[SYSTEMDS-2340] Missing indexing hop size reset on negative reconcile after loops

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: SystemML 1.2
• Epic Link: Improved Size Propagation
• Assignee: Matthias Boehm
• Reporter: Matthias Boehm
• Created: 23/May/18 04:24
• Updated: 19/Jun/18 01:58
• Resolved: 19/Jun/18 01:58

Description

The below script incorrectly returns 100 instead of 98. Although the difference is detected during reconciliation after size propagation through the loop, the indexing hop current does not allow for size reset and thus the correction pass is ineffective here.

X = rand(rows=100, cols=1);
Y = X
# two loop iterationn -> nrow(X)=98
for( i in seq(1,2,1) ) {
   n1 = nrow(Y) + 0.0;
   Y = Y[2:n1,] - Y[1:n1-1,];
}
print(nrow(Y));