[PATCH 7/8] RISC-V: Support to add implicit extensions for G.
Nelson Chu
nelson.chu@sifive.com
Fri Nov 27 02:33:09 GMT 2020
G is a special case, consider the ISA spec github issue as follows,
https://github.com/riscv/riscv-isa-manual/issues/575
My understand is that - i, m, a, f and d extensions are not g's implicit
extensions, they are g's expansions. The zifencei is the implicit extension
of g, and so is zicsr, since it is implicited by f (or i2p1). However,
we add the g with the RISCV_UNKNOWN_VERSION to the subset list, and it
will not output to the arch string, it is only used to check what implicit
extensions are need to be added.
bfd/
* elfxx-riscv.c (riscv_parse_add_subset): Allow to add g with
RISCV_UNKNOWN_VERSION versions.
(riscv_parse_std_ext): Add g to the subset list, we only use it
to add the implicit extensions, but won't output it to arch string.
(riscv_parse_add_implicit_subsets): Add implicit zicsr and zifencei
for g extension.
(riscv_arch_str1): Do not output g to the arch string.
* elfxx-riscv.h (RISCV_UNKNOWN_VERSION): Moved to include/opcode/riscv.h.
gas/
* testsuite/gas/riscv/attribute-10.d: Updated.
* testsuite/gas/riscv/march-imply-g.d: New testcase for g.
* testsuite/gas/riscv/march-imply-unsupported.d: The zicsr and zifencei
are not supported in the ISA spec v2.2, so don't add and output them.
include/
* opcode/riscv.h (RISCV_UNKNOWN_VERSION): added.
---
bfd/elfxx-riscv.c | 27 ++++++++++++++++++-----
bfd/elfxx-riscv.h | 2 --
gas/testsuite/gas/riscv/attribute-10.d | 2 +-
gas/testsuite/gas/riscv/march-imply-g.d | 6 +++++
gas/testsuite/gas/riscv/march-imply-unsupported.d | 6 +++++
include/opcode/riscv.h | 2 ++
6 files changed, 36 insertions(+), 9 deletions(-)
create mode 100644 gas/testsuite/gas/riscv/march-imply-g.d
create mode 100644 gas/testsuite/gas/riscv/march-imply-unsupported.d
diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
index b4bd278..ec883e4 100644
--- a/bfd/elfxx-riscv.c
+++ b/bfd/elfxx-riscv.c
@@ -1173,6 +1173,7 @@ riscv_parse_add_subset (riscv_parse_subset_t *rps,
rps->get_default_version (subset, &major_version, &minor_version);
if (!implicit
+ && strcmp (subset, "g") != 0
&& (major_version == RISCV_UNKNOWN_VERSION
|| minor_version == RISCV_UNKNOWN_VERSION))
{
@@ -1354,8 +1355,6 @@ riscv_parse_std_ext (riscv_parse_subset_t *rps,
break;
case 'g':
- /* The g-ext shouldn't has the version, so we just
- skip the setting if user set a version to it. */
p = riscv_parsing_subset_version (rps, march, ++p,
&major_version,
&minor_version, TRUE);
@@ -1363,6 +1362,11 @@ riscv_parse_std_ext (riscv_parse_subset_t *rps,
riscv_parse_add_subset (rps, "i",
RISCV_UNKNOWN_VERSION,
RISCV_UNKNOWN_VERSION, FALSE);
+ /* g-ext is used to add the implicit extensions, but will
+ not be output to the arch string. */
+ riscv_parse_add_subset (rps, "g",
+ major_version,
+ minor_version, FALSE);
for ( ; *std_exts != 'q'; std_exts++)
{
subset[0] = *std_exts;
@@ -1737,6 +1741,16 @@ riscv_parse_add_implicit_subsets (riscv_parse_subset_t *rps)
riscv_parse_add_subset (rps, "zicsr",
RISCV_UNKNOWN_VERSION,
RISCV_UNKNOWN_VERSION, TRUE);
+
+ if ((riscv_lookup_subset (rps->subset_list, "g", &subset)))
+ {
+ riscv_parse_add_subset (rps, "zicsr",
+ RISCV_UNKNOWN_VERSION,
+ RISCV_UNKNOWN_VERSION, TRUE);
+ riscv_parse_add_subset (rps, "zifencei",
+ RISCV_UNKNOWN_VERSION,
+ RISCV_UNKNOWN_VERSION, TRUE);
+ }
}
/* Function for parsing arch string.
@@ -1906,10 +1920,11 @@ riscv_arch_str1 (riscv_subset_t *subset,
strncat (attr_str, buf, bufsz);
- /* Skip 'i' extension after 'e'. */
- if ((strcasecmp (subset->name, "e") == 0)
- && subset->next
- && (strcasecmp (subset->next->name, "i") == 0))
+ /* Skip 'i' extension after 'e', and skip 'g' extension. */
+ if (subset->next
+ && ((strcmp (subset->name, "e") == 0
+ && strcmp (subset->next->name, "i") == 0)
+ || strcmp (subset->next->name, "g") == 0))
riscv_arch_str1 (subset->next->next, attr_str, buf, bufsz);
else
riscv_arch_str1 (subset->next, attr_str, buf, bufsz);
diff --git a/bfd/elfxx-riscv.h b/bfd/elfxx-riscv.h
index 89d4abb..4e03ce1 100644
--- a/bfd/elfxx-riscv.h
+++ b/bfd/elfxx-riscv.h
@@ -33,8 +33,6 @@ riscv_reloc_type_lookup (bfd *, bfd_reloc_code_real_type);
extern reloc_howto_type *
riscv_elf_rtype_to_howto (bfd *, unsigned int r_type);
-#define RISCV_UNKNOWN_VERSION -1
-
/* The information of architecture attribute. */
struct riscv_subset_t
{
diff --git a/gas/testsuite/gas/riscv/attribute-10.d b/gas/testsuite/gas/riscv/attribute-10.d
index ba903d1..30b82d7 100644
--- a/gas/testsuite/gas/riscv/attribute-10.d
+++ b/gas/testsuite/gas/riscv/attribute-10.d
@@ -3,4 +3,4 @@
#source: empty.s
Attribute Section: riscv
File Attributes
- Tag_RISCV_arch: "rv32i2p1_m2p0_a2p1_f2p2_d2p2_c2p0_zicsr2p0"
+ Tag_RISCV_arch: "rv32i2p1_m2p0_a2p1_f2p2_d2p2_c2p0_zicsr2p0_zifencei2p0"
diff --git a/gas/testsuite/gas/riscv/march-imply-g.d b/gas/testsuite/gas/riscv/march-imply-g.d
new file mode 100644
index 0000000..33a243d
--- /dev/null
+++ b/gas/testsuite/gas/riscv/march-imply-g.d
@@ -0,0 +1,6 @@
+#as: -march=rv32g -march-attr -misa-spec=20191213
+#readelf: -A
+#source: empty.s
+Attribute Section: riscv
+File Attributes
+ Tag_RISCV_arch: "rv32i2p1_m2p0_a2p1_f2p2_d2p2_zicsr2p0_zifencei2p0"
diff --git a/gas/testsuite/gas/riscv/march-imply-unsupported.d b/gas/testsuite/gas/riscv/march-imply-unsupported.d
new file mode 100644
index 0000000..2e19e09
--- /dev/null
+++ b/gas/testsuite/gas/riscv/march-imply-unsupported.d
@@ -0,0 +1,6 @@
+#as: -march=rv32g -march-attr -misa-spec=2.2
+#readelf: -A
+#source: empty.s
+Attribute Section: riscv
+File Attributes
+ Tag_RISCV_arch: "rv32i2p0_m2p0_a2p0_f2p0_d2p0"
diff --git a/include/opcode/riscv.h b/include/opcode/riscv.h
index 94a1380..680780a 100644
--- a/include/opcode/riscv.h
+++ b/include/opcode/riscv.h
@@ -354,6 +354,8 @@ enum riscv_isa_spec_class
ISA_SPEC_CLASS_20191213
};
+#define RISCV_UNKNOWN_VERSION -1
+
/* This structure holds version information for specific ISA. */
struct riscv_ext_version
--
2.7.4
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