Update HP_TIMING_NOW for _ISOMAC in sysdeps/generic/hp-timing.h

commit e9698175b0
Author: Lukasz Majewski <lukma@denx.de>
Date:   Mon Mar 16 08:31:41 2020 +0100

    y2038: Replace __clock_gettime with __clock_gettime64

breaks benchtests with sysdeps/generic/hp-timing.h:

In file included from ./bench-timing.h:23,
                 from ./bench-skeleton.c:25,
                 from
/export/build/gnu/tools-build/glibc-gitlab/build-x86_64-linux/benchtests/bench-rint.c:45:
./bench-skeleton.c: In function ‘main’:
../sysdeps/generic/hp-timing.h:37:23: error: storage size of ‘tv’ isn’t known
   37 |   struct __timespec64 tv;      \
      |                       ^~

Define HP_TIMING_NOW with clock_gettime in sysdeps/generic/hp-timing.h
if _ISOMAC is defined.  Don't define __clock_gettime in bench-timing.h
since it is no longer needed.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

benchtests/bench-timing.h

@@ -18,7 +18,6 @@
 
 #undef attribute_hidden
 #define attribute_hidden
-#define __clock_gettime __clock_gettime64
 #include <hp-timing.h>
 #include <stdint.h>
 

sysdeps/generic/hp-timing.h

@@ -32,11 +32,20 @@ typedef uint64_t hp_timing_t;
 /* The clock_gettime (CLOCK_MONOTONIC) has unspecified starting time,
    nano-second accuracy, and for some architectues is implemented as
    vDSO symbol.  */
-#define HP_TIMING_NOW(var) \
+#ifdef _ISOMAC
+# define HP_TIMING_NOW(var) \
+({								\
+  struct timespec tv;						\
+  clock_gettime (CLOCK_MONOTONIC, &tv);				\
+  (var) = (tv.tv_nsec + UINT64_C(1000000000) * tv.tv_sec);	\
+})
+#else
+# define HP_TIMING_NOW(var) \
 ({								\
   struct __timespec64 tv;						\
   __clock_gettime64 (CLOCK_MONOTONIC, &tv);			\
   (var) = (tv.tv_nsec + UINT64_C(1000000000) * tv.tv_sec);	\
 })
+#endif
 
 #endif	/* hp-timing.h */