From: Marco Costalba <mcostalba@gmail.com>
Date: Sat, 7 Jul 2012 18:00:05 +0000 (+0100)
Subject: Revert to -O3 with Clang
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=089e54c7fdeb754f7375fea06aa6a464be1297cb;ds=sidebyside

Revert to -O3 with Clang

Instead of -O4 option that does not work with both mingw and
Linux gcc (tested with Clang 3.1).

As reported by Reed Kotler:
Turns out that -O4 is not a valid option for clang unless you have
the proper gold linker and plugins built. That's because -O4 enables
LTO, which writes out bitcode files during the compile, and then loads
those and optimizes them during the link phase.

It requires a linker that supports LLVM's LTO. There is a plugin for
Gold available as part of LLVM.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
---

diff --git a/src/Makefile b/src/Makefile
index 2a03492f..dea8db04 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -270,7 +270,8 @@ ifeq ($(optimize),yes)
 	endif
 
 	ifeq ($(comp),clang)
-		CXXFLAGS += -O4
+		### -O4 requires a linker that supports LLVM's LTO
+		CXXFLAGS += -O3
 
 		ifeq ($(os),osx)
 			ifeq ($(arch),i386)