1 files changed, 60 insertions, 0 deletions
diff --git a/lib/builtins/divdc3.c b/lib/builtins/divdc3.c
new file mode 100644
index 000000000000..7de78c8711e1
--- /dev/null
+++ b/lib/builtins/divdc3.c
@@ -0,0 +1,60 @@
+/* ===-- divdc3.c - Implement __divdc3 -------------------------------------===
+ *
+ *                     The LLVM Compiler Infrastructure
+ *
+ * This file is dual licensed under the MIT and the University of Illinois Open
+ * Source Licenses. See LICENSE.TXT for details.
+ *
+ * ===----------------------------------------------------------------------===
+ *
+ * This file implements __divdc3 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "int_lib.h"
+#include "int_math.h"
+
+/* Returns: the quotient of (a + ib) / (c + id) */
+
+COMPILER_RT_ABI double _Complex
+__divdc3(double __a, double __b, double __c, double __d)
+{
+    int __ilogbw = 0;
+    double __logbw = crt_logb(crt_fmax(crt_fabs(__c), crt_fabs(__d)));
+    if (crt_isfinite(__logbw))
+    {
+        __ilogbw = (int)__logbw;
+        __c = crt_scalbn(__c, -__ilogbw);
+        __d = crt_scalbn(__d, -__ilogbw);
+    }
+    double __denom = __c * __c + __d * __d;
+    double _Complex z;
+    __real__ z = crt_scalbn((__a * __c + __b * __d) / __denom, -__ilogbw);
+    __imag__ z = crt_scalbn((__b * __c - __a * __d) / __denom, -__ilogbw);
+    if (crt_isnan(__real__ z) && crt_isnan(__imag__ z))
+    {
+        if ((__denom == 0.0) && (!crt_isnan(__a) || !crt_isnan(__b)))
+        {
+            __real__ z = crt_copysign(CRT_INFINITY, __c) * __a;
+            __imag__ z = crt_copysign(CRT_INFINITY, __c) * __b;
+        }
+        else if ((crt_isinf(__a) || crt_isinf(__b)) &&
+                 crt_isfinite(__c) && crt_isfinite(__d))
+        {
+            __a = crt_copysign(crt_isinf(__a) ? 1.0 : 0.0, __a);
+            __b = crt_copysign(crt_isinf(__b) ? 1.0 : 0.0, __b);
+            __real__ z = CRT_INFINITY * (__a * __c + __b * __d);
+            __imag__ z = CRT_INFINITY * (__b * __c - __a * __d);
+        }
+        else if (crt_isinf(__logbw) && __logbw > 0.0 &&
+                 crt_isfinite(__a) && crt_isfinite(__b))
+        {
+            __c = crt_copysign(crt_isinf(__c) ? 1.0 : 0.0, __c);
+            __d = crt_copysign(crt_isinf(__d) ? 1.0 : 0.0, __d);
+            __real__ z = 0.0 * (__a * __c + __b * __d);
+            __imag__ z = 0.0 * (__b * __c - __a * __d);
+        }
+    }
+    return z;
+}