From: Richard Henderson <rth@redhat.com>
Date: Thu, 4 Apr 2002 22:48:16 +0000 (-0800)
Subject: re PR rtl-optimization/6165 ([i686] stack frame freed too early)
X-Git-Tag: releases/gcc-3.3.0~5886
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c4484b8fe055db414048860502d480c63e7ee6b1;p=thirdparty%2Fgcc.git

re PR rtl-optimization/6165 ([i686] stack frame freed too early)

        PR opt/6165
        * alias.c (true_dependence): Force (mem:blk (scratch)) to conflict.
        (write_dependence_p): Likewise.

From-SVN: r51882
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 23e407a49dec..d14b04c413f7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2002-04-04  Richard Henderson  <rth@redhat.com>
+
+	PR opt/6165
+	* alias.c (true_dependence): Force (mem:blk (scratch)) to conflict.
+	(write_dependence_p): Likewise.
+
 2002-04-04  Richard Henderson  <rth@redhat.com>
 
 	* predict.c (estimate_bb_frequencies): Do frequency calculation
diff --git a/gcc/alias.c b/gcc/alias.c
index 42d8e18210df..29da8ffafb3f 100644
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -2039,6 +2039,13 @@ true_dependence (mem, mem_mode, x, varies)
   if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
     return 1;
 
+  /* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
+     This is used in epilogue deallocation functions.  */
+  if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
+    return 1;
+  if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
+    return 1;
+
   if (DIFFERENT_ALIAS_SETS_P (x, mem))
     return 0;
 
@@ -2173,6 +2180,13 @@ write_dependence_p (mem, x, writep)
   if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
     return 1;
 
+  /* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
+     This is used in epilogue deallocation functions.  */
+  if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
+    return 1;
+  if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
+    return 1;
+
   if (DIFFERENT_ALIAS_SETS_P (x, mem))
     return 0;