From: Steven Bosscher <steven@gcc.gnu.org>
Date: Thu, 30 Nov 2006 07:24:03 +0000 (+0000)
Subject: cselib.c (cselib_init): Use special MEM rtx form for callmem.
X-Git-Tag: releases/gcc-4.3.0~8211
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ac3768f69a29b98a3db963b3cc17cc1d721572d8;p=thirdparty%2Fgcc.git

cselib.c (cselib_init): Use special MEM rtx form for callmem.

	* cselib.c (cselib_init): Use special MEM rtx form for callmem.
	* alias.c (canon_true_dependence): Update comment.

From-SVN: r119358
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index dd83c8e84ccb..9a5419e9f779 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2006-11-30  Steven Bosscher  <steven@gcc.gnu.org>
+
+	* cselib.c (cselib_init): Use special MEM rtx form for callmem.
+	* alias.c (canon_true_dependence): Update comment.
+
 2006-11-30  Steven Bosscher  <steven@gcc.gnu.org>
 
 	* cgraphunit.c (cgraph_finalize_compilation_unit): Add a newline
diff --git a/gcc/alias.c b/gcc/alias.c
index a3634ac1f93f..7a36284cb3af 100644
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -2151,7 +2151,7 @@ true_dependence (rtx mem, enum machine_mode mem_mode, rtx x,
     return 1;
 
   /* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
-     This is used in epilogue deallocation functions.  */
+     This is used in epilogue deallocation functions, and in cselib.  */
   if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
     return 1;
   if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
diff --git a/gcc/cselib.c b/gcc/cselib.c
index 4070da7c01f0..460538857214 100644
--- a/gcc/cselib.c
+++ b/gcc/cselib.c
@@ -1473,9 +1473,11 @@ cselib_init (bool record_memory)
 				       sizeof (cselib_val), 10);
   value_pool = create_alloc_pool ("value", RTX_CODE_SIZE (VALUE), 100);
   cselib_record_memory = record_memory;
-  /* This is only created once.  */
+
+  /* (mem:BLK (scratch)) is a special mechanism to conflict with everything,
+     see canon_true_dependence.  This is only created once.  */
   if (! callmem)
-    callmem = gen_rtx_MEM (BLKmode, const0_rtx);
+    callmem = gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode));
 
   cselib_nregs = max_reg_num ();