svn commit: r334813 - head/sys/sys

[Randall Stewart]

Author: rrs
Date: Thu Jun  7 19:57:55 2018
New Revision: 334813
URL: https://svnweb.freebsd.org/changeset/base/334813

Log:
  Fix build issue with const and volatile and the
  myriad ways that the various compliers treat this. The
  only safe prefetch appears to be for AMD. The other
  compilers either are not volatile or are not const :(
  
  Reported by:	Michael Tuexen

Modified:
  head/sys/sys/kern_prefetch.h

Modified: head/sys/sys/kern_prefetch.h
==============================================================================
--- head/sys/sys/kern_prefetch.h	Thu Jun  7 19:48:49 2018	(r334812)
+++ head/sys/sys/kern_prefetch.h	Thu Jun  7 19:57:55 2018	(r334813)
@@ -34,7 +34,7 @@ kern_prefetch(const volatile void *addr, void* before)
 #if defined(__amd64__)
 	__asm __volatile("prefetcht1 (%1)":"=rm"(*((int32_t *)before)):"r"(addr):);
 #else
-	__builtin_prefetch(addr);
+/*	__builtin_prefetch(addr);*/
 #endif
 }