Re: [PATCH AArch64/V3]Add new patterns for vcond_mask and vec_cmp

["Bin.Cheng" <amker dot cheng at gmail dot com>]

On Thu, Aug 11, 2016 at 8:08 AM, Andreas Schwab <schwab@suse.de> wrote:
> ../../gcc/config/aarch64/aarch64-simd.md: In function 'rtx_def* gen_vec_cmpv2sfv2si(rtx, rtx, rtx, rtx)':
> ../../gcc/config/aarch64/aarch64-simd.md:2498:17: error: 'comparison' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>        emit_insn (comparison (operands[0], operands[2], operands[3]));
>        ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../../gcc/config/aarch64/aarch64-simd.md:2416:9: note: 'comparison' was declared here
>    rtx (*comparison) (rtx, rtx, rtx);
>          ^~~~~~~~~~
> ../../gcc/config/aarch64/aarch64-simd.md: In function 'rtx_def* gen_vec_cmpv4sfv4si(rtx, rtx, rtx, rtx)':
> ../../gcc/config/aarch64/aarch64-simd.md:2498:17: error: 'comparison' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>        emit_insn (comparison (operands[0], operands[2], operands[3]));
>        ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../../gcc/config/aarch64/aarch64-simd.md:2416:9: note: 'comparison' was declared here
>    rtx (*comparison) (rtx, rtx, rtx);
>          ^~~~~~~~~~
> ../../gcc/config/aarch64/aarch64-simd.md: In function 'rtx_def* gen_vec_cmpv2dfv2di(rtx, rtx, rtx, rtx)':
> ../../gcc/config/aarch64/aarch64-simd.md:2498:17: error: 'comparison' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>        emit_insn (comparison (operands[0], operands[2], operands[3]));
>        ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../../gcc/config/aarch64/aarch64-simd.md:2416:9: note: 'comparison' was declared here
>    rtx (*comparison) (rtx, rtx, rtx);
>          ^~~~~~~~~~

Hi Andreas,
Thanks very much for reporting this.

I also got below error messages:
../../gcc/gcc/config/aarch64/aarch64-simd.md: In function ‘rtx_def*
gen_vcondv8qiv8qi(rtx, rtx, rtx, rtx, rtx, rtx)’:
../../gcc/gcc/config/aarch64/aarch64-simd.md:2574:17: error: unused
variable ‘code’ [-Werror=unused-variable]
   enum rtx_code code = GET_CODE (operands[3]);
                 ^~~~
../../gcc/gcc/config/aarch64/aarch64-simd.md: In function ‘rtx_def*
gen_vcondv16qiv16qi(rtx, rtx, rtx, rtx, rtx, rtx)’:
../../gcc/gcc/config/aarch64/aarch64-simd.md:2574:17: error: unused
variable ‘code’ [-Werror=unused-variable]
   enum rtx_code code = GET_CODE (operands[3]);
                 ^~~~
../../gcc/gcc/config/aarch64/aarch64-simd.md: In function ‘rtx_def*
gen_vcondv4hiv4hi(rtx, rtx, rtx, rtx, rtx, rtx)’:
../../gcc/gcc/config/aarch64/aarch64-simd.md:2574:17: error: unused
variable ‘code’ [-Werror=unused-variable]
   enum rtx_code code = GET_CODE (operands[3]);
                 ^~~~
My bad forgetting to remove this when separating the patch set, the
following patch
@https://gcc.gnu.org/ml/gcc-patches/2016-08/msg00842.html will fix
this.

For the reported error message, I think it's a bug in
maybe-unintialized warning, because all uses of "comparison" are
initialized in the previous switch statement.  I will initialize it
explicitly, also file a PR for recording.

Thanks,
bin
>
> Andreas.
>
> --
> Andreas Schwab, SUSE Labs, schwab@suse.de
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