Add subtraction and addition with carry/borrow and add abs_diff1.2

Signed-off-by: Mattias Andrée <m@maandree.se>

1 files changed, 26 insertions, 0 deletions

diff --git a/libj2_j2u_sub_j2u.3 b/libj2_j2u_sub_j2u.3
index cbadfd2..4ed6863 100644
--- a/libj2_j2u_sub_j2u.3
+++ b/libj2_j2u_sub_j2u.3
@@ -25,6 +25,9 @@ int \fBlibj2_j2u_sub_ju_overflow_p\fP(const struct libj2_j2u *\fIa\fP, uintmax_t
 int \fBlibj2_ju_sub_j2u_overflow_p\fP(uintmax_t \fIa\fP, const struct libj2_j2u *\fIb\fP);
 int \fBlibj2_ju_sub_ju_overflow_p\fP(uintmax_t \fIa\fP, uintmax_t \fIb\fP);
 
+void \fBlibj2_j2u_sub_j2u_borrow\fP(struct libj2_j2u *\fIa\fP, const struct libj2_j2u *\fIb\fP, int *\fIc\fP);
+void \fBlibj2_j2u_sub_j2u_to_j2u_borrow\fP(const struct libj2_j2u *\fIa\fP, const struct libj2_j2u *\fIb\fP, struct libj2_j2u *\fIr\fP, int *\fIc\fP);
+
 void \fBlibj2_j2u_rsub_j2u\fP(struct libj2_j2u *\fIb\fP, const struct libj2_j2u *\fIa\fP);
 void \fBlibj2_j2u_rsub_ju\fP(struct libj2_j2u *\fIb\fP, uintmax_t \fIa\fP);
 
@@ -34,6 +37,8 @@ int \fBlibj2_j2u_rsub_ju_overflow\fP(struct libj2_j2u *\fIb\fP, uintmax_t \fIa\f
 int \fBlibj2_j2u_rsub_j2u_overflow_p\fP(const struct libj2_j2u *\fIb\fP, const struct libj2_j2u *\fIa\fP);
 int \fBlibj2_j2u_rsub_ju_overflow_p\fP(const struct libj2_j2u *\fIb\fP, uintmax_t \fIa\fP);
 
+void \fBlibj2_j2u_rsub_j2u_borrow\fP(struct libj2_j2u *\fIb\fP, const struct libj2_j2u *\fIa\fP, int *\fIc\fP);
+
 void \fBlibj2_j2u_sat_sub_j2u\fP(struct libj2_j2u *\fIa\fP, const struct libj2_j2u *\fIb\fP);
 void \fBlibj2_j2u_sat_sub_j2u_to_j2u\fP(const struct libj2_j2u *\fIa\fP, const struct libj2_j2u *\fIb\fP, struct libj2_j2u *\fIr\fP);
 void \fBlibj2_j2u_sat_sub_ju\fP(struct libj2_j2u *\fIa\fP, uintmax_t \fIb\fP);
@@ -88,6 +93,18 @@ with word
 .B overflow
 in their name), detect arithmetic overflow.
 .PP
+The
+.BR libj2_j2u_sub_j2u_borrow (),
+.BR libj2_j2u_sub_j2u_to_j2u_borrow (),
+and
+.BR libj2_j2u_rsub_j2u_borrow ()
+functions subtract
+.IR *c ,
+which must be 1 or 0,
+from the result, and sets
+.I *c
+to 1 on overflow, and 0 otherwise.
+.PP
 The result is truncated to the least significant
 bits, as many as can be stored, in case of overflow;
 that is, modular arithmetics is used. However, the
@@ -149,6 +166,14 @@ and
 .BR libj2_j2u_sat_rsub_ju ()
 functions were added in version 1.1 of
 .BR libj2 .
+.PP
+The
+.BR libj2_j2u_sub_j2u_borrow (),
+.BR libj2_j2u_sub_j2u_to_j2u_borrow (),
+and
+.BR libj2_j2u_rsub_j2u_borrow ()
+functions were added in version 1.2 of
+.BR libj2 .
 
 .SH NOTES
 The return value 1 represents negative
@@ -157,6 +182,7 @@ overflow. Positive overflow is impossible.
 .SH SEE ALSO
 .BR libj2 (7),
 .BR libj2_j2i_sub_j2i (3),
+.BR libj2_j2u_abs_diff_j2u (3),
 .BR libj2_j2i_add_j2i (3),
 .BR libj2_j2i_mul_j2i (3),
 .BR libj2_j2i_divmod_j2i (3)