From: Jeff Law <law@gcc.gnu.org>
Date: Thu, 20 May 1999 00:41:26 +0000 (-0600)
Subject: jump.c (can_reverse_comparison_p): Do not abort if the comparison insn for a conditio... 
X-Git-Tag: releases/libgcj-2.95.0~447
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f8d41a69eeb83daaeff527ce512bd6ef78d7ad07;p=thirdparty%2Fgcc.git

jump.c (can_reverse_comparison_p): Do not abort if the comparison insn for a conditional jump can not be found.

p
        * jump.c (can_reverse_comparison_p): Do not abort if the comparison
        insn for a conditional jump can not be found.

From-SVN: r27043
---

diff --git a/gcc/jump.c b/gcc/jump.c
index 9b727fa32c85..01df0dbba759 100644
--- a/gcc/jump.c
+++ b/gcc/jump.c
@@ -3151,8 +3151,17 @@ can_reverse_comparison_p (comparison, insn)
       )
     {
       rtx prev = prev_nonnote_insn (insn);
-      rtx set = single_set (prev);
+      rtx set;
 
+      /* If the comparison itself was a loop invariant, it could have been
+	 hoisted out of the loop.  If we proceed to unroll such a loop, then
+	 we may not be able to find the comparison when copying the loop.
+
+	 Returning zero in that case is the safe thing to do.  */
+      if (prev == 0)
+	return 0;
+
+      set = single_set (prev);
       if (set == 0 || SET_DEST (set) != arg0)
 	return 0;