Backport a change to the 2.95 branch

From-SVN: r37878

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6bfed8719ff6f624870edf4f7bdd50a058a5c025..9c60312f0f8c33594c61a9ad46d3551e4cfc38cb 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 2000-11-30  Bernd Schmidt  <bernds@redhat.co.uk>
 
+       Thu Apr 13 19:39:56 2000  Clinton Popetz  <cpopetz@cygnus.com>
+       * emit-rtl.c (try_split): Avoid infinite loop if the split
+       results in a sequence that contains the original insn.
+
        1999-12-14  Bernd Schmidt  <bernds@cygnus.co.uk>
        * combine.c (combine_simplify_rtx): Don't make shared rtl.
        (simplify_logical): Likewise.

diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index 36b030ae7b6b42fbba568fb496bc3fabca47dfad..222a1a937f096b24f1a6a5f650ed69957d7c65b1 100644 (file)
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -2359,10 +2359,18 @@ try_split (pat, trial, last)
         it, in turn, will be split (SFmode on the 29k is an example).  */
       if (GET_CODE (seq) == SEQUENCE)
        {
+         int i;
+
+         /* Avoid infinite loop if any insn of the result matches 
+            the original pattern.  */
+         for (i = 0; i < XVECLEN (seq, 0); i++)
+           if (GET_CODE (XVECEXP (seq, 0, i)) == INSN 
+               && rtx_equal_p (PATTERN (XVECEXP (seq, 0, i)), pat))
+             return trial;
+
          /* If we are splitting a JUMP_INSN, look for the JUMP_INSN in
             SEQ and copy our JUMP_LABEL to it.  If JUMP_LABEL is non-zero,
             increment the usage count so we don't delete the label.  */
-         int i;
 
          if (GET_CODE (trial) == JUMP_INSN)
            for (i = XVECLEN (seq, 0) - 1; i >= 0; i--)