From 238e08d64326572c3d1cf0f8ebd5e3932184a50d Mon Sep 17 00:00:00 2001
From: jacquesguan <Jianjian.Guan@streamcomputing.com>
Date: Wed, 7 Sep 2022 12:45:57 +0000
Subject: [PATCH] [mlir][Math] Fix RoundEven constant folder.

Use roundToIntegral instead roundeven of libm to avoid window build failed.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D133402
---
 mlir/lib/Dialect/Math/IR/MathOps.cpp | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/mlir/lib/Dialect/Math/IR/MathOps.cpp b/mlir/lib/Dialect/Math/IR/MathOps.cpp
index 667c0e66bcd6..567e53b4fad7 100644
--- a/mlir/lib/Dialect/Math/IR/MathOps.cpp
+++ b/mlir/lib/Dialect/Math/IR/MathOps.cpp
@@ -420,17 +420,11 @@ OpFoldResult math::TanhOp::fold(ArrayRef<Attribute> operands) {
 //===----------------------------------------------------------------------===//
 
 OpFoldResult math::RoundEvenOp::fold(ArrayRef<Attribute> operands) {
-  return constFoldUnaryOpConditional<FloatAttr>(
-      operands, [](const APFloat &a) -> Optional<APFloat> {
-        switch (a.getSizeInBits(a.getSemantics())) {
-        case 64:
-          return APFloat(roundeven(a.convertToDouble()));
-        case 32:
-          return APFloat(roundevenf(a.convertToFloat()));
-        default:
-          return {};
-        }
-      });
+  return constFoldUnaryOp<FloatAttr>(operands, [](const APFloat &a) {
+    APFloat result(a);
+    result.roundToIntegral(llvm::RoundingMode::NearestTiesToEven);
+    return result;
+  });
 }
 
 /// Materialize an integer or floating point constant.