h8300: library functions

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
diff --git a/arch/h8300/lib/lshrdi3.c b/arch/h8300/lib/lshrdi3.c
new file mode 100644
index 0000000..a86bbe3
--- /dev/null
+++ b/arch/h8300/lib/lshrdi3.c
@@ -0,0 +1,23 @@
+#include "libgcc.h"
+
+DWtype __lshrdi3(DWtype u, word_type b)
+{
+	const DWunion uu = {.ll = u};
+	const word_type bm = (sizeof (Wtype) * BITS_PER_UNIT) - b;
+	DWunion w;
+
+	if (b == 0)
+		return u;
+
+	if (bm <= 0) {
+		w.s.high = 0;
+		w.s.low = (UWtype) uu.s.high >> -bm;
+	} else {
+		const UWtype carries = (UWtype) uu.s.high << bm;
+
+		w.s.high = (UWtype) uu.s.high >> b;
+		w.s.low = ((UWtype) uu.s.low >> b) | carries;
+	}
+
+	return w.ll;
+}