There are several problems with the existing sgemm integration. The main problem I find is an if-else/ifdef-else ladder determines BLAS provider where we verbose provide precedence and also check for existence.
This begins in CMakeLists.txt. Then trickles down into CPP source. sgemm routes through an sgemm which follows the BLAS defined API to MKL to CBLAS to ONNX SGEMM under ifdefs and multiple wraps. There is also a ProdBatched giving way to a ProdBatchedOld as another level of indirection?
At two ifdefs / ifs are acceptable. At more than two some form of switch/dispatch needs to appear to reduce headhurt. The suggestion to do f32 sgemm with ruy in #79 (review) is also the addition of a fourth provider.
There are ODR compatible ways for multiple sgemm to exist, and what seems to perhaps better in my opinion is a provider::sgemm(...) with sgemm following a standard API. It is possible to allow multiple providers (MKL, OpenBLAS, Accelerate etc) to exist in an ODR compatible way and give them ranks and a mechanism to prioritize which one at runtime (maybe decide at compile-time even).
There are several problems with the existing sgemm integration. The main problem I find is an if-else/ifdef-else ladder determines BLAS provider where we verbose provide precedence and also check for existence.
This begins in
CMakeLists.txt. Then trickles down into CPP source. sgemm routes through an sgemm which follows the BLAS defined API to MKL to CBLAS to ONNX SGEMM under ifdefs and multiple wraps. There is also aProdBatchedgiving way to aProdBatchedOldas another level of indirection?At two ifdefs / ifs are acceptable. At more than two some form of switch/dispatch needs to appear to reduce headhurt. The suggestion to do f32 sgemm with ruy in #79 (review) is also the addition of a fourth provider.
There are ODR compatible ways for multiple sgemm to exist, and what seems to perhaps better in my opinion is a
provider::sgemm(...)with sgemm following a standard API. It is possible to allow multiple providers (MKL, OpenBLAS, Accelerate etc) to exist in an ODR compatible way and give them ranks and a mechanism to prioritize which one at runtime (maybe decide at compile-time even).