diff options
Diffstat (limited to 'man7/math_error.7')
| -rw-r--r-- | man7/math_error.7 | 38 |
1 files changed, 19 insertions, 19 deletions
diff --git a/man7/math_error.7 b/man7/math_error.7 index 46e90a06f..b7d65c8e9 100644 --- a/man7/math_error.7 +++ b/man7/math_error.7 @@ -24,12 +24,12 @@ There are two error-reporting mechanisms: the older one sets .IR errno ; the newer one uses the floating-point exception mechanism (the use of -.BR feclearexcept (3) +.MR feclearexcept 3 and -.BR fetestexcept (3), +.MR fetestexcept 3 , as outlined below) described in -.BR fenv (3). +.MR fenv 3 . .P A portable program that needs to check for an error from a mathematical function should set @@ -47,7 +47,7 @@ before calling a mathematical function. Upon return from the mathematical function, if .I errno is nonzero, or the following call (see -.BR fenv (3)) +.MR fenv 3 ) returns nonzero .P .in +4n @@ -76,7 +76,7 @@ A occurs when a mathematical function is supplied with an argument whose value falls outside the domain for which the function is defined (e.g., giving a negative argument to -.BR log (3)). +.MR log 3 ). When a domain error occurs, math functions commonly return a NaN (though some functions return a different value in this case); @@ -173,7 +173,7 @@ This identifier is supposed to indicate which of the two error-notification mechanisms .RI ( errno , exceptions retrievable via -.BR fetestexcept (3)) +.MR fetestexcept 3 ) is in use. The standards require that at least one be in use, but permit both to be available. @@ -190,13 +190,13 @@ See the individual manual pages for details. To avoid the complexities of using .I errno and -.BR fetestexcept (3) +.MR fetestexcept 3 for error checking, it is often advised that one should instead check for bad argument values before each call. .\" http://www.securecoding.cert.org/confluence/display/seccode/FLP32-C.+Prevent+or+detect+domain+and+range+errors+in+math+functions For example, the following code ensures that -.BR log (3)'s +.MR log 3 's argument is not a NaN and is not zero (a pole error) or less than zero (a domain error): .P @@ -219,7 +219,7 @@ which in general are not required to return errors by C99 and POSIX.1. .P The -.BR gcc (1) +.MR gcc 1 .I "\-fno\-math\-errno" option causes the executable to employ implementations of some mathematical functions that are faster than the standard @@ -227,20 +227,20 @@ implementations, but do not set .I errno on error. (The -.BR gcc (1) +.MR gcc 1 .I "\-ffast\-math" option also enables .IR "\-fno\-math\-errno" .) An error can still be tested for using -.BR fetestexcept (3). +.MR fetestexcept 3 . .SH SEE ALSO -.BR gcc (1), -.BR errno (3), -.BR fenv (3), -.BR fpclassify (3), -.BR INFINITY (3), -.BR isgreater (3), -.BR matherr (3), -.BR nan (3) +.MR gcc 1 , +.MR errno 3 , +.MR fenv 3 , +.MR fpclassify 3 , +.MR INFINITY 3 , +.MR isgreater 3 , +.MR matherr 3 , +.MR nan 3 .P .I "info libc" |