re PR target/70496 (inadvertent change to ASM_APP_OFF for .arm / .thumb directives.)

Fix PR target/70496

While doing the unified asm rewrite - I inadvertently changed the
meaning of ASM_APP_OFF which causes failures when folks who know what
they are doing switch between arm and thumb states within a
function. The intent of the unified asm rewrite was not to affect any
inline assembler code in that it would remain in divided syntax by
default and switching back to unified asm in normal compiled code
after the inline assembler block. Thanks to Jim Wilson for pointing it
out on the linaro list.

Fixed thusly and a test is added. Tested arm-none-eabi cross and
applied.

Ramana

2016-04-01  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>

	PR target/70496
	* config/arm/arm.h (ASM_APP_OFF): Handle TARGET_ARM
	and TARGET_THUMB.

2016-04-01  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>

	PR target/70496
	* gcc.target/arm/pr70496.c: New test.

From-SVN: r234675

gcc/ChangeLog

+2016-04-01  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>
+
+	PR target/70496
+	* config/arm/arm.h (ASM_APP_OFF): Handle TARGET_ARM
+	and TARGET_THUMB.
+
 2016-04-01  Nathan Sidwell  <nathan@acm.org>
 
 	* tree.def (TRY_CATCH_EXPR): Correct documentation.

gcc/config/arm/arm.h

@@ -2037,7 +2037,8 @@ extern int making_const_table;
 		    "\t.syntax divided\n")
 
 #undef  ASM_APP_OFF
-#define ASM_APP_OFF "\t.syntax unified\n"
+#define ASM_APP_OFF (TARGET_ARM ? "\t.arm\n\t.syntax unified\n" : \
+		     "\t.thumb\n\t.syntax unified\n")
 
 /* Output a push or a pop instruction (only used when profiling).
    We can't push STATIC_CHAIN_REGNUM (r12) directly with Thumb-1.  We know

gcc/testsuite/ChangeLog

+2016-04-01  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>
+
+	PR target/70496
+	* gcc.target/arm/pr70496.c: New test.
+
 2016-04-01  Nathan Sidwell  <nathan@acm.org>
 
 	PR c++/68475

gcc/testsuite/gcc.target/arm/pr70496.c

+/* { dg-do assemble } */
+/* { dg-options "-mthumb -O2" } */
+/* { dg-require-effective-target arm_thumb2_ok } */
+
+int i;
+void
+main (void)
+{
+  __asm__ volatile (".arm");
+  i = 0;
+  __asm__ volatile ("\n cbz r0, 2f\n2:");
+}