tree-optimization/113552 - fix num_call accounting in simd clone vectorization

The following avoids using exact_log2 on the number of SIMD clone calls
to be emitted when vectorizing calls since that can easily be not
a power of two in which case it will return -1.  For different simd
clones the number of calls will differ by a multiply with a power of two
only so using floor_log2 is good enough here.

	PR tree-optimization/113552
	* tree-vect-stmts.cc (vectorizable_simd_clone_call): Use
	floor_log2 instead of exact_log2 on the number of calls.

diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index 09749ae38174eb5dddd8460c41d8a1d2277897ae..1dbe1115da4d7dd4fc590e5830a9c7f05be6945a 100644 (file)
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -4071,7 +4071,7 @@ vectorizable_simd_clone_call (vec_info *vinfo, stmt_vec_info stmt_info,
            || (nargs != simd_nargs))
          continue;
        if (num_calls != 1)
-         this_badness += exact_log2 (num_calls) * 4096;
+         this_badness += floor_log2 (num_calls) * 4096;
        if (n->simdclone->inbranch)
          this_badness += 8192;
        int target_badness = targetm.simd_clone.usable (n);