From: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date: Thu, 11 Jun 2015 10:01:11 +0000 (+0000)
Subject: [ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=06b8f7acf3786fafb54e402ebdf794e7ee3caa3e;p=gcc.git

[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
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f89cbb6c9d2..409171ca2f4 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+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
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 353c2c599d9..5744f955f20 100644
--- a/gcc/config/arm/arm.c
+++ b/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.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0accb7c3d71..cf2c0d6cc06 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+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
diff --git a/gcc/testsuite/gcc.target/arm/short-it-ifcvt-1.c b/gcc/testsuite/gcc.target/arm/short-it-ifcvt-1.c
new file mode 100644
index 00000000000..f3d29b7d234
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/short-it-ifcvt-1.c
@@ -0,0 +1,23 @@
+/* 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)" } } */
diff --git a/gcc/testsuite/gcc.target/arm/short-it-ifcvt-2.c b/gcc/testsuite/gcc.target/arm/short-it-ifcvt-2.c
new file mode 100644
index 00000000000..9ac8153069f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/short-it-ifcvt-2.c
@@ -0,0 +1,21 @@
+/* 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)" } } */