phi4

See doc/ folder for description.

Build

Supports GCC 4.6, ICC 13.0 and Clang 3.0 or higher.

Requires Intel SVML library coming with ICC for SIMD builds using non-ICC compilers.

To build executable with default configuration use:

make

Building other configurations

Following build options may be combined. Changing build options changes final executable suffix indicating used options.

SIMD version via SIMD=<size>, i.e.:
```
 make SIMD=4
```
Enabling OpenMP:
```
 make OPENMP=1
```
Different float type via FLOAT=<type>, i.e.:
```
 make FLOAT=float
```
Different compiler via CC=<compiler>, i.e.:
```
 make CC=icc
```
Enabling cache optimization:
```
 make CACHE=1
```
Enabling index optimization: (implies only 2^n lattice sizes)
```
 make FAST_INDEXER=1
```
Enable SVML fix for ICC<13 when using non-ICC compilers and SIMD
```
 make SVML_FIX=1
```
Use old legacy code (used in publications) max AVX
```
 make LEGACY=1
```

Notes about source code

Source code in src/ is split into several logical modules and versions described by prefixes.

Modules

types.h core configuration and type dispatch header
swep_* files implementing single sweep
random_* fused Tausworthe/LCG random number generator
partition_* partitioning (satisfying Markov Chain constraints)
indexer, *_index memory indexers implementation
legacy/* legacy versions of modules above (used in publications)

Prefixes

_simd SIMD version of module
_test Gtest files (deprecated)

Operations

This is rough estimation of number operations in the algorithm.

NOTE: It skips lattice index calculation operations, memory operations, register transfers and variable initialization. So it estimates minimum number of operations, not average.

Corona gather (plus est. for Comp=1 Dim=3)

 Corona = Comp * ( Dim * (4 + 2*(Dim-1)) - Dim + 6 )
 	  ~=	1 * (	3 * (4 + 2*	  2	  ) -	3 + 6 )
 	   = 27

Fused Tausworthe + LCG random number generator

 Rng	   = Taus * 3 + LCG + 3
 	   = 6 * 3 + 6
 	   = 24

Initial action before updates (plus est. for Comp=1)
```
 Init   = Comp * 4 + 2
 	  ~= 6
```

Update ops for given Hits (plus est. for Comp=1 Dim=3)

 Update = Hits * ( (Comp+1) * Rng + (Comp-1) * 6 + Log + 10 )
 	  ~= Hits * (		2  * Rng +				  Log + 10 )
 	   = Hits * ( 58 + Log								   )

Gives altogether for Comp=1 Dim=3:

Total  = 33 + Hits * ( 58 + Log )

GPU Implementation

GPU implementation is available as separate project phi4_cuda.

License

Copyright (C) 2012-2013 Piotr Bialas, Adam Strzelecki

This file is part of phi4.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

ujhpc/phi4