diff options
Diffstat (limited to '')
| -rw-r--r-- | libj2.h | 6 | ||||
| -rw-r--r-- | libj2.h.0 | 134 |
2 files changed, 137 insertions, 3 deletions
@@ -67,7 +67,7 @@ struct libj2_j2u { /** * Most significant half */ - uintmax_t high; + uintmax_t high; /** * Least significant half @@ -98,7 +98,7 @@ struct libj2_j2i { * Most significant half, of which the most * significant bit is the sign bit */ - uintmax_t high; + uintmax_t high; /** * Least significant half @@ -131,7 +131,7 @@ enum libj2_overflow { * Overflow prediction stopped * (due to high cost) */ - LIBJ2_OVERFLOW_UNKNOWN + LIBJ2_OVERFLOW_UNKNOWN = 2 }; diff --git a/libj2.h.0 b/libj2.h.0 new file mode 100644 index 0000000..b9e434e --- /dev/null +++ b/libj2.h.0 @@ -0,0 +1,134 @@ +.TH LIBJ2.H 0 LIBJ2 +.SH NAME +libj2.h \- Double-max precision integers header file + +.SH SYNOPSIS +.nf +#include <libj2.h> + +#define \fBLIBJ2_JU_BIT\fP /* implementation omitted */ +#define \fBLIBJ2_J2U_BIT\fP (2U * LIBJ2_JU_BIT) +#define \fBLIBJ2_J2I_BIT\fP LIBJ2_J2U_BIT +#define \fBLIBJ2_J2I_VBIT\fP (LIBJ2_J2I_BIT - 1U) + +\fBstruct libj2_j2u\fP { + uintmax_t \fIhigh\fP; + uintmax_t \fIlow\fP; +}; + +\fBstruct libj2_j2i\fP { + uintmax_t \fIhigh\fP; + uintmax_t \fIlow\fP; +}; + +\fBenum libj2_overflow\fP { + \fBLIBJ2_NO_OVERFLOW\fP = 0, + \fBLIBJ2_OVERFLOW\fP = 1, + \fBLIBJ2_OVERFLOW_UNKNOWN\fP = 2 +}; + +.fi +.PP +Link with +.IR -lj2 . + +.SH DESCRIPTION +The +.B libj2.h +header file, provides definitions used for the +.B libj2 +double-max precision integer library. +.PP +The header file defines the type +.B struct\ libj2_j2u +for unsigned integers with double the width of +.BR uintmax_t , +and the type +.B struct\ libj2_j2i +for signed integers with the same width, including +one bit for signess. +.B struct\ libj2_j2i +uses two's complement, and is designed to be +storage-wise identical to +.BR struct\ libj2_j2u . +It is guaranteed for both types that, +.I high +is the first member, and +.I low +is the second member, and that those are the only +members, of the +.IR struct s. +.I high +stores the most significant half, including the +sign-bit as the most significant bit for +.BR struct\ libj2_j2i , +and +.I low +stores the least significant half. +Each half stores +.B LIBJ2_JU_BIT +bits, for a sum of +.B LIBJ2_J2U_BIT +bits for the entire +.I struct . +.PP +.B LIBJ2_J2I_BIT +is a synonym for +.BR LIBJ2_J2U_BIT . +.B LIBJ2_J2I_BIT +is preferable in the context of the width of +.BR struct\ libj2_j2i , +whereas +.B LIBJ2_J2U_BIT +is preferable in the context of the width of +.BR struct\ libj2_j2u . +.PP +.B LIBJ2_J2I_VBIT +specifies the number of value-bits in a +.BR struct\ libj2_j2i , +that is, the number of bits it holds less +the sign-bit. +.PP +.BR LIBJ2_JU_BIT , +.BR LIBJ2_J2U_BIT , +.BR LIBJ2_J2I_BIT , +and +.B LIBJ2_J2I_VBIT +are compile-time constants, but not +preprocessor-time constants. +.PP +.B enum\ libj2_overflow +is used as the return-type by some +overflow-prediction functions. +.B LIBJ2_NO_OVERFLOW +signifies that the result is fully representable. +.B LIBJ2_OVERFLOW +signifies that the result is positive but too large +to be fully represented. +.B LIBJ2_OVERFLOW_UNKNOWN +signifies that the function bailed out making the +overflow prediction, but that the result is positive. +.PP +See +.BR libj2 (7) +for a listing of functions defined by the +header file. + +.SH HISTORY +.BR LIBJ2_JU_BIT , +.BR LIBJ2_J2U_BIT , +.BR struct\ libj2_j2u , +and +.B enum\ libj2_overflow +where added in version 1.0 of +.BR libj2 . +.PP +.BR LIBJ2_J2I_BIT , +.BR LIBJ2_J2I_VBIT , +and +.B struct\ libj2_j2i +where added in version 1.1 of +.BR libj2 . + +.SH SEE ALSO +.BR libj2 (7) |