portelli/Grid
1
0
Fork 0
mirror of https://github.com/paboyle/Grid.git synced 2025-04-09 21:50:45 +01:00
Code Releases Activity

Overflow fix

Browse Source
This commit is contained in:
paboyle 2018-06-04 13:42:07 +01:00
parent 6eed167f0c
commit 84685c9bc3
1 changed files with 10 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
lib/lattice/Lattice_rng.h
View File

@ -158,10 +158,19 @@ namespace Grid {
// tens of seconds per trajectory so this is clean in all reasonable cases, // tens of seconds per trajectory so this is clean in all reasonable cases,
// and margin of safety is orders of magnitude. // and margin of safety is orders of magnitude.
// We could hack Sitmo to skip in the higher order words of state if necessary // We could hack Sitmo to skip in the higher order words of state if necessary
//
// Replace with 2^30 ; avoid problem on large volumes
//
///////////////////////////////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////////////////////////////////
// uint64_t skip = site+1; // Old init Skipped then drew. Checked compat with faster init // uint64_t skip = site+1; // Old init Skipped then drew. Checked compat with faster init
const int shift = 30;
uint64_t skip = site; uint64_t skip = site;
skip = skip<<40;
skip = skip<<shift;
assert((skip >> shift)==site); // check for overflow
eng.discard(skip); eng.discard(skip);
// std::cout << " Engine " <<site << " state " <<eng<<std::endl; // std::cout << " Engine " <<site << " state " <<eng<<std::endl;
} }