[libc] [llvm] [libc][complex] Testing infra for MPC (PR #121261)

[Shourya Goel via llvm-commits]

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@@ -0,0 +1,356 @@
+//===-- Utils which wrap MPC ----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "MPCUtils.h"
+
+#include "src/__support/CPP/array.h"
+#include "src/__support/CPP/stringstream.h"
+#include "utils/MPFRWrapper/MPCommon.h"
+
+#include <stdint.h>
+
+#include "mpc.h"
+
+template <typename T> using FPBits = LIBC_NAMESPACE::fputil::FPBits<T>;
+
+namespace LIBC_NAMESPACE_DECL {
+namespace testing {
+namespace mpc {
+
+static inline cpp::string str(RoundingMode mode) {
+  switch (mode) {
+  case RoundingMode::Upward:
+    return "MPFR_RNDU";
+  case RoundingMode::Downward:
+    return "MPFR_RNDD";
+  case RoundingMode::TowardZero:
+    return "MPFR_RNDZ";
+  case RoundingMode::Nearest:
+    return "MPFR_RNDN";
+  }
+}
+
+class MPCNumber {
+private:
+  unsigned int precision;
+  mpc_t value;
+  mpc_rnd_t mpc_rounding;
+
+public:
+  MPCNumber(unsigned int p) : precision(p), mpc_rounding(MPC_RNDNN) {
+    mpc_init2(value, precision);
+  }
+
+  MPCNumber() : precision(256), mpc_rounding(MPC_RNDNN) {
+    mpc_init2(value, 256);
+  }
+
+  template <typename XType,
+            cpp::enable_if_t<cpp::is_same_v<_Complex float, XType>, bool> = 0>
+  MPCNumber(XType x,
+            unsigned int precision = mpfr::ExtraPrecision<float>::VALUE,
+            RoundingMode rnd = RoundingMode::Nearest)
+      : precision(precision),
+        mpc_rounding(MPC_RND(mpfr::get_mpfr_rounding_mode(rnd),
+                             mpfr::get_mpfr_rounding_mode(rnd))) {
+    mpc_init2(value, precision);
+    Complex<float> x_c = cpp::bit_cast<Complex<float>>(x);
+    mpfr_t real, imag;
----------------
Sh0g0-1758 wrote:

but why though ? That wrapper is not required here. `mpfr_t` here is only used since MPC does not allow us to use floats to initialize an `mpc_t`

https://github.com/llvm/llvm-project/pull/121261