Re: PING^5: [PATCH] mips: add MSA vec_cmp and vec_cmpu expand pattern [PR101132]

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

Xi Ruoyao <xry111@mengyan1223.wang> writes:
> Ping again.

Sorry that this has gone unreviewed for so long.  I think in practice
the MIPS port is essentially unmaintained at this point -- it would
be great if someone would volunteer :-)

It isn't really appropriate for me to review MIPS stuff given that I work
for a company that has a competing architecture.  I think Jeff expressed
similar concerns given his new role.

That said, the patch looks clearly correct to me, so please go ahead
and apply (to trunk and GCC 11).  Thanks for your patience.

Richard

> On Mon, 2021-06-21 at 21:42 +0800, Xi Ruoyao wrote:
>> Middle-end started to emit vec_cmp and vec_cmpu since GCC 11, causing
>> ICE on MIPS with MSA enabled.  Add the pattern to prevent it.
>> 
>> Bootstrapped and regression tested on mips64el-linux-gnu.
>> Ok for trunk?
>> 
>> gcc/
>> 
>>         * config/mips/mips-protos.h (mips_expand_vec_cmp_expr):
>> Declare.
>>         * config/mips/mips.c (mips_expand_vec_cmp_expr): New function.
>>         * config/mips/mips-msa.md (vec_cmp<MSA:mode><mode_i>): New
>>           expander.
>>           (vec_cmpu<IMSA:mode><mode_i>): New expander.
>> ---
>>  gcc/config/mips/mips-msa.md   | 22 ++++++++++++++++++++++
>>  gcc/config/mips/mips-protos.h |  1 +
>>  gcc/config/mips/mips.c        | 11 +++++++++++
>>  3 files changed, 34 insertions(+)
>> 
>> diff --git a/gcc/config/mips/mips-msa.md b/gcc/config/mips/mips-msa.md
>> index 3ecf2bde19f..3a67f25be56 100644
>> --- a/gcc/config/mips/mips-msa.md
>> +++ b/gcc/config/mips/mips-msa.md
>> @@ -435,6 +435,28 @@
>>    DONE;
>>  })
>>  
>> +(define_expand "vec_cmp<MSA:mode><mode_i>"
>> +  [(match_operand:<VIMODE> 0 "register_operand")
>> +   (match_operator 1 ""
>> +     [(match_operand:MSA 2 "register_operand")
>> +      (match_operand:MSA 3 "register_operand")])]
>> +  "ISA_HAS_MSA"
>> +{
>> +  mips_expand_vec_cmp_expr (operands);
>> +  DONE;
>> +})
>> +
>> +(define_expand "vec_cmpu<IMSA:mode><mode_i>"
>> +  [(match_operand:<VIMODE> 0 "register_operand")
>> +   (match_operator 1 ""
>> +     [(match_operand:IMSA 2 "register_operand")
>> +      (match_operand:IMSA 3 "register_operand")])]
>> +  "ISA_HAS_MSA"
>> +{
>> +  mips_expand_vec_cmp_expr (operands);
>> +  DONE;
>> +})
>> +
>>  (define_insn "msa_insert_<msafmt_f>"
>>    [(set (match_operand:MSA 0 "register_operand" "=f,f")
>>         (vec_merge:MSA
>> diff --git a/gcc/config/mips/mips-protos.h b/gcc/config/mips/mips-
>> protos.h
>> index 2cf4ed50292..a685f7f7dd5 100644
>> --- a/gcc/config/mips/mips-protos.h
>> +++ b/gcc/config/mips/mips-protos.h
>> @@ -385,6 +385,7 @@ extern mulsidi3_gen_fn mips_mulsidi3_gen_fn (enum
>> rtx_code);
>>  
>>  extern void mips_register_frame_header_opt (void);
>>  extern void mips_expand_vec_cond_expr (machine_mode, machine_mode,
>> rtx *);
>> +extern void mips_expand_vec_cmp_expr (rtx *);
>>  
>>  /* Routines implemented in mips-d.c  */
>>  extern void mips_d_target_versions (void);
>> diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
>> index 00a8eef96aa..8f043399a8e 100644
>> --- a/gcc/config/mips/mips.c
>> +++ b/gcc/config/mips/mips.c
>> @@ -22321,6 +22321,17 @@ mips_expand_msa_cmp (rtx dest, enum rtx_code
>> cond, rtx op0, rtx op1)
>>      }
>>  }
>>  
>> +void
>> +mips_expand_vec_cmp_expr (rtx *operands)
>> +{
>> +  rtx cond = operands[1];
>> +  rtx op0 = operands[2];
>> +  rtx op1 = operands[3];
>> +  rtx res = operands[0];
>> +
>> +  mips_expand_msa_cmp (res, GET_CODE (cond), op0, op1);
>> +}
>> +
>>  /* Expand VEC_COND_EXPR, where:
>>     MODE is mode of the result
>>     VIMODE equivalent integer mode