Add a rewrite pattern that transforms an instance of
`HLFHELinalg.zero` into an instance of `linalg.generate` with an
appropriate region yielding a zero value.
Example:
%out = "HLFHELinalg.zero"() : () -> tensor<MxNx!HLFHE.eint<p>>
becomes:
%0 = tensor.generate {
^bb0(%arg2: index, %arg3: index):
%zero = "HLFHE.zero"() : () -> !HLFHE.eint<p>
tensor.yield %zero : !HLFHE.eint<p>
} : tensor<MxNx!HLFHE.eint<p>>
Operations with regions currently need explicit patterns for type
conversion throughout lowering. This change adds the required patterns
for `tensor.generate` to the lowering passes, such that the operation
can be used starting from the lowering from HLFHE to MidLFHE.
Replace `LinalgGenericTypeConverterPattern`, specialized for
`linalg.generic` with a generic type converter pattern
`RegionOpTypeConverterPattern` that can be instantiated for any
operation that has one or more regions.
Further enhancements:
- Supports multiple regions
- Uses more idiomatic instantiations of `llvm::for_each` instead of
manual iterations using for loops
output size of keyswiting wasn't set properly. As this information must
come from the selected parameters, it should goes down from the MidLFHE
to the appropriate call to ciphertext allocation
The polynomialSize is currently holding its log2 instead of the actual
value. This should be fixed later, but in the meantime, we need to
compute it from log2
This changes the semantics of `HLFHE.dot_eint_int` from memref-based
reference semantics to tensor-based value semantics. The former:
"HLFHE.dot_eint_int"(%arg0, %arg1, %arg2) :
(memref<Nx!HLFHE.eint<0>>, memref<Nxi32>, memref<!HLFHE.eint<0>>) -> ()
becomes:
"HLFHE.dot_eint_int"(%arg0, %arg1) :
(tensor<Nx!HLFHE.eint<0>>, tensor<Nxi32>) -> !HLFHE.eint<0>
As a side effect, data-flow analyses become much easier. With the
previous memref type of the plaintext argument it is difficult to
check whether the plaintext values are statically defined constants or
originate from a memory region changed at execution time (e.g., for
analyses evaluating the impact on noise). Changing the plaintext type
from `memref` to `vector` makes such analyses significantly easier.
