Fixes bug in sspaddmm (#45113)

[vfdev-5]

Fixes #45113

Description:

• Fixed bug in sspaddmm by calling contiguous on indices.
• Added tests

We have to make indices contiguous as we use indices.data_ptr in _to_csr which assumes row-contiguous storage:

pytorch/aten/src/ATen/native/sparse/SparseTensorMath.cpp

Lines 1087 to 1090 in be45c34

	LongTensor indices = sparse._indices();
	Tensor values = sparse._values();
	LongTensor csr = _to_csr(indices.data_ptr<int64_t>(), dim_i, nnz);

Part 1 of fixing this is probably to document sspaddmm. Part 2 may be to rewrite it using other ops. (#45113 (comment))

• Docs will be written here: Revised sparse tensor documentation. #45400

[vfdev-5]

@ngimel thanks for the review. I rework the tests as you suggested.

[codecov]

Codecov Report

Merging #45963 into master will increase coverage by 0.00%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #45963   +/-   ##
=======================================
  Coverage   68.20%   68.20%           
=======================================
  Files         410      410           
  Lines       53453    53453           
=======================================
+ Hits        36457    36458    +1     
+ Misses      16996    16995    -1     

Impacted Files	Coverage Δ
torch/testing/_internal/expecttest.py	78.57% <0.00%> (+1.02%)	⬆️

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[pearu]

LGTM

[dr-ci]

💊 CI failures summary and remediations

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This comment has been revised 3 times.

[ngimel]

Lint failure is real, otherwise looks good.

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[facebook-github-bot]

@ngimel merged this pull request in dc7cd97.