/* tc-riscv.c -- RISC-V assembler
- Copyright (C) 2011-2018 Free Software Foundation, Inc.
+ Copyright (C) 2011-2020 Free Software Foundation, Inc.
Contributed by Andrew Waterman (andrew@sifive.com).
Based on MIPS target.
#include "itbl-ops.h"
#include "dwarf2dbg.h"
#include "dw2gencfi.h"
-#include "struc-symbol.h"
+#include "bfd/elfxx-riscv.h"
#include "elf/riscv.h"
#include "opcode/riscv.h"
#define DEFAULT_ARCH "riscv64"
#endif
+#ifndef DEFAULT_RISCV_ATTR
+#define DEFAULT_RISCV_ATTR 0
+#endif
+
static const char default_arch[] = DEFAULT_ARCH;
static unsigned xlen = 0; /* width of an x-register */
int rvc; /* Generate RVC code. */
int rve; /* Generate RVE code. */
int relax; /* Emit relocs the linker is allowed to relax. */
+ int arch_attr; /* Emit arch attribute. */
};
static struct riscv_set_options riscv_opts =
0, /* rvc */
0, /* rve */
1, /* relax */
+ DEFAULT_RISCV_ATTR, /* arch_attr */
};
static void
riscv_opts.rve = rve_value;
}
-struct riscv_subset
-{
- const char *name;
-
- struct riscv_subset *next;
-};
-
-static struct riscv_subset *riscv_subsets;
+static riscv_subset_list_t riscv_subsets;
static bfd_boolean
riscv_subset_supports (const char *feature)
{
- struct riscv_subset *s;
- char *p;
- unsigned xlen_required = strtoul (feature, &p, 10);
-
- if (xlen_required && xlen != xlen_required)
- return FALSE;
-
- for (s = riscv_subsets; s != NULL; s = s->next)
- if (strcasecmp (s->name, p) == 0)
- return TRUE;
+ if (riscv_opts.rvc && (strcasecmp (feature, "c") == 0))
+ return TRUE;
- return FALSE;
+ return riscv_lookup_subset (&riscv_subsets, feature) != NULL;
}
-static void
-riscv_clear_subsets (void)
+static bfd_boolean
+riscv_multi_subset_supports (enum riscv_insn_class insn_class)
{
- while (riscv_subsets != NULL)
+ switch (insn_class)
{
- struct riscv_subset *next = riscv_subsets->next;
- free ((void *) riscv_subsets->name);
- free (riscv_subsets);
- riscv_subsets = next;
- }
-}
+ case INSN_CLASS_I: return riscv_subset_supports ("i");
+ case INSN_CLASS_C: return riscv_subset_supports ("c");
+ case INSN_CLASS_A: return riscv_subset_supports ("a");
+ case INSN_CLASS_M: return riscv_subset_supports ("m");
+ case INSN_CLASS_F: return riscv_subset_supports ("f");
+ case INSN_CLASS_D: return riscv_subset_supports ("d");
+ case INSN_CLASS_D_AND_C:
+ return riscv_subset_supports ("d") && riscv_subset_supports ("c");
-static void
-riscv_add_subset (const char *subset)
-{
- struct riscv_subset *s = xmalloc (sizeof *s);
+ case INSN_CLASS_F_AND_C:
+ return riscv_subset_supports ("f") && riscv_subset_supports ("c");
- s->name = xstrdup (subset);
- s->next = riscv_subsets;
- riscv_subsets = s;
+ case INSN_CLASS_Q: return riscv_subset_supports ("q");
+
+ default:
+ as_fatal ("Unreachable");
+ return FALSE;
+ }
}
/* Set which ISA and extensions are available. */
static void
riscv_set_arch (const char *s)
{
- const char *all_subsets = "imafdqc";
- char *extension = NULL;
- const char *p = s;
-
- riscv_clear_subsets();
-
- if (strncmp (p, "rv32", 4) == 0)
- {
- xlen = 32;
- p += 4;
- }
- else if (strncmp (p, "rv64", 4) == 0)
- {
- xlen = 64;
- p += 4;
- }
- else
- as_fatal ("-march=%s: ISA string must begin with rv32 or rv64", s);
-
- switch (*p)
- {
- case 'i':
- break;
-
- case 'e':
- p++;
- riscv_add_subset ("e");
- riscv_add_subset ("i");
-
- if (xlen > 32)
- as_fatal ("-march=%s: rv%de is not a valid base ISA", s, xlen);
-
- break;
-
- case 'g':
- p++;
- for ( ; *all_subsets != 'q'; all_subsets++)
- {
- const char subset[] = {*all_subsets, '\0'};
- riscv_add_subset (subset);
- }
- break;
-
- default:
- as_fatal ("-march=%s: first ISA subset must be `e', `i' or `g'", s);
- }
-
- while (*p)
- {
- if (*p == 'x')
- {
- char *subset = xstrdup (p);
- char *q = subset;
-
- while (*++q != '\0' && *q != '_')
- ;
- *q = '\0';
-
- if (extension)
- as_fatal ("-march=%s: only one non-standard extension is supported"
- " (found `%s' and `%s')", s, extension, subset);
- extension = subset;
- riscv_add_subset (subset);
- p += strlen (subset);
- }
- else if (*p == '_')
- p++;
- else if ((all_subsets = strchr (all_subsets, *p)) != NULL)
- {
- const char subset[] = {*p, 0};
- riscv_add_subset (subset);
- all_subsets++;
- p++;
- }
- else
- as_fatal ("-march=%s: unsupported ISA subset `%c'", s, *p);
- }
-
- if (riscv_subset_supports ("e") && riscv_subset_supports ("f"))
- as_fatal ("-march=%s: rv32e does not support the `f' extension", s);
+ riscv_parse_subset_t rps;
+ rps.subset_list = &riscv_subsets;
+ rps.error_handler = as_fatal;
+ rps.xlen = &xlen;
- if (riscv_subset_supports ("d") && !riscv_subset_supports ("f"))
- as_fatal ("-march=%s: `d' extension requires `f' extension", s);
-
- if (riscv_subset_supports ("q") && !riscv_subset_supports ("d"))
- as_fatal ("-march=%s: `q' extension requires `d' extension", s);
-
- if (riscv_subset_supports ("q") && xlen < 64)
- as_fatal ("-march=%s: rv32 does not support the `q' extension", s);
-
- free (extension);
+ riscv_release_subset_list (&riscv_subsets);
+ riscv_parse_subset (&rps, s);
}
/* Handle of the OPCODE hash table. */
/* or 0d1.2345e12 */
const char FLT_CHARS[] = "rRsSfFdDxXpP";
+/* Indicate we are already assemble any instructions or not. */
+static bfd_boolean start_assemble = FALSE;
+
+/* Indicate arch attribute is explictly set. */
+static bfd_boolean explicit_arch_attr = FALSE;
+
/* Macros for encoding relaxation state for RVC branches and far jumps. */
#define RELAX_BRANCH_ENCODE(uncond, rvc, length) \
((relax_substateT) \
return o;
}
-struct regname
-{
- const char *name;
- unsigned int num;
-};
-
enum reg_class
{
RCLASS_GPR,
static unsigned int
reg_lookup_internal (const char *s, enum reg_class class)
{
- struct regname *r = (struct regname *) hash_find (reg_names_hash, s);
+ void *r = hash_find (reg_names_hash, s);
if (r == NULL || DECODE_REG_CLASS (r) != class)
return -1;
case 'v': used_bits |= ENCODE_RVC_IMM (-1U); break;
case 'w': break; /* RS1S, constrained to equal RD */
case 'x': break; /* RS2S, constrained to equal RD */
+ case 'z': break; /* RS2S, contrained to be x0 */
case 'K': used_bits |= ENCODE_RVC_ADDI4SPN_IMM (-1U); break;
case 'L': used_bits |= ENCODE_RVC_ADDI16SP_IMM (-1U); break;
case 'M': used_bits |= ENCODE_RVC_SWSP_IMM (-1U); break;
case 'F': /* funct */
switch (c = *p++)
{
+ case '6': USE_BITS (OP_MASK_CFUNCT6, OP_SH_CFUNCT6); break;
case '4': USE_BITS (OP_MASK_CFUNCT4, OP_SH_CFUNCT4); break;
case '3': USE_BITS (OP_MASK_CFUNCT3, OP_SH_CFUNCT3); break;
+ case '2': USE_BITS (OP_MASK_CFUNCT2, OP_SH_CFUNCT2); break;
default:
as_bad (_("internal: bad RISC-V opcode"
" (unknown operand type `CF%c'): %s %s"),
case '[': break;
case ']': break;
case '0': break;
+ case '1': break;
case 'F': /* funct */
switch (c = *p++)
{
append_insn (&insn, ep, r);
}
+/* Build an instruction created by a macro expansion. Like md_assemble but
+ accept a printf-style format string and arguments. */
+
+static void
+md_assemblef (const char *format, ...)
+{
+ char *buf = NULL;
+ va_list ap;
+ int r;
+
+ va_start (ap, format);
+
+ r = vasprintf (&buf, format, ap);
+
+ if (r < 0)
+ as_fatal (_("internal error: vasprintf failed"));
+
+ md_assemble (buf);
+ free(buf);
+
+ va_end (ap);
+}
+
/* Sign-extend 32-bit mode constants that have bit 31 set and all higher bits
unset. */
static void
load_const (int reg, expressionS *ep)
{
int shift = RISCV_IMM_BITS;
+ bfd_vma upper_imm, sign = (bfd_vma) 1 << (RISCV_IMM_BITS - 1);
expressionS upper = *ep, lower = *ep;
- lower.X_add_number = (int32_t) ep->X_add_number << (32-shift) >> (32-shift);
+ lower.X_add_number = ((ep->X_add_number & (sign + sign - 1)) ^ sign) - sign;
upper.X_add_number -= lower.X_add_number;
if (ep->X_op != O_constant)
upper.X_add_number = (int64_t) upper.X_add_number >> shift;
load_const (reg, &upper);
- macro_build (NULL, "slli", "d,s,>", reg, reg, shift);
+ md_assemblef ("slli x%d, x%d, 0x%x", reg, reg, shift);
if (lower.X_add_number != 0)
- macro_build (&lower, "addi", "d,s,j", reg, reg, BFD_RELOC_RISCV_LO12_I);
+ md_assemblef ("addi x%d, x%d, %" BFD_VMA_FMT "d", reg, reg,
+ lower.X_add_number);
}
else
{
if (upper.X_add_number != 0)
{
- macro_build (ep, "lui", "d,u", reg, BFD_RELOC_RISCV_HI20);
+ /* Discard low part and zero-extend upper immediate. */
+ upper_imm = ((uint32_t)upper.X_add_number >> shift);
+
+ md_assemblef ("lui x%d, 0x%" BFD_VMA_FMT "x", reg, upper_imm);
hi_reg = reg;
}
if (lower.X_add_number != 0 || hi_reg == 0)
- macro_build (ep, ADD32_INSN, "d,s,j", reg, hi_reg,
- BFD_RELOC_RISCV_LO12_I);
+ md_assemblef ("%s x%d, x%d, %" BFD_VMA_FMT "d", ADD32_INSN, reg, hi_reg,
+ lower.X_add_number);
}
}
{0, 0}
};
+static const struct percent_op_match percent_op_null[] =
+{
+ {0, 0}
+};
+
/* Return true if *STR points to a relocation operator. When returning true,
move *STR over the operator and store its relocation code in *RELOC.
Leave both *STR and *RELOC alone when returning false. */
unsigned crux_depth, str_depth, regno;
char *crux;
- /* First, check for integer registers. */
+ /* First, check for integer registers. No callers can accept a reg, but
+ we need to avoid accidentally creating a useless undefined symbol below,
+ if this is an instruction pattern that can't match. A glibc build fails
+ if this is removed. */
if (reg_lookup (&str, RCLASS_GPR, ®no))
{
ep->X_op = O_register;
ep->X_add_number = regno;
+ expr_end = str;
return 0;
}
argsStart = s;
for ( ; insn && insn->name && strcmp (insn->name, str) == 0; insn++)
{
- if (!riscv_subset_supports (insn->subset))
+ if ((insn->xlen_requirement != 0) && (xlen != insn->xlen_requirement))
+ continue;
+
+ if (!riscv_multi_subset_supports (insn->insn_class))
continue;
create_insn (ip, insn);
|| regno != X_SP)
break;
continue;
+ case 'z': /* RS2, contrained to equal x0. */
+ if (!reg_lookup (&s, RCLASS_GPR, ®no)
+ || regno != 0)
+ break;
+ continue;
case '>':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
case 'F':
switch (*++args)
{
+ case '6':
+ if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
+ || imm_expr->X_op != O_constant
+ || imm_expr->X_add_number < 0
+ || imm_expr->X_add_number >= 64)
+ {
+ as_bad (_("bad value for funct6 field, "
+ "value must be 0...64"));
+ break;
+ }
+
+ INSERT_OPERAND (CFUNCT6, *ip, imm_expr->X_add_number);
+ imm_expr->X_op = O_absent;
+ s = expr_end;
+ continue;
case '4':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
imm_expr->X_op = O_absent;
s = expr_end;
continue;
+ case '2':
+ if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
+ || imm_expr->X_op != O_constant
+ || imm_expr->X_add_number < 0
+ || imm_expr->X_add_number >= 4)
+ {
+ as_bad (_("bad value for funct2 field, "
+ "value must be 0...3"));
+ break;
+ }
+ INSERT_OPERAND (CFUNCT2, *ip, imm_expr->X_add_number);
+ imm_expr->X_op = O_absent;
+ s = expr_end;
+ continue;
default:
as_bad (_("bad compressed FUNCT field"
" specifier 'CF%c'\n"),
continue;
case 'j': /* Sign-extended immediate. */
- *imm_reloc = BFD_RELOC_RISCV_LO12_I;
p = percent_op_itype;
+ *imm_reloc = BFD_RELOC_RISCV_LO12_I;
goto alu_op;
case 'q': /* Store displacement. */
p = percent_op_stype;
p = percent_op_itype;
*imm_reloc = BFD_RELOC_RISCV_LO12_I;
goto load_store;
- case '0': /* AMO "displacement," which must be zero. */
+ case '1': /* 4-operand add, must be %tprel_add. */
p = percent_op_rtype;
- *imm_reloc = BFD_RELOC_UNUSED;
+ goto alu_op;
+ case '0': /* AMO "displacement," which must be zero. */
+ p = percent_op_null;
load_store:
if (riscv_handle_implicit_zero_offset (imm_expr, s))
continue;
normalize_constant_expr (imm_expr);
if (imm_expr->X_op != O_constant
|| (*args == '0' && imm_expr->X_add_number != 0)
+ || (*args == '1')
|| imm_expr->X_add_number >= (signed)RISCV_IMM_REACH/2
|| imm_expr->X_add_number < -(signed)RISCV_IMM_REACH/2)
break;
case 'u': /* Upper 20 bits. */
p = percent_op_utype;
- if (!my_getSmallExpression (imm_expr, imm_reloc, s, p)
- && imm_expr->X_op == O_constant)
+ if (!my_getSmallExpression (imm_expr, imm_reloc, s, p))
{
+ if (imm_expr->X_op != O_constant)
+ break;
+
if (imm_expr->X_add_number < 0
|| imm_expr->X_add_number >= (signed)RISCV_BIGIMM_REACH)
as_bad (_("lui expression not in range 0..1048575"));
const char *error = riscv_ip (str, &insn, &imm_expr, &imm_reloc, op_hash);
+ start_assemble = TRUE;
+
if (error)
{
as_bad ("%s `%s'", error, str);
OPTION_MABI,
OPTION_RELAX,
OPTION_NO_RELAX,
+ OPTION_ARCH_ATTR,
+ OPTION_NO_ARCH_ATTR,
OPTION_END_OF_ENUM
};
{"mabi", required_argument, NULL, OPTION_MABI},
{"mrelax", no_argument, NULL, OPTION_RELAX},
{"mno-relax", no_argument, NULL, OPTION_NO_RELAX},
+ {"march-attr", no_argument, NULL, OPTION_ARCH_ATTR},
+ {"mno-arch-attr", no_argument, NULL, OPTION_NO_ARCH_ATTR},
{NULL, no_argument, NULL, 0}
};
riscv_opts.relax = FALSE;
break;
+ case OPTION_ARCH_ATTR:
+ riscv_opts.arch_attr = TRUE;
+ break;
+
+ case OPTION_NO_ARCH_ATTR:
+ riscv_opts.arch_attr = FALSE;
+ break;
+
default:
return 0;
}
as_bad ("unknown default architecture `%s'", default_arch);
}
- if (riscv_subsets == NULL)
+ if (riscv_subsets.head == NULL)
riscv_set_arch (xlen == 64 ? "rv64g" : "rv32g");
/* Add the RVC extension, regardless of -march, to support .option rvc. */
riscv_set_rvc (FALSE);
if (riscv_subset_supports ("c"))
riscv_set_rvc (TRUE);
- else
- riscv_add_subset ("c");
/* Enable RVE if specified by the -march option. */
riscv_set_rve (FALSE);
if (float_abi == FLOAT_ABI_DEFAULT)
{
- struct riscv_subset *subset;
+ riscv_subset_t *subset;
/* Assume soft-float unless D extension is present. */
float_abi = FLOAT_ABI_SOFT;
- for (subset = riscv_subsets; subset != NULL; subset = subset->next)
+ for (subset = riscv_subsets.head; subset != NULL; subset = subset->next)
{
if (strcasecmp (subset->name, "D") == 0)
float_abi = FLOAT_ABI_DOUBLE;
/* Insert float_abi into the EF_RISCV_FLOAT_ABI field of elf_flags. */
elf_flags |= float_abi * (EF_RISCV_FLOAT_ABI & ~(EF_RISCV_FLOAT_ABI << 1));
+
+ /* If the CIE to be produced has not been overridden on the command line,
+ then produce version 3 by default. This allows us to use the full
+ range of registers in a .cfi_return_column directive. */
+ if (flag_dwarf_cie_version == -1)
+ flag_dwarf_cie_version = 3;
}
long
if (frag->fr_type == rs_cfa)
{
expressionS exp;
+ expressionS *symval;
- symbolS *add_symbol = frag->fr_symbol->sy_value.X_add_symbol;
- symbolS *op_symbol = frag->fr_symbol->sy_value.X_op_symbol;
-
+ symval = symbol_get_value_expression (frag->fr_symbol);
exp.X_op = O_subtract;
- exp.X_add_symbol = add_symbol;
+ exp.X_add_symbol = symval->X_add_symbol;
exp.X_add_number = 0;
- exp.X_op_symbol = op_symbol;
+ exp.X_op_symbol = symval->X_op_symbol;
fix_new_exp (frag, (int) frag->fr_offset, 1, &exp, 0,
BFD_RELOC_RISCV_CFA);
-mabi=ABI set the RISC-V ABI\n\
-mrelax enable relax (default)\n\
-mno-relax disable relax\n\
+ -march-attr generate RISC-V arch attribute\n\
+ -mno-arch-attr don't generate RISC-V arch attribute\n\
"));
}
if ((reg = reg_lookup_internal (regname, RCLASS_FPR)) >= 0)
return reg + 32;
+ /* CSRs are numbered 4096 -> 8191. */
+ if ((reg = reg_lookup_internal (regname, RCLASS_CSR)) >= 0)
+ return reg + 4096;
+
as_bad (_("unknown register `%s'"), regname);
return -1;
}
demand_empty_rest_of_line ();
}
+/* Update arch attributes. */
+
+static void
+riscv_write_out_arch_attr (void)
+{
+ const char *arch_str = riscv_arch_str (xlen, &riscv_subsets);
+
+ bfd_elf_add_proc_attr_string (stdoutput, Tag_RISCV_arch, arch_str);
+
+ xfree ((void *)arch_str);
+}
+
+/* Add the default contents for the .riscv.attributes section. */
+
+static void
+riscv_set_public_attributes (void)
+{
+ if (riscv_opts.arch_attr || explicit_arch_attr)
+ /* Re-write arch attribute to normalize the arch string. */
+ riscv_write_out_arch_attr ();
+}
+
+/* Called after all assembly has been done. */
+
+void
+riscv_md_end (void)
+{
+ riscv_set_public_attributes ();
+}
+
+/* Given a symbolic attribute NAME, return the proper integer value.
+ Returns -1 if the attribute is not known. */
+
+int
+riscv_convert_symbolic_attribute (const char *name)
+{
+ static const struct
+ {
+ const char * name;
+ const int tag;
+ }
+ attribute_table[] =
+ {
+ /* When you modify this table you should
+ also modify the list in doc/c-riscv.texi. */
+#define T(tag) {#tag, Tag_RISCV_##tag}, {"Tag_RISCV_" #tag, Tag_RISCV_##tag}
+ T(arch),
+ T(priv_spec),
+ T(priv_spec_minor),
+ T(priv_spec_revision),
+ T(unaligned_access),
+ T(stack_align),
+#undef T
+ };
+
+ unsigned int i;
+
+ if (name == NULL)
+ return -1;
+
+ for (i = 0; i < ARRAY_SIZE (attribute_table); i++)
+ if (strcmp (name, attribute_table[i].name) == 0)
+ return attribute_table[i].tag;
+
+ return -1;
+}
+
+/* Parse a .attribute directive. */
+
+static void
+s_riscv_attribute (int ignored ATTRIBUTE_UNUSED)
+{
+ int tag = obj_elf_vendor_attribute (OBJ_ATTR_PROC);
+
+ if (tag == Tag_RISCV_arch)
+ {
+ unsigned old_xlen = xlen;
+
+ explicit_arch_attr = TRUE;
+ obj_attribute *attr;
+ attr = elf_known_obj_attributes_proc (stdoutput);
+ if (!start_assemble)
+ riscv_set_arch (attr[Tag_RISCV_arch].s);
+ else
+ as_fatal (_(".attribute arch must set before any instructions"));
+
+ if (old_xlen != xlen)
+ {
+ /* We must re-init bfd again if xlen is changed. */
+ unsigned long mach = xlen == 64 ? bfd_mach_riscv64 : bfd_mach_riscv32;
+ bfd_find_target (riscv_target_format (), stdoutput);
+
+ if (! bfd_set_arch_mach (stdoutput, bfd_arch_riscv, mach))
+ as_warn (_("Could not set architecture and machine"));
+ }
+ }
+}
+
/* Pseudo-op table. */
static const pseudo_typeS riscv_pseudo_table[] =
{"uleb128", s_riscv_leb128, 0},
{"sleb128", s_riscv_leb128, 1},
{"insn", s_riscv_insn, 0},
+ {"attribute", s_riscv_attribute, 0},
{ NULL, NULL, 0 },
};