[ARM] Make gcc.target/arm/its.c more robust

2017-06-15  Thomas Preud'homme  <thomas.preudhomme@arm.com>

    gcc/testsuite/
    * gcc.target/arm/its.c: Check that no IT blocks has more than 2
    instructions in it rather than the number of IT blocks being 2.
    Transfer scan directive arm_thumb2 restriction to the whole
    testcase and restrict further to Thumb-only targets.

From-SVN: r249215

gcc/testsuite/ChangeLog

+2017-06-15  Thomas Preud'homme  <thomas.preudhomme@arm.com>
+
+	* gcc.target/arm/its.c: Check that no IT blocks has more than 2
+	instructions in it rather than the number of IT blocks being 2.
+	Transfer scan directive arm_thumb2 restriction to the whole
+	testcase and restrict further to Thumb-only targets.
+
 2017-06-15  Tamar Christina  <tamar.christina@arm.com>
 
 	* gcc.target/arm/sdiv_costs_1.c:

gcc/testsuite/gcc.target/arm/its.c

 /* { dg-do compile } */
+/* { dg-require-effective-target arm_cortex_m } */
+/* { dg-require-effective-target arm_thumb2 } */
 /* { dg-options "-O2" }  */
 int test (int a, int b)
 {
@@ -17,4 +19,6 @@ int test (int a, int b)
     r -= 3;
   return r;
 }
-/* { dg-final { scan-assembler-times "\tit" 2 { target arm_thumb2 } } } */
+/* Ensure there is no IT block with more than 2 instructions, ie. we only allow
+   IT, ITT and ITE.  */
+/* { dg-final { scan-assembler-not "\\sit\[te\]{2}" } } */