X-Git-Url: http://git.sourceforge.jp/view?p=pf3gnuchains%2Fgcc-fork.git;a=blobdiff_plain;f=gcc%2Fbuiltins.c;h=1a9e96653df90c381d79852c2a6711d052f5926f;hp=025c1694e4c13e87ac5d7eaa04aec0cfcefef21b;hb=49e436b506b7817a4ef645c95ba158e88deda840;hpb=f3aba4fafc1e6e77271a1e20147573165b208cd8

diff --git a/gcc/builtins.c b/gcc/builtins.c
index 025c1694e4c..1a9e96653df 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -8737,15 +8737,18 @@ fold_builtin_pow (location_t loc, tree fndecl, tree arg0, tree arg1, tree type)
 	    }
 	}
 
-      /* Optimize pow(pow(x,y),z) = pow(x,y*z).  */
+      /* Optimize pow(pow(x,y),z) = pow(x,y*z) iff x is nonnegative.  */
       if (fcode == BUILT_IN_POW
 	  || fcode == BUILT_IN_POWF
 	  || fcode == BUILT_IN_POWL)
 	{
 	  tree arg00 = CALL_EXPR_ARG (arg0, 0);
-	  tree arg01 = CALL_EXPR_ARG (arg0, 1);
-	  tree narg1 = fold_build2_loc (loc, MULT_EXPR, type, arg01, arg1);
-	  return build_call_expr_loc (loc, fndecl, 2, arg00, narg1);
+	  if (tree_expr_nonnegative_p (arg00))
+	    {
+	      tree arg01 = CALL_EXPR_ARG (arg0, 1);
+	      tree narg1 = fold_build2_loc (loc, MULT_EXPR, type, arg01, arg1);
+	      return build_call_expr_loc (loc, fndecl, 2, arg00, narg1);
+	    }
 	}
     }