> -----Original Message-----
> From: Richard Biener <richard.guent...@gmail.com>
> Sent: Tuesday, April 18, 2023 11:38 AM
> To: Tamar Christina <tamar.christ...@arm.com>
> Cc: gcc-patches@gcc.gnu.org; nd <n...@arm.com>; rguent...@suse.de;
> j...@ventanamicro.com
> Subject: Re: [PATCH 1/3]middle-end match.pd: don't emit label if not needed
>
> On Tue, Apr 18, 2023 at 12:21 PM Tamar Christina via Gcc-patches <gcc-
> patc...@gcc.gnu.org> wrote:
> >
> > Hi All,
> >
> > This is a small QoL codegen improvement for match.pd to not emit
> > labels when they are not needed. The codegen is nice and there is a
> > small (but consistent) improvement in compile time.
> >
> > Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
> >
> > Ok for master?
>
> OK. Btw - how many labels does this remove? (just wc -l the generated files?)
Not terribly much anymore, it's about 160 lines. Though when benchmarking it
shows a consistent 2-5% speedup in compile time (I take the geomean of about
100 compiles).
Regards,
Tamar
>
> Richard.
>
> > Thanks,
> > Tamar
> >
> > gcc/ChangeLog:
> >
> > PR bootstrap/84402
> > * genmatch.cc (dt_simplify::gen_1): Only emit labels if used.
> >
> > --- inline copy of patch --
> > diff --git a/gcc/genmatch.cc b/gcc/genmatch.cc index
> >
> 4fab4135347c43d95546a7df0bb1c4d074937288..638606b2502f640e595
> 27fc5a0b2
> > 3fa3bedd0cee 100644
> > --- a/gcc/genmatch.cc
> > +++ b/gcc/genmatch.cc
> > @@ -3352,6 +3352,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool
> gimple, operand *result)
> > char local_fail_label[256];
> > snprintf (local_fail_label, 256, "next_after_fail%u", ++fail_label_cnt);
> > fail_label = local_fail_label;
> > + bool needs_label = false;
> >
> > /* Analyze captures and perform early-outs on the incoming arguments
> > that cover cases we cannot handle. */ @@ -3366,6 +3367,7 @@
> > dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
> > fprintf_indent (f, indent,
> > "if (TREE_SIDE_EFFECTS (_p%d)) goto %s;\n",
> > i, fail_label);
> > + needs_label = true;
> > if (verbose >= 1)
> > warning_at (as_a <expr *> (s->match)->ops[i]->location,
> > "forcing toplevel operand to have no "
> > @@ -3381,6 +3383,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool
> gimple, operand *result)
> > fprintf_indent (f, indent,
> > "if (TREE_SIDE_EFFECTS (captures[%d])) "
> > "goto %s;\n", i, fail_label);
> > + needs_label = true;
> > if (verbose >= 1)
> > warning_at (cinfo.info[i].c->location,
> > "forcing captured operand to have no "
> > @@ -3423,7 +3426,10 @@ dt_simplify::gen_1 (FILE *f, int indent, bool
> gimple, operand *result)
> > }
> >
> > if (s->kind == simplify::SIMPLIFY)
> > - fprintf_indent (f, indent, "if (UNLIKELY (!dbg_cnt (match))) goto
> > %s;\n",
> fail_label);
> > + {
> > + fprintf_indent (f, indent, "if (UNLIKELY (!dbg_cnt (match))) goto
> > %s;\n",
> fail_label);
> > + needs_label = true;
> > + }
> >
> > fprintf_indent (f, indent, "if (UNLIKELY (dump_file && (dump_flags &
> TDF_FOLDING))) "
> > "fprintf (dump_file, \"%s ", @@ -3496,9 +3502,12 @@
> > dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
> > "res_op->resimplify (%s, valueize);\n",
> > !e->force_leaf ? "lseq" : "NULL");
> > if (e->force_leaf)
> > - fprintf_indent (f, indent,
> > - "if (!maybe_push_res_to_seq (res_op, NULL))
> > "
> > - "goto %s;\n", fail_label);
> > + {
> > + fprintf_indent (f, indent,
> > + "if (!maybe_push_res_to_seq (res_op,
> > NULL)) "
> > + "goto %s;\n", fail_label);
> > + needs_label = true;
> > + }
> > }
> > }
> > else if (result->type == operand::OP_CAPTURE @@ -3554,9
> > +3563,12 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand
> *result)
> > continue;
> > if (cinfo.info[i].result_use_count
> > > cinfo.info[i].match_use_count)
> > - fprintf_indent (f, indent,
> > - "if (! tree_invariant_p (captures[%d])) "
> > - "goto %s;\n", i, fail_label);
> > + {
> > + fprintf_indent (f, indent,
> > + "if (! tree_invariant_p (captures[%d]))
> > "
> > + "goto %s;\n", i, fail_label);
> > + needs_label = true;
> > + }
> > }
> > for (unsigned j = 0; j < e->ops.length (); ++j)
> > {
> > @@ -3607,6 +3619,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool
> gimple, operand *result)
> > {
> > fprintf_indent (f, indent, "if (!_r)\n");
> > fprintf_indent (f, indent, " goto %s;\n",
> > fail_label);
> > + needs_label = true;
> > }
> > }
> > }
> > @@ -3647,7 +3660,8 @@ dt_simplify::gen_1 (FILE *f, int indent, bool
> gimple, operand *result)
> > }
> > indent -= 2;
> > fprintf_indent (f, indent, "}\n");
> > - fprintf (f, "%s:;\n", fail_label);
> > + if (needs_label)
> > + fprintf (f, "%s:;\n", fail_label);
> > fail_label = NULL;
> > }
> >
> >
> >
> >
> >
> > --
