[ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place

	* config/arm/arm.c (arm_option_params_internal): When optimising
	for speed set max_insns_skipped when arm_restrict_it.

	* gcc.target/arm/short-it-ifcvt-1.c: New test.
	* gcc.target/arm/short-it-ifcvt-2.c: Likewise.

From-SVN: r224367

gcc/ChangeLog

+2015-06-11  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* config/arm/arm.c (arm_option_params_internal): When optimising
+	for speed set max_insns_skipped when arm_restrict_it.
+
 2015-06-11  Christian Bruel  <christian.bruel@st.com>
 
 	PR target/52144

gcc/config/arm/arm.c

@@ -2788,7 +2788,10 @@ arm_option_params_internal (struct gcc_options *opts)
         max_insns_skipped = opts->x_arm_restrict_it ? 1 : 4;
     }
   else
-    max_insns_skipped = current_tune->max_insns_skipped;
+    /* When -mrestrict-it is in use tone down the if-conversion.  */
+    max_insns_skipped
+      = (TARGET_THUMB2_P (opts->x_target_flags) && opts->x_arm_restrict_it)
+         ? 1 : current_tune->max_insns_skipped;
 }
 
 /* Options after initial target override.  */

gcc/testsuite/ChangeLog

+2015-06-11  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* gcc.target/arm/short-it-ifcvt-1.c: New test.
+	* gcc.target/arm/short-it-ifcvt-2.c: Likewise.
+
 2015-06-11  Christian Bruel  <christian.bruel@st.com>
 
 	PR target/52144

gcc/testsuite/gcc.target/arm/short-it-ifcvt-1.c

+/* Test that ifcvt is not being too aggressive when -mrestrict-it.  */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mrestrict-it" } */
+/* { dg-require-effective-target arm_thumb2_ok } */
+
+int
+f1(int x, int y, int z)
+{
+  if (x > 100)
+    {
+      x++;
+      z = -z;
+    }
+  else
+    {
+      x = -x;
+      y = -y;
+      z = 1;
+    }
+  return x + y + z;
+}
+
+/* { dg-final { scan-assembler "b(gt|le)" } } */

gcc/testsuite/gcc.target/arm/short-it-ifcvt-2.c

+/* Test that ifcvt is not being too aggressive when -mrestrict-it.  */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mrestrict-it" } */
+/* { dg-require-effective-target arm_thumb2_ok } */
+
+int
+f1(int x, int y, int z)
+{
+  if (x > 100)
+    {
+      x++;
+      z = -z;
+    }
+  else
+    {
+      x = -x;
+      y = -y;
+    }
+  return x + y + z;
+}
+/* { dg-final { scan-assembler "b(gt|le)" } } */