Rewrite link time optimization in Makefile

[stockfish] / src / Makefile

diff --git a/src/Makefile b/src/Makefile
index 9650c7f615d39fbca602894ba32075306650f93a..1e765faad581025f642e44dce80baf18a9306a9f 100644 (file)
--- a/src/Makefile
+++ b/src/Makefile
@@ -308,15 +308,19 @@ endif
 
 ### 3.10 popcnt
 ifeq ($(popcnt),yes)
 
 ### 3.10 popcnt
 ifeq ($(popcnt),yes)

-       CXXFLAGS += -DUSE_POPCNT
-
-    ### For gcc we add also msse3 support and Link Time Optimization, note that
-    ### this is a mix of compile and link time options because the lto link phase
-    ### needs access to the optimization flags.
-    ifeq ($(comp),gcc)
-        CXXFLAGS += -msse3 -flto
-        LDFLAGS += $(CXXFLAGS)
-    endif
+       CXXFLAGS += -msse3 -DUSE_POPCNT
+endif
+
+### 3.11 Link Time Optimization, it works since gcc 4.5 but not on mingw.
+### This is a mix of compile and link time options because the lto link phase
+### needs access to the optimization flags.
+ifeq ($(comp),gcc)
+       GCC_MAJOR := `gcc -dumpversion | cut -f1 -d.`
+       GCC_MINOR := `gcc -dumpversion | cut -f2 -d.`
+       ifeq (1,$(shell expr \( $(GCC_MAJOR) \> 4 \) \| \( $(GCC_MAJOR) \= 4 \& $(GCC_MINOR) \>= 5 \)))
+               CXXFLAGS += -flto
+               LDFLAGS += $(CXXFLAGS)
+       endif

 endif
 
 ### ==========================================================================
 endif
 
 ### ==========================================================================