[Mlir-commits] [mlir] [mlir] Add FP software implementation lowering pass: `arith-to-apfloat` (PR #166618)

[Maksim Levental]

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+//===- ArithToAPFloat.cpp - Arithmetic to APFloat Conversion --------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/Conversion/ArithToAPFloat/ArithToAPFloat.h"
+
+#include "mlir/Dialect/Arith/IR/Arith.h"
+#include "mlir/Dialect/Arith/Transforms/Passes.h"
+#include "mlir/Dialect/Func/IR/FuncOps.h"
+#include "mlir/Dialect/Func/Utils/Utils.h"
+#include "mlir/IR/PatternMatch.h"
+#include "mlir/IR/Verifier.h"
+#include "mlir/Transforms/WalkPatternRewriteDriver.h"
+
+namespace mlir {
+#define GEN_PASS_DEF_ARITHTOAPFLOATCONVERSIONPASS
+#include "mlir/Conversion/Passes.h.inc"
+} // namespace mlir
+
+using namespace mlir;
+using namespace mlir::func;
+
+/// Helper function to look up or create the symbol for a runtime library
+/// function for a binary arithmetic operation.
+///
+/// Parameter 1: APFloat semantics
+/// Parameter 2: Left-hand side operand
+/// Parameter 3: Right-hand side operand
+///
+/// This function will return a failure if the function is found but has an
+/// unexpected signature.
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makslevental wrote:

full disclosure: this is a copy-paste from the LLVM https://github.com/llvm/llvm-project/blob/b713f607b27984b2eff561169f51b941b2ee2b06/mlir/lib/Dialect/LLVMIR/IR/FunctionCallUtils.cpp#L66

Which is not to say that I don't understand it (it's straightforward code...), I just mean the pattern, which implements (effectively) intrinsic/builtin lookup/decl, I believe makes sense here.

https://github.com/llvm/llvm-project/pull/166618