diff options
Diffstat (limited to 'libj2_j2u_sub_j2u.3')
| -rw-r--r-- | libj2_j2u_sub_j2u.3 | 38 |
1 files changed, 34 insertions, 4 deletions
diff --git a/libj2_j2u_sub_j2u.3 b/libj2_j2u_sub_j2u.3 index 7fb94c5..cbadfd2 100644 --- a/libj2_j2u_sub_j2u.3 +++ b/libj2_j2u_sub_j2u.3 @@ -33,6 +33,16 @@ 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_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); +void \fBlibj2_j2u_sat_sub_ju_to_j2u\fP(const struct libj2_j2u *\fIa\fP, uintmax_t \fIb\fP, struct libj2_j2u *\fIr\fP); +void \fBlibj2_ju_sat_sub_j2u_to_j2u\fP(uintmax_t \fIa\fP, const struct libj2_j2u *\fIb\fP, struct libj2_j2u *\fIr\fP); +void \fBlibj2_ju_sat_sub_ju_to_j2u\fP(uintmax_t \fIa\fP, uintmax_t \fIb\fP, struct libj2_j2u *\fIr\fP); + +void \fBlibj2_j2u_sat_rsub_j2u\fP(struct libj2_j2u *\fIb\fP, const struct libj2_j2u *\fIa\fP); +void \fBlibj2_j2u_sat_rsub_ju\fP(struct libj2_j2u *\fIb\fP, uintmax_t \fIa\fP); .fi .PP Link with @@ -59,15 +69,17 @@ except the functions .BR libj2_ju_sub_ju_overflow_p (), .BR libj2_j2u_rsub_j2u_overflow_p (), and -.BR libj2_j2u_rsub_ju_overflow_p (), +.BR libj2_j2u_rsub_ju_overflow_p () only predict overflow, and do not calculate the difference, and therefore does store it anywhere; and except the functions .BR libj2_j2u_rsub_j2u (), .BR libj2_j2u_rsub_ju (), .BR libj2_j2u_rsub_j2u_overflow (), -and .BR libj2_j2u_rsub_ju_overflow (), +.BR libj2_j2u_sat_rsub_j2u (), +and +.BR libj2_j2u_sat_rsub_ju () store the result in .IR b . .PP @@ -78,8 +90,13 @@ in their name), detect arithmetic overflow. .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. - +that is, modular arithmetics is used. However, the +.BR sat_sub - +and +.BR sat_rsub -functions +use saturated arithmetics, meaning that the result +will be the maximum representable value on positive +overflow and the value zero on negative overflow. .PP The arguments are assumed to be .RI non- NULL . @@ -119,6 +136,19 @@ and .BR libj2_j2u_rsub_ju_overflow_p () functions were added in version 1.0 of .BR libj2 . +.PP +The +.BR libj2_j2u_sat_sub_j2u (), +.BR libj2_j2u_sat_sub_j2u_to_j2u (), +.BR libj2_j2u_sat_sub_ju (), +.BR libj2_j2u_sat_sub_ju_to_j2u (), +.BR libj2_ju_sat_sub_j2u_to_j2u (), +.BR libj2_ju_sat_sub_ju_to_j2u (), +.BR libj2_j2u_sat_rsub_j2u (), +and +.BR libj2_j2u_sat_rsub_ju () +functions were added in version 1.1 of +.BR libj2 . .SH NOTES The return value 1 represents negative |