1 files changed, 40 insertions, 0 deletions
diff --git a/compiler-rt/lib/builtins/floatunditf.c b/compiler-rt/lib/builtins/floatunditf.c
new file mode 100644
index 000000000000..8d310851e179
--- /dev/null
+++ b/compiler-rt/lib/builtins/floatunditf.c
@@ -0,0 +1,40 @@
+//===-- lib/floatunditf.c - uint -> quad-precision conversion -----*- C -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements du_int to quad-precision conversion for the
+// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even
+// mode.
+//
+//===----------------------------------------------------------------------===//
+
+#define QUAD_PRECISION
+#include "fp_lib.h"
+
+#if defined(CRT_HAS_128BIT) && defined(CRT_LDBL_128BIT)
+COMPILER_RT_ABI fp_t __floatunditf(du_int a) {
+
+  const int aWidth = sizeof a * CHAR_BIT;
+
+  // Handle zero as a special case to protect clz
+  if (a == 0)
+    return fromRep(0);
+
+  // Exponent of (fp_t)a is the width of abs(a).
+  const int exponent = (aWidth - 1) - __builtin_clzll(a);
+  rep_t result;
+
+  // Shift a into the significand field and clear the implicit bit.
+  const int shift = significandBits - exponent;
+  result = (rep_t)a << shift ^ implicitBit;
+
+  // Insert the exponent
+  result += (rep_t)(exponent + exponentBias) << significandBits;
+  return fromRep(result);
+}
+
+#endif