[SPARC] Support for --with-{cpu,tune}-{32,64} in sparc*-* targets

[jose dot marchesi at oracle dot com (Jose E. Marchesi)]

Hi people.

This patch adds support for the --with-{cpu,tune}-{32,64} configure
options to sparc*-* targets.  This allows to separately select cpus and
tune options for -m32 and -m64 modes in multilib compilers.

Tested in sparc64-*-* and sparcv9-*-* targets.

2016-04-28  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* config.gcc (sparc*-*-*): Support cpu_32, cpu_64, tune_32 and
	tune_64.
	* doc/install.texi (--with-cpu-32, --with-cpu-64): Document
	support on SPARC.
	* config/sparc/linux64.h (OPTION_DEFAULT_SPECS): Add entries for
	cpu_32, cpu_64, tune_32 and tune_64.



diff --git a/gcc/config.gcc b/gcc/config.gcc
index f66e48c..e4bf17a 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -4280,9 +4280,9 @@ case "${target}" in
 		esac
 		;;
 	sparc*-*-*)
-		supported_defaults="cpu float tune"
+		supported_defaults="cpu cpu_32 cpu_64 float tune tune_32 tune_64"
 
-		for which in cpu tune; do
+		for which in cpu cpu_32 cpu_64 tune tune_32 tune_64; do
 			eval "val=\$with_$which"
 			case ${val} in
 			"" | sparc | sparcv9 | sparc64 \
diff --git a/gcc/config/sparc/linux64.h b/gcc/config/sparc/linux64.h
index a1ef325..9d53c29 100644
--- a/gcc/config/sparc/linux64.h
+++ b/gcc/config/sparc/linux64.h
@@ -164,22 +164,42 @@ extern const char *host_detect_local_cpu (int argc, const char **argv);
 #endif
 
 /* Support for a compile-time default CPU, et cetera.  The rules are:
-   --with-cpu is ignored if -mcpu is specified.
-   --with-tune is ignored if -mtune is specified.
+   --with-cpu is ignored if -mcpu is specified; likewise --with-cpu-32
+     and --with-cpu-64.
+   --with-tune is ignored if -mtune is specified; likewise --with-tune-32
+     and --with-tune-64.
    --with-float is ignored if -mhard-float, -msoft-float, -mfpu, or -mno-fpu
      are specified.
    In the SPARC_BI_ARCH compiler we cannot pass %{!mcpu=*:-mcpu=%(VALUE)}
    here, otherwise say -mcpu=v7 would be passed even when -m64.
-   CC1_SPEC above takes care of this instead.  */
+   CC1_SPEC above takes care of this instead.
+
+   Note that the order of the cpu* and tune* options matters: the
+   config.gcc file always sets with_cpu to some value, even if the
+   user didn't use --with-cpu when invoking the configure script.
+   This value is based on the target name.  Therefore we have to make
+   sure that --with-cpu-32 takes precedence to --with-cpu in < v9
+   systems, and that --with-cpu-64 takes precedence to --with-cpu in
+   >= v9 systems.  As for the tune* options, in some platforms
+   config.gcc also sets a default value for it if the user didn't use
+   --with-tune when invoking the configure script.  */
 #undef OPTION_DEFAULT_SPECS
 #if DEFAULT_ARCH32_P
 #define OPTION_DEFAULT_SPECS \
+  {"cpu_32", "%{!m64:%{!mcpu=*:-mcpu=%(VALUE)}}" }, \
+  {"cpu_64", "%{m64:%{!mcpu=*:-mcpu=%(VALUE)}}" }, \
   {"cpu", "%{!m64:%{!mcpu=*:-mcpu=%(VALUE)}}" }, \
+  {"tune_32", "%{!m64:%{!mtune=*:-mtune=%(VALUE)}}" }, \
+  {"tune_64", "%{m64:%{!mtune=*:-mtune=%(VALUE)}}" }, \
   {"tune", "%{!mtune=*:-mtune=%(VALUE)}" }, \
   {"float", "%{!msoft-float:%{!mhard-float:%{!mfpu:%{!mno-fpu:-m%(VALUE)-float}}}}" }
 #else
 #define OPTION_DEFAULT_SPECS \
+  {"cpu_32", "%{m32:%{!mcpu=*:-mcpu=%(VALUE)}}" }, \
+  {"cpu_64", "%{!m32:%{!mcpu=*:-mcpu=%(VALUE)}}" }, \
   {"cpu", "%{!m32:%{!mcpu=*:-mcpu=%(VALUE)}}" }, \
+  {"tune_32", "%{m32:%{!mtune=*:-mtune=%(VALUE)}}" },	\
+  {"tune_64", "%{!m32:%{!mtune=*:-mtune=%(VALUE)}}" },	\
   {"tune", "%{!mtune=*:-mtune=%(VALUE)}" }, \
   {"float", "%{!msoft-float:%{!mhard-float:%{!mfpu:%{!mno-fpu:-m%(VALUE)-float}}}}" }
 #endif
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index e1ca26c..ee2494e 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -1241,7 +1241,7 @@ This option is only supported on some targets, including ARC, ARM, i386, M68k,
 PowerPC, and SPARC@.  It is mandatory for ARC@.  The @option{--with-cpu-32} and
 @option{--with-cpu-64} options specify separate default CPUs for
 32-bit and 64-bit modes; these options are only supported for i386,
-x86-64 and PowerPC.
+x86-64, PowerPC, and SPARC@.
 
 @item --with-schedule=@var{cpu}
 @itemx --with-arch=@var{cpu}