have_func: checking for labs() in stdlib.h... -------------------- yes

"gcc -o conftest -I../../.ext/include/x86_64-linux -I../.././include -I../.././ext/bigdecimal     -O3 -fno-fast-math -ggdb3 -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wunused-variable -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration -Wdeprecated-declarations -Wno-packed-bitfield-compat  -fPIC conftest.c  -L. -L../.. -L. -fstack-protector -rdynamic -Wl,-export-dynamic     -Wl,-R/usr/local/rvm/rubies/ruby-2.2.10/lib -L/usr/local/rvm/rubies/ruby-2.2.10/lib -lruby-static  -lpthread -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:15:43: warning: cast between incompatible function types from ‘__attribute__((const)) long int (*)(long int)’ to ‘void (*)()’ [-Wcast-function-type]
 int t(void) { void ((*volatile p)()); p = (void ((*)()))labs; return 0; }
                                           ^
conftest.c:15:32: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
 int t(void) { void ((*volatile p)()); p = (void ((*)()))labs; return 0; }
                                ^
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: #include <stdlib.h>
 4: 
 5: /*top*/
 6: extern int t(void);
 7: int main(int argc, char **argv)
 8: {
 9:   if (argc > 1000000) {
10:     printf("%p", &t);
11:   }
12: 
13:   return 0;
14: }
15: int t(void) { void ((*volatile p)()); p = (void ((*)()))labs; return 0; }
/* end */

--------------------

have_func: checking for llabs() in stdlib.h... -------------------- yes

"gcc -o conftest -I../../.ext/include/x86_64-linux -I../.././include -I../.././ext/bigdecimal     -O3 -fno-fast-math -ggdb3 -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wunused-variable -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration -Wdeprecated-declarations -Wno-packed-bitfield-compat  -fPIC conftest.c  -L. -L../.. -L. -fstack-protector -rdynamic -Wl,-export-dynamic     -Wl,-R/usr/local/rvm/rubies/ruby-2.2.10/lib -L/usr/local/rvm/rubies/ruby-2.2.10/lib -lruby-static  -lpthread -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:15:43: warning: cast between incompatible function types from ‘__attribute__((const)) long long int (*)(long long int)’ to ‘void (*)()’ [-Wcast-function-type]
 int t(void) { void ((*volatile p)()); p = (void ((*)()))llabs; return 0; }
                                           ^
conftest.c:15:32: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
 int t(void) { void ((*volatile p)()); p = (void ((*)()))llabs; return 0; }
                                ^
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: #include <stdlib.h>
 4: 
 5: /*top*/
 6: extern int t(void);
 7: int main(int argc, char **argv)
 8: {
 9:   if (argc > 1000000) {
10:     printf("%p", &t);
11:   }
12: 
13:   return 0;
14: }
15: int t(void) { void ((*volatile p)()); p = (void ((*)()))llabs; return 0; }
/* end */

--------------------

extconf.h is:
/* begin */
1: #ifndef EXTCONF_H
2: #define EXTCONF_H
3: #define HAVE_LABS 1
4: #define HAVE_LLABS 1
5: #endif
/* end */