From: Jean-Francois Romang <jeanfrancois.romang@gmail.com>
Date: Fri, 5 Oct 2012 20:30:22 +0000 (+0800)
Subject: Allow prefetching on non-x86 platforms with gcc
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=b8948e84b881c6b3cfaa26fa5512fe4c1800baa0

Allow prefetching on non-x86 platforms with gcc

In particular on ARM processors. Original patch by
Jean-Francois, sligtly modified by me to preserve
the meaning of NO_PREFETCH flag.

Verified with gcc, clang and icc that prefetch instruction
is correctly created.

No functional change.
---

diff --git a/src/misc.cpp b/src/misc.cpp
index fefa8d4f..167eedb3 100644
--- a/src/misc.cpp
+++ b/src/misc.cpp
@@ -237,8 +237,13 @@ void prefetch(char* addr) {
    __asm__ ("");
 #  endif
 
+#  if defined(__INTEL_COMPILER) || defined(__ICL) || defined(_MSC_VER)
   _mm_prefetch(addr, _MM_HINT_T2);
   _mm_prefetch(addr+64, _MM_HINT_T2); // 64 bytes ahead
+#  else
+  __builtin_prefetch(addr);
+  __builtin_prefetch(addr+64);
+#  endif
 }
 
 #endif