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Make genmatch transform failure handling more consistent

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Currently whether a fail during the transform stage is fatal or
whether following patterns are still considers is a bit random
depending on whether the pattern is wrapped in a for for example.
The follwing makes it consistent by replacing early returns with
gotos to the end of the pattern processing.

2020-08-05  Richard Biener  <rguenther@suse.de>

	* genmatch.c (fail_label): New global.
	(expr::gen_transform): Branch to fail_label instead of
	returning.  Fix indent of call argument checking.
	(dt_simplify::gen_1): Compute and emit fail_label, branch
	to it instead of returning early.
This commit is contained in:
Richard Biener 2020-08-05 12:00:07 +02:00
parent 9f3abfb84e
commit f0699540f3
1 changed files with 29 additions and 15 deletions

44
gcc/genmatch.c

@ -2352,6 +2352,10 @@ capture_info::walk_c_expr (c_expr *e)
}
/* The current label failing the current matched pattern during
code generation. */
static char *fail_label;
/* Code generation off the decision tree and the refered AST nodes. */
bool
@ -2527,8 +2531,8 @@ expr::gen_transform (FILE *f, int indent, const char *dest, bool gimple,
"_r%d = maybe_push_res_to_seq (&tem_op, %s);\n", depth,
!force_leaf ? "lseq" : "NULL");
fprintf_indent (f, indent,
"if (!_r%d) return false;\n",
depth);
"if (!_r%d) goto %s;\n",
depth, fail_label);
if (*opr == CONVERT_EXPR)
{
indent -= 4;
@ -2560,7 +2564,7 @@ expr::gen_transform (FILE *f, int indent, const char *dest, bool gimple,
if (opr->kind != id_base::CODE)
{
fprintf_indent (f, indent, " if (!_r%d)\n", depth);
fprintf_indent (f, indent, " return NULL_TREE;\n");
fprintf_indent (f, indent, " goto %s;\n", fail_label);
fprintf_indent (f, indent, "}\n");
}
if (*opr == CONVERT_EXPR)
@ -3068,12 +3072,12 @@ dt_node::gen_kids_1 (FILE *f, int indent, bool gimple, int depth,
/* We need to be defensive against bogus prototypes allowing
calls with not enough arguments. */
fprintf_indent (f, indent,
" if (gimple_call_num_args (_c%d) == %d)\n"
" {\n", depth, e->ops.length ());
" if (gimple_call_num_args (_c%d) == %d)\n",
depth, e->ops.length ());
fprintf_indent (f, indent, " {\n");
fns[i]->gen (f, indent + 6, true, depth);
fprintf_indent (f, indent,
" }\n"
" break;\n");
fprintf_indent (f, indent, " }\n");
fprintf_indent (f, indent, " break;\n");
}
fprintf_indent (f, indent, "default:;\n");
@ -3278,6 +3282,11 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
}
}
static unsigned fail_label_cnt;
char local_fail_label[256];
snprintf (local_fail_label, 256, "next_after_fail%u", ++fail_label_cnt);
fail_label = local_fail_label;
/* Analyze captures and perform early-outs on the incoming arguments
that cover cases we cannot handle. */
capture_info cinfo (s, result, gimple);
@ -3289,8 +3298,8 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
if (cinfo.force_no_side_effects & (1 << i))
{
fprintf_indent (f, indent,
"if (TREE_SIDE_EFFECTS (_p%d)) return NULL_TREE;\n",
i);
"if (TREE_SIDE_EFFECTS (_p%d)) goto %s;\n",
i, fail_label);
if (verbose >= 1)
warning_at (as_a <expr *> (s->match)->ops[i]->location,
"forcing toplevel operand to have no "
@ -3305,7 +3314,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
{
fprintf_indent (f, indent,
"if (TREE_SIDE_EFFECTS (captures[%d])) "
"return NULL_TREE;\n", i);
"goto %s;\n", i, fail_label);
if (verbose >= 1)
warning_at (cinfo.info[i].c->location,
"forcing captured operand to have no "
@ -3348,8 +3357,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
}
if (s->kind == simplify::SIMPLIFY)
fprintf_indent (f, indent, "if (__builtin_expect (!dbg_cnt (match), 0)) return %s;\n",
gimple ? "false" : "NULL_TREE");
fprintf_indent (f, indent, "if (__builtin_expect (!dbg_cnt (match), 0)) goto %s;\n", fail_label);
fprintf_indent (f, indent, "if (__builtin_expect (dump_file && (dump_flags & TDF_FOLDING), 0)) "
"fprintf (dump_file, \"%s ",
@ -3361,6 +3369,8 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
true);
fprintf (f, ", __FILE__, __LINE__);\n");
fprintf_indent (f, indent, "{\n");
indent += 2;
if (!result)
{
/* If there is no result then this is a predicate implementation. */
@ -3474,7 +3484,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
> cinfo.info[i].match_use_count)
fprintf_indent (f, indent,
"if (! tree_invariant_p (captures[%d])) "
"return NULL_TREE;\n", i);
"goto %s;\n", i, fail_label);
}
for (unsigned j = 0; j < e->ops.length (); ++j)
{
@ -3524,7 +3534,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
if (!is_a <operator_id *> (opr))
{
fprintf_indent (f, indent, "if (!_r)\n");
fprintf_indent (f, indent, " return NULL_TREE;\n");
fprintf_indent (f, indent, " goto %s;\n", fail_label);
}
}
}
@ -3563,6 +3573,10 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
fprintf_indent (f, indent, "return _r;\n");
}
}
indent -= 2;
fprintf_indent (f, indent, "}\n");
fprintf (f, "%s:;\n", fail_label);
fail_label = NULL;
}
/* Generate code for the '(if ...)', '(with ..)' and actual transform