From: Tim 'mithro' Ansell <me@mith.ro>
Date: Tue, 27 Nov 2018 08:48:44 +0000 (-0800)
Subject: software: enable link time optimization (LTO)
X-Git-Tag: 24jan2021_ls180~636^2
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=718a65c3c9353a9b920dd568a63b60e7d9a6a950;p=litex.git

software: enable link time optimization (LTO)

Co-authored-by: Pawel Czarnecki <pczarnecki@internships.antmicro.com>
---

diff --git a/litex/soc/software/bios/Makefile b/litex/soc/software/bios/Makefile
index 66be372c..6966ff97 100755
--- a/litex/soc/software/bios/Makefile
+++ b/litex/soc/software/bios/Makefile
@@ -29,7 +29,7 @@ bios.elf: $(BIOS_DIRECTORY)/linker.ld $(OBJECTS)
 
 
 %.elf: ../libbase/crt0-$(CPU)-ctr.o ../libnet/libnet.a ../libbase/libbase-nofloat.a ../libcompiler_rt/libcompiler_rt.a
-	$(LD) $(LDFLAGS) -T $(BIOS_DIRECTORY)/linker.ld -N -o $@ \
+	$(CC) $(LDFLAGS) -T $(BIOS_DIRECTORY)/linker.ld -N -o $@ \
 		../libbase/crt0-$(CPU)-ctr.o \
 		$(OBJECTS) \
 		-L../libnet \
diff --git a/litex/soc/software/common.mak b/litex/soc/software/common.mak
index 18fc50c3..259ff473 100644
--- a/litex/soc/software/common.mak
+++ b/litex/soc/software/common.mak
@@ -14,7 +14,7 @@ else
 CC_normal      := $(TARGET_PREFIX)gcc -std=gnu99
 CX_normal      := $(TARGET_PREFIX)g++
 endif
-AR_normal      := $(TARGET_PREFIX)ar
+AR_normal      := $(TARGET_PREFIX)gcc-ar
 LD_normal      := $(TARGET_PREFIX)ld
 OBJCOPY_normal := $(TARGET_PREFIX)objcopy
 
@@ -46,10 +46,10 @@ DEPFLAGS += -MD -MP
 # Toolchain options
 #
 INCLUDES = -I$(SOC_DIRECTORY)/software/include/base -I$(SOC_DIRECTORY)/software/include -I$(SOC_DIRECTORY)/common -I$(BUILDINC_DIRECTORY)
-COMMONFLAGS = $(DEPFLAGS) -Os $(CPUFLAGS) -g3 -fomit-frame-pointer -Wall -fno-builtin -nostdinc $(INCLUDES)
+COMMONFLAGS = $(DEPFLAGS) -Os $(CPUFLAGS) -g3 -fomit-frame-pointer -Wall -fno-builtin -nostdinc $(INCLUDES) -flto -fuse-linker-plugin -ffunction-sections -fdata-sections -nostartfiles -nostdlib -nodefaultlibs
 CFLAGS = $(COMMONFLAGS) -fexceptions -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes
 CXXFLAGS = $(COMMONFLAGS) -std=c++11 -I$(SOC_DIRECTORY)/software/include/basec++ -fexceptions -fno-rtti -ffreestanding
-LDFLAGS = -nostdlib -nodefaultlibs -L$(BUILDINC_DIRECTORY)
+LDFLAGS = -nostdlib -nodefaultlibs -Os $(CPUFLAGS) -L$(BUILDINC_DIRECTORY)
 
 define compilexx
 $(CX) -c $(CXXFLAGS) $(1) $< -o $@