On Mon, Feb 02, 2015 at 02:51:43PM -0800, Andrew Pinski wrote:
> While trying to build the GCC 5 with GCC 5, I ran into an ICE when
> building libcpp at -O0. The problem is the C++ front-end was not
> folding sizeof(a)/sizeof(a[0]) when passed to a function at -O0. The
> C++ front-end keeps around sizeof until the gimplifier and there is no
> way to fold the expressions that involve them. So to work around the
> issue we need to change __builtin_aarch64_im_lane_boundsi to accept an
> extra argument and change the first two arguments to size_t type so we
> don't get an extra cast there and do the division inside the compiler
> itself.
Relying on anything being folded at -O0 when the language does not guarantee
it is going to be more and more of a problem. So I think your patch is
reasonable (of course, I'll defer this to target maintainers).
> + rtx totalsize = expand_normal (CALL_EXPR_ARG (exp, 0));
> + rtx elementsize = expand_normal (CALL_EXPR_ARG (exp, 1));
> + if (CONST_INT_P (totalsize) && CONST_INT_P (elementsize))
> + {
> + rtx lane_idx = expand_normal (CALL_EXPR_ARG (exp, 2));
> + if (CONST_INT_P (lane_idx))
> + aarch64_simd_lane_bounds (lane_idx, 0, UINTVAL (totalsize)/UINTVAL
> (elementsize), exp);
Too long line? Also, missing spaces around / . And, ICE if
somebody uses __builtin_aarch64_im_lane_boundsi (4, 0, 0);
So you need to check and complain for zero elementsize too.
> + else
> + error ("%Klane index must be a constant immediate", exp);
> + }
> else
> - error ("%Klane index must be a constant immediate", exp);
> + sorry ("%Ktotal size and element size must be a constant immediate",
> exp);
But why sorry? If you say the builtin requires constant arguments, then it
is not sorry, but error, it is not an unimplemented feature.
Jakub
