Re: [Patch][Aarch64] Implement Aarch64 SIMD ABI and aarch64_vector_pcs attribute

[Kyrill Tkachov <kyrylo.tkachov@foss.arm.com>]

Hi Steve,

On 20/08/18 18:37, Steve Ellcey wrote:
> On Tue, 2018-08-07 at 12:15 -0500, Segher Boessenkool wrote:
>
> > > +/* { dg-final { scan-assembler-not "\[ \t\]stp\tq\[01234567\]" } }
> > > */
> > That's [0-7] but maybe you find [01234567] more readable here.
>
> Segher,  I fixed all the issues you pointed out except this one.  Since
> there are some uses of non consecutive numbers in one of the tests I
> decided to leave [01234567] instead of using [0-7].  Here is the
> latest version of the patch, there are no semantic changes, just
> syntactical ones to address the issues that you pointed out.
>
> Steve Ellcey
> sellcey@cavium.com
>

One more comment below.
It looks sensible enough to me otherwise, but I haven't done a deep review of the logic.

Thanks,
Kyrill

>
> 2018-08-20  Steve Ellcey  <sellcey@cavium.com>
>
>         * config/aarch64/aarch64-protos.h (aarch64_use_simple_return_insn_p):
>         New prototype.
>         (aarch64_epilogue_uses): Ditto.
>         * config/aarch64/aarch64.c (aarch64_attribute_table): New array.
>         (aarch64_simd_decl_p): New function.
>         (aarch64_reg_save_mode): New function.
>         (aarch64_is_simd_call_p): New function.
>         (aarch64_function_ok_for_sibcall): Check for simd calls.
>         (aarch64_layout_frame): Check for simd function.
>         (aarch64_gen_storewb_pair): Handle E_TFmode.
>         (aarch64_push_regs): Use aarch64_reg_save_mode to get mode.
>         (aarch64_gen_loadwb_pair): Handle E_TFmode.
>         (aarch64_pop_regs): Use aarch64_reg_save_mode to get mode.
>         (aarch64_gen_store_pair): Handle E_TFmode.
>         (aarch64_gen_load_pair): Ditto.
>         (aarch64_save_callee_saves): Handle different mode sizes.
>         (aarch64_restore_callee_saves): Ditto.
>         (aarch64_components_for_bb): Check for simd function.
>         (aarch64_epilogue_uses): New function.
>         (aarch64_process_components): Check for simd function.
>         (aarch64_expand_prologue): Ditto.
>         (aarch64_expand_epilogue): Ditto.
>         (aarch64_expand_call): Ditto.
>         (TARGET_ATTRIBUTE_TABLE): New define.
>         * config/aarch64/aarch64.h (EPILOGUE_USES): Redefine.
>         (FP_SIMD_SAVED_REGNUM_P): New macro.
>         * config/aarch64/aarch64.md (V23_REGNUM) New constant.
>         (simple_return): New define_expand.
>         (load_pair_dw_tftf): New instruction.
>         (store_pair_dw_tftf): Ditto.
>         (loadwb_pair<TX:mode>_<P:mode>): Ditto.
>         ("storewb_pair<TX:mode>_<P:mode>): Ditto.
>
> 2018-08-20  Steve Ellcey  <sellcey@cavium.com>
>
>         * gcc.target/aarch64/torture/aarch64-torture.exp: New file.
>         * gcc.target/aarch64/torture/simd-abi-1.c: New test.
>         * gcc.target/aarch64/torture/simd-abi-2.c: Ditto.
>         * gcc.target/aarch64/torture/simd-abi-3.c: Ditto.
>         * gcc.target/aarch64/torture/simd-abi-4.c: Ditto.

@@ -4469,6 +4536,9 @@ aarch64_restore_callee_saves (machine_mode mode,
    unsigned regno;
    unsigned regno2;
    poly_int64 offset;
+  HOST_WIDE_INT mode_size;
+
+  gcc_assert (GET_MODE_SIZE (mode).is_constant(&mode_size));
  
I think you want to use the gcc_unreachable approach here:

   if (!GET_MODE_SIZE (mode).is_constant(&mode_size))
     gcc_unreachable ();

just in case the gcc_assert is compiled out.