From edc77c591add0a9c7740a9ed9f7e40358bf65dbf Mon Sep 17 00:00:00 2001 From: Nelson Chu Date: Thu, 4 Nov 2021 14:31:48 +0800 Subject: [PATCH] RISC-V: Clarify the behavior of .option rvc or norvc. Add/Remove the rvc extension to/from the riscv_subsets once the .option rvc/norvc is set. So that we don't need to always check the riscv_opts.rvc in the riscv_subset_supports, just call the riscv_lookup_subset to search the subset list is enough. Besides, we will need to dump the instructions according to the elf architecture attributes. That means the dis-assembler needs to parse the architecture string from the elf attribute before dumping any instructions, and also needs to recognized the INSN_CLASS* classes from riscv_opcodes. Therefore, I suppose some functions will need to be moved from gas/config/tc-riscv.c to bfd/elfxx-riscv.c, including riscv_multi_subset_supports and riscv_subset_supports. This is one of the reasons why we need this patch. This patch passes the gcc/binutils regressions of rv32emc-elf, rv32i-elf, rv64gc-elf and rv64gc-linux toolchains. bfd/ * elfxx-riscv.c (riscv_remove_subset): Remove the extension from the subset list. (riscv_update_subset): Add/Remove an extension to/from the subset list. This is used for the .option rvc or norvc. * elfxx-riscv.h: Added the extern bool riscv_update_subset. gas/ * config/tc-riscv.c (riscv_set_options): Removed the unused rve flag. (riscv_opts): Likewise. (riscv_set_rve): Removed. (riscv_subset_supports): Removed the riscv_opts.rvc check. (riscv_set_arch): Don't need to call riscv_set_rve. (reg_lookup_internal): Call riscv_subset_supports to check whether the rve is supported. (s_riscv_option): Add/Remove the rvc extension to/from the subset list once the .option rvc/norvc is set. --- bfd/elfxx-riscv.c | 65 +++++++++++++++++++++++++++++++++++++++++++ bfd/elfxx-riscv.h | 3 ++ gas/config/tc-riscv.c | 39 ++++++++++++-------------- 3 files changed, 86 insertions(+), 21 deletions(-) diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c index cdb4fa0996a..65bb1cab756 100644 --- a/bfd/elfxx-riscv.c +++ b/bfd/elfxx-riscv.c @@ -2030,3 +2030,68 @@ riscv_arch_str (unsigned xlen, const riscv_subset_list_t *subset) return attr_str; } + +/* Remove the SUBSET from the subset list. */ + +static void +riscv_remove_subset (riscv_subset_list_t *subset_list, + const char *subset) +{ + riscv_subset_t *current = subset_list->head; + riscv_subset_t *pre = NULL; + for (; current != NULL; pre = current, current = current->next) + { + if (strcmp (current->name, subset) == 0) + { + if (pre == NULL) + subset_list->head = current->next; + else + pre->next = current->next; + if (current->next == NULL) + subset_list->tail = pre; + free ((void *) current->name); + free (current); + break; + } + } +} + +/* Add/Remove an extension to/from the subset list. This is used for + the .option rvc or norvc. */ + +bool +riscv_update_subset (riscv_parse_subset_t *rps, + const char *subset, + bool removed) +{ + if (strlen (subset) == 0 + || (strlen (subset) == 1 + && riscv_ext_order[(*subset - 'a')] == 0) + || (strlen (subset) > 1 + && rps->check_unknown_prefixed_ext + && !riscv_recognized_prefixed_ext (subset))) + { + rps->error_handler + (_("riscv_update_subset: unknown ISA extension `%s'"), subset); + return false; + } + + if (removed) + { + if (strcmp (subset, "i") == 0) + { + rps->error_handler + (_("riscv_update_subset: cannot remove extension i from " + "the subset list")); + return false; + } + riscv_remove_subset (rps->subset_list, subset); + } + else + riscv_parse_add_subset (rps, subset, + RISCV_UNKNOWN_VERSION, + RISCV_UNKNOWN_VERSION, true); + + riscv_parse_add_implicit_subsets (rps); + return riscv_parse_check_conflicts (rps); +} diff --git a/bfd/elfxx-riscv.h b/bfd/elfxx-riscv.h index 3af8fd99d9a..17620fd2c95 100644 --- a/bfd/elfxx-riscv.h +++ b/bfd/elfxx-riscv.h @@ -92,6 +92,9 @@ riscv_estimate_digit (unsigned); extern int riscv_compare_subsets (const char *, const char *); +extern bool +riscv_update_subset (riscv_parse_subset_t *, const char *, bool); + extern void bfd_elf32_riscv_set_data_segment_info (struct bfd_link_info *, int *); extern void diff --git a/gas/config/tc-riscv.c b/gas/config/tc-riscv.c index eb626f8e1d5..90d960a5031 100644 --- a/gas/config/tc-riscv.c +++ b/gas/config/tc-riscv.c @@ -203,7 +203,6 @@ struct riscv_set_options { int pic; /* Generate position-independent code. */ int rvc; /* Generate RVC code. */ - int rve; /* Generate RVE code. */ int relax; /* Emit relocs the linker is allowed to relax. */ int arch_attr; /* Emit architecture and privileged elf attributes. */ int csr_check; /* Enable the CSR checking. */ @@ -213,7 +212,6 @@ static struct riscv_set_options riscv_opts = { 0, /* pic */ 0, /* rvc */ - 0, /* rve */ 1, /* relax */ DEFAULT_RISCV_ATTR, /* arch_attr */ 0, /* csr_check */ @@ -231,14 +229,6 @@ riscv_set_rvc (bool rvc_value) riscv_opts.rvc = rvc_value; } -/* Enable or disable the rve flags for riscv_opts. */ - -static void -riscv_set_rve (bool rve_value) -{ - riscv_opts.rve = rve_value; -} - /* This linked list records all enabled extensions, which are parsed from the architecture string. The architecture string can be set by the -march option, the elf architecture attributes, and the --with-arch @@ -252,10 +242,6 @@ static bool riscv_subset_supports (const char *feature) { struct riscv_subset_t *subset; - - if (riscv_opts.rvc && (strcasecmp (feature, "c") == 0)) - return true; - return riscv_lookup_subset (&riscv_subsets, feature, &subset); } @@ -329,13 +315,9 @@ riscv_set_arch (const char *s) riscv_release_subset_list (&riscv_subsets); riscv_parse_subset (&rps, s); - /* To support .option rvc and rve. */ riscv_set_rvc (false); if (riscv_subset_supports ("c")) riscv_set_rvc (true); - riscv_set_rve (false); - if (riscv_subset_supports ("e")) - riscv_set_rve (true); } /* Indicate -mabi option is explictly set. */ @@ -1013,7 +995,9 @@ reg_lookup_internal (const char *s, enum reg_class class) if (r == NULL || DECODE_REG_CLASS (r) != class) return -1; - if (riscv_opts.rve && class == RCLASS_GPR && DECODE_REG_NUM (r) > 15) + if (riscv_subset_supports ("e") + && class == RCLASS_GPR + && DECODE_REG_NUM (r) > 15) return -1; return DECODE_REG_NUM (r); @@ -3380,10 +3364,23 @@ s_riscv_option (int x ATTRIBUTE_UNUSED) ch = *input_line_pointer; *input_line_pointer = '\0'; + riscv_parse_subset_t rps; + rps.subset_list = &riscv_subsets; + rps.error_handler = as_bad; + rps.xlen = &xlen; + rps.isa_spec = default_isa_spec; + rps.check_unknown_prefixed_ext = true; + if (strcmp (name, "rvc") == 0) - riscv_set_rvc (true); + { + riscv_update_subset (&rps, "c", false); + riscv_set_rvc (true); + } else if (strcmp (name, "norvc") == 0) - riscv_set_rvc (false); + { + riscv_update_subset (&rps, "c", true); + riscv_set_rvc (false); + } else if (strcmp (name, "pic") == 0) riscv_opts.pic = true; else if (strcmp (name, "nopic") == 0) -- 2.30.2