On Thu, Feb 04, 2016 at 01:50:31PM +0000, Kyrill Tkachov wrote:
> Hi all,
>
> As part of the target attributes and pragmas support for GCC 6 I changed the
> aarch64 port to emit a .arch assembly directive for each function that
> describes the architectural features used by that function. This is a change
> from GCC 5 behaviour where we output a single .arch directive at the
> beginning of the assembly file corresponding to architectural features given
> on the command line.
<snip>
> Bootstrapped and tested on aarch64-none-linux-gnu. With this patch I managed
> to build a recent allyesconfig Linux kernel where before the build would fail
> when assembling the LSE instructions.
>
> Ok for trunk?
One comment, that I'm willing to be convinced on...
>
> Thanks,
> Kyrill
>
> 2016-02-04 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
>
> * config/aarch64/aarch64.c (struct aarch64_output_asm_info):
> New struct definition.
> (aarch64_previous_asm_output): New variable.
> (aarch64_declare_function_name): Only output .arch assembler
> directive if it will be different from the previously output
> directive.
> (aarch64_start_file): New function.
> (TARGET_ASM_FILE_START): Define.
>
> 2016-02-04 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
>
> * gcc.target/aarch64/assembler_arch_1.c: Add -dA to dg-options.
> Delete unneeded -save-temps.
> * gcc.target/aarch64/assembler_arch_7.c: Likewise.
> * gcc.target/aarch64/target_attr_15.c: Scan assembly for
> .arch armv8-a\n.
> * gcc.target/aarch64/assembler_arch_1.c: New test.
> commit 2df0f24332e316b8d18d4571438f76726a0326e7
> Author: Kyrylo Tkachov <kyrylo.tkac...@arm.com>
> Date: Wed Jan 27 12:54:54 2016 +0000
>
> [AArch64] Only update assembler .arch directive when necessary
>
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index 5ca2ae8..0751440 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -11163,6 +11163,17 @@ aarch64_asm_preferred_eh_data_format (int code
> ATTRIBUTE_UNUSED, int global)
> return (global ? DW_EH_PE_indirect : 0) | DW_EH_PE_pcrel | type;
> }
>
> +struct aarch64_output_asm_info
> +{
> + const struct processor *arch;
> + const struct processor *cpu;
> + unsigned long isa_flags;
Why not just keep the last string you printed, and use a string compare
to decide whether to print or not? Sure we'll end up doing a bit more
work, but the logic becomes simpler to follow and we don't need to pass
around another struct...
Thanks,
James
