[all-commits] [llvm/llvm-project] 019136: [MLIR] Add f8E4M3 IEEE 754 type (#97118)

[Alexander Pivovarov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 019136e30fea8b8e6ef9c6dda1f9dd20a504c573
      https://github.com/llvm/llvm-project/commit/019136e30fea8b8e6ef9c6dda1f9dd20a504c573
  Author: Alexander Pivovarov <pivovaa at amazon.com>
  Date:   2024-07-22 (Mon, 22 Jul 2024)

  Changed paths:
    M mlir/include/mlir-c/BuiltinTypes.h
    M mlir/include/mlir/IR/Builders.h
    M mlir/include/mlir/IR/BuiltinTypes.h
    M mlir/include/mlir/IR/BuiltinTypes.td
    M mlir/include/mlir/IR/CommonTypeConstraints.td
    M mlir/include/mlir/IR/Types.h
    M mlir/lib/AsmParser/TokenKinds.def
    M mlir/lib/AsmParser/TypeParser.cpp
    M mlir/lib/Bindings/Python/IRTypes.cpp
    M mlir/lib/CAPI/IR/BuiltinTypes.cpp
    M mlir/lib/Conversion/LLVMCommon/TypeConverter.cpp
    M mlir/lib/Dialect/Arith/Transforms/EmulateUnsupportedFloats.cpp
    M mlir/lib/IR/AsmPrinter.cpp
    M mlir/lib/IR/Builders.cpp
    M mlir/lib/IR/BuiltinTypes.cpp
    M mlir/lib/IR/MLIRContext.cpp
    M mlir/lib/IR/Types.cpp
    M mlir/python/mlir/_mlir_libs/_mlir/ir.pyi
    M mlir/python/mlir/extras/types.py
    M mlir/test/IR/attribute.mlir
    M mlir/test/Target/LLVMIR/llvmir.mlir
    M mlir/test/python/ir/builtin_types.py
    M mlir/utils/lldb-scripts/mlirDataFormatters.py
    M mlir/utils/tree-sitter-mlir/grammar.js

  Log Message:
  -----------
  [MLIR] Add f8E4M3 IEEE 754 type (#97118)

This PR adds `f8E4M3` type to mlir.

`f8E4M3` type  follows IEEE 754 convention

```c
f8E4M3 (IEEE 754)
- Exponent bias: 7
- Maximum stored exponent value: 14 (binary 1110)
- Maximum unbiased exponent value: 14 - 7 = 7
- Minimum stored exponent value: 1 (binary 0001)
- Minimum unbiased exponent value: 1 − 7 = −6
- Precision specifies the total number of bits used for the significand (mantisa), 
    including implicit leading integer bit = 3 + 1 = 4
- Follows IEEE 754 conventions for representation of special values
- Has Positive and Negative zero
- Has Positive and Negative infinity
- Has NaNs

Additional details:
- Max exp (unbiased): 7
- Min exp (unbiased): -6
- Infinities (+/-): S.1111.000
- Zeros (+/-): S.0000.000
- NaNs: S.1111.{001, 010, 011, 100, 101, 110, 111}
- Max normal number: S.1110.111 = +/-2^(7) x (1 + 0.875) = +/-240
- Min normal number: S.0001.000 = +/-2^(-6)
- Max subnormal number: S.0000.111 = +/-2^(-6) x 0.875 = +/-2^(-9) x 7
- Min subnormal number: S.0000.001 = +/-2^(-6) x 0.125 = +/-2^(-9)
```

Related PRs:
- [PR-97179](https://github.com/llvm/llvm-project/pull/97179) [APFloat]
Add support for f8E4M3 IEEE 754 type



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