diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/intprops.h | 18 | ||||
| -rw-r--r-- | include/regex.h | 3 |
2 files changed, 16 insertions, 5 deletions
diff --git a/include/intprops.h b/include/intprops.h index 2b6e5e93ed..3fe64e82e9 100644 --- a/include/intprops.h +++ b/include/intprops.h @@ -132,7 +132,8 @@ operators might not yield numerically correct answers due to arithmetic overflow. They do not rely on undefined or implementation-defined behavior. Their implementations are simple - and straightforward, but they are a bit harder to use than the + and straightforward, but they are harder to use and may be less + efficient than the INT_<op>_WRAPV, INT_<op>_OK, and INT_<op>_OVERFLOW macros described below. Example usage: @@ -157,6 +158,9 @@ must have minimum value MIN and maximum MAX. Unsigned types should use a zero MIN of the proper type. + Because all arguments are subject to integer promotions, these + macros typically do not work on types narrower than 'int'. + These macros are tuned for constant MIN and MAX. For commutative operations such as A + B, they are also tuned for constant B. */ @@ -338,9 +342,15 @@ arguments should not have side effects. The WRAPV macros are not constant expressions. They support only - +, binary -, and *. Because the WRAPV macros convert the result, - they report overflow in different circumstances than the OVERFLOW - macros do. + +, binary -, and *. + + Because the WRAPV macros convert the result, they report overflow + in different circumstances than the OVERFLOW macros do. For + example, in the typical case with 16-bit 'short' and 32-bit 'int', + if A, B and R are all of type 'short' then INT_ADD_OVERFLOW (A, B) + returns false because the addition cannot overflow after A and B + are converted to 'int', whereas INT_ADD_WRAPV (A, B, &R) returns + true or false depending on whether the sum fits into 'short'. These macros are tuned for their last input argument being a constant. diff --git a/include/regex.h b/include/regex.h index 24eca2c297..34fb67d855 100644 --- a/include/regex.h +++ b/include/regex.h @@ -37,7 +37,8 @@ extern int __regcomp (regex_t *__preg, const char *__pattern, int __cflags); libc_hidden_proto (__regcomp) extern int __regexec (const regex_t *__preg, const char *__string, - size_t __nmatch, regmatch_t __pmatch[], int __eflags); + size_t __nmatch, regmatch_t __pmatch[__nmatch], + int __eflags); libc_hidden_proto (__regexec) extern size_t __regerror (int __errcode, const regex_t *__preg, |