4 files changed, 26 insertions, 27 deletions

diff --git a/gcc/config/arm/arm-c.c b/gcc/config/arm/arm-c.c
index c336a167086..7dee28ec52d 100644
--- a/gcc/config/arm/arm-c.c
+++ b/gcc/config/arm/arm-c.c
@@ -66,8 +66,8 @@ arm_cpu_builtins (struct cpp_reader* pfile)
   def_or_undef_macro (pfile, "__ARM_FEATURE_SAT", TARGET_ARM_SAT);
   def_or_undef_macro (pfile, "__ARM_FEATURE_CRYPTO", TARGET_CRYPTO);
 
-  if (unaligned_access)
-    builtin_define ("__ARM_FEATURE_UNALIGNED");
+  def_or_undef_macro (pfile, "__ARM_FEATURE_UNALIGNED", unaligned_access);
+
   if (TARGET_CRC32)
     builtin_define ("__ARM_FEATURE_CRC32");
 
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index e0cdc209734..362329d5f37 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -2876,6 +2876,28 @@ arm_option_override_internal (struct gcc_options *opts,
   if (!TARGET_THUMB2_P (opts->x_target_flags))
     opts->x_arm_restrict_it = 0;
 
+  /* Enable -munaligned-access by default for
+     - all ARMv6 architecture-based processors when compiling for a 32-bit ISA
+     i.e. Thumb2 and ARM state only.
+     - ARMv7-A, ARMv7-R, and ARMv7-M architecture-based processors.
+     - ARMv8 architecture-base processors.
+
+     Disable -munaligned-access by default for
+     - all pre-ARMv6 architecture-based processors
+     - ARMv6-M architecture-based processors.  */
+
+  if (! opts_set->x_unaligned_access)
+    {
+      opts->x_unaligned_access = (TARGET_32BIT_P (opts->x_target_flags)
+			  && arm_arch6 && (arm_arch_notm || arm_arch7));
+    }
+  else if (opts->x_unaligned_access == 1
+	   && !(arm_arch6 && (arm_arch_notm || arm_arch7)))
+    {
+      warning (0, "target CPU does not support unaligned accesses");
+     opts->x_unaligned_access = 0;
+    }
+
   /* Don't warn since it's on by default in -O2.  */
   if (TARGET_THUMB1_P (opts->x_target_flags))
     opts->x_flag_schedule_insns = 0;
@@ -3281,30 +3303,6 @@ arm_option_override (void)
 	fix_cm3_ldrd = 0;
     }
 
-  /* Enable -munaligned-access by default for
-     - all ARMv6 architecture-based processors when compiling for a 32-bit ISA
-     i.e. Thumb2 and ARM state only.
-     - ARMv7-A, ARMv7-R, and ARMv7-M architecture-based processors.
-     - ARMv8 architecture-base processors.
-
-     Disable -munaligned-access by default for
-     - all pre-ARMv6 architecture-based processors
-     - ARMv6-M architecture-based processors.  */
-
-  if (unaligned_access == 2)
-    {
-      if (TARGET_32BIT && arm_arch6 && (arm_arch_notm || arm_arch7))
-	unaligned_access = 1;
-      else
-	unaligned_access = 0;
-    }
-  else if (unaligned_access == 1
-	   && !(arm_arch6 && (arm_arch_notm || arm_arch7)))
-    {
-      warning (0, "target CPU does not support unaligned accesses");
-      unaligned_access = 0;
-    }
-
   /* Hot/Cold partitioning is not currently supported, since we can't
      handle literal pool placement in that case.  */
   if (flag_reorder_blocks_and_partition)
diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index 6ed8ad3823e..fd999dd0941 100644
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -131,6 +131,7 @@ extern void (*arm_lang_output_object_attributes_hook)(void);
 #define TARGET_ARM_P(flags)    (!TARGET_THUMB_P (flags))
 #define TARGET_THUMB1_P(flags) (TARGET_THUMB_P (flags) && !arm_arch_thumb2)
 #define TARGET_THUMB2_P(flags) (TARGET_THUMB_P (flags) && arm_arch_thumb2)
+#define TARGET_32BIT_P(flags)  (TARGET_ARM_P (flags) || TARGET_THUMB2_P (flags))
 
 /* Run-time Target Specification.  */
 #define TARGET_SOFT_FLOAT		(arm_float_abi == ARM_FLOAT_ABI_SOFT)
diff --git a/gcc/config/arm/arm.opt b/gcc/config/arm/arm.opt
index 6f2db8f3a0d..1e438a9c092 100644
--- a/gcc/config/arm/arm.opt
+++ b/gcc/config/arm/arm.opt
@@ -267,7 +267,7 @@ Avoid overlapping destination and address registers on LDRD instructions
 that may trigger Cortex-M3 errata.
 
 munaligned-access
-Target Report Var(unaligned_access) Init(2)
+Target Report Var(unaligned_access) Init(2) Save
 Enable unaligned word and halfword accesses to packed data.
 
 mneon-for-64bits