Ooops, I just click send too fast, I want to say "Only few minor
comment on the md file"
On Thu, Jul 27, 2023 at 2:52 PM Kito Cheng <kito.ch...@gmail.com> wrote:
>
> Hi Juzhe-Zhong:
>
> Only
>
> > diff --git a/gcc/config/riscv/autovec-vls.md
> > b/gcc/config/riscv/autovec-vls.md
> > new file mode 100644
> > index 00000000000..c67ff386e50
> > --- /dev/null
> > +++ b/gcc/config/riscv/autovec-vls.md
> > +(define_insn_and_split "mov<mode>"
> > + [(set (match_operand:VLS_AVL_IMM 0 "reg_or_mem_operand" "=vr, m, vr")
> > + (match_operand:VLS_AVL_IMM 1 "general_operand" " m,vr, vr"))]
> > + "TARGET_VECTOR"
> > + "@
> > + #
> > + #
> > + vmv%m1r.v\t%0,%1"
> > + "&& (!register_operand (operands[0], <MODE>mode)
> > + || !register_operand (operands[1], <MODE>mode))"
> > + [(const_int 0)]
> > + {
> > + unsigned size = GET_MODE_BITSIZE (<MODE>mode).to_constant ();
> > + if (size <= MAX_BITS_PER_WORD
> > + && MEM_P (operands[0]) && MEM_P (operands[1]))
>
> I am thinking, is it possible to split this part into a standalone
> define_split pattern
> and be guarded with can_create_pseudo_p ()?
>
> Since this should not work after RA, and also will cause some
> suboptimal code for those modes larger than MAX_BITS_PER_WORD.
>
> Consider that case: the mode size is larger than MAX_BITS_PER_WORD,
> and the it get combined into (set (mem) (mem)), but RA didn't found
> suitable constraint...so go to reload
>
> And then we can add some check on this mov pattern to constrain it to
> must be at least one
> register operand like other mov patterns.
>
> > +
> > +(define_insn_and_split "*mov<VLS_AVL_REG:mode><P:mode>_lra"
> > + [(set (match_operand:VLS_AVL_REG 0 "reg_or_mem_operand" "=vr, m,vr")
> > + (match_operand:VLS_AVL_REG 1 "reg_or_mem_operand" " m,vr,vr"))
> > + (clobber (match_scratch:P 2 "=&r,&r,X"))]
> > + "TARGET_VECTOR && (lra_in_progress || reload_completed)"
>
> Add && (register_operand (operands[0], <MODE>mode) || register_operand
> (operands[1], <MODE>mode))
