From: Zhenqiang Chen <zhenqiang.chen@arm.com>
Date: Fri, 17 Jan 2014 05:43:45 +0000 (+0000)
Subject: arm.c (arm_v7m_tune): Set max_insns_skipped to 2.
X-Git-Tag: releases/gcc-4.9.0~1618
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=82a197a2bb8198cc98bcd10c76be89dcfb3cdf9c;p=thirdparty%2Fgcc.git

arm.c (arm_v7m_tune): Set max_insns_skipped to 2.

ChangeLog:
2014-01-17  Zhenqiang Chen  <zhenqiang.chen@arm.com>

	* config/arm/arm.c (arm_v7m_tune): Set max_insns_skipped to 2.
	(thumb2_final_prescan_insn): Set max to MAX_INSN_PER_IT_BLOCK.

testsuite/ChangeLog:
2014-01-17  Zhenqiang Chen  <zhenqiang.chen@arm.com>

	* gcc.target/arm/its.c: New test.

From-SVN: r206698
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5b0795dae239..eaa192715b14 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2014-01-17  Zhenqiang Chen  <zhenqiang.chen@arm.com>
+
+	* config/arm/arm.c (arm_v7m_tune): Set max_insns_skipped to 2.
+	(thumb2_final_prescan_insn): Set max to MAX_INSN_PER_IT_BLOCK.
+
 2014-01-16  Ilya Enkovich  <ilya.enkovich@intel.com>
 
 	* ipa-ref.c (ipa_remove_stmt_references): Fix references
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 7684db955e31..fc81bf684072 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -1696,7 +1696,7 @@ const struct tune_params arm_v7m_tune =
   &v7m_extra_costs,
   NULL,						/* Sched adj cost.  */
   1,						/* Constant limit.  */
-  5,						/* Max cond insns.  */
+  2,						/* Max cond insns.  */
   ARM_PREFETCH_NOT_BENEFICIAL,
   true,						/* Prefer constant pool.  */
   arm_cortex_m_branch_cost,
@@ -22138,11 +22138,11 @@ thumb2_final_prescan_insn (rtx insn)
   int mask;
   int max;
 
-  /* Maximum number of conditionally executed instructions in a block
-     is minimum of the two max values: maximum allowed in an IT block
-     and maximum that is beneficial according to the cost model and tune.  */
-  max = (max_insns_skipped < MAX_INSN_PER_IT_BLOCK) ?
-    max_insns_skipped : MAX_INSN_PER_IT_BLOCK;
+  /* max_insns_skipped in the tune was already taken into account in the
+     cost model of ifcvt pass when generating COND_EXEC insns.  At this stage
+     just emit the IT blocks as we can.  It does not make sense to split
+     the IT blocks.  */
+  max = MAX_INSN_PER_IT_BLOCK;
 
   /* Remove the previous insn from the count of insns to be output.  */
   if (arm_condexec_count)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a85acbeac849..665d9034d276 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2014-01-17  Zhenqiang Chen  <zhenqiang.chen@arm.com>
+
+	* gcc.target/arm/its.c: New testcase.
+
 2014-01-16  Jan Hubicka  <jh@suse.cz>
 
 	PR ipa/59775
diff --git a/gcc/testsuite/gcc.target/arm/its.c b/gcc/testsuite/gcc.target/arm/its.c
new file mode 100644
index 000000000000..5425f1e92059
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/its.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" }  */
+int test (int a, int b)
+{
+  int r;
+  if (a > 10)
+    {
+      r = a - b;
+      r += 10;
+    }
+  else
+    {
+      r = b - a;
+      r -= 7;
+    }
+  if (r > 0)
+    r -= 3;
+  return r;
+}
+/* { dg-final { scan-assembler-times "\tit" 2 { target arm_thumb2 } } } */