I pushed this. --- ChangeLog | 16 ++++++++++ lib/autoconf/types.m4 | 74 ++++++++++++++++++++++++++---------------------- 2 files changed, 56 insertions(+), 34 deletions(-)
diff --git a/ChangeLog b/ChangeLog index fbfbc53..79b9058 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,19 @@ +2011-02-16 Paul Eggert <[email protected]> + + autoconf: tune long long tests, particularly for c99 + + This change is imported from gnulib. + * lib/autoconf/types.m4 (AC_TYPE_LONG_LONG_INT): Don't bother compiling + or running anything if c99, or if unsigned long long int does not + work. In either case, we know the answer without further tests. + Do not compile _AC_TYPE_LONG_LONG_SNIPPET twice. Instead, compile + it at most once, and use its results for both long long int and + unsigned long long int. This is more likely to be efficient in + the common case where the program wants to check for both long + long int and unsigned long long int. + (AC_TYPE_UNSIGNED_LONG_LONG_INT): Don't bother compiling if c99, + since the answer is already known. + 2011-02-15 Eric Blake <[email protected]> doc: fix debug advice typo diff --git a/lib/autoconf/types.m4 b/lib/autoconf/types.m4 index 6583cb0..166aeb5 100644 --- a/lib/autoconf/types.m4 +++ b/lib/autoconf/types.m4 @@ -500,37 +500,40 @@ AC_DEFUN([_AC_TYPE_LONG_LONG_SNIPPET], # --------------------- AC_DEFUN([AC_TYPE_LONG_LONG_INT], [ + AC_REQUIRE([AC_TYPE_UNSIGNED_LONG_LONG_INT]) AC_CACHE_CHECK([for long long int], [ac_cv_type_long_long_int], - [AC_LINK_IFELSE( - [_AC_TYPE_LONG_LONG_SNIPPET], - [dnl This catches a bug in Tandem NonStop Kernel (OSS) cc -O circa 2004. - dnl If cross compiling, assume the bug isn't important, since - dnl nobody cross compiles for this platform as far as we know. - AC_RUN_IFELSE( - [AC_LANG_PROGRAM( - [[@%:@include <limits.h> - @%:@ifndef LLONG_MAX - @%:@ define HALF \ - (1LL << (sizeof (long long int) * CHAR_BIT - 2)) - @%:@ define LLONG_MAX (HALF - 1 + HALF) - @%:@endif]], - [[long long int n = 1; - int i; - for (i = 0; ; i++) - { - long long int m = n << i; - if (m >> i != n) - return 1; - if (LLONG_MAX / 2 < m) - break; - } - return 0;]])], - [ac_cv_type_long_long_int=yes], - [ac_cv_type_long_long_int=no], - [ac_cv_type_long_long_int=yes])], - [ac_cv_type_long_long_int=no])]) + [ac_cv_type_long_long_int=yes + if test "x${ac_cv_prog_cc_c99-no}" = xno; then + ac_cv_type_long_long_int=$ac_cv_type_unsigned_long_long_int + if test $ac_cv_type_long_long_int = yes; then + dnl Catch a bug in Tandem NonStop Kernel (OSS) cc -O circa 2004. + dnl If cross compiling, assume the bug is not important, since + dnl nobody cross compiles for this platform as far as we know. + AC_RUN_IFELSE( + [AC_LANG_PROGRAM( + [[@%:@include <limits.h> + @%:@ifndef LLONG_MAX + @%:@ define HALF \ + (1LL << (sizeof (long long int) * CHAR_BIT - 2)) + @%:@ define LLONG_MAX (HALF - 1 + HALF) + @%:@endif]], + [[long long int n = 1; + int i; + for (i = 0; ; i++) + { + long long int m = n << i; + if (m >> i != n) + return 1; + if (LLONG_MAX / 2 < m) + break; + } + return 0;]])], + [], + [ac_cv_type_long_long_int=no]) + fi + fi]) if test $ac_cv_type_long_long_int = yes; then - AC_DEFINE([HAVE_LONG_LONG_INT], 1, + AC_DEFINE([HAVE_LONG_LONG_INT], [1], [Define to 1 if the system has the type `long long int'.]) fi ]) @@ -542,12 +545,15 @@ AC_DEFUN([AC_TYPE_UNSIGNED_LONG_LONG_INT], [ AC_CACHE_CHECK([for unsigned long long int], [ac_cv_type_unsigned_long_long_int], - [AC_LINK_IFELSE( - [_AC_TYPE_LONG_LONG_SNIPPET], - [ac_cv_type_unsigned_long_long_int=yes], - [ac_cv_type_unsigned_long_long_int=no])]) + [ac_cv_type_unsigned_long_long_int=yes + if test "x${ac_cv_prog_cc_c99-no}" = xno; then + AC_LINK_IFELSE( + [_AC_TYPE_LONG_LONG_SNIPPET], + [], + [ac_cv_type_unsigned_long_long_int=no]) + fi]) if test $ac_cv_type_unsigned_long_long_int = yes; then - AC_DEFINE([HAVE_UNSIGNED_LONG_LONG_INT], 1, + AC_DEFINE([HAVE_UNSIGNED_LONG_LONG_INT], [1], [Define to 1 if the system has the type `unsigned long long int'.]) fi ]) -- 1.7.4
