diff options
-rw-r--r-- | configure.in | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/configure.in b/configure.in index e47c76dad..06ebd118a 100644 --- a/configure.in +++ b/configure.in @@ -851,10 +851,12 @@ AC_CHECK_FUNCS(asinh acosh atanh copysign finite sincos trunc) # C99 specifies isinf and isnan as macros. # HP-UX provides only macros, no functions. -# Glibc 2.3.2 provides both macros and functions. +# glibc 2.3.2 provides both macros and functions. +# IRIX 6.5 and Solaris 8 only provide functions. # -# We're concerned that some systems may have only functions, the following -# tests are designed to detect both functions and macros. +# The following tests detect isinf and isnan either as functions or as +# macros from <math.h>. Plain AC_CHECK_FUNCS is insufficient, it doesn't +# use <math.h> so doesn't detect on macro-only systems like HP-UX. # AC_MSG_CHECKING([for isinf]) AC_LINK_IFELSE( |