forked from OSchip/llvm-project
ac2a655e87
Arithmetic and comparison instructions are necessary to implement, e.g., control flow when lowering MLFunctions to CFGFunctions. (While it is possible to replace some of the arithmetics by affine_apply instructions for loop bounds, it is still necessary for loop bounds checking, steps, if-conditions, non-trivial memref subscripts, etc.) Furthermore, working with indirect accesses in, e.g., lookup tables for large embeddings, may require operating on tensors of indexes. For example, the equivalents to C code "LUT[Index[i]]" or "ResultIndex[i] = i + j" where i, j are loop induction variables require the arithmetics on indices as well as the possibility to operate on tensors thereof. Allow arithmetic and comparison operations to apply to index types by declaring them integer-like. Allow tensors whose element type is index for indirection purposes. The absence of vectors with "index" element type is explicitly tested, but the only justification for this restriction in the CL introducing the test is "because we don't need them". Do NOT enable vectors of index types, although it makes vector and tensor types inconsistent with respect to allowed element types. PiperOrigin-RevId: 220614055 |
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| includes | ||
| Canonicalization.md | ||
| LangRef.md | ||
| Rationale.md | ||