[libc][math] Add scalbln{,f,l,f128} math functions (#102219)

Co-authored-by: OverMighty <its.overmighty@gmail.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/libc/src/math/generic/scalbln.cpp b/libc/src/math/generic/scalbln.cpp
new file mode 100644
index 000000000000..f97619954237
--- /dev/null
+++ b/libc/src/math/generic/scalbln.cpp
@@ -0,0 +1,25 @@
+//===-- Implementation of scalbln function --------------------------------===//
+//
+// 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 "src/math/scalbln.h"
+#include "hdr/float_macros.h"
+#include "src/__support/FPUtil/ManipulationFunctions.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+#if FLT_RADIX != 2
+#error "FLT_RADIX != 2 is not supported."
+#endif
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(double, scalbln, (double x, long n)) {
+  return fputil::ldexp(x, n);
+}
+
+} // namespace LIBC_NAMESPACE_DECL