Diff: math/mul/fp_mul.c

Revision:

0:35aa5be3b78d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/math/mul/fp_mul.c	Fri Jun 06 10:49:02 2014 +0000
@@ -0,0 +1,128 @@
+/* TomsFastMath, a fast ISO C bignum library.
+ * 
+ * This project is meant to fill in where LibTomMath
+ * falls short.  That is speed ;-)
+ *
+ * This project is public domain and free for all purposes.
+ * 
+ * Tom St Denis, tomstdenis@gmail.com
+ */
+#include <tfm.h>
+
+/* c = a * b */
+void fp_mul(fp_int *A, fp_int *B, fp_int *C)
+{
+    int   y, yy;
+
+    /* call generic if we're out of range */
+    if (A->used + B->used > FP_SIZE) {
+       fp_mul_comba(A, B, C);
+       return ;
+    }
+
+     y  = MAX(A->used, B->used);
+     yy = MIN(A->used, B->used);
+    /* pick a comba (unrolled 4/8/16/32 x or rolled) based on the size
+       of the largest input.  We also want to avoid doing excess mults if the 
+       inputs are not close to the next power of two.  That is, for example,
+       if say y=17 then we would do (32-17)^2 = 225 unneeded multiplications 
+    */
+
+#ifdef TFM_MUL3
+        if (y <= 3) {
+           fp_mul_comba3(A,B,C);
+           return;
+        }
+#endif
+#ifdef TFM_MUL4
+        if (y == 4) {
+           fp_mul_comba4(A,B,C);
+           return;
+        }
+#endif
+#ifdef TFM_MUL6
+        if (y <= 6) {
+           fp_mul_comba6(A,B,C);
+           return;
+        }
+#endif
+#ifdef TFM_MUL7
+        if (y == 7) {
+           fp_mul_comba7(A,B,C);
+           return;
+        }
+#endif
+#ifdef TFM_MUL8
+        if (y == 8) {
+           fp_mul_comba8(A,B,C);
+           return;
+        }
+#endif
+#ifdef TFM_MUL9
+        if (y == 9) {
+           fp_mul_comba9(A,B,C);
+           return;
+        }
+#endif
+#ifdef TFM_MUL12
+        if (y <= 12) {
+           fp_mul_comba12(A,B,C);
+           return;
+        }
+#endif
+#ifdef TFM_MUL17
+        if (y <= 17) {
+           fp_mul_comba17(A,B,C);
+           return;
+        }
+#endif
+
+#ifdef TFM_SMALL_SET
+        if (y <= 16) {
+           fp_mul_comba_small(A,B,C);
+           return;
+        }
+#endif        
+#if defined(TFM_MUL20)
+        if (y <= 20) {
+           fp_mul_comba20(A,B,C);
+           return;
+        }
+#endif
+#if defined(TFM_MUL24)
+        if (yy >= 16 && y <= 24) {
+           fp_mul_comba24(A,B,C);
+           return;
+        }
+#endif
+#if defined(TFM_MUL28)
+        if (yy >= 20 && y <= 28) {
+           fp_mul_comba28(A,B,C);
+           return;
+        }
+#endif
+#if defined(TFM_MUL32)
+        if (yy >= 24 && y <= 32) {
+           fp_mul_comba32(A,B,C);
+           return;
+        }
+#endif
+#if defined(TFM_MUL48)
+        if (yy >= 40 && y <= 48) {
+           fp_mul_comba48(A,B,C);
+           return;
+        }
+#endif        
+#if defined(TFM_MUL64)
+        if (yy >= 56 && y <= 64) {
+           fp_mul_comba64(A,B,C);
+           return;
+        }
+#endif
+        fp_mul_comba(A,B,C);
+}
+
+
+/* $Source: /cvs/libtom/tomsfastmath/src/mul/fp_mul.c,v $ */
+/* $Revision: 1.1 $ */
+/* $Date: 2006/12/31 21:25:53 $ */