X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/397041a943bdba47467a0393d7042c7fc99a5f3d..962dd3329d51f1d18313a17eb0cb4695ee4421a0:/mp.h

diff --git a/mp.h b/mp.h
index f7a703c..c38bb3c 100644
--- a/mp.h
+++ b/mp.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: mp.h,v 1.15 2002/10/15 19:18:31 mdw Exp $
+ * $Id: mp.h,v 1.17 2003/05/16 09:09:24 mdw Exp $
  *
  * Simple multiprecision arithmetic
  *
@@ -30,6 +30,12 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: mp.h,v $
+ * Revision 1.17  2003/05/16 09:09:24  mdw
+ * Fix @mp_lsl2c@.  Turns out to be surprisingly tricky.
+ *
+ * Revision 1.16  2002/10/15 22:57:22  mdw
+ * Handy new comparison macros.
+ *
  * Revision 1.15  2002/10/15 19:18:31  mdw
  * New operation to negate numbers.
  *
@@ -723,16 +729,22 @@ extern int mp_testbit(mp */*x*/, unsigned long /*n*/);
 extern mp *mp_setbit(mp */*d*/, mp */*x*/, unsigned long /*n*/);
 extern mp *mp_clearbit(mp */*d*/, mp */*x*/, unsigned long /*n*/);
 
-/* --- @mp_lsl@, @mp_lsr@ --- *
+/* --- @mp_lsl@, @mp_lslc@, @mp_lsr@ --- *
  *
  * Arguments:	@mp *d@ = destination
  *		@mp *a@ = source
  *		@size_t n@ = number of bits to move
  *
  * Returns:	Result, @a@ shifted left or right by @n@.
+ *
+ * Use:		Bitwise shift operators.  @mp_lslc@ fills the bits introduced
+ *		on the right with ones instead of zeroes: it's used
+ *		internally by @mp_lsl2c@, though it may be useful on its
+ *		own.
  */
 
 extern mp *mp_lsl(mp */*d*/, mp */*a*/, size_t /*n*/);
+extern mp *mp_lslc(mp */*d*/, mp */*a*/, size_t /*n*/);
 extern mp *mp_lsr(mp */*d*/, mp */*a*/, size_t /*n*/);
 
 /* --- @mp_not2c@ --- *
@@ -839,6 +851,12 @@ extern int mp_cmp(const mp */*a*/, const mp */*b*/);
 
 #define MP_CMP(a, op, b) (mp_cmp((a), (b)) op 0)
 
+/* --- Other handy macros --- */
+
+#define MP_ISNEG(x) ((x)->f & MP_NEG)
+#define MP_ISZERO(x) MP_EQ((x), MP_ZERO)
+#define MP_ISPOS(x) (!MP_ISNEG(x) && !MP_ISZERO(x))
+
 /*----- Arithmetic operations ---------------------------------------------*/
 
 /* --- @mp_neg@ --- *