Re: [PATCH]middle-end Use subregs to expand COMPLEX_EXPR to set the lowpart.

[Richard Sandiford <richard.sandiford@arm.com>]

Tamar Christina <Tamar.Christina@arm.com> writes:
>> > so that the multiple_p test is skipped if the structure is undefined.
>> 
>> Actually, we should probably skip the constant_multiple_p test as well.
>> Keeping it would only be meaningful for little-endian.
>> 
>> simplify_gen_subreg should alread do the necessary checks to make sure
>> that the subreg can be formed (via validate_subreg).
>> 
>
> Bootstrapped Regtested on aarch64-none-linux-gnu, x86_64-pc-linux-gnu
> and no issues.
>
> Ok for master?
>
> Thanks,
> Tamar
>
> gcc/ChangeLog:
>
> 	* expmed.cc (store_bit_field):
>         * expmed.cc (store_bit_field_1): Add parameter that indicates if value is
> 	still undefined and if so emit a subreg move instead.
> 	(store_integral_bit_field): Likewise.
> 	(store_bit_field): Likewise.
> 	* expr.h (write_complex_part): Likewise.
> 	* expmed.h (store_bit_field): Add new parameter.
> 	* builtins.cc (expand_ifn_atomic_compare_exchange_into_call): Use new
> 	parameter.
> 	(expand_ifn_atomic_compare_exchange): Likewise.
> 	* calls.cc (store_unaligned_arguments_into_pseudos): Likewise.
> 	* emit-rtl.cc (validate_subreg): Likewise.
> 	* expr.cc (emit_group_store): Likewise.
> 	(copy_blkmode_from_reg): Likewise.
> 	(copy_blkmode_to_reg): Likewise.
> 	(clear_storage_hints): Likewise.
> 	(write_complex_part):  Likewise.
> 	(emit_move_complex_parts): Likewise.
> 	(expand_assignment): Likewise.
> 	(store_expr): Likewise.
> 	(store_field): Likewise.
> 	(expand_expr_real_2): Likewise.
> 	* ifcvt.cc (noce_emit_move_insn): Likewise.
> 	* internal-fn.cc (expand_arith_set_overflow): Likewise.
> 	(expand_arith_overflow_result_store): Likewise.
> 	(expand_addsub_overflow): Likewise.
> 	(expand_neg_overflow): Likewise.
> 	(expand_mul_overflow): Likewise.
> 	(expand_arith_overflow): Likewise.
>
> gcc/testsuite/ChangeLog:
>
> 	* g++.target/aarch64/complex-init.C: New test.
>
> --- inline copy of patch ---
>
> […]
> diff --git a/gcc/testsuite/g++.target/aarch64/complex-init.C b/gcc/testsuite/g++.target/aarch64/complex-init.C
> new file mode 100644
> index 0000000000000000000000000000000000000000..d3fd3e88d04a87bacf1c4ee74ce25282c6ff81e8
> --- /dev/null
> +++ b/gcc/testsuite/g++.target/aarch64/complex-init.C
> @@ -0,0 +1,40 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +/* { dg-final { check-function-bodies "**" "" "" { target { le } } } } */
> +
> +/*
> +** _Z1fii:
> +** ...
> +** 	bfi	x0, x1, 32, 32
> +** 	ret
> +** ...

Sorry for the test nit, but: it shouldn't be necessary to add ...
after the ret.  Same for the other tests.

OK with that change, thanks.

Richard

> +*/
> +_Complex int f(int a, int b) {
> +    _Complex int t = a + b * 1i;
> +    return t;
> +}
> +
> +/*
> +** _Z2f2ii:
> +** ...
> +** 	bfi	x0, x1, 32, 32
> +** 	ret
> +** ...
> +*/
> +_Complex int f2(int a, int b) {
> +    _Complex int t = {a, b};
> +    return t;
> +}
> +
> +/* 
> +** _Z12f_convolutedii:
> +** ...
> +** 	bfi	x0, x1, 32, 32
> +** 	ret
> +** ...
> +*/
> +_Complex int f_convoluted(int a, int b) {
> +    _Complex int t = (_Complex int)a;
> +    __imag__ t = b;
> +    return t;
> +}