add numerical recipes library

2025-09-12 18:55:25 +09:00
parent d4dff245bd
commit 2c75620ec9
1344 changed files with 63869 additions and 0 deletions
--- a/lib/nr/cpp/recipes/psdes.cpp
+++ b/lib/nr/cpp/recipes/psdes.cpp
@@ -0,0 +1,21 @@
+#include "nr.h"
+
+void NR::psdes(unsigned long &lword, unsigned long &irword)
+{
+	const int NITER=4;
+	static const unsigned long c1[NITER]={
+		0xbaa96887L, 0x1e17d32cL, 0x03bcdc3cL, 0x0f33d1b2L};
+	static const unsigned long c2[NITER]={
+		0x4b0f3b58L, 0xe874f0c3L, 0x6955c5a6L, 0x55a7ca46L};
+	unsigned long i,ia,ib,iswap,itmph=0,itmpl=0;
+
+	for (i=0;i<NITER;i++) {
+		ia=(iswap=irword) ^ c1[i];
+		itmpl = ia & 0xffff;
+		itmph = ia >> 16;
+		ib=itmpl*itmpl+ ~(itmph*itmph);
+		irword=lword ^ (((ia = (ib >> 16) |
+			((ib & 0xffff) << 16)) ^ c2[i])+itmpl*itmph);
+		lword=iswap;
+	}
+}