Author: Rik Huijzer Date: 2023-11-30T10:11:50+01:00 New Revision: f1fba63f1282a21e6adc5f7732e8583c52792744
URL: https://github.com/llvm/llvm-project/commit/f1fba63f1282a21e6adc5f7732e8583c52792744 DIFF: https://github.com/llvm/llvm-project/commit/f1fba63f1282a21e6adc5f7732e8583c52792744.diff LOG: [mlir][vector][doc] 0D vectors (#73792) Currently, the only mention of 0d vectors in the MLIR source code that I could find was: > 0D vectors are allowed by omitting the dimension: `vector<f32>`. in [`BuiltinTypes.td`](https://github.com/llvm/llvm-project/blob/437a48b2d9bfc6e38a0ca43f1cee48ceaf0fe249/mlir/include/mlir/IR/BuiltinTypes.td#L1046-L1047). This patch adds a summary of https://discourse.llvm.org/t/what-is-the-semantics-of-memref-0xf32-and-tensor-0xf32/3557 and https://discourse.llvm.org/t/should-we-have-0-d-vectors/3097/5. Added: Modified: mlir/docs/Dialects/Vector.md Removed: ################################################################################ diff --git a/mlir/docs/Dialects/Vector.md b/mlir/docs/Dialects/Vector.md index a907d59566366bb..6d05d9b90467662 100644 --- a/mlir/docs/Dialects/Vector.md +++ b/mlir/docs/Dialects/Vector.md @@ -247,7 +247,19 @@ which conveys higher-D meaning. But it also is one of the most overloaded terms in compilers and hardware. For now, we generally use the `n-D` `vector` name and are open to better suggestions. -## DeeperDive +## 0D Vectors + +Vectors of dimension 0 (or _0-D vectors_ or _0D vectors_) are allowed inside +MLIR. For instance, a `f32` vector containing one scalar can be denoted as +`vector<f32>`. This is similar to the `tensor<f32>` type that is available in +TensorFlow or the `memref<f32>` type that is available in MLIR. + +Generally, a 0D `vector` can be interpreted as a scalar. The benefit of 0D +`vector`s, `tensor`s, and `memref`s is that they make it easier to lower code +from various frontends such as TensorFlow and make it easier to handle corner +cases such as unrolling a loop from 1D to 0D. + +## LLVM Lowering Tradeoffs This section describes the tradeoffs involved in lowering the MLIR n-D vector type and operations on it to LLVM-IR. Putting aside the _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
