Ping
Richard Sandiford <richard.sandif...@arm.com> writes:
> pass_return_slot::execute has:
>
> /* Ignore internal functions without direct optabs,
> those are expanded specially and aggregate_value_p
> on their result might result in undesirable warnings
> with some backends. */
> && (!gimple_call_internal_p (stmt)
> || direct_internal_fn_p (gimple_call_internal_fn (stmt)))
> && aggregate_value_p (TREE_TYPE (gimple_call_lhs (stmt)),
> gimple_call_fndecl (stmt)))
>
> But what the comment says applies to directly-mapped internal functions
> too, since they're only used if the target supports them without a
> libcall.
>
> This was triggering an ICE on the attached testcase. The svld3 call
> is folded to an IFN_LOAD_LANES, which returns an array of vectors with
> VNx48QImode. Since no such return type can exist in C, the target hook
> was complaining about an unexpected use of SVE modes. (And we want to
> keep asserting for that, so that we don't accidentally define an ABI for
> an unexpected corner case.)
>
> Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
>
> Richard
>
>
> 2019-12-12 Richard Sandiford <richard.sandif...@arm.com>
>
> gcc/
> * tree-nrv.c (pass_return_slot::execute): Handle all internal
> functions the same way, rather than singling out those that
> aren't mapped directly to optabs.
>
> gcc/testsuite/
> * gcc.target/aarch64/sve/acle/general/nrv_1.c: New test.
>
> Index: gcc/tree-nrv.c
> ===================================================================
> --- gcc/tree-nrv.c 2019-03-08 18:15:26.824777889 +0000
> +++ gcc/tree-nrv.c 2019-12-12 15:11:48.662767466 +0000
> @@ -378,12 +378,10 @@ pass_return_slot::execute (function *fun
> if (stmt
> && gimple_call_lhs (stmt)
> && !gimple_call_return_slot_opt_p (stmt)
> - /* Ignore internal functions without direct optabs,
> - those are expanded specially and aggregate_value_p
> - on their result might result in undesirable warnings
> - with some backends. */
> - && (!gimple_call_internal_p (stmt)
> - || direct_internal_fn_p (gimple_call_internal_fn (stmt)))
> + /* Ignore internal functions, those are expanded specially
> + and aggregate_value_p on their result might result in
> + undesirable warnings with some backends. */
> + && !gimple_call_internal_p (stmt)
> && aggregate_value_p (TREE_TYPE (gimple_call_lhs (stmt)),
> gimple_call_fndecl (stmt)))
> {
> Index: gcc/testsuite/gcc.target/aarch64/sve/acle/general/nrv_1.c
> ===================================================================
> --- /dev/null 2019-09-17 11:41:18.176664108 +0100
> +++ gcc/testsuite/gcc.target/aarch64/sve/acle/general/nrv_1.c 2019-12-12
> 15:11:48.662767466 +0000
> @@ -0,0 +1,17 @@
> +/* { dg-options "-O -msve-vector-bits=256" } */
> +
> +#include <arm_sve.h>
> +
> +typedef uint8_t v32qi __attribute__((vector_size (32)));
> +
> +struct triple { v32qi v0, v1, v2; };
> +
> +struct triple f (uint8_t *ptr)
> +{
> + svuint8x3_t data = svld3 (svptrue_b8 (), ptr);
> + struct triple res;
> + res.v0 = svget3 (data, 0);
> + res.v1 = svget3 (data, 1);
> + res.v2 = svget3 (data, 2);
> + return res;
> +}
