[arm] PR 80389 - if architecture and cpu mismatch, don't print an architecture name as a CPU name

In this PR we incorrectly print the architecture name in a .cpu
directive in the assembly file when the -mcpu and -march options
conflict (don't target the same base architecture).  In this case the
.arch overrides the .cpu directive and we should emit a .arch option.

PR target/80389
* config/arm/arm.c (arm_configure_build_target): When -mcpu and -arch conflict,
set target->arch_name instead of target->cpu_name.

From-SVN: r246843

gcc/ChangeLog

+2017-04-11  Richard Earnshaw  <rearnsha@arm.com>
+
+	PR target/80389
+	* config/arm/arm.c (arm_configure_build_target): When -mcpu and -arch
+	conflict, set target->arch_name instead of target->cpu_name.
+
 2017-04-11  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/80374

gcc/config/arm/arm.c

@@ -3098,15 +3098,15 @@ arm_configure_build_target (struct arm_build_target *target,
 		arm_selected_tune = arm_selected_cpu;
 
 	      arm_selected_cpu = arm_selected_arch;
+	      target->arch_name = arm_selected_arch->name;
 	    }
 	  else
 	    {
 	      /* Architecture and CPU are essentially the same.
 		 Prefer the CPU setting.  */
 	      arm_selected_arch = NULL;
+	      target->core_name = arm_selected_cpu->name;
 	    }
-
-	  target->core_name = arm_selected_cpu->name;
 	}
       else
 	{