This option adds a per-multilib variant that specifies -Os
instead of the default.
Signed-off-by: Keith Packard <kei...@keithp.com>
---
config-ml.in | 2 +-
gcc/Makefile.in | 32 +++++++++++++++++++++++++++-----
gcc/configure | 13 +++++++++++++
gcc/configure.ac | 7 +++++++
gcc/doc/install.texi | 12 ++++++++++++
5 files changed, 60 insertions(+), 6 deletions(-)
diff --git a/config-ml.in b/config-ml.in
index 7934a1ddf4b..c01fe4741c2 100644
--- a/config-ml.in
+++ b/config-ml.in
@@ -175,7 +175,7 @@ eval scan_arguments "${ac_configure_args}"
unset scan_arguments
# Only do this if --enable-multilib.
-if [ "${enable_multilib}" = yes ]; then
+if [ "${enable_multilib}" = yes -o "${enable_multilib_space}" = yes ]; then
# Compute whether this is the library's top level directory
# (ie: not a multilib subdirectory, and not a subdirectory like newlib/src).
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 9ca389a9c61..c2263fae1d5 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -2470,25 +2470,47 @@ libgcc.mvars: config.status Makefile specs xgcc$(exeext)
mv tmp-libgcc.mvars libgcc.mvars
+ifeq (@enable_multilib_space@,yes)
+MULTILIB_OPTIONS += Os
+MULTILIB_DIRNAMES += space
+MULTILIB_MATCHES += Os=Oz
+
+MULTILIB_OSDIRNAMES_SPACE = $(MULTILIB_OSDIRNAMES)\
+ $(if $(findstring =,$(MULTILIB_OSDIRNAMES)),\
+ $(foreach OSD,$(MULTILIB_OSDIRNAMES),$(subst =,/Os=,$(OSD))/space),\
+ $(if $(MULTILIB_OSDIRNAMES),space,))
+MULTILIB_REQUIRED_SPACE = $(if $(MULTILIB_REQUIRED),Os $(foreach REQ,
$(MULTILIB_REQUIRED), $(REQ) $(REQ)/Os),)
+MULTILIB_EXCEPTIONS_SPACE = $(foreach EXC, $(MULTILIB_EXCEPTIONS), $(EXC)
$(EXC)/Os)
+MULTILIB_REUSE_SPACE = $(foreach REU, $(MULTILIB_REUSE), $(REU) $(subst
=,/Os=,$(REU))/Os)
+MULTILIB_ENABLE = yes
+else
+MULTILIB_OSDIRNAMES_SPACE = $(MULTILIB_OSDIRNAMES)
+MULTILIB_REQUIRED_SPACE = $(MULTILIB_REQUIRED)
+MULTILIB_EXCEPTIONS_SPACE = $(MULTILIB_EXCEPTIONS)
+MULTILIB_REUSE_SPACE = $(MULTILIB_REUSE)
+MULTILIB_ENABLE = @enable_multilib@
+endif
+
# Use the genmultilib shell script to generate the information the gcc
# driver program needs to select the library directory based on the
# switches.
multilib.h: s-mlib; @true
s-mlib: $(srcdir)/genmultilib Makefile
if test @enable_multilib@ = yes \
+ || test @enable_multilib_space@ = yes \
|| test -n "$(MULTILIB_OSDIRNAMES)"; then \
$(SHELL) $(srcdir)/genmultilib \
"$(MULTILIB_OPTIONS)" \
"$(MULTILIB_DIRNAMES)" \
"$(MULTILIB_MATCHES)" \
- "$(MULTILIB_EXCEPTIONS)" \
+ "$(MULTILIB_EXCEPTIONS_SPACE)" \
"$(MULTILIB_EXTRA_OPTS)" \
"$(MULTILIB_EXCLUSIONS)" \
- "$(MULTILIB_OSDIRNAMES)" \
- "$(MULTILIB_REQUIRED)" \
+ "$(MULTILIB_OSDIRNAMES_SPACE)" \
+ "$(MULTILIB_REQUIRED_SPACE)" \
"$(if $(MULTILIB_OSDIRNAMES),,$(MULTIARCH_DIRNAME))" \
- "$(MULTILIB_REUSE)" \
- "@enable_multilib@" \
+ "$(MULTILIB_REUSE_SPACE)" \
+ "$(MULTILIB_ENABLE)" \
> tmp-mlib.h; \
else \
$(SHELL) $(srcdir)/genmultilib '' '' '' '' '' '' '' '' \
diff --git a/gcc/configure b/gcc/configure
index 063b9ce6701..08d23c0ccb6 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -859,6 +859,7 @@ DEFAULT_MATCHPD_PARTITIONS
with_float
with_cpu
enable_multiarch
+enable_multilib_space
enable_multilib
coverage_flags
valgrind_command
@@ -980,6 +981,7 @@ enable_coverage
enable_gather_detailed_mem_stats
enable_valgrind_annotations
enable_multilib
+enable_multilib_space
enable_multiarch
with_stack_clash_protection_guard_size
with_matchpd_partitions
@@ -1723,6 +1725,7 @@ Optional Features:
--enable-valgrind-annotations
enable valgrind runtime interaction
--enable-multilib enable library support for multiple ABIs
+ --enable-multilib-space enable extra -Os variant for every multilib ABI
--enable-multiarch enable support for multiarch paths
--enable-__cxa_atexit enable __cxa_atexit for C++
--enable-decimal-float={no,yes,bid,dpd}
@@ -7860,6 +7863,16 @@ fi
+# Determine whether or not -Os multilibs are enabled.
+# Check whether --enable-multilib-space was given.
+if test "${enable_multilib_space+set}" = set; then :
+ enableval=$enable_multilib_space;
+else
+ enable_multilib_space=no
+fi
+
+
+
# Determine whether or not multiarch is enabled.
# Check whether --enable-multiarch was given.
if test "${enable_multiarch+set}" = set; then :
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 3243472680c..0ab6a6a6858 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -864,6 +864,13 @@ AC_ARG_ENABLE(multilib,
[], [enable_multilib=yes])
AC_SUBST(enable_multilib)
+# Determine whether or not -Os multilibs are enabled.
+AC_ARG_ENABLE(multilib-space,
+[AS_HELP_STRING([--enable-multilib-space],
+ [enable extra -Os variant for every multilib ABI])],
+[], [enable_multilib_space=no])
+AC_SUBST(enable_multilib_space)
+
# Determine whether or not multiarch is enabled.
AC_ARG_ENABLE(multiarch,
[AS_HELP_STRING([--enable-multiarch],
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index b5509ff0c86..49523a2bac1 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -1324,6 +1324,18 @@ for aarch64*-*-*, amdgcn*-*-*, arm*-*-*, loongarch*-*-*,
nvptx-*, riscv*-*-*,
sh*-*-* and x86-64-*-linux*.
The accepted values and meaning for each target is given below.
+@item --enable-multilib-space
+Double the set of target libraries built by building two versions of
+each specified by the options above, one using @option{-O2 }and
+another using @option{-Os}. During linking, the @option{-O2} variant
+will be selected by default. Select the @option{-Os} variant by
+including @option{-Os} or @option{-Oz} in the linker command
+line. Note: because multilib selection only looks for the presence of
+compiler flags (unlike options controlling the compiler optimization
+level), a subsequent optimization flag other than @option{-Os} or or
+@option{-Oz} will not switch back to the @option{-O2} library
+versions.
+
@table @code
@item aarch64*-*-*
@var{list} is a comma separated list of @code{ilp32}, and @code{lp64}
--
2.49.0
