improve test case

Author: matthias-springer

mlir/test/Integration/Dialect/Arith/CPU/test-apfloat-emulation.mlir

@@ -1,19 +1,34 @@
+// Case 1: All floating-point arithmetics is lowered through APFloat.
 // RUN: mlir-opt %s --convert-arith-to-apfloat --convert-to-llvm | \
-// RUN:   mlir-runner -e entry --entry-point-result=void \
-// RUN:               --shared-libs=%mlir_c_runner_utils | FileCheck %s
+// RUN: mlir-runner -e entry --entry-point-result=void \
+// RUN:             --shared-libs=%mlir_c_runner_utils | FileCheck %s
+
+// Case 2: Only unsupported arithmetics (f8E4M3FN) is lowered through APFloat.
+//         Arithmetics on f32 is lowered directly to LLVM.
+// RUN: mlir-opt %s --convert-to-llvm --convert-arith-to-apfloat \
+// RUN:          --convert-to-llvm --reconcile-unrealized-casts | \
+// RUN: mlir-runner -e entry --entry-point-result=void \
+// RUN:             --shared-libs=%mlir_c_runner_utils | FileCheck %s
 
 // Put rhs into separate function so that it won't be constant-folded.
-func.func @foo() -> f8E4M3FN {
-  %cst = arith.constant 2.2 : f8E4M3FN
-  return %cst : f8E4M3FN
+func.func @foo() -> (f8E4M3FN, f32) {
+  %cst1 = arith.constant 2.2 : f8E4M3FN
+  %cst2 = arith.constant 2.2 : f32
+  return %cst1, %cst2 : f8E4M3FN, f32
 }
 
 func.func @entry() {
-  %a = arith.constant 1.4 : f8E4M3FN
-  %b = func.call @foo() : () -> (f8E4M3FN)
-  %c = arith.addf %a, %b : f8E4M3FN
+  %a1 = arith.constant 1.4 : f8E4M3FN
+  %a2 = arith.constant 1.4 : f32
+  %b1, %b2 = func.call @foo() : () -> (f8E4M3FN, f32)
+  %c1 = arith.addf %a1, %b1 : f8E4M3FN  // not supported by LLVM
+  %c2 = arith.addf %a2, %b2 : f32       // supported by LLVM
 
   // CHECK: 3.5
-  vector.print %c : f8E4M3FN
+  vector.print %c1 : f8E4M3FN
+
+  // CHECK: 3.6
+  vector.print %c2 : f32
+
   return
 }