[Mlir-commits] [llvm] [mlir] [mlir][EmitC] Add MathToEmitC pass for math function lowering to EmitC (PR #113799)

[Tomer Solomon]

================
@@ -0,0 +1,99 @@
+
+//===- MathToEmitC.cpp - Math to EmitC Pass Implementation ----------===//
+//
+// 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/MathToEmitC/MathToEmitC.h"
+#include "mlir/Dialect/EmitC/IR/EmitC.h"
+#include "mlir/Dialect/Math/IR/Math.h"
+#include "mlir/Pass/Pass.h"
+#include "mlir/Transforms/DialectConversion.h"
+
+namespace mlir {
+#define GEN_PASS_DEF_CONVERTMATHTOEMITC
+#include "mlir/Conversion/Passes.h.inc"
+} // namespace mlir
+
+using namespace mlir;
+namespace {
+
+//  Replaces Math operations with `emitc.call_opaque` operations.
+struct ConvertMathToEmitCPass
+    : public impl::ConvertMathToEmitCBase<ConvertMathToEmitCPass> {
+public:
+  void runOnOperation() final;
+};
+
+} // end anonymous namespace
+
+template <typename OpType>
+class LowerToEmitCCallOpaque : public mlir::OpRewritePattern<OpType> {
+  std::string calleeStr;
+
+public:
+  LowerToEmitCCallOpaque(MLIRContext *context, std::string calleeStr)
+      : OpRewritePattern<OpType>(context), calleeStr(calleeStr) {}
+
+  LogicalResult matchAndRewrite(OpType op,
+                                PatternRewriter &rewriter) const override;
+};
+
+// Populates patterns to replace `math` operations with `emitc.call_opaque`,
+// using function names consistent with those in <math.h>.
+static void populateConvertMathToEmitCPatterns(RewritePatternSet &patterns) {
+  auto *context = patterns.getContext();
+  patterns.insert<LowerToEmitCCallOpaque<math::FloorOp>>(context, "floor");
+  patterns.insert<LowerToEmitCCallOpaque<math::RoundEvenOp>>(context, "rint");
+  patterns.insert<LowerToEmitCCallOpaque<math::ExpOp>>(context, "exp");
+  patterns.insert<LowerToEmitCCallOpaque<math::CosOp>>(context, "cos");
+  patterns.insert<LowerToEmitCCallOpaque<math::SinOp>>(context, "sin");
+  patterns.insert<LowerToEmitCCallOpaque<math::AcosOp>>(context, "acos");
+  patterns.insert<LowerToEmitCCallOpaque<math::AsinOp>>(context, "asin");
+  patterns.insert<LowerToEmitCCallOpaque<math::Atan2Op>>(context, "atan2");
+  patterns.insert<LowerToEmitCCallOpaque<math::CeilOp>>(context, "ceil");
+  patterns.insert<LowerToEmitCCallOpaque<math::AbsFOp>>(context, "fabs");
+  patterns.insert<LowerToEmitCCallOpaque<math::FPowIOp>>(context, "powf");
+  patterns.insert<LowerToEmitCCallOpaque<math::IPowIOp>>(context, "pow");
----------------
recursion-man wrote:

Sounds right. I’ve limited the conversion to only floating-point operations:

```
patterns.insert<LowerToEmitCCallOpaque<math::PowFOp>>(context, "pow");
```


https://github.com/llvm/llvm-project/pull/113799