1 files changed, 65 insertions, 0 deletions
diff --git a/compiler-rt/lib/builtins/multc3.c b/compiler-rt/lib/builtins/multc3.c
new file mode 100644
index 000000000000..bb7f6aabfe2c
--- /dev/null
+++ b/compiler-rt/lib/builtins/multc3.c
@@ -0,0 +1,65 @@
+//===-- multc3.c - Implement __multc3 -------------------------------------===//
+//
+// 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 __multc3 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "int_lib.h"
+#include "int_math.h"
+
+// Returns: the product of a + ib and c + id
+
+COMPILER_RT_ABI long double _Complex __multc3(long double a, long double b,
+                                              long double c, long double d) {
+  long double ac = a * c;
+  long double bd = b * d;
+  long double ad = a * d;
+  long double bc = b * c;
+  long double _Complex z;
+  __real__ z = ac - bd;
+  __imag__ z = ad + bc;
+  if (crt_isnan(__real__ z) && crt_isnan(__imag__ z)) {
+    int recalc = 0;
+    if (crt_isinf(a) || crt_isinf(b)) {
+      a = crt_copysignl(crt_isinf(a) ? 1 : 0, a);
+      b = crt_copysignl(crt_isinf(b) ? 1 : 0, b);
+      if (crt_isnan(c))
+        c = crt_copysignl(0, c);
+      if (crt_isnan(d))
+        d = crt_copysignl(0, d);
+      recalc = 1;
+    }
+    if (crt_isinf(c) || crt_isinf(d)) {
+      c = crt_copysignl(crt_isinf(c) ? 1 : 0, c);
+      d = crt_copysignl(crt_isinf(d) ? 1 : 0, d);
+      if (crt_isnan(a))
+        a = crt_copysignl(0, a);
+      if (crt_isnan(b))
+        b = crt_copysignl(0, b);
+      recalc = 1;
+    }
+    if (!recalc &&
+        (crt_isinf(ac) || crt_isinf(bd) || crt_isinf(ad) || crt_isinf(bc))) {
+      if (crt_isnan(a))
+        a = crt_copysignl(0, a);
+      if (crt_isnan(b))
+        b = crt_copysignl(0, b);
+      if (crt_isnan(c))
+        c = crt_copysignl(0, c);
+      if (crt_isnan(d))
+        d = crt_copysignl(0, d);
+      recalc = 1;
+    }
+    if (recalc) {
+      __real__ z = CRT_INFINITY * (a * c - b * d);
+      __imag__ z = CRT_INFINITY * (a * d + b * c);
+    }
+  }
+  return z;
+}