[PATCH] Improve -Ofast vectorization of std::sin etc. (PR libstdc++/81706)

[Jason Merrill]

On 09/29/2017 08:32 AM, Jakub Jelinek wrote:
> +	  tree b = builtin_decl_explicit (DECL_FUNCTION_CODE (newdecl));
> +	  if (b)
> +	    duplicate_one_attribute (&DECL_ATTRIBUTES (b),
> +				     DECL_ATTRIBUTES (newdecl),
> +				     "omp declare simd");

It occurs to me that we're likely to want to propagate other attributes 
to the builtin, too.  In the testcase, nothrow and leaf also seem 
appropriate.  Do we want a broader copy_attributes_to_builtin function, 
even if it only copies this omp attribute for now?

Jason