Configuring Time::HiRes...
Have syscall()... looking for syscall.h... cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
tmp2751.c:5:21: syscall.h: No such file or directory
cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
found <sys/syscall.h>.
Looking for gettimeofday()... found.
Looking for setitimer()... found.
Looking for getitimer()... found.
You have interval timers (both setitimer and getitimer).
Looking for ualarm()... found.
Looking for usleep()... found.
Looking for nanosleep()... testing... cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
Running ./tmp2751...found.
You can mix subsecond sleeps with signals, if you want to.
(It's still not portable, though.)
Looking for clock_gettime()... cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
tmp2751.c: In function `main':
tmp2751.c:7: error: `CLOCK_REALTIME' undeclared (first use in this function)
tmp2751.c:7: error: (Each undeclared identifier is reported only once
tmp2751.c:7: error: for each function it appears in.)
cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
tmp2751.c: In function `main':
tmp2751.c:10: error: `SYS_clock_gettime' undeclared (first use in this function)
tmp2751.c:10: error: (Each undeclared identifier is reported only once
tmp2751.c:10: error: for each function it appears in.)
tmp2751.c:10: error: `CLOCK_REALTIME' undeclared (first use in this function)
NOT found.
Looking for clock_getres()... cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
tmp2751.c: In function `main':
tmp2751.c:7: error: `CLOCK_REALTIME' undeclared (first use in this function)
tmp2751.c:7: error: (Each undeclared identifier is reported only once
tmp2751.c:7: error: for each function it appears in.)
cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
tmp2751.c: In function `main':
tmp2751.c:10: error: `SYS_clock_getres' undeclared (first use in this function)
tmp2751.c:10: error: (Each undeclared identifier is reported only once
tmp2751.c:10: error: for each function it appears in.)
tmp2751.c:10: error: `CLOCK_REALTIME' undeclared (first use in this function)
NOT found.
Looking for clock_nanosleep()... cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
tmp2751.c: In function `main':
tmp2751.c:7: error: storage size of `ts1' isn't known
tmp2751.c:8: error: storage size of `ts2' isn't known
tmp2751.c:11: error: `CLOCK_MONOTONIC' undeclared (first use in this function)
tmp2751.c:11: error: (Each undeclared identifier is reported only once
tmp2751.c:11: error: for each function it appears in.)
NOT found.
Looking for clock()... cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
Running ./tmp2751...found.
Trying struct stat st_atimespec.tv_nsec...cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
found.
Trying struct stat st_atimensec...cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
tmp2751.c: In function `main':
tmp2751.c:17: error: structure has no member named `st_atimensec'
NOT found.
Trying struct stat st_atime_n...cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
tmp2751.c: In function `main':
tmp2751.c:17: error: structure has no member named `st_atime_n'
NOT found.
Trying struct stat st_atim.tv_nsec...cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
tmp2751.c: In function `main':
tmp2751.c:17: error: structure has no member named `st_atim'
NOT found.
Trying struct stat st_uatime...cccmd = cc -o tmp2751 -fno-common -DPERL_DARWIN -no-cpp-precomp -fno-strict-aliasing -pipe -I/usr/local/lib/perl5/5.8.8/darwin-2level/CORE tmp2751.c  
tmp2751.c: In function `main':
tmp2751.c:17: error: structure has no member named `st_uatime'
NOT found.
You seem to have stat subsecond timestamps.
(Your struct stat has them, but the filesystems must help.)
Writing Makefile for Time::HiRes
Now you may issue 'make'.  Do not forget also 'make test'.