X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Ftree-if-conv.c;h=fc6584584c14763e6fcccb2ba025369967f61452;hb=54c0191177db8bc27fb599a7d0d7a5866c5046fb;hp=17b66721e5d25b3227643037fb1290c1af9f509c;hpb=df4ae4c4516593909d0074d4ddea3da9c0243fda;p=pf3gnuchains%2Fgcc-fork.git

diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c
index 17b66721e5d..fc6584584c1 100644
--- a/gcc/tree-if-conv.c
+++ b/gcc/tree-if-conv.c
@@ -1224,7 +1224,7 @@ predicate_scalar_phi (gimple phi, tree cond,
 {
   gimple new_stmt;
   basic_block bb;
-  tree rhs, res, arg;
+  tree rhs, res, arg, scev;
 
   gcc_assert (gimple_code (phi) == GIMPLE_PHI
 	      && gimple_phi_num_args (phi) == 2);
@@ -1236,8 +1236,12 @@ predicate_scalar_phi (gimple phi, tree cond,
 
   bb = gimple_bb (phi);
 
-  arg = degenerate_phi_result (phi);
-  if (arg)
+  if ((arg = degenerate_phi_result (phi))
+      || ((scev = analyze_scalar_evolution (gimple_bb (phi)->loop_father,
+					    res))
+	  && !chrec_contains_undetermined (scev)
+	  && scev != res
+	  && (arg = gimple_phi_arg_def (phi, 0))))
     rhs = arg;
   else
     {