[mlir] Add Expm1 tp ComplexOps.td.

[bkramer]

lg

mlir/include/mlir/Dialect/Complex/IR/ComplexOps.td

let description = [{
     %a = complex.exp %b : complex<f32>
     ```
   }];
 
   let results = (outs Complex<AnyFloat>:$result);
 }
 
 //===----------------------------------------------------------------------===//
+// Expm1Op
+//===----------------------------------------------------------------------===//
+
+def Expm1Op : ComplexUnaryOp<"expm1", [SameOperandsAndResultType]> {
+  let summary = "computes exponential of a complex number minus 1";
+  let description = [{
+    Syntax:
+
+    ```
+    operation ::= ssa-id `=` `complex.expm1` ssa-use `:` type
+    ```
+
+    complex.expm1(x) := complex.exp(x) - 1
+
+    Example:
+
+    ```mlir
+    %a = complex.expm1 %b : complex<f32>
+    ```
+  }];
+
+  let results = (outs Complex<AnyFloat>:$result);
+}
+
+//===----------------------------------------------------------------------===//
 // ImOp
 //===----------------------------------------------------------------------===//
 
 def ImOp : ComplexUnaryOp<"im",
     [TypesMatchWith<"complex element type matches result type",
                     "complex", "imaginary",
                     "$_self.cast<ComplexType>().getElementType()">]> {
   let summary = "extracts the imaginary part of a complex number";

mlir/test/Dialect/Complex/ops.mlir

func.func @ops(%f: f32) {
   %div = complex.div %complex, %complex : complex<f32>
 
   // CHECK: complex.eq %[[C]], %[[C]] : complex<f32>
   %eq = complex.eq %complex, %complex : complex<f32>
 
   // CHECK: complex.exp %[[C]] : complex<f32>
   %exp = complex.exp %complex : complex<f32>
 
+  // CHECK: complex.expm1 %[[C]] : complex<f32>
+  %expm1 = complex.expm1 %complex : complex<f32>
+
   // CHECK: complex.log %[[C]] : complex<f32>
   %log = complex.log %complex : complex<f32>
 
   // CHECK: complex.log1p %[[C]] : complex<f32>
   %log1p = complex.log1p %complex : complex<f32>
 
   // CHECK: complex.mul %[[C]], %[[C]] : complex<f32>
   %prod = complex.mul %complex, %complex : complex<f32>