From e57d3cce4e4fdf50fa59b807ea43c8b14c5c1711 Mon Sep 17 00:00:00 2001
From: Andre Vieira <andre.simoesdiasvieira@arm.com>
Date: Mon, 19 Aug 2024 09:38:41 +0100
Subject: [PATCH] rtl: Enable the use of rtx values with int and mode
attributes
The 'code' part of a 'define_code_attr' refers to the type of the key, in other
words, it uses a code_iterator to pick the 'value' from their (key "value") pair
list.
However, rtx_alloc_for_name requires a code_attribute to be used when the
'value' needs to be a type. In other words, no other type of attributes could be
used, before this patch, to produce a rtx typed 'value'.
This patch removes that restriction and allows the backend to use any kind of
attribute as long as that attribute always produces a valid code typed 'value'.
gcc/ChangeLog:
* read-rtl.cc (rtx_reader::rtx_alloc_for_name): Allow all attribute
types to produce code 'values'.
(check_code_attribute): Rename ...
(check_attribute_codes): ... to this. And change comments to refer to
* doc/md.texi: Add paragraph to document that you can use int and mode
attributes to produce codes.
---
gcc/doc/md.texi | 5 +++++
gcc/read-rtl.cc | 21 ++++++++++++++-------
2 files changed, 19 insertions(+), 7 deletions(-)
diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
index 5dc0d55edd63..a92591122517 100644
--- a/gcc/doc/md.texi
+++ b/gcc/doc/md.texi
@@ -12077,6 +12077,11 @@ while the unsigned version uses @code{umax} and @code{umin}. There
are no versions that pair @code{smax} with @code{umin} or @code{umax}
with @code{smin}.
+It is also possible to use other types of attributes as codes,
+in a similar way. For example, an int iterator could be used to
+iterate over @code{unspec} numbers, with an int attribute specifying
+an associated rtx code. @xref{Int Iterators}.
+
Here's an example of code iterators in action, taken from the MIPS port:
@smallexample
diff --git a/gcc/read-rtl.cc b/gcc/read-rtl.cc
index 4f09e449c81f..bfce806f9d69 100644
--- a/gcc/read-rtl.cc
+++ b/gcc/read-rtl.cc
@@ -1423,21 +1423,21 @@ check_code_iterator (struct mapping *iterator)
consistent format. Return a representative code. */
static rtx_code
-check_code_attribute (mapping *attr)
+check_attribute_codes (mapping *attr)
{
rtx_code bellwether = UNKNOWN;
for (map_value *v = attr->values; v != 0; v = v->next)
{
rtx_code code = maybe_find_code (v->string);
if (code == UNKNOWN)
- fatal_with_file_and_line ("code attribute `%s' contains "
+ fatal_with_file_and_line ("attribute `%s' contains "
"unrecognized rtx code `%s'",
attr->name, v->string);
if (bellwether == UNKNOWN)
bellwether = code;
else if (strcmp (GET_RTX_FORMAT (bellwether),
GET_RTX_FORMAT (code)) != 0)
- fatal_with_file_and_line ("code attribute `%s' combines "
+ fatal_with_file_and_line ("attribute `%s' combines "
"`%s' and `%s', which have different "
"rtx formats", attr->name,
GET_RTX_NAME (bellwether),
@@ -1604,7 +1604,7 @@ parse_reg_note_name (const char *string)
fatal_with_file_and_line ("unrecognized REG_NOTE name: `%s'", string);
}
-/* Allocate an rtx for code NAME. If NAME is a code iterator or code
+/* Allocate an rtx for code NAME. If NAME is a code iterator or an
attribute, record its use for later and use one of its possible
values as an interim rtx code. */
@@ -1627,13 +1627,20 @@ rtx_reader::rtx_alloc_for_name (const char *name)
attr = deferred_name;
/* Find the attribute itself. */
- mapping *m = (mapping *) htab_find (codes.attrs, &attr);
+ mapping *m = nullptr;
+ for (auto attrs : { codes.attrs, ints.attrs, modes.attrs })
+ if (auto *newm = (mapping *) htab_find (attrs, &attr))
+ {
+ if (m)
+ fatal_with_file_and_line ("ambiguous attribute `%s`", attr);
+ m = newm;
+ }
if (!m)
- fatal_with_file_and_line ("unknown code attribute `%s'", attr);
+ fatal_with_file_and_line ("unknown attribute `%s'", attr);
/* Pick the first possible code for now, and record the attribute
use for later. */
- rtx x = rtx_alloc (check_code_attribute (m));
+ rtx x = rtx_alloc (check_attribute_codes (m));
record_attribute_use (&codes, get_current_location (),
x, 0, deferred_name);
return x;
--
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