* loop-invariant.c (create_new_invariant): Use different magic number.

From-SVN: r153022

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2a3bda14241ad46e9a88637d69bc9812e1a5e980..3dfa1bbbc07d193f5116e8287fb822c2f72c340f 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2009-10-20  Michael Matz  <matz@suse.de>
+
+       * loop-invariant.c (create_new_invariant): Use different magic number.
+
 2009-10-20  Richard Earnshaw  <rearnsha@arm.com>
 
        PR target/39247

diff --git a/gcc/loop-invariant.c b/gcc/loop-invariant.c
index 8cbfdb30a92200d5e7fef8172e0979c73f7a62b4..901ce51ac89cfbee77e426d3b787fa5d85227f3d 100644 (file)
--- a/gcc/loop-invariant.c
+++ b/gcc/loop-invariant.c
@@ -705,8 +705,17 @@ create_new_invariant (struct def *def, rtx insn, bitmap depends_on,
   if (def)
     {
       inv->cost = rtx_cost (set, SET, speed);
+      /* ??? Try to determine cheapness of address computation.  Unfortunately
+         the address cost is only a relative measure, we can't really compare
+        it with any absolute number, but only with other address costs.
+        But here we don't have any other addresses, so compare with a magic
+        number anyway.  It has to be large enough to not regress PR33928
+        (by avoiding to move reg+8,reg+16,reg+24 invariants), but small
+        enough to not regress 410.bwaves either (by still moving reg+reg
+        invariants).
+        See http://gcc.gnu.org/ml/gcc-patches/2009-10/msg01210.html .  */
       inv->cheap_address = address_cost (SET_SRC (set), word_mode,
-                                        speed) < COSTS_N_INSNS (1);
+                                        speed) < 3;
     }
   else
     {