build: build softfloat with pic and provide shared library

vector unit tests need identical floating library to generate golden
pattern

Signed-off-by: Chih-Min Chao <chihmin.chao@sifive.com>

Makefile.in

@@ -209,11 +209,15 @@ $(2)_reverse_deps   := $$(call reverse_list,$$($(2)_subproject_deps))
 $(2)_lib_libs       := $$($(2)_reverse_deps)
 $(2)_lib_libnames   := $$(patsubst %, lib%.a, $$($(2)_lib_libs))
 $(2)_lib_libarg     := $$(patsubst %, -l%, $$($(2)_lib_libs))
+$(2)_lib_libnames_shared	:= $$(if $$($(2)_install_shared_lib),lib$(1).so,)
 
 lib$(1).a : $$($(2)_objs) $$($(2)_c_objs) $$($(2)_lib_libnames)
 	$(AR) rcs $$@ $$^
+lib$(1).so : $$($(2)_objs) $$($(2)_c_objs) $$($(2)_lib_libnames_shared)
+	$(LINK) -shared -o $$@ $(if $(filter Darwin,$(shell uname -s)),-install_name $(install_libs_dir)/$$@) $$^ $$($(2)_lib_libarg) $(LIBS)
 
 $(2)_junk += lib$(1).a
+$(2)_junk += $$(if $$($(2)_install_shared_lib),lib$(1).so,)
 
 # Build unit tests
 
@@ -303,6 +307,7 @@ test_outs += $$($(2)_test_outs)
 
 install_hdrs += $$(addprefix $(src_dir)/$(1)/, $$($(2)_install_hdrs))
 install_libs += $$(if $$($(2)_install_lib),lib$(1).a,)
+install_libs += $$(if $$($(2)_install_shared_lib),lib$(1).so,)
 install_exes += $$($(2)_install_prog_exes)
 install_pcs  += riscv-$(1).pc
 

softfloat/softfloat.mk.in

@@ -225,6 +225,10 @@ softfloat_c_srcs = \
 	ui64_to_f32.c \
 	ui64_to_f64.c \
 
+softfloat_CFLAGS = -fPIC
+
+softfloat_install_shared_lib = yes
+
 softfloat_test_srcs =
 
 softfloat_install_prog_srcs =