Changeset: a42cc7f6030c for MonetDB URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=a42cc7f6030c Modified Files: configure.ag Branch: Dec2016 Log Message:
Work around a smart clang optimizer that optimizes the test away. diffs (16 lines): diff --git a/configure.ag b/configure.ag --- a/configure.ag +++ b/configure.ag @@ -2600,8 +2600,11 @@ AC_MSG_CHECKING([__builtin_add_overflow] # to the runtime that contains the required function __muloti4. Also # see https://llvm.org/bugs/show_bug.cgi?id=16404 which is a similar # issue. +# Note that the program being compiled is complicated so that we work +# around a too smart clang optimizer. AC_LINK_IFELSE( - [AC_LANG_PROGRAM([[]], [[__int128 a, b, c; __builtin_mul_overflow(a, b, &c);]])], + [AC_LANG_PROGRAM([[@%:@include <stdlib.h> +@%:@include <stdio.h>]], [[__int128 a=(__int128)atoll(getenv("a"))<<64, b=(__int128)atoll(getenv("b"))<<64, c; if (!__builtin_mul_overflow(a, b, &c)) printf("%lld %lld\n",(long long)(c>>64), (long long)c);]])], [AC_DEFINE([HAVE___BUILTIN_ADD_OVERFLOW], 1, [Define if you have the `__builtin_{add,sub,mul}_overflow' functions.]) AC_MSG_RESULT(yes)], _______________________________________________ checkin-list mailing list checkin-list@monetdb.org https://www.monetdb.org/mailman/listinfo/checkin-list
