[ARM] fix big.LITTLE spec rewriting

gcc/

	* common/config/arm/arm-common.c
	(arm_rewrite_mcpu): Handle multiple names.
	* config/arm/arm.h
	(BIG_LITTLE_SPEC): Do not discard mcpu switches.

From-SVN: r207133

gcc/ChangeLog

 2014-01-27  James Greenhalgh  <james.greenhalgh@arm.com>
 
+	* common/config/arm/arm-common.c
+	(arm_rewrite_mcpu): Handle multiple names.
+	* config/arm/arm.h
+	(BIG_LITTLE_SPEC): Do not discard mcpu switches.
+
+2014-01-27  James Greenhalgh  <james.greenhalgh@arm.com>
+
 	* gimple-builder.h (create_gimple_tmp): Delete.
 
 2014-01-27  Christian Bruel  <christian.bruel@st.com>

gcc/common/config/arm/arm-common.c

@@ -86,13 +86,15 @@ arm_rewrite_selected_cpu (const char *name)
 
 /* Called by the driver to rewrite a name passed to the -mcpu
    argument in preparation to be passed to the assembler.  The
-   name will be in ARGV[0], ARGC should always be 1.  */
+   names passed from the command line will be in ARGV, we want
+   to use the right-most argument, which should be in
+   ARGV[ARGC - 1].  ARGC should always be greater than 0.  */
 
 const char *
 arm_rewrite_mcpu (int argc, const char **argv)
 {
-  gcc_assert (argc == 1);
-  return arm_rewrite_selected_cpu (argv[0]);
+  gcc_assert (argc);
+  return arm_rewrite_selected_cpu (argv[argc - 1]);
 }
 
 #undef ARM_CPU_NAME_LENGTH

gcc/config/arm/arm.h

@@ -2356,7 +2356,7 @@ extern int making_const_table;
 #define MAX_LDM_STM_OPS 4
 
 #define BIG_LITTLE_SPEC \
-   " %{mcpu=*:%<mcpu=* -mcpu=%:rewrite_mcpu(%{mcpu=*:%*})}" \
+   " %{mcpu=*:-mcpu=%:rewrite_mcpu(%{mcpu=*:%*})}"
 
 extern const char *arm_rewrite_mcpu (int argc, const char **argv);
 #define BIG_LITTLE_CPU_SPEC_FUNCTIONS \