llvm/mlir/test/Integration/data/wide.mtx

%%MatrixMarket matrix coordinate integer general
%
% This is a test sparse matrix in Matrix Market Exchange Format.
% see https://math.nist.gov/MatrixMarket
%
4 256 17
1 1    -1
1 127   2
1 128  -3
1 255   4
2 2    -5
2 254   6
3 3    -7
4 1     8
4 2    -9
4 4    10
4 99  -11
4 127  12
4 128 -13
4 129  14
4 250 -15
4 254  16
4 256 -17