[PATCH v2] x86: Remove "%!" before ret

H.J. Lu hjl.tools@gmail.com
Wed Nov 17 20:32:32 GMT 2021


On Wed, Nov 17, 2021 at 11:46 AM Uros Bizjak <ubizjak@gmail.com> wrote:
>
> On Wed, Nov 17, 2021 at 8:44 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> >
> > Before MPX was removed, "%!" was mapped to
> >
> >         case '!':
> >           if (ix86_bnd_prefixed_insn_p (current_output_insn))
> >             fputs ("bnd ", file);
> >           return;
> >
> > After CET was added and MPX was removed, "%!" was mapped to
> >
> >        case '!':
> >           if (ix86_notrack_prefixed_insn_p (current_output_insn))
> >             fputs ("notrack ", file);
> >           return;
> >
> > ix86_notrack_prefixed_insn_p always returns false on ret since the
> > notrack prefix is only for indirect branches.  Remove the unused "%!"
> > before ret.
> >
> >         PR target/103307
> >         * config/i386/i386.c (ix86_code_end): Remove "%!" before ret.
> >         (ix86_output_function_return): Likewise.
> >         * config/i386/i386.md (simple_return_pop_internal): Likewise.
> > ---
> >  gcc/config/i386/i386.c  | 4 ++--
> >  gcc/config/i386/i386.md | 2 +-
> >  2 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> > index 73c4d5115bb..95d238e9efc 100644
> > --- a/gcc/config/i386/i386.c
> > +++ b/gcc/config/i386/i386.c
> > @@ -6116,7 +6116,7 @@ ix86_code_end (void)
> >        xops[0] = gen_rtx_REG (Pmode, regno);
> >        xops[1] = gen_rtx_MEM (Pmode, stack_pointer_rtx);
> >        output_asm_insn ("mov%z0\t{%1, %0|%0, %1}", xops);
> > -      output_asm_insn ("%!ret", NULL);
> > +      output_asm_insn ("ret", NULL);
>
> This can use fputs.

Fixed.   Here is the v2 patch.

> Uros.
>
> >        final_end_function ();
> >        init_insn_lengths ();
> >        free_after_compilation (cfun);
> > @@ -16278,7 +16278,7 @@ ix86_output_function_return (bool long_p)
> >      }
> >
> >    if (!long_p)
> > -    return "%!ret";
> > +    return "ret";
> >
> >    return "rep%; ret";
> >  }
> > diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
> > index 73d15de88b2..7b2de60706d 100644
> > --- a/gcc/config/i386/i386.md
> > +++ b/gcc/config/i386/i386.md
> > @@ -14705,7 +14705,7 @@ (define_insn_and_split "simple_return_pop_internal"
> >    [(simple_return)
> >     (use (match_operand:SI 0 "const_int_operand"))]
> >    "reload_completed"
> > -  "%!ret\t%0"
> > +  "ret\t%0"
> >    "&& cfun->machine->function_return_type != indirect_branch_keep"
> >    [(const_int 0)]
> >    "ix86_split_simple_return_pop_internal (operands[0]); DONE;"
> > --
> > 2.33.1
> >



-- 
H.J.
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