From: Pat Haugen <pthaugen@us.ibm.com>
Date: Tue, 22 Apr 2008 19:28:56 +0000 (+0000)
Subject: rs6000.c (rs6000_register_move_cost): Increase cost of LR/CTR moves for Power6.
X-Git-Tag: releases/gcc-4.4.0~5312
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=aafc759a8a4e404469bf39a92bb10522baf4a281;p=thirdparty%2Fgcc.git

rs6000.c (rs6000_register_move_cost): Increase cost of LR/CTR moves for Power6.

	* config/rs6000/rs6000.c (rs6000_register_move_cost): Increase cost
	of LR/CTR moves for Power6.

From-SVN: r134565
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8127c33dbe4c..761cf7ff9948 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2008-04-22  Pat Haugen  <pthaugen@us.ibm.com>
+
+	* config/rs6000/rs6000.c (rs6000_register_move_cost): Increase cost
+	of LR/CTR moves for Power6.
+
 2008-04-22  Kenneth Zadeck <zadeck@naturalbridge.com>
 
 	PR middle-end/36003
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 024c140b2745..6ac9ee159f97 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -21331,6 +21331,12 @@ rs6000_register_move_cost (enum machine_mode mode,
       else if (from == CR_REGS)
 	return 4;
 
+      /* Power6 has slower LR/CTR moves so make them more expensive than
+	 memory in order to bias spills to memory .*/
+      else if (rs6000_cpu == PROCESSOR_POWER6
+	       && reg_classes_intersect_p (from, LINK_OR_CTR_REGS))
+        return 6 * hard_regno_nregs[0][mode];
+
       else
 	/* A move will cost one instruction per GPR moved.  */
 	return 2 * hard_regno_nregs[0][mode];