arm.c (arm_arch6m): New variable to denote armv6-m architecture.

2012-10-11  Terry Guo  <terry.guo@arm.com>

        * config/arm/arm.c (arm_arch6m): New variable to denote armv6-m
        architecture.
        * config/arm/arm.h (TARGET_HAVE_DMB): The armv6-m also has DMB
        instruction.

From-SVN: r192346

gcc/ChangeLog

+2012-10-11  Terry Guo  <terry.guo@arm.com>
+
+	* config/arm/arm.c (arm_arch6m): New variable to denote armv6-m
+	architecture.
+	* config/arm/arm.h (TARGET_HAVE_DMB): The armv6-m also has DMB
+	instruction.
+
 2012-10-11  Hans-Peter Nilsson  <hp@bitrange.com>
 
 	PR target/54373

gcc/config/arm/arm.c

@@ -753,6 +753,9 @@ int arm_arch6 = 0;
 /* Nonzero if this chip supports the ARM 6K extensions.  */
 int arm_arch6k = 0;
 
+/* Nonzero if instructions present in ARMv6-M can be used.  */
+int arm_arch6m = 0;
+
 /* Nonzero if this chip supports the ARM 7 extensions.  */
 int arm_arch7 = 0;
 
@@ -1737,6 +1740,7 @@ arm_option_override (void)
   arm_arch6 = (insn_flags & FL_ARCH6) != 0;
   arm_arch6k = (insn_flags & FL_ARCH6K) != 0;
   arm_arch_notm = (insn_flags & FL_NOTM) != 0;
+  arm_arch6m = arm_arch6 && !arm_arch_notm;
   arm_arch7 = (insn_flags & FL_ARCH7) != 0;
   arm_arch7em = (insn_flags & FL_ARCH7EM) != 0;
   arm_arch_thumb2 = (insn_flags & FL_THUMB2) != 0;

gcc/config/arm/arm.h

@@ -325,7 +325,7 @@ extern void (*arm_lang_output_object_attributes_hook)(void);
 #define TARGET_UNIFIED_ASM TARGET_THUMB2
 
 /* Nonzero if this chip provides the DMB instruction.  */
-#define TARGET_HAVE_DMB		(arm_arch7)
+#define TARGET_HAVE_DMB		(arm_arch6m || arm_arch7)
 
 /* Nonzero if this chip implements a memory barrier via CP15.  */
 #define TARGET_HAVE_DMB_MCR	(arm_arch6 && ! TARGET_HAVE_DMB \
@@ -470,6 +470,9 @@ extern int arm_arch6;
 /* Nonzero if this chip supports the ARM Architecture 6k extensions.  */
 extern int arm_arch6k;
 
+/* Nonzero if instructions present in ARMv6-M can be used.  */
+extern int arm_arch6m;
+
 /* Nonzero if this chip supports the ARM Architecture 7 extensions.  */
 extern int arm_arch7;