[Mlir-commits] [mlir] [mlir][math] Add conversions for acosh, asinh, atanh (PR #90718)

[llvmlistbot at llvm.org]

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@@ -89,54 +89,14 @@ static LogicalResult convertCoshOp(math::CoshOp op, PatternRewriter &rewriter) {
   ImplicitLocOpBuilder b(op->getLoc(), rewriter);
   Value operand = op.getOperand();
   Type opType = operand.getType();
-  Value exp = b.create<math::ExpOp>(operand);
 
-  Value one = createFloatConst(op->getLoc(), opType, 1.0, rewriter);
-  Value nexp = b.create<arith::DivFOp>(one, exp);
+  Value exp = b.create<math::ExpOp>(operand);
+  Value neg = b.create<arith::NegFOp>(operand);
+  Value nexp = b.create<math::ExpOp>(neg);
   Value add = b.create<arith::AddFOp>(exp, nexp);
-  Value two = createFloatConst(op->getLoc(), opType, 2.0, rewriter);
-  Value div = b.create<arith::DivFOp>(add, two);
-  rewriter.replaceOp(op, div);
-  return success();
-}
-
-/// Expands tanh op into
-/// 1-exp^{-2x} / 1+exp^{-2x}
-/// To avoid overflow we exploit the reflection symmetry `tanh(-x) = -tanh(x)`.
-/// We compute a "signs" value which is -1 if input is negative and +1 if input
-/// is positive.  Then multiply the input by this value, guaranteeing that the
-/// result is positive, which also guarantees `exp^{-2x * sign(x)}` is in (0,
-/// 1]. Expand the computation on the input `x * sign(x)`, then multiply the
-/// result by `sign(x)` to retain sign of the real result.
-static LogicalResult convertTanhOp(math::TanhOp op, PatternRewriter &rewriter) {
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jinchen62 wrote:

I removed it because tanh op has polynomial approximation. Yes make sense, I have reverted it.

https://github.com/llvm/llvm-project/pull/90718