From: wilson <wilson@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed, 13 Jun 2001 02:48:45 +0000 (+0000)
Subject: Fix for PR 3128, IA-64 linux kernel miscompile
X-Git-Url: http://git.sourceforge.jp/view?p=pf3gnuchains%2Fgcc-fork.git;a=commitdiff_plain;h=af10ea53121a86f956b160e5872af0930ae931ab

Fix for PR 3128, IA-64 linux kernel miscompile
	* loop.c (strength_reduce): Move bl->all_reduced set before
	check_ext_dependant_givs call.
	(check_ext_dependant_givs): Clear bl->all_reduced when ignoring givs.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@43298 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 91162d51ee9..a6f3f681024 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2001-06-12  Jim Wilson  <wilson@redhat.com>
+
+	* loop.c (strength_reduce): Move bl->all_reduced set before
+	check_ext_dependant_givs call.
+	(check_ext_dependant_givs): Clear bl->all_reduced when ignoring givs.
+
 2001-06-12  Alexandre Oliva  <aoliva@redhat.com>
 
 	* doc/extend.texi (Function Attributes): Document SH's sp_switch
diff --git a/gcc/loop.c b/gcc/loop.c
index fac9a840bc8..ec8dc0ac261 100644
--- a/gcc/loop.c
+++ b/gcc/loop.c
@@ -4306,6 +4306,11 @@ strength_reduce (loop, flags)
 	 provided all givs are reduced.  */
       bl->eliminable = loop_biv_eliminable_p (loop, bl, threshold, insn_count);
 
+      /* This will be true at the end, if all givs which depend on this
+	 biv have been strength reduced.
+	 We can't (currently) eliminate the biv unless this is so.  */
+      bl->all_reduced = 1;
+
       /* Check each extension dependent giv in this class to see if its
 	 root biv is safe from wrapping in the interior mode.  */
       check_ext_dependant_givs (bl, loop_info);
@@ -4313,11 +4318,6 @@ strength_reduce (loop, flags)
       /* Combine all giv's for this iv_class.  */
       combine_givs (regs, bl);
 
-      /* This will be true at the end, if all givs which depend on this
-	 biv have been strength reduced.
-	 We can't (currently) eliminate the biv unless this is so.  */
-      bl->all_reduced = 1;
-
       for (v = bl->giv; v; v = v->next_iv)
 	{
 	  struct induction *tv;
@@ -6660,6 +6660,7 @@ check_ext_dependant_givs (bl, loop_info)
 			 INSN_UID (v->insn), why);
 	      }
 	    v->ignore = 1;
+	    bl->all_reduced = 0;
 	  }
       }
 }