[mlir][nvvm] Add conversion for math.erfc (#129329)

Add missing pattern to convert `math.erfc` operation to `__nv_erfcf` or
`__nv_erfc` function call.

Author: clementval

mlir/lib/Conversion/GPUToNVVM/LowerGpuOpsToNVVMOps.cpp

@@ -540,6 +540,8 @@ void mlir::populateLibDeviceConversionPatterns(
                                    "__nv_cosh");
   populateOpPatterns<math::ErfOp>(converter, patterns, benefit, "__nv_erff",
                                   "__nv_erf");
+  populateOpPatterns<math::ErfcOp>(converter, patterns, benefit, "__nv_erfcf",
+                                   "__nv_erfc");
   populateOpPatterns<math::ExpOp>(converter, patterns, benefit, "__nv_expf",
                                   "__nv_exp", "__nv_fast_expf");
   populateOpPatterns<math::Exp2Op>(converter, patterns, benefit, "__nv_exp2f",

mlir/test/Conversion/GPUToNVVM/gpu-to-nvvm.mlir

@@ -1095,3 +1095,16 @@ gpu.module @test_module_54 {
     return %0, %1, %2, %3, %4, %5 : i1, i1, i1, i1, i1, i1
   }
 }
+
+gpu.module @test_module_55 {
+  // CHECK: llvm.func @__nv_erfcf(f32) -> f32
+  // CHECK: llvm.func @__nv_erfc(f64) -> f64
+  // CHECK-LABEL: func @gpu_erf
+  func.func @gpu_erfc(%arg_f32 : f32, %arg_f64 : f64) -> (f32, f64) {
+    %result32 = math.erfc %arg_f32 : f32
+    // CHECK: llvm.call @__nv_erfcf(%{{.*}}) : (f32) -> f32
+    %result64 = math.erfc %arg_f64 : f64
+    // CHECK: llvm.call @__nv_erfc(%{{.*}}) : (f64) -> f64
+    func.return %result32, %result64 : f32, f64
+  }
+}