPEC/CINT2000/164_gzip/164_gzip                                        
21.9532   22.8344   4.01%   0.0074
External/SPEC/CFP2000/183_equake/183_equake                                     
11.2462   11.6433   3.53%   0.0444
MultiSource/Applications/siod/siod                                              
4.3631    4.5159    3.50%   0.0090
MultiSource/Applications/aha/aha                                                
3.4522    3.5723    3.48%   0.0016
MultiSource/Benchmarks/sim/sim                                                  
19.7369   20.4045   3.38%   0.0068
External/SPEC/CINT2006/471_omnetpp/471_omnetpp                                  
1.2566    1.2855    2.30%   0.0027
SingleSource/Benchmarks/Polybench/linear-algebra/solvers/gramschmidt/gramschmidt
19.8913   20.2556   1.83%   0.0200
MultiSource/Benchmarks/MallocBench/espresso/espresso                            
1.4505    1.4696    1.32%   0.0049
SingleSource/Benchmarks/Misc-C++/Large/ray                                      
5.5605    5.6181    1.04%   0.0064
MultiSource/Benchmarks/VersaBench/dbms/dbms                                     
8.6059    8.6775    0.83%   0.0171
External/SPEC/CINT2000/175_vpr/175_vpr                                          
5.4864    5.5294    0.78%   0.0121
SingleSource/Benchmarks/BenchmarkGame/Large/fasta                               
3.9053    3.9339    0.73%   0.0205
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/2mm/2mm                
62.4370   62.8789   0.71%   0.0465
MultiSource/Benchmarks/Ptrdist/anagram/anagram                                  
2.1400    2.1536    0.64%   0.0037
SingleSource/Benchmarks/Misc/fbench                                             
3.8568    3.8805    0.61%   0.0012
MultiSource/Applications/minisat/minisat                                        
17.7843   17.8932   0.61%   0.0186
SingleSource/Benchmarks/Misc/ffbench                                            
2.3597    2.3737    0.59%   0.0102
SingleSource/Benchmarks/McGill/chomp                                            
2.5608    2.5755    0.57%   0.0097
SingleSource/Benchmarks/Misc-C++-EH/spirit                                      
79.2880   79.7056   0.53%   0.2736
External/SPEC/CFP2000/179_art/179_art                                           
1.8351    1.8438    0.47%   0.0125
MultiSource/Benchmarks/Prolangs-C++/life/life                                   
6.4227    6.4505    0.43%   0.0025
MultiSource/Benchmarks/Ptrdist/ks/ks                                            
2.1927    2.2014    0.40%   0.0011
SingleSource/Benchmarks/Shootout/heapsort                                       
5.9351    5.9578    0.38%   0.0050
MultiSource/Benchmarks/MiBench/automotive-basicmath/automotive-basicmath        
1.2302    1.2347    0.37%   0.0034
External/SPEC/CINT2000/253_perlbmk/253_perlbmk                                  
13.0019   13.0500   0.37%   0.0367
MultiSource/Benchmarks/MallocBench/cfrac/cfrac                                  
4.9374    4.9549    0.35%   0.0041
External/SPEC/CINT2000/181_mcf/181_mcf                                          
16.0710   16.1268   0.35%   0.0175
MultiSource/Applications/SPASS/SPASS                                            
24.9780   25.0625   0.34%   0.0538
SingleSource/Benchmarks/Shootout-C++/hash                                       
2.0198    2.0262    0.32%   0.0041
External/SPEC/CINT2006/403_gcc/403_gcc                                          
3.5535    3.5646    0.31%   0.0029
MultiSource/Benchmarks/Olden/tsp/tsp                                            
2.8420    2.8503    0.29%   0.0115
SingleSource/Benchmarks/Shootout-C++/heapsort                                   
5.9312    5.9463    0.25%   0.0062
MultiSource/Applications/lua/lua                                                
46.1691   46.2676   0.21%   0.0345
MultiSource/Benchmarks/MiBench/consumer-typeset/consumer-typeset                
1.1586    1.1608    0.19%   0.0019
MultiSource/Applications/lemon/lemon                                            
5.0917    5.1007    0.18%   0.0105
External/SPEC/CINT2000/254_gap/254_gap                                          
3.9326    3.9384    0.15%   0.0016
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/doitgen/doitgen        
44.8336   44.8965   0.14%   0.0153
External/SPEC/CFP2000/177_mesa/177_mesa                                         
5.0751    5.0824    0.14%   0.0065
SingleSource/Benchmarks/Shootout/fib2                                           
5.1268    5.1335    0.13%   0.0009
SingleSource/Benchmarks/Polybench/stencils/seidel-2d/seidel-2d                  
21.4724   21.5013   0.13%   0.0111
SingleSource/Benchmarks/BenchmarkGame/spectral-norm                             
1.2974    1.2989    0.12%   0.0012
MultiSource/Applications/spiff/spiff                                            
7.9347    7.9442    0.12%   0.0045
External/SPEC/CINT2006/401_bzip2/401_bzip2                                      
5.4607    5.4674    0.12%   0.0129
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/gemm/gemm              
42.9808   43.0270   0.11%   0.0458
SingleSource/Benchmarks/CoyoteBench/almabench                                   
14.9431   14.9590   0.11%   0.0016
MultiSource/Benchmarks/mafft/pairlocalalign                                     
43.3389   43.3860   0.11%   0.0189
MultiSource/Benchmarks/VersaBench/beamformer/beamformer                         
2.0441    2.0464    0.11%   0.0016
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/trmm/trmm              
25.7529   25.7798   0.10%   0.0232
SingleSource/Benchmarks/Misc-C++/Large/sphereflake                              
15.7138   15.7301   0.10%   0.0021
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/syrk/syrk              
28.8875   28.9144   0.09%   0.0158
SingleSource/Benchmarks/Misc/perlin                                             
3.6677    3.6709    0.09%   0.0012
SingleSource/Benchmarks/Adobe-C++/simple_types_loop_invariant                   
5.2340    5.2388    0.09%   0.0009
MultiSource/Benchmarks/Trimaran/enc-md5/enc-md5                                 
3.3993    3.4025    0.09%   0.0009
MultiSource/Benchmarks/TSVC/ControlFlow-flt/ControlFlow-flt                     
7.5897    7.5965    0.09%   0.0011
SingleSource/Benchmarks/Shootout-C++/ary3                                       
3.4389    3.4417    0.08%   0.0034
MultiSource/Applications/viterbi/viterbi                                        
3.3764    3.3791    0.08%   0.0124
SingleSource/Benchmarks/Misc/dt                                                 
2.1518    2.1533    0.07%   0.0004
MultiSource/Benchmarks/Olden/bh/bh                                              
5.2680    5.2718    0.07%   0.0022
MultiSource/Benchmarks/ASC_Sequoia/CrystalMk/CrystalMk                          
12.5760   12.5847   0.07%   0.0054
MultiSource/Benchmarks/ASC_Sequoia/AMGmk/AMGmk                                  
27.7489   27.7697   0.07%   0.0262
SingleSource/Benchmarks/Shootout/matrix                                         
8.1274    8.1321    0.06%   0.0064
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/cholesky/cholesky      
22.5187   22.5329   0.06%   0.0009
SingleSource/Benchmarks/Misc-C++/bigfib                                         
1.0933    1.0940    0.06%   0.0025
MultiSource/Benchmarks/TSVC/Symbolics-flt/Symbolics-flt                         
3.0828    3.0847    0.06%   0.0029
SingleSource/Benchmarks/Shootout-C++/fibo                                       
5.1254    5.1281    0.05%   0.0043
SingleSource/Benchmarks/Polybench/stencils/fdtd-2d/fdtd-2d                      
60.3410   60.3728   0.05%   0.0186
SingleSource/Benchmarks/Polybench/datamining/correlation/correlation            
28.9262   28.9399   0.05%   0.0249
SingleSource/Benchmarks/Misc/oourafft                                           
7.3429    7.3463    0.05%   0.0023
External/SPEC/CINT2000/255_vortex/255_vortex                                    
4.0073    4.0095    0.05%   0.0167
SingleSource/UnitTests/Vector/build2                                            
4.8375    4.8393    0.04%   0.0026
MultiSource/Benchmarks/TSVC/GlobalDataFlow-flt/GlobalDataFlow-flt               
4.3792    4.3808    0.04%   0.0030
MultiSource/Benchmarks/TSVC/CrossingThresholds-flt/CrossingThresholds-flt       
5.9010    5.9035    0.04%   0.0031
SingleSource/UnitTests/Vectorizer/gcc-loops                                     
7.0147    7.0165    0.03%   0.0018
SingleSource/Benchmarks/Polybench/stencils/adi/adi                              
28.9532   28.9609   0.03%   0.0031
SingleSource/Benchmarks/CoyoteBench/huffbench                                   
30.0285   30.0367   0.03%   0.0053
SingleSource/Benchmarks/CoyoteBench/fftbench                                    
2.7896    2.7905    0.03%   0.0167
SingleSource/Benchmarks/Adobe-C++/simple_types_constant_folding                 
7.3225    7.3247    0.03%   0.0025
MultiSource/Benchmarks/TSVC/InductionVariable-flt/InductionVariable-flt         
8.9059    8.9088    0.03%   0.0031
MultiSource/Benchmarks/TSVC/InductionVariable-dbl/InductionVariable-dbl         
12.0051   12.0085   0.03%   0.0076
MultiSource/Benchmarks/SciMark2-C/scimark2                                      
93.3103   93.3358   0.03%   0.1591
MultiSource/Benchmarks/7zip/7zip-benchmark                                      
20.6589   20.6641   0.03%   0.0124
External/SPEC/CFP2000/188_ammp/188_ammp                                         
37.1753   37.1857   0.03%   0.0110
SingleSource/Benchmarks/Shootout/hash                                           
11.4575   11.4599   0.02%   0.0386
SingleSource/Benchmarks/Misc/himenobmtxpa                                       
4.1632    4.1642    0.02%   0.0076
SingleSource/Benchmarks/Misc/flops-6                                            
2.8494    2.8499    0.02%   0.0013
MultiSource/Benchmarks/TSVC/Reductions-flt/Reductions-flt                       
11.7863   11.7886   0.02%   0.0015
MultiSource/Benchmarks/TSVC/NodeSplitting-dbl/NodeSplitting-dbl                 
10.9588   10.9613   0.02%   0.0022
MultiSource/Benchmarks/TSVC/GlobalDataFlow-dbl/GlobalDataFlow-dbl               
8.2816    8.2834    0.02%   0.0035
SingleSource/Benchmarks/Shootout/ary3                                           
3.4459    3.4461    0.01%   0.0009
MultiSource/Benchmarks/TSVC/ControlLoops-dbl/ControlLoops-dbl                   
7.8174    7.8180    0.01%   0.0049
External/SPEC/CFP2006/444_namd/444_namd                                         
24.6662   24.6697   0.01%   0.0101
SingleSource/Benchmarks/Polybench/stencils/jacobi-2d-imper/jacobi-2d-imper      
20.6729   20.6731   0.00%   0.0168
SingleSource/Benchmarks/Misc/flops-8                                            
4.4988    4.4986    -0.00%  0.0013
SingleSource/Benchmarks/Misc/flops-4                                            
2.3163    2.3162    -0.00%  0.0006
SingleSource/Benchmarks/Misc/flops-3                                            
5.1341    5.1340    -0.00%  0.0023
MultiSource/Benchmarks/TSVC/Searching-flt/Searching-flt                         
7.0536    7.0533    -0.00%  0.0016
MultiSource/Benchmarks/TSVC/LoopRerolling-flt/LoopRerolling-flt                 
9.4046    9.4042    -0.00%  0.0038
MultiSource/Applications/SIBsim4/SIBsim4                                        
5.7070    5.7068    -0.00%  0.0337
SingleSource/Benchmarks/Shootout/random                                         
6.4056    6.4050    -0.01%  0.0018
SingleSource/Benchmarks/Polybench/linear-algebra/solvers/dynprog/dynprog        
1.5024    1.5023    -0.01%  0.0025
SingleSource/Benchmarks/Misc/fp-convert                                         
6.3689    6.3682    -0.01%  0.0020
SingleSource/Benchmarks/SmallPT/smallpt                                         
17.3723   17.3689   -0.02%  0.0185
SingleSource/Benchmarks/Shootout-C++/random                                     
6.4061    6.4048    -0.02%  0.0038
SingleSource/Benchmarks/Misc-C++/stepanov_v1p2                                  
31.6586   31.6512   -0.02%  0.0062
MultiSource/Benchmarks/VersaBench/ecbdes/ecbdes                                 
5.7215    5.7205    -0.02%  0.0050
MultiSource/Benchmarks/VersaBench/8b10b/8b10b                                   
4.5487    4.5477    -0.02%  0.0033
MultiSource/Benchmarks/Trimaran/enc-rc4/enc-rc4                                 
1.8434    1.8430    -0.02%  0.0008
MultiSource/Benchmarks/TSVC/Reductions-dbl/Reductions-dbl                       
11.7529   11.7501   -0.02%  0.0009
MultiSource/Benchmarks/TSVC/Expansion-flt/Expansion-flt                         
5.2616    5.2606    -0.02%  0.0017
MultiSource/Benchmarks/Olden/bisort/bisort                                      
1.5467    1.5464    -0.02%  0.0067
MultiSource/Benchmarks/NPB-serial/is/is                                         
23.2431   23.2382   -0.02%  0.0090
MultiSource/Benchmarks/MiBench/telecomm-CRC32/telecomm-CRC32                    
8.5092    8.5075    -0.02%  0.0033
External/SPEC/CINT2000/197_parser/197_parser                                    
5.1147    5.1137    -0.02%  0.0015
SingleSource/Benchmarks/Shootout/methcall                                       
6.4458    6.4437    -0.03%  0.0075
SingleSource/Benchmarks/Misc/lowercase                                          
13.5456   13.5417   -0.03%  0.0066
SingleSource/Benchmarks/Misc/flops-1                                            
2.9235    2.9227    -0.03%  0.0031
SingleSource/Benchmarks/Misc/flops                                              
11.4648   11.4617   -0.03%  0.0030
MultiSource/Benchmarks/TSVC/NodeSplitting-flt/NodeSplitting-flt                 
8.2453    8.2432    -0.03%  0.0060
MultiSource/Benchmarks/TSVC/LinearDependence-flt/LinearDependence-flt           
7.3856    7.3834    -0.03%  0.0055
MultiSource/Benchmarks/TSVC/Expansion-dbl/Expansion-dbl                         
8.1743    8.1720    -0.03%  0.0047
MultiSource/Benchmarks/TSVC/Equivalencing-flt/Equivalencing-flt                 
4.1145    4.1134    -0.03%  0.0039
MultiSource/Benchmarks/Olden/em3d/em3d                                          
4.7882    4.7869    -0.03%  0.0074
MultiSource/Benchmarks/TSVC/Symbolics-dbl/Symbolics-dbl                         
6.1398    6.1372    -0.04%  0.0019
MultiSource/Benchmarks/TSVC/Recurrences-dbl/Recurrences-dbl                     
15.4533   15.4465   -0.04%  0.0078
MultiSource/Benchmarks/TSVC/Equivalencing-dbl/Equivalencing-dbl                 
4.9759    4.9740    -0.04%  0.0022
External/SPEC/CFP2006/447_dealII/447_dealII                                     
46.2282   46.2074   -0.04%  0.0252
SingleSource/Benchmarks/Shootout-C++/lists                                      
36.0278   36.0094   -0.05%  0.0632
SingleSource/Benchmarks/Polybench/datamining/covariance/covariance              
31.2489   31.2321   -0.05%  0.0126
SingleSource/Benchmarks/Misc-C++/mandel-text                                    
5.2266    5.2240    -0.05%  0.0007
SingleSource/Benchmarks/BenchmarkGame/n-body                                    
2.5714    2.5700    -0.05%  0.0043
SingleSource/Benchmarks/Adobe-C++/functionobjects                               
6.7637    6.7604    -0.05%  0.0103
MultiSource/Benchmarks/TSVC/Searching-dbl/Searching-dbl                         
7.0214    7.0177    -0.05%  0.0039
MultiSource/Benchmarks/TSVC/Recurrences-flt/Recurrences-flt                     
13.4103   13.4037   -0.05%  0.0046
MultiSource/Benchmarks/TSVC/Packing-dbl/Packing-dbl                             
8.2158    8.2116    -0.05%  0.0027
MultiSource/Benchmarks/TSVC/LoopRerolling-dbl/LoopRerolling-dbl                 
11.7576   11.7519   -0.05%  0.0049
MultiSource/Benchmarks/TSVC/ControlLoops-flt/ControlLoops-flt                   
5.2467    5.2439    -0.05%  0.0063
SingleSource/Benchmarks/Misc/flops-5                                            
3.1762    3.1743    -0.06%  0.0007
SingleSource/Benchmarks/Dhrystone/fldry                                         
1.1614    1.1607    -0.06%  0.0005
SingleSource/Benchmarks/BenchmarkGame/nsieve-bits                               
1.7750    1.7740    -0.06%  0.0017
External/SPEC/CFP2006/433_milc/433_milc                                         
33.8436   33.8237   -0.06%  0.0363
SingleSource/Benchmarks/Shootout-C++/matrix                                     
8.9047    8.8989    -0.07%  0.0030
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/syr2k/syr2k            
34.5594   34.5358   -0.07%  0.0247
MultiSource/Benchmarks/TSVC/IndirectAddressing-flt/IndirectAddressing-flt       
8.8731    8.8669    -0.07%  0.0070
MultiSource/Benchmarks/TSVC/CrossingThresholds-dbl/CrossingThresholds-dbl       
8.4914    8.4855    -0.07%  0.0100
MultiSource/Benchmarks/ASC_Sequoia/IRSmk/IRSmk                                  
16.6098   16.5980   -0.07%  0.0228
MultiSource/Benchmarks/ASCI_Purple/SMG2000/smg2000                              
6.0691    6.0649    -0.07%  0.0045
External/SPEC/CINT2000/256_bzip2/256_bzip2                                      
16.4431   16.4322   -0.07%  0.0243
SingleSource/Benchmarks/Polybench/medley/floyd-warshall/floyd-warshall          
24.8368   24.8162   -0.08%  0.0274
SingleSource/Benchmarks/Misc/whetstone                                          
3.3019    3.2992    -0.08%  0.0021
MultiSource/Benchmarks/TSVC/LinearDependence-dbl/LinearDependence-dbl           
8.4315    8.4250    -0.08%  0.0036
MultiSource/Benchmarks/TSVC/IndirectAddressing-dbl/IndirectAddressing-dbl       
10.9391   10.9305   -0.08%  0.0118
SingleSource/Benchmarks/Misc/flops-2                                            
2.0506    2.0486    -0.10%  0.0009
MultiSource/Benchmarks/TSVC/StatementReordering-flt/StatementReordering-flt     
7.2996    7.2923    -0.10%  0.0048
MultiSource/Benchmarks/TSVC/Packing-flt/Packing-flt                             
7.6079    7.6006    -0.10%  0.0060
SingleSource/Benchmarks/Shootout/sieve                                          
10.2211   10.2097   -0.11%  0.0022
SingleSource/Benchmarks/Misc-C++/stepanov_container                             
12.4799   12.4667   -0.11%  0.0238
MultiSource/Benchmarks/TSVC/LoopRestructuring-dbl/LoopRestructuring-dbl         
8.5261    8.5170    -0.11%  0.0169
SingleSource/Benchmarks/Stanford/FloatMM                                        
1.0081    1.0069    -0.12%  0.0009
SingleSource/Benchmarks/Linpack/linpack-pc                                      
10.4873   10.4747   -0.12%  0.0072
SingleSource/Benchmarks/Adobe-C++/stepanov_abstraction                          
15.8164   15.7968   -0.12%  0.0128
MultiSource/Benchmarks/Trimaran/netbench-url/netbench-url                       
8.8264    8.8162    -0.12%  0.0134
MultiSource/Benchmarks/TSVC/ControlFlow-dbl/ControlFlow-dbl                     
9.0248    9.0136    -0.12%  0.0070
SingleSource/Benchmarks/Shootout-C++/methcall                                   
10.6864   10.6724   -0.13%  0.0362
SingleSource/Benchmarks/Misc/flops-7                                            
3.7619    3.7570    -0.13%  0.0033
MultiSource/Benchmarks/Trimaran/netbench-crc/netbench-crc                       
2.2602    2.2572    -0.13%  0.0017
SingleSource/Benchmarks/CoyoteBench/lpbench                                     
7.5007    7.4897    -0.15%  0.0128
MultiSource/Benchmarks/Trimaran/enc-3des/enc-3des                               
3.7517    3.7460    -0.15%  0.0033
SingleSource/Benchmarks/Shootout/lists                                          
13.1471   13.1267   -0.16%  0.0551
SingleSource/Benchmarks/Shootout-C++/hash2                                      
4.7540    4.7462    -0.16%  0.0034
SingleSource/Benchmarks/BenchmarkGame/fannkuch                                  
6.0614    6.0518    -0.16%  0.0045
SingleSource/Benchmarks/Adobe-C++/stepanov_vector                               
8.0509    8.0378    -0.16%  0.0083
MultiSource/Benchmarks/PAQ8p/paq8p                                              
149.6876  149.4524  -0.16%  0.0519
External/SPEC/CINT2006/429_mcf/429_mcf                                          
6.9057    6.8944    -0.16%  0.0380
External/SPEC/CINT2006/458_sjeng/458_sjeng                                      
9.0737    9.0581    -0.17%  0.0019
SingleSource/Benchmarks/Misc/pi                                                 
1.6726    1.6696    -0.18%  0.0005
MultiSource/Benchmarks/VersaBench/bmm/bmm                                       
4.1654    4.1581    -0.18%  0.0039
MultiSource/Benchmarks/TSVC/StatementReordering-dbl/StatementReordering-dbl     
9.0921    9.0753    -0.18%  0.0112
MultiSource/Benchmarks/TSVC/LoopRestructuring-flt/LoopRestructuring-flt         
6.6077    6.5958    -0.18%  0.0046
MultiSource/Benchmarks/Ptrdist/bc/bc                                            
2.1649    2.1610    -0.18%  0.0093
MultiSource/Benchmarks/Olden/health/health                                      
1.1067    1.1046    -0.19%  0.0059
MultiSource/Benchmarks/Bullet/bullet                                            
12.9644   12.9401   -0.19%  0.0022
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/symm/symm              
48.4500   48.3520   -0.20%  0.1228
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/3mm/3mm                
81.3587   81.1940   -0.20%  0.1381
SingleSource/Benchmarks/Polybench/stencils/fdtd-apml/fdtd-apml                  
21.9017   21.8559   -0.21%  0.0250
External/SPEC/CINT2000/300_twolf/300_twolf                                      
6.7851    6.7709    -0.21%  0.0233
MultiSource/Applications/hexxagon/hexxagon                                      
11.6343   11.6038   -0.26%  0.0055
SingleSource/Benchmarks/Adobe-C++/loop_unroll                                   
4.8459    4.8323    -0.28%  0.0053
MultiSource/Benchmarks/BitBench/five11/five11                                   
16.4992   16.4471   -0.32%  0.0301
External/SPEC/CINT2006/456_hmmer/456_hmmer                                      
6.2090    6.1893    -0.32%  0.0400
MultiSource/Benchmarks/Ptrdist/ft/ft                                            
2.7223    2.7127    -0.35%  0.0117
MultiSource/Applications/kimwitu++/kc                                           
1.2440    1.2397    -0.35%  0.0035
External/Povray/povray                                                          
6.2752    6.2534    -0.35%  0.0092
External/SPEC/CINT2006/473_astar/473_astar                                      
18.3398   18.2675   -0.39%  0.0330
External/SPEC/CFP2006/470_lbm/470_lbm                                           
8.7915    8.7450    -0.53%  0.0142
SingleSource/Benchmarks/Misc/salsa20                                            
12.1149   12.0498   -0.54%  0.0042
MultiSource/Applications/sqlite3/sqlite3                                        
9.6281    9.5603    -0.70%  0.0071
SingleSource/Benchmarks/Shootout-C++/sieve                                      
3.8675    3.8400    -0.71%  0.0052
External/SPEC/CINT2006/464_h264ref/464_h264ref                                  
29.3124   29.0909   -0.76%  0.0209
SingleSource/Benchmarks/BenchmarkGame/recursive                                 
2.0749    2.0584    -0.80%  0.0087
MultiSource/Benchmarks/llubenchmark/llu                                         
16.9753   16.8235   -0.89%  0.6042
SingleSource/Benchmarks/Shootout-C++/lists1                                     
1.5553    1.5377    -1.13%  0.0525
External/SPEC/CINT2000/176_gcc/176_gcc                                          
2.3017    2.2752    -1.15%  0.0046
MultiSource/Applications/lambda-0_1_3/lambda                                    
8.5209    8.4160    -1.23%  0.0298
SingleSource/Benchmarks/Misc/richards_benchmark                                 
2.0727    2.0469    -1.24%  0.0023
SingleSource/Benchmarks/Misc/ReedSolomon                                        
11.1675   11.0251   -1.28%  0.0116
MultiSource/Benchmarks/Fhourstones/fhourstones                                  
2.6764    2.6422    -1.28%  0.0013
MultiSource/Applications/JM/lencod/lencod                                       
11.6660   11.5088   -1.35%  0.0380
MultiSource/Benchmarks/Olden/power/power                                        
3.3588    3.3125    -1.38%  0.0090
SingleSource/Benchmarks/McGill/queens                                           
4.3032    4.2279    -1.75%  0.0017
MultiSource/Benchmarks/Fhourstones-3_1/fhourstones3_1                           
2.7329    2.6841    -1.79%  0.0136
SingleSource/Benchmarks/Shootout-C++/ackermann                                  
1.7911    1.7417    -2.76%  0.0535
External/SPEC/CINT2000/186_crafty/186_crafty                                    
9.2726    8.9953    -2.99%  0.0307
MultiSource/Benchmarks/Trimaran/enc-pc1/enc-pc1                                 
1.9760    1.8928    -4.21%  0.0041
-------------- next part --------------
Name                                                                            
Prev      Current   %        σ
Geometric_Mean                                                                  
10.5869   10.5672   -0.19%   -
External/SPEC/CFP2006/447_dealII/447_dealII                                     
67.2395   70.2412   4.46%    0.0157
External/SPEC/CINT2006/471_omnetpp/471_omnetpp                                  
2.5765    2.6774    3.92%    0.0060
MultiSource/Applications/viterbi/viterbi                                        
6.4184    6.6424    3.49%    0.0140
External/SPEC/CINT2006/400_perlbench/400_perlbench                              
28.2597   29.0212   2.69%    0.0086
External/SPEC/CINT2000/176_gcc/176_gcc                                          
4.2152    4.2763    1.45%    0.0018
SingleSource/Benchmarks/BenchmarkGame/Large/fasta                               
7.2906    7.3895    1.36%    0.0126
MultiSource/Benchmarks/MiBench/consumer-typeset/consumer-typeset                
2.2512    2.2805    1.30%    0.0018
SingleSource/Benchmarks/Misc/fbench                                             
7.3290    7.4000    0.97%    0.0001
MultiSource/Benchmarks/Olden/power/power                                        
4.0953    4.1303    0.85%    0.0055
External/Povray/povray                                                          
11.2566   11.3514   0.84%    0.0275
SingleSource/Benchmarks/Shootout-C++/ary3                                       
2.5008    2.5194    0.74%    0.0000
MultiSource/Benchmarks/Fhourstones-3_1/fhourstones3_1                           
4.2135    4.2448    0.74%    0.0001
MultiSource/Benchmarks/Ptrdist/bc/bc                                            
4.3017    4.3329    0.73%    0.0839
MultiSource/Benchmarks/Ptrdist/yacr2/yacr2                                      
2.5940    2.6120    0.69%    0.0004
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/gesummv/gesummv        
1.2450    1.2527    0.62%    0.0298
External/SPEC/CINT2000/164_gzip/164_gzip                                        
42.6990   42.9624   0.62%    0.0020
SingleSource/Benchmarks/Shootout-C++/hash                                       
3.1169    3.1326    0.50%    0.0026
MultiSource/Benchmarks/Olden/em3d/em3d                                          
9.0344    9.0743    0.44%    0.0029
MultiSource/Benchmarks/PAQ8p/paq8p                                              
203.8303  204.5563  0.36%    0.0777
MultiSource/Benchmarks/FreeBench/distray/distray                                
1.0886    1.0923    0.34%    0.0011
SingleSource/Benchmarks/Shootout/strcat                                         
1.0068    1.0100    0.32%    0.0054
MultiSource/Benchmarks/Fhourstones/fhourstones                                  
4.2599    4.2737    0.32%    0.0077
SingleSource/Benchmarks/Polybench/linear-algebra/solvers/durbin/durbin          
1.5734    1.5778    0.28%    0.0007
External/SPEC/CINT2006/401_bzip2/401_bzip2                                      
9.6590    9.6849    0.27%    0.0037
SingleSource/Benchmarks/Shootout/hash                                           
18.5884   18.6371   0.26%    0.0870
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/gemver/gemver          
1.2968    1.2999    0.24%    0.0017
SingleSource/Benchmarks/Misc/richards_benchmark                                 
3.7366    3.7455    0.24%    0.0011
MultiSource/Benchmarks/TSVC/ControlFlow-dbl/ControlFlow-dbl                     
16.6973   16.7363   0.23%    0.0034
MultiSource/Benchmarks/Olden/health/health                                      
1.6507    1.6543    0.22%    0.0098
SingleSource/Benchmarks/Polybench/medley/floyd-warshall/floyd-warshall          
45.8621   45.9599   0.21%    0.0023
MultiSource/Applications/minisat/minisat                                        
26.0747   26.1273   0.20%    0.0457
External/SPEC/CINT2000/175_vpr/175_vpr                                          
10.7064   10.7270   0.19%    0.0080
MultiSource/Benchmarks/Olden/treeadd/treeadd                                    
1.6336    1.6365    0.18%    0.0005
MultiSource/Benchmarks/TSVC/NodeSplitting-flt/NodeSplitting-flt                 
14.5233   14.5480   0.17%    0.0027
MultiSource/Applications/JM/lencod/lencod                                       
21.3973   21.4331   0.17%    0.0097
MultiSource/Benchmarks/Olden/voronoi/voronoi                                    
1.5845    1.5871    0.16%    0.0001
MultiSource/Applications/lua/lua                                                
84.3032   84.4422   0.16%    0.0119
SingleSource/Benchmarks/Misc/whetstone                                          
6.3760    6.3857    0.15%    0.0040
SingleSource/Benchmarks/Misc/dt                                                 
4.0528    4.0589    0.15%    0.0032
External/SPEC/CFP2006/433_milc/433_milc                                         
44.9927   45.0582   0.15%    0.0760
SingleSource/Benchmarks/Polybench/stencils/adi/adi                              
52.6780   52.7451   0.13%    0.0699
MultiSource/Benchmarks/TSVC/InductionVariable-flt/InductionVariable-flt         
16.0171   16.0341   0.11%    0.0036
MultiSource/Benchmarks/TSVC/Expansion-flt/Expansion-flt                         
9.8227    9.8332    0.11%    0.0002
MultiSource/Benchmarks/TSVC/Expansion-dbl/Expansion-dbl                         
14.4773   14.4928   0.11%    0.0003
SingleSource/Benchmarks/Misc/flops-3                                            
9.6567    9.6664    0.10%    0.0008
MultiSource/Benchmarks/Bullet/bullet                                            
21.4226   21.4438   0.10%    0.0202
SingleSource/Benchmarks/Misc/flops-6                                            
8.1478    8.1552    0.09%    0.0002
MultiSource/Benchmarks/TSVC/Searching-dbl/Searching-dbl                         
13.2342   13.2460   0.09%    0.0028
MultiSource/Benchmarks/TSVC/Reductions-dbl/Reductions-dbl                       
27.1836   27.2068   0.09%    0.0015
MultiSource/Benchmarks/MiBench/telecomm-CRC32/telecomm-CRC32                    
16.1273   16.1416   0.09%    0.0038
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/symm/symm              
84.6112   84.6768   0.08%    0.1243
MultiSource/Benchmarks/Trimaran/enc-rc4/enc-rc4                                 
3.4261    3.4289    0.08%    0.0012
SingleSource/Benchmarks/Shootout/fib2                                           
9.6467    9.6536    0.07%    0.0022
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/syr2k/syr2k            
64.3661   64.4095   0.07%    0.0219
SingleSource/Benchmarks/Misc/flops                                              
19.0371   19.0512   0.07%    0.0056
MultiSource/Benchmarks/TSVC/IndirectAddressing-dbl/IndirectAddressing-dbl       
20.1492   20.1639   0.07%    0.0101
MultiSource/Benchmarks/TSVC/ControlLoops-flt/ControlLoops-flt                   
13.1223   13.1310   0.07%    0.0263
MultiSource/Benchmarks/TSVC/ControlFlow-flt/ControlFlow-flt                     
14.3561   14.3666   0.07%    0.0050
SingleSource/Benchmarks/Polybench/datamining/covariance/covariance              
58.2370   58.2718   0.06%    0.0053
SingleSource/Benchmarks/Misc-C++/Large/sphereflake                              
27.9345   27.9508   0.06%    0.0086
SingleSource/Benchmarks/CoyoteBench/lpbench                                     
8.8731    8.8780    0.06%    0.0019
MultiSource/Benchmarks/VersaBench/beamformer/beamformer                         
3.8410    3.8432    0.06%    0.0015
MultiSource/Benchmarks/TSVC/Symbolics-dbl/Symbolics-dbl                         
12.5129   12.5201   0.06%    0.0010
SingleSource/Benchmarks/Shootout/methcall                                       
12.1446   12.1503   0.05%    0.0044
SingleSource/Benchmarks/Misc/fp-convert                                         
11.8017   11.8073   0.05%    0.0042
SingleSource/Benchmarks/Dhrystone/fldry                                         
2.1822    2.1832    0.05%    0.0011
MultiSource/Applications/hexxagon/hexxagon                                      
38.8084   38.8262   0.05%    0.0040
External/SPEC/CFP2006/444_namd/444_namd                                         
46.4356   46.4600   0.05%    0.0151
SingleSource/Benchmarks/Shootout-C++/methcall                                   
20.1204   20.1293   0.04%    0.0442
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/syrk/syrk              
54.0330   54.0550   0.04%    0.0073
SingleSource/Benchmarks/Misc/flops-4                                            
4.3561    4.3580    0.04%    0.0021
SingleSource/Benchmarks/BenchmarkGame/n-body                                    
4.7856    4.7875    0.04%    0.0027
SingleSource/Benchmarks/Adobe-C++/simple_types_loop_invariant                   
9.2258    9.2291    0.04%    0.0077
MultiSource/Benchmarks/VersaBench/8b10b/8b10b                                   
24.2272   24.2367   0.04%    0.0095
MultiSource/Benchmarks/TSVC/Equivalencing-dbl/Equivalencing-dbl                 
9.0187    9.0221    0.04%    0.0014
MultiSource/Benchmarks/TSVC/CrossingThresholds-dbl/CrossingThresholds-dbl       
15.1459   15.1525   0.04%    0.0050
MultiSource/Benchmarks/Prolangs-C++/life/life                                   
12.2587   12.2631   0.04%    0.0068
SingleSource/Benchmarks/Shootout/sieve                                          
19.2302   19.2352   0.03%    0.0006
SingleSource/Benchmarks/CoyoteBench/huffbench                                   
59.0514   59.0703   0.03%    0.0402
MultiSource/Benchmarks/Trimaran/enc-3des/enc-3des                               
7.0538    7.0557    0.03%    0.0055
MultiSource/Benchmarks/TSVC/NodeSplitting-dbl/NodeSplitting-dbl                 
18.6089   18.6152   0.03%    0.0138
MultiSource/Benchmarks/Olden/bh/bh                                              
7.1381    7.1403    0.03%    0.0017
MultiSource/Benchmarks/TSVC/InductionVariable-dbl/InductionVariable-dbl         
20.6407   20.6458   0.02%    0.0005
MultiSource/Benchmarks/ASC_Sequoia/CrystalMk/CrystalMk                          
23.7325   23.7384   0.02%    0.0030
External/SPEC/CFP2000/179_art/179_art                                           
3.2527    3.2535    0.02%    0.0020
SingleSource/UnitTests/Vectorizer/gcc-loops                                     
11.5070   11.5087   0.01%    0.0025
SingleSource/Benchmarks/Misc/flops-7                                            
7.0714    7.0721    0.01%    0.0013
SingleSource/Benchmarks/Misc/flops-2                                            
3.8555    3.8558    0.01%    0.0020
SingleSource/Benchmarks/Dhrystone/dry                                           
1.8572    1.8574    0.01%    0.0016
MultiSource/Benchmarks/VersaBench/bmm/bmm                                       
7.8049    7.8059    0.01%    0.0042
MultiSource/Benchmarks/TSVC/StatementReordering-dbl/StatementReordering-dbl     
16.6236   16.6253   0.01%    0.0034
MultiSource/Benchmarks/ASC_Sequoia/IRSmk/IRSmk                                  
27.6958   27.6980   0.01%    0.0297
External/SPEC/CINT2006/473_astar/473_astar                                      
34.3679   34.3704   0.01%    0.0584
External/SPEC/CINT2000/256_bzip2/256_bzip2                                      
29.7645   29.7685   0.01%    0.0033
SingleSource/Benchmarks/Shootout-C++/random                                     
12.0664   12.0667   0.00%    0.0035
SingleSource/Benchmarks/Misc/matmul_f64_4x4                                     
3.8693    3.8693    0.00%    0.0033
SingleSource/Benchmarks/Adobe-C++/stepanov_abstraction                          
29.4658   29.4649   -0.00%   0.0041
SingleSource/Benchmarks/Adobe-C++/functionobjects                               
13.3742   13.3739   -0.00%   0.0015
MultiSource/Benchmarks/Trimaran/netbench-crc/netbench-crc                       
4.1236    4.1236    0.00%    0.0052
MultiSource/Benchmarks/Trimaran/enc-md5/enc-md5                                 
6.4056    6.4053    -0.00%   0.0067
MultiSource/Benchmarks/TSVC/LoopRestructuring-dbl/LoopRestructuring-dbl         
15.8606   15.8609   0.00%    0.0052
MultiSource/Benchmarks/TSVC/LoopRerolling-dbl/LoopRerolling-dbl                 
22.0044   22.0051   0.00%    0.0007
MultiSource/Benchmarks/TSVC/GlobalDataFlow-flt/GlobalDataFlow-flt               
7.3534    7.3534    0.00%    0.0046
MultiSource/Benchmarks/7zip/7zip-benchmark                                      
36.0418   36.0428   0.00%    0.0088
External/SPEC/CINT2000/181_mcf/181_mcf                                          
24.8176   24.8179   0.00%    0.0247
SingleSource/Benchmarks/Shootout/heapsort                                       
9.0304    9.0296    -0.01%   0.0023
SingleSource/Benchmarks/Shootout-C++/matrix                                     
16.7011   16.6988   -0.01%   0.0013
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/trmm/trmm              
47.8234   47.8176   -0.01%   0.0084
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/2mm/2mm                
102.9151  102.9050  -0.01%   0.0121
External/SPEC/CFP2006/470_lbm/470_lbm                                           
12.9028   12.9016   -0.01%   0.0095
SingleSource/Benchmarks/Misc-C++/stepanov_v1p2                                  
59.7152   59.7029   -0.02%   0.0129
SingleSource/Benchmarks/CoyoteBench/almabench                                   
28.7084   28.7021   -0.02%   0.0037
SingleSource/Benchmarks/Adobe-C++/loop_unroll                                   
7.0497    7.0481    -0.02%   0.0029
MultiSource/Benchmarks/TSVC/StatementReordering-flt/StatementReordering-flt     
13.7407   13.7376   -0.02%   0.0007
MultiSource/Benchmarks/TSVC/LinearDependence-dbl/LinearDependence-dbl           
14.8833   14.8804   -0.02%   0.0117
External/SPEC/CINT2000/254_gap/254_gap                                          
6.8229    6.8214    -0.02%   0.0114
SingleSource/UnitTests/Vector/build2                                            
9.1135    9.1106    -0.03%   0.0009
SingleSource/Benchmarks/Misc/salsa20                                            
21.5502   21.5445   -0.03%   0.0065
SingleSource/Benchmarks/Misc/pi                                                 
3.1478    3.1468    -0.03%   0.0006
SingleSource/Benchmarks/Misc/himenobmtxpa                                       
8.4782    8.4758    -0.03%   0.0004
SingleSource/Benchmarks/Adobe-C++/stepanov_vector                               
15.0206   15.0165   -0.03%   0.0012
SingleSource/Benchmarks/Adobe-C++/simple_types_constant_folding                 
13.5083   13.5042   -0.03%   0.0046
MultiSource/Benchmarks/Trimaran/netbench-url/netbench-url                       
16.5930   16.5881   -0.03%   0.0027
MultiSource/Benchmarks/TSVC/Packing-dbl/Packing-dbl                             
14.7625   14.7582   -0.03%   0.0063
SingleSource/Benchmarks/Shootout-C++/heapsort                                   
9.0328    9.0292    -0.04%   0.0046
MultiSource/Benchmarks/VersaBench/ecbdes/ecbdes                                 
11.2640   11.2600   -0.04%   0.0047
MultiSource/Benchmarks/TSVC/LinearDependence-flt/LinearDependence-flt           
14.0157   14.0107   -0.04%   0.0062
External/SPEC/CINT2006/456_hmmer/456_hmmer                                      
11.2880   11.2839   -0.04%   0.0255
SingleSource/Benchmarks/Shootout/matrix                                         
7.1550    7.1517    -0.05%   0.0008
SingleSource/Benchmarks/Misc/flops-8                                            
8.4762    8.4720    -0.05%   0.0002
SingleSource/Benchmarks/Misc/flops-5                                            
8.2136    8.2098    -0.05%   0.0071
SingleSource/Benchmarks/Misc-C++/bigfib                                         
1.9124    1.9115    -0.05%   0.0036
SingleSource/Benchmarks/Misc-C++/Large/ray                                      
9.2812    9.2769    -0.05%   0.0088
SingleSource/Benchmarks/BenchmarkGame/spectral-norm                             
2.4673    2.4660    -0.05%   0.0046
MultiSource/Benchmarks/TSVC/ControlLoops-dbl/ControlLoops-dbl                   
18.4625   18.4531   -0.05%   0.0033
External/SPEC/CINT2006/458_sjeng/458_sjeng                                      
15.8751   15.8668   -0.05%   0.0054
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/3mm/3mm                
131.4519  131.3674  -0.06%   0.0614
MultiSource/Benchmarks/TSVC/Recurrences-flt/Recurrences-flt                     
25.3504   25.3364   -0.06%   0.0017
MultiSource/Benchmarks/TSVC/GlobalDataFlow-dbl/GlobalDataFlow-dbl               
13.0418   13.0344   -0.06%   0.0058
SingleSource/Benchmarks/Misc/flops-1                                            
5.5064    5.5023    -0.07%   0.0057
SingleSource/Benchmarks/Misc-C++/stepanov_container                             
20.8460   20.8313   -0.07%   0.0138
MultiSource/Benchmarks/TSVC/Searching-flt/Searching-flt                         
13.2449   13.2354   -0.07%   0.0099
MultiSource/Benchmarks/TSVC/Recurrences-dbl/Recurrences-dbl                     
29.2329   29.2124   -0.07%   0.0084
SingleSource/Benchmarks/Shootout/random                                         
12.0630   12.0532   -0.08%   0.0049
SingleSource/Benchmarks/Polybench/stencils/seidel-2d/seidel-2d                  
40.1327   40.1015   -0.08%   0.0044
SingleSource/Benchmarks/Polybench/stencils/fdtd-apml/fdtd-apml                  
40.9448   40.9136   -0.08%   0.0271
MultiSource/Benchmarks/Ptrdist/ks/ks                                            
4.1315    4.1280    -0.08%   0.0003
MultiSource/Benchmarks/MiBench/automotive-basicmath/automotive-basicmath        
2.2459    2.2442    -0.08%   0.0061
SingleSource/UnitTests/Vector/multiplies                                        
1.4981    1.4968    -0.09%   0.0008
SingleSource/Benchmarks/Shootout-C++/hash2                                      
8.9958    8.9875    -0.09%   0.0063
MultiSource/Benchmarks/TSVC/Reductions-flt/Reductions-flt                       
26.4367   26.4125   -0.09%   0.0131
MultiSource/Benchmarks/NPB-serial/is/is                                         
39.7440   39.7065   -0.09%   0.0185
MultiSource/Benchmarks/TSVC/IndirectAddressing-flt/IndirectAddressing-flt       
16.8347   16.8171   -0.10%   0.0003
SingleSource/Benchmarks/BenchmarkGame/nsieve-bits                               
2.9601    2.9569    -0.11%   0.0040
External/SPEC/CINT2000/197_parser/197_parser                                    
9.1718    9.1619    -0.11%   0.0088
External/SPEC/CFP2000/177_mesa/177_mesa                                         
8.6173    8.6080    -0.11%   0.0132
SingleSource/Benchmarks/Polybench/linear-algebra/solvers/dynprog/dynprog        
2.8281    2.8246    -0.12%   0.0001
External/SPEC/CINT2006/403_gcc/403_gcc                                          
6.5736    6.5655    -0.12%   0.0046
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/doitgen/doitgen        
83.9004   83.7948   -0.13%   0.0978
SingleSource/Benchmarks/McGill/queens                                           
7.9352    7.9249    -0.13%   0.0072
MultiSource/Benchmarks/SciMark2-C/scimark2                                      
197.3006  197.0500  -0.13%   0.9087
MultiSource/Benchmarks/ASC_Sequoia/AMGmk/AMGmk                                  
51.3858   51.3187   -0.13%   0.1052
SingleSource/Benchmarks/Misc-C++/mandel-text                                    
9.8456    9.8317    -0.14%   0.0046
MultiSource/Benchmarks/TSVC/LoopRestructuring-flt/LoopRestructuring-flt         
12.8381   12.8206   -0.14%   0.0079
MultiSource/Benchmarks/TSVC/Symbolics-flt/Symbolics-flt                         
7.3114    7.3004    -0.15%   0.0065
MultiSource/Benchmarks/TSVC/LoopRerolling-flt/LoopRerolling-flt                 
17.0470   17.0217   -0.15%   0.0126
SingleSource/Benchmarks/Shootout-C++/fibo                                       
9.6620    9.6468    -0.16%   0.0069
MultiSource/Benchmarks/TSVC/Packing-flt/Packing-flt                             
12.9542   12.9316   -0.17%   0.0129
MultiSource/Benchmarks/TSVC/Equivalencing-flt/Equivalencing-flt                 
7.1249    7.1126    -0.17%   0.0010
MultiSource/Benchmarks/Olden/tsp/tsp                                            
4.3922    4.3849    -0.17%   0.0000
SingleSource/Benchmarks/Shootout/lists                                          
24.9095   24.8635   -0.18%   0.1084
SingleSource/Benchmarks/Stanford/FloatMM                                        
1.8683    1.8648    -0.19%   0.0026
SingleSource/Benchmarks/SmallPT/smallpt                                         
32.5939   32.5323   -0.19%   0.0220
SingleSource/Benchmarks/BenchmarkGame/recursive                                 
3.9489    3.9413    -0.19%   0.0047
MultiSource/Applications/kimwitu++/kc                                           
2.3180    2.3135    -0.19%   0.0033
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/bicg/bicg              
1.1623    1.1600    -0.20%   0.0033
SingleSource/Benchmarks/Misc/oourafft                                           
14.0678   14.0391   -0.20%   0.0016
SingleSource/Benchmarks/Polybench/stencils/jacobi-2d-imper/jacobi-2d-imper      
38.5470   38.4656   -0.21%   0.0298
MultiSource/Benchmarks/TSVC/CrossingThresholds-flt/CrossingThresholds-flt       
11.1176   11.0940   -0.21%   0.0076
MultiSource/Applications/sqlite3/sqlite3                                        
15.5954   15.5630   -0.21%   0.0004
External/SPEC/CINT2000/253_perlbmk/253_perlbmk                                  
25.2330   25.1798   -0.21%   0.0496
SingleSource/Benchmarks/Misc-C++/oopack_v1p8                                    
1.0764    1.0740    -0.22%   0.0006
MultiSource/Benchmarks/tramp3d-v4/tramp3d-v4                                    
1.4849    1.4817    -0.22%   0.0051
MultiSource/Applications/spiff/spiff                                            
14.4858   14.4545   -0.22%   0.0574
MultiSource/Benchmarks/Olden/perimeter/perimeter                                
1.2419    1.2391    -0.23%   0.0077
SingleSource/Benchmarks/Polybench/datamining/correlation/correlation            
54.0652   53.9381   -0.24%   0.0382
SingleSource/Benchmarks/Misc/ReedSolomon                                        
20.9796   20.9287   -0.24%   0.0067
MultiSource/Benchmarks/BitBench/five11/five11                                   
31.1810   31.1057   -0.24%   0.0457
MultiSource/Benchmarks/Ptrdist/anagram/anagram                                  
4.2150    4.2045    -0.25%   0.0036
MultiSource/Benchmarks/Prolangs-C++/primes/primes                               
1.2353    1.2321    -0.26%   0.0031
External/SPEC/CINT95/132_ijpeg/132_ijpeg                                        
1.0627    1.0599    -0.26%   0.0002
SingleSource/Benchmarks/BenchmarkGame/partialsums                               
1.1037    1.1007    -0.27%   0.0005
MultiSource/Benchmarks/Trimaran/enc-pc1/enc-pc1                                 
3.1418    3.1326    -0.29%   0.0045
MultiSource/Benchmarks/McCat/12-IOtest/iotest                                   
1.1610    1.1576    -0.29%   0.0086
MultiSource/Benchmarks/ASCI_Purple/SMG2000/smg2000                              
9.5529    9.5252    -0.29%   0.0118
SingleSource/Benchmarks/Misc/perlin                                             
6.8606    6.8402    -0.30%   0.0062
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/cholesky/cholesky      
41.9528   41.8198   -0.32%   0.0167
SingleSource/Benchmarks/BenchmarkGame/fannkuch                                  
11.7015   11.6642   -0.32%   0.0188
External/SPEC/CFP2000/188_ammp/188_ammp                                         
58.6433   58.4554   -0.32%   0.1549
MultiSource/Benchmarks/Ptrdist/ft/ft                                            
4.5580    4.5429    -0.33%   0.0054
SingleSource/Benchmarks/Shootout-C++/lists                                      
67.9327   67.6826   -0.37%   0.2186
SingleSource/Benchmarks/Polybench/stencils/fdtd-2d/fdtd-2d                      
112.8710  112.4582  -0.37%   0.3840
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/gemm/gemm              
72.8211   72.5548   -0.37%   0.2036
MultiSource/Applications/aha/aha                                                
8.0554    8.0258    -0.37%   0.0124
MultiSource/Benchmarks/Olden/bisort/bisort                                      
2.4604    2.4507    -0.39%   0.0024
SingleSource/Benchmarks/BenchmarkGame/puzzle                                    
1.2789    1.2736    -0.41%   0.0004
MultiSource/Benchmarks/mafft/pairlocalalign                                     
117.3061  116.8098  -0.42%   0.4370
MultiSource/Benchmarks/MallocBench/espresso/espresso                            
2.6729    2.6616    -0.42%   0.0042
External/SPEC/CINT2000/255_vortex/255_vortex                                    
9.5583    9.5180    -0.42%   0.0146
MultiSource/Applications/lemon/lemon                                            
9.3665    9.3263    -0.43%   0.0143
MultiSource/Applications/SIBsim4/SIBsim4                                        
10.3535   10.3081   -0.44%   0.0232
SingleSource/Benchmarks/Shootout-C++/sieve                                      
7.1308    7.0986    -0.45%   0.0037
SingleSource/Benchmarks/Misc/ffbench                                            
4.4971    4.4769    -0.45%   0.0027
MultiSource/Benchmarks/MallocBench/cfrac/cfrac                                  
9.7051    9.6584    -0.48%   0.0130
SingleSource/Benchmarks/Shootout/ary3                                           
2.5090    2.4968    -0.49%   0.0004
External/SPEC/CINT2006/429_mcf/429_mcf                                          
10.8008   10.7476   -0.49%   0.0219
SingleSource/Benchmarks/Polybench/linear-algebra/kernels/mvt/mvt                
1.3281    1.3215    -0.50%   0.0078
External/SPEC/CINT2006/464_h264ref/464_h264ref                                  
51.1022   50.8415   -0.51%   0.0348
MultiSource/Benchmarks/MiBench/telecomm-gsm/telecomm-gsm                        
1.4626    1.4550    -0.52%   0.0002
External/SPEC/CINT95/147_vortex/147_vortex                                      
1.6119    1.6028    -0.56%   0.0056
External/SPEC/CINT95/099_go/099_go                                              
1.1234    1.1171    -0.56%   0.0051
SingleSource/Benchmarks/Misc-C++-EH/spirit                                      
149.3092  148.4177  -0.60%   0.4042
SingleSource/Benchmarks/Misc/lowercase                                          
10.3197   10.2445   -0.73%   0.0181
SingleSource/Benchmarks/Polybench/linear-algebra/solvers/gramschmidt/gramschmidt
37.1810   36.8926   -0.78%   0.1427
SingleSource/Benchmarks/CoyoteBench/fftbench                                    
4.3798    4.3458    -0.78%   0.0187
MultiSource/Benchmarks/VersaBench/dbms/dbms                                     
15.8694   15.7439   -0.79%   0.1101
External/SPEC/CINT2000/186_crafty/186_crafty                                    
17.4896   17.3513   -0.79%   0.0155
SingleSource/Benchmarks/McGill/chomp                                            
4.8088    4.7626    -0.96%   0.0173
External/SPEC/CINT2000/300_twolf/300_twolf                                      
13.5453   13.4135   -0.97%   0.0221
MultiSource/Applications/SPASS/SPASS                                            
45.1814   44.6753   -1.12%   0.3057
MultiSource/Benchmarks/sim/sim                                                  
40.6488   40.1364   -1.26%   0.0127
External/SPEC/CFP2000/183_equake/183_equake                                     
18.2451   17.9627   -1.55%   0.1728
MultiSource/Applications/siod/siod                                              
7.2801    7.1457    -1.85%   0.0022
SingleSource/Benchmarks/Shootout-C++/lists1                                     
2.9642    2.8584    -3.57%   0.0336
MultiSource/Applications/lambda-0_1_3/lambda                                    
16.3782   15.7493   -3.84%   0.0309
MultiSource/Benchmarks/llubenchmark/llu                                         
28.5323   27.3668   -4.08%   0.8212
SingleSource/Benchmarks/Linpack/linpack-pc                                      
11.7001   11.1437   -4.76%   0.0122
SingleSource/Benchmarks/Shootout-C++/ackermann                                  
3.6398    3.3878    -6.92%   0.0678
MultiSource/Benchmarks/nbench/nbench                                            
42.8617   34.7371   -18.96%  3.9575

Hi Ahmed,

Did you run these experiments on a platform with a linker that makes
use of the AArch64CollectLOH-pass-produced information?
I'm guessing that the AArch64CollectLOH-pass information and a linker
that makes use of that information could affect the profitability of
the GlobalMerge pass?

Thanks,

Kristof
> -----Original Message-----
> From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at
cs.uiuc.edu]
> On Behalf Of Ahmed Bougacha
> Sent: 26 February 2015 01:13
> To: LLVM Dev
> Subject: Re: [LLVMdev] [RFC] AArch64: Should we disable GlobalMerge?
> 
> With the numbers!
> -Ahmed
> 
> 
> On Wed, Feb 25, 2015 at 4:57 PM, Ahmed Bougacha
> <ahmed.bougacha at gmail.com> wrote:
> > Hi all,
> >
> > I've started looking at the GlobalMerge pass, enabled by default
on
> > ARM and AArch64.  I think we should reconsider that, at least for
> > AArch64.
> >
> > As is, the pass just merges all globals together, in groups of 4KB
> > (AArch64, 128B on ARM).
> >
> > At the time it was enabled, the general thinking was "it's
almost
> > free, it doesn't affect performance much, we might as well use
it".
> > Now, it's preventing some link-time optimizations (as acknowledged
in
> > one of the FIXMEs).
> >
> >
> > -- Performance impact
> > Overall, it isn't that profitable on the test-suite, and actually
> > degrades performance on a lot of other - "non-benchmark" -
projects I
> > tried (where the main reason to use a global is file- or function-
> > static variables, only accessed through a single getter function).
> >
> > Across several runs on the entire test-suite, when disabling the pass,
> > I measured:
> > without LTO, a -0.19% geomean improvement with LTO, a +0.11% geomean
> > regression.
> >
> > As for just SPEC2006, there are two big regressions: 400.perlbench
> > (10.6% w/ LTO, 2.7% w/o) and 471.omnetpp (2.3% w/, 3.9% w/o).
> >
> > Numbers are attached.
> >
> >
> > -- A way forward
> > One obvious way to improve it is: look at uses of globals, and try to
> > form sets of globals commonly used together.  The tricky part is to
> > define heuristics for "commonly".  Also, the pass then
becomes much
> > more expensive.  I'm currently looking into improving it, and will
> > report if I come up with a good solution.  But this shouldn't stop
us
> > from disabling it, for now.
> >
> > Also, the pass seems like a good candidate for
> > -O3/CodeGenOpt::Aggressive.  However, the latter is implied by LTO,
> > which IMO shouldn't include these not-always-profitable
optimizations.
> > That's another problem though.
> >
> >
> >
> > Right now, I think we should disable the pass by default, until
it's
> > deemed profitable enough.
> >
> > -Ahmed

On 26 February 2015 at 00:57, Ahmed Bougacha <ahmed.bougacha at gmail.com>
wrote:
> -- A way forward
> One obvious way to improve it is: look at uses of globals, and try to
> form sets of globals commonly used together.  The tricky part is to
> define heuristics for "commonly".  Also, the pass then becomes
much
> more expensive.  I'm currently looking into improving it, and will
> report if I come up with a good solution.  But this shouldn't stop us
> from disabling it, for now.
Hi Ahmed,

Before "moving forward", it would be good to understand what in
GlobalMerge is impacting what in LTO.

With LTO becoming more important nowadays, I agree we have to balance
the compiler optimisations to work well with it, but by turning things
off we might be impacting unknown code in an unknown way.

We'll never know how unknown code behaves, but if at least we
understand what of GM affects what of LTO, then people using unknown
code will have a more informed view on what to disable, when.

cheers,
--renato

Hi Ahmed,

Yes. I'd share with Kristof and Renato's concerns, and the
impact/dependence upon link-time tool should be clarified before disabling
this pass.

On the other hand, actually the test on our hardware shows disabling this
pass without LTO considered, some spec benchmarks would have big
regressions, (positive is bad)

spec.cpu2000.ref.253_perlbmk 3.27%
spec.cpu2000.ref.254_gap 3.18%

although I do see some improvements like below, (negative is good)

spec.cpu2006.ref.400_perlbench -1.90%
spec.cpu2006.ref.471_omnetpp -1.64%
spec.cpu2006.ref.482_sphinx3 -1.03%

Thanks,
-Jiangning


2015-02-26 20:09 GMT+08:00 Renato Golin <renato.golin at linaro.org>:
> On 26 February 2015 at 00:57, Ahmed Bougacha <ahmed.bougacha at
gmail.com>
> wrote:
> > -- A way forward
> > One obvious way to improve it is: look at uses of globals, and try to
> > form sets of globals commonly used together.  The tricky part is to
> > define heuristics for "commonly".  Also, the pass then
becomes much
> > more expensive.  I'm currently looking into improving it, and will
> > report if I come up with a good solution.  But this shouldn't stop
us
> > from disabling it, for now.
>
> Hi Ahmed,
>
> Before "moving forward", it would be good to understand what in
> GlobalMerge is impacting what in LTO.
>
> With LTO becoming more important nowadays, I agree we have to balance
> the compiler optimisations to work well with it, but by turning things
> off we might be impacting unknown code in an unknown way.
>
> We'll never know how unknown code behaves, but if at least we
> understand what of GM affects what of LTO, then people using unknown
> code will have a more informed view on what to disable, when.
>
> cheers,
> --renato
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
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On Thu, Feb 26, 2015 at 4:09 AM, Renato Golin <renato.golin at linaro.org>
wrote:
> On 26 February 2015 at 00:57, Ahmed Bougacha <ahmed.bougacha at
gmail.com> wrote:
>> -- A way forward
>> One obvious way to improve it is: look at uses of globals, and try to
>> form sets of globals commonly used together.  The tricky part is to
>> define heuristics for "commonly".  Also, the pass then
becomes much
>> more expensive.  I'm currently looking into improving it, and will
>> report if I come up with a good solution.  But this shouldn't stop
us
>> from disabling it, for now.
>
> Hi Ahmed,
>
> Before "moving forward", it would be good to understand what in
> GlobalMerge is impacting what in LTO.
>
> With LTO becoming more important nowadays, I agree we have to balance
> the compiler optimisations to work well with it, but by turning things
> off we might be impacting unknown code in an unknown way.
>
> We'll never know how unknown code behaves, but if at least we
> understand what of GM affects what of LTO, then people using unknown
> code will have a more informed view on what to disable, when.
Fair enough.  First, a couple things to note:
- GlobalMerge runs as a pre-ISel pass, so very late in the mid-level pipeline.
- GlobalMerge (by default) only looks at internal globals.

Internal globals come up with file- or function- static variables.  In
LTO, all module-level globals are internalized, and are eligible for
merging.

So, we can generally group global usage into a few categories:
- a function that uses a local static variable (say, llvm::outs())
- a function that uses several globals at once.  For instance,
400.perlbench's interpreter has a bunch of those, as does its
parser/lexer.
- a set of functions that share a few common globals (say, an inlined
reference to a function-local static variable), but otherwise each use
several other globals (again, perl's interpreter).


GlobalMerge is only ever a win if we are able to share base pointers.
This requires:
- several globals being referenced
- the references being close enough (otherwise we'll just
rematerialize the base, or worse, increase register pressure)

There is one obvious special case for the first requirement:  if a
global is only ever used alone, there's no point in merging it
anywhere. (this is improvement #1).
Once we can determine the set of used globals for each function, we
can try to merge those sets only. (#2)

We can try to better handle the second requirement, by having some
more precise metric for distance between uses.  One trivially
available such metric is grouping used sets by parent basic-block
rather than function (#3).



Experimentally, #1 catches a lot of the singleton-ish globals out
there, which is the majority in some of the more "modern" code
I've
looked at.  It leaves the legitimate merging in perl alone.

#2 (and even moreso #3) is actually too aggressive, and doesn't catch
a lot/most of the profitable cases in perl.  Consider:
- a "g_log" global (or, say, LLVM's outs/dbgs/errs), used pretty
much everywhere
- several sets of globals, used in different parts of the program
(perl's interpreter vs parser)

You'd pick one of the latter sets, and add the "g_log" global to
it.
Now you made it more expensive everywhere you use "g_log", without the
benefit of base sharing in all the other functions.

So you need to be smart when picking the sets.  You can combine some
of them, using some cost metric.  (#4)  This is where it gets
complicated.


I'll try measuring some of those, see what happens on benchmarks.
Again, that shouldn't stop us from enabling GlobalMerge less often.
Hopefully it's clear that the pass isn't always a win, so -O3 should
be OK.  I'm less comfortable with disabling it on Darwin only, but
that seems like the obvious next step.

Thanks for the feedback!

-Ahmed
> cheers,
> --renato