[PATCH v1 30/35] Assume __has_builtin(__builtin_ppc_get_timebase)

[Alejandro Colomar]

We already assume that GCC is at least GCC 5,
and we also assume that Clang is at least Clang 4.

Clang added support for __builtin_ppc_get_timebase() in Clang 3.8:

llvm.git 65e1e4dbe0f1 (2015-08-31; "[PowerPC] Support __builtin_ppc_get_timebase")

	$ git describe --contains 65e1e4dbe0f1
	llvmorg-3.8.0-rc1~10647

Signed-off-by: Alejandro Colomar <alx@kernel.org>
---
 sysdeps/powerpc/sys/platform/ppc.h | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/sysdeps/powerpc/sys/platform/ppc.h b/sysdeps/powerpc/sys/platform/ppc.h
index b0e7b0abfb..0b9f370db3 100644
--- a/sysdeps/powerpc/sys/platform/ppc.h
+++ b/sysdeps/powerpc/sys/platform/ppc.h
@@ -27,27 +27,7 @@
 static __inline__ uint64_t
 __ppc_get_timebase (void)
 {
-#if __GNUC_PREREQ (4, 8)
   return __builtin_ppc_get_timebase ();
-#else
-# ifdef __powerpc64__
-  uint64_t __tb;
-  /* "volatile" is necessary here, because the user expects this assembly
-     isn't moved after an optimization.  */
-  __asm__ volatile ("mfspr %0, 268" : "=r" (__tb));
-  return __tb;
-# else  /* not __powerpc64__ */
-  uint32_t __tbu, __tbl, __tmp; \
-  __asm__ volatile ("0:\n\t"
-		    "mftbu %0\n\t"
-		    "mftbl %1\n\t"
-		    "mftbu %2\n\t"
-		    "cmpw %0, %2\n\t"
-		    "bne- 0b"
-		    : "=r" (__tbu), "=r" (__tbl), "=r" (__tmp));
-  return (((uint64_t) __tbu << 32) | __tbl);
-# endif  /* not __powerpc64__ */
-#endif
 }
 
 /* The following functions provide hints about the usage of shared processor
-- 
2.51.0