[mlir][complex] Fastmath flag support for complex.angle

Author: Lewuathe

mlir/lib/Conversion/ComplexToStandard/ComplexToStandard.cpp

@@ -1143,13 +1143,14 @@ struct AngleOpConversion : public OpConversionPattern<complex::AngleOp> {
                   ConversionPatternRewriter &rewriter) const override {
     auto loc = op.getLoc();
     auto type = op.getType();
+    arith::FastMathFlagsAttr fmf = op.getFastMathFlagsAttr();
 
     Value real =
         rewriter.create<complex::ReOp>(loc, type, adaptor.getComplex());
     Value imag =
         rewriter.create<complex::ImOp>(loc, type, adaptor.getComplex());
 
-    rewriter.replaceOpWithNewOp<math::Atan2Op>(op, imag, real);
+    rewriter.replaceOpWithNewOp<math::Atan2Op>(op, imag, real, fmf);
 
     return success();
   }

mlir/test/Conversion/ComplexToStandard/convert-to-standard.mlir

@@ -2035,4 +2035,17 @@ func.func @complex_tanh_with_fmf(%arg: complex<f32>) -> complex<f32> {
 // CHECK: %[[NUM:.*]] = complex.create %[[TANH_A]], %[[TAN_B]] : complex<f32>
 // CHECK: %[[ONE:.*]] = arith.constant 1.000000e+00 : f32
 // CHECK: %[[MUL:.*]] = arith.mulf %[[TANH_A]], %[[TAN_B]] fastmath<nnan,contract> : f32
-// CHECK: %[[DENOM:.*]] = complex.create %[[ONE]], %[[MUL]] : complex<f32>
+// CHECK: %[[DENOM:.*]] = complex.create %[[ONE]], %[[MUL]] : complex<f32>
+
+// -----
+
+// CHECK-LABEL:   func.func @complex_angle_with_fmf
+// CHECK-SAME: %[[ARG:.*]]: complex<f32>
+func.func @complex_angle_with_fmf(%arg: complex<f32>) -> f32 {
+  %angle = complex.angle %arg fastmath<nnan,contract> : complex<f32>
+  return %angle : f32
+}
+// CHECK: %[[REAL:.*]] = complex.re %[[ARG]] : complex<f32>
+// CHECK: %[[IMAG:.*]] = complex.im %[[ARG]] : complex<f32>
+// CHECK: %[[RESULT:.*]] = math.atan2 %[[IMAG]], %[[REAL]] fastmath<nnan,contract> : f32
+// CHECK: return %[[RESULT]] : f32