Added gcc lto (Link Time Optimization) option

[stockfish] / src / Makefile

diff --git a/src/Makefile b/src/Makefile
index eb6390aa13462b765aa72206abe01974c1fffe0e..0a56e263ee800442434b6baf1ea4a5ad295d8c67 100644 (file)
--- a/src/Makefile
+++ b/src/Makefile
@@ -52,6 +52,7 @@ OBJS = benchmark.o bitbase.o bitboard.o book.o endgame.o evaluate.o main.o \
 # bsfq = no/yes       --- -DUSE_BSFQ  --- Use bsfq x86_64 asm-instruction
 #                                     --- (Works only with GCC and ICC 64-bit)
 # popcnt = no/yes     --- -DUSE_POPCNT --- Use popcnt x86_64 asm-instruction
+# lto = no/yes        --- -flto       --- gcc Link Time Optimization
 #
 # Note that Makefile is space sensitive, so when adding new architectures
 # or modifying existing flags, you have to make sure there are no extra spaces
@@ -123,6 +124,7 @@ ifeq ($(ARCH),x86-64-modern)
        prefetch = yes
        bsfq = yes
        popcnt = yes
+       lto = yes
 endif
 
 ifeq ($(ARCH),x86-32)
@@ -311,13 +313,18 @@ ifeq ($(popcnt),yes)
        CXXFLAGS += -DUSE_POPCNT
 endif
 
+### 3.11 lto.
+### Note that this is a mix of compile and link time options
+### because the lto link phase needs access to the optimization flags
+ifeq ($(lto),yes)
+       CXXFLAGS += -flto
+       LDFLAGS += $(CXXFLAGS) -static
+endif
+
 ### ==========================================================================
 ### Section 4. Public targets
 ### ==========================================================================
 
-default:
-       $(MAKE) ARCH=$(ARCH) COMP=$(COMP) build
-
 help:
        @echo ""
        @echo "To compile stockfish, type: "
@@ -431,6 +438,9 @@ clean:
 testrun:
        @$(PGOBENCH)
 
+default:
+       help
+
 ### ==========================================================================
 ### Section 5. Private targets
 ### ==========================================================================