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Retro68/binutils/gas/config/tc-riscv.c
Wolfgang Thaller 65c83606fb Update gcc to 7.2.0, binutils to 2.29, newlib to 2.5.0
2017-10-07 02:16:47 +02:00

2589 lines
69 KiB
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/* tc-riscv.c -- RISC-V assembler
Copyright (C) 2011-2017 Free Software Foundation, Inc.
Contributed by Andrew Waterman (andrew@sifive.com).
Based on MIPS target.
This file is part of GAS.
GAS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING3. If not,
see <http://www.gnu.org/licenses/>. */
#include "as.h"
#include "config.h"
#include "subsegs.h"
#include "safe-ctype.h"
#include "itbl-ops.h"
#include "dwarf2dbg.h"
#include "dw2gencfi.h"
#include "struc-symbol.h"
#include "elf/riscv.h"
#include "opcode/riscv.h"
#include <stdint.h>
/* Information about an instruction, including its format, operands
and fixups. */
struct riscv_cl_insn
{
/* The opcode's entry in riscv_opcodes. */
const struct riscv_opcode *insn_mo;
/* The encoded instruction bits. */
insn_t insn_opcode;
/* The frag that contains the instruction. */
struct frag *frag;
/* The offset into FRAG of the first instruction byte. */
long where;
/* The relocs associated with the instruction, if any. */
fixS *fixp;
};
#ifndef DEFAULT_ARCH
#define DEFAULT_ARCH "riscv64"
#endif
static const char default_arch[] = DEFAULT_ARCH;
static unsigned xlen = 0; /* width of an x-register */
static unsigned abi_xlen = 0; /* width of a pointer in the ABI */
#define LOAD_ADDRESS_INSN (abi_xlen == 64 ? "ld" : "lw")
#define ADD32_INSN (xlen == 64 ? "addiw" : "addi")
static unsigned elf_flags = 0;
/* This is the set of options which the .option pseudo-op may modify. */
struct riscv_set_options
{
int pic; /* Generate position-independent code. */
int rvc; /* Generate RVC code. */
int relax; /* Emit relocs the linker is allowed to relax. */
};
static struct riscv_set_options riscv_opts =
{
0, /* pic */
0, /* rvc */
1, /* relax */
};
static void
riscv_set_rvc (bfd_boolean rvc_value)
{
if (rvc_value)
elf_flags |= EF_RISCV_RVC;
riscv_opts.rvc = rvc_value;
}
struct riscv_subset
{
const char *name;
struct riscv_subset *next;
};
static struct riscv_subset *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;
return FALSE;
}
static void
riscv_clear_subsets (void)
{
while (riscv_subsets != NULL)
{
struct riscv_subset *next = riscv_subsets->next;
free ((void *) riscv_subsets->name);
free (riscv_subsets);
riscv_subsets = next;
}
}
static void
riscv_add_subset (const char *subset)
{
struct riscv_subset *s = xmalloc (sizeof *s);
s->name = xstrdup (subset);
s->next = riscv_subsets;
riscv_subsets = s;
}
/* Set which ISA and extensions are available. */
static void
riscv_set_arch (const char *s)
{
const char *all_subsets = "imafdc";
const 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 'g':
p++;
for ( ; *all_subsets != 'c'; all_subsets++)
{
const char subset[] = {*all_subsets, '\0'};
riscv_add_subset (subset);
}
break;
default:
as_fatal ("-march=%s: first ISA subset must be `i' or `g'", s);
}
while (*p)
{
if (*p == 'x')
{
char *subset = xstrdup (p), *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);
free (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 if (*p == 'q')
{
const char subset[] = {*p, 0};
riscv_add_subset (subset);
p++;
}
else
as_fatal ("-march=%s: unsupported ISA subset `%c'", s, *p);
}
}
/* Handle of the OPCODE hash table. */
static struct hash_control *op_hash = NULL;
/* This array holds the chars that always start a comment. If the
pre-processor is disabled, these aren't very useful */
const char comment_chars[] = "#";
/* This array holds the chars that only start a comment at the beginning of
a line. If the line seems to have the form '# 123 filename'
.line and .file directives will appear in the pre-processed output */
/* Note that input_file.c hand checks for '#' at the beginning of the
first line of the input file. This is because the compiler outputs
#NO_APP at the beginning of its output. */
/* Also note that C style comments are always supported. */
const char line_comment_chars[] = "#";
/* This array holds machine specific line separator characters. */
const char line_separator_chars[] = ";";
/* Chars that can be used to separate mant from exp in floating point nums */
const char EXP_CHARS[] = "eE";
/* Chars that mean this number is a floating point constant */
/* As in 0f12.456 */
/* or 0d1.2345e12 */
const char FLT_CHARS[] = "rRsSfFdDxXpP";
/* Macros for encoding relaxation state for RVC branches and far jumps. */
#define RELAX_BRANCH_ENCODE(uncond, rvc, length) \
((relax_substateT) \
(0xc0000000 \
| ((uncond) ? 1 : 0) \
| ((rvc) ? 2 : 0) \
| ((length) << 2)))
#define RELAX_BRANCH_P(i) (((i) & 0xf0000000) == 0xc0000000)
#define RELAX_BRANCH_LENGTH(i) (((i) >> 2) & 0xF)
#define RELAX_BRANCH_RVC(i) (((i) & 2) != 0)
#define RELAX_BRANCH_UNCOND(i) (((i) & 1) != 0)
/* Is the given value a sign-extended 32-bit value? */
#define IS_SEXT_32BIT_NUM(x) \
(((x) &~ (offsetT) 0x7fffffff) == 0 \
|| (((x) &~ (offsetT) 0x7fffffff) == ~ (offsetT) 0x7fffffff))
/* Is the given value a zero-extended 32-bit value? Or a negated one? */
#define IS_ZEXT_32BIT_NUM(x) \
(((x) &~ (offsetT) 0xffffffff) == 0 \
|| (((x) &~ (offsetT) 0xffffffff) == ~ (offsetT) 0xffffffff))
/* Change INSN's opcode so that the operand given by FIELD has value VALUE.
INSN is a riscv_cl_insn structure and VALUE is evaluated exactly once. */
#define INSERT_OPERAND(FIELD, INSN, VALUE) \
INSERT_BITS ((INSN).insn_opcode, VALUE, OP_MASK_##FIELD, OP_SH_##FIELD)
/* Determine if an instruction matches an opcode. */
#define OPCODE_MATCHES(OPCODE, OP) \
(((OPCODE) & MASK_##OP) == MATCH_##OP)
static char *expr_end;
/* The default target format to use. */
const char *
riscv_target_format (void)
{
return xlen == 64 ? "elf64-littleriscv" : "elf32-littleriscv";
}
/* Return the length of instruction INSN. */
static inline unsigned int
insn_length (const struct riscv_cl_insn *insn)
{
return riscv_insn_length (insn->insn_opcode);
}
/* Initialise INSN from opcode entry MO. Leave its position unspecified. */
static void
create_insn (struct riscv_cl_insn *insn, const struct riscv_opcode *mo)
{
insn->insn_mo = mo;
insn->insn_opcode = mo->match;
insn->frag = NULL;
insn->where = 0;
insn->fixp = NULL;
}
/* Install INSN at the location specified by its "frag" and "where" fields. */
static void
install_insn (const struct riscv_cl_insn *insn)
{
char *f = insn->frag->fr_literal + insn->where;
md_number_to_chars (f, insn->insn_opcode, insn_length (insn));
}
/* Move INSN to offset WHERE in FRAG. Adjust the fixups accordingly
and install the opcode in the new location. */
static void
move_insn (struct riscv_cl_insn *insn, fragS *frag, long where)
{
insn->frag = frag;
insn->where = where;
if (insn->fixp != NULL)
{
insn->fixp->fx_frag = frag;
insn->fixp->fx_where = where;
}
install_insn (insn);
}
/* Add INSN to the end of the output. */
static void
add_fixed_insn (struct riscv_cl_insn *insn)
{
char *f = frag_more (insn_length (insn));
move_insn (insn, frag_now, f - frag_now->fr_literal);
}
static void
add_relaxed_insn (struct riscv_cl_insn *insn, int max_chars, int var,
relax_substateT subtype, symbolS *symbol, offsetT offset)
{
frag_grow (max_chars);
move_insn (insn, frag_now, frag_more (0) - frag_now->fr_literal);
frag_var (rs_machine_dependent, max_chars, var,
subtype, symbol, offset, NULL);
}
/* Compute the length of a branch sequence, and adjust the stored length
accordingly. If FRAGP is NULL, the worst-case length is returned. */
static unsigned
relaxed_branch_length (fragS *fragp, asection *sec, int update)
{
int jump, rvc, length = 8;
if (!fragp)
return length;
jump = RELAX_BRANCH_UNCOND (fragp->fr_subtype);
rvc = RELAX_BRANCH_RVC (fragp->fr_subtype);
length = RELAX_BRANCH_LENGTH (fragp->fr_subtype);
/* Assume jumps are in range; the linker will catch any that aren't. */
length = jump ? 4 : 8;
if (fragp->fr_symbol != NULL
&& S_IS_DEFINED (fragp->fr_symbol)
&& !S_IS_WEAK (fragp->fr_symbol)
&& sec == S_GET_SEGMENT (fragp->fr_symbol))
{
offsetT val = S_GET_VALUE (fragp->fr_symbol) + fragp->fr_offset;
bfd_vma rvc_range = jump ? RVC_JUMP_REACH : RVC_BRANCH_REACH;
val -= fragp->fr_address + fragp->fr_fix;
if (rvc && (bfd_vma)(val + rvc_range/2) < rvc_range)
length = 2;
else if ((bfd_vma)(val + RISCV_BRANCH_REACH/2) < RISCV_BRANCH_REACH)
length = 4;
else if (!jump && rvc)
length = 6;
}
if (update)
fragp->fr_subtype = RELAX_BRANCH_ENCODE (jump, rvc, length);
return length;
}
struct regname
{
const char *name;
unsigned int num;
};
enum reg_class
{
RCLASS_GPR,
RCLASS_FPR,
RCLASS_CSR,
RCLASS_MAX
};
static struct hash_control *reg_names_hash = NULL;
#define ENCODE_REG_HASH(cls, n) \
((void *)(uintptr_t)((n) * RCLASS_MAX + (cls) + 1))
#define DECODE_REG_CLASS(hash) (((uintptr_t)(hash) - 1) % RCLASS_MAX)
#define DECODE_REG_NUM(hash) (((uintptr_t)(hash) - 1) / RCLASS_MAX)
static void
hash_reg_name (enum reg_class class, const char *name, unsigned n)
{
void *hash = ENCODE_REG_HASH (class, n);
const char *retval = hash_insert (reg_names_hash, name, hash);
if (retval != NULL)
as_fatal (_("internal error: can't hash `%s': %s"), name, retval);
}
static void
hash_reg_names (enum reg_class class, const char * const names[], unsigned n)
{
unsigned i;
for (i = 0; i < n; i++)
hash_reg_name (class, names[i], i);
}
static unsigned int
reg_lookup_internal (const char *s, enum reg_class class)
{
struct regname *r = (struct regname *) hash_find (reg_names_hash, s);
if (r == NULL || DECODE_REG_CLASS (r) != class)
return -1;
return DECODE_REG_NUM (r);
}
static bfd_boolean
reg_lookup (char **s, enum reg_class class, unsigned int *regnop)
{
char *e;
char save_c;
int reg = -1;
/* Find end of name. */
e = *s;
if (is_name_beginner (*e))
++e;
while (is_part_of_name (*e))
++e;
/* Terminate name. */
save_c = *e;
*e = '\0';
/* Look for the register. Advance to next token if one was recognized. */
if ((reg = reg_lookup_internal (*s, class)) >= 0)
*s = e;
*e = save_c;
if (regnop)
*regnop = reg;
return reg >= 0;
}
static bfd_boolean
arg_lookup (char **s, const char *const *array, size_t size, unsigned *regnop)
{
const char *p = strchr (*s, ',');
size_t i, len = p ? (size_t)(p - *s) : strlen (*s);
for (i = 0; i < size; i++)
if (array[i] != NULL && strncmp (array[i], *s, len) == 0)
{
*regnop = i;
*s += len;
return TRUE;
}
return FALSE;
}
/* For consistency checking, verify that all bits are specified either
by the match/mask part of the instruction definition, or by the
operand list. */
static bfd_boolean
validate_riscv_insn (const struct riscv_opcode *opc)
{
const char *p = opc->args;
char c;
insn_t used_bits = opc->mask;
int insn_width = 8 * riscv_insn_length (opc->match);
insn_t required_bits = ~0ULL >> (64 - insn_width);
if ((used_bits & opc->match) != (opc->match & required_bits))
{
as_bad (_("internal: bad RISC-V opcode (mask error): %s %s"),
opc->name, opc->args);
return FALSE;
}
#define USE_BITS(mask,shift) (used_bits |= ((insn_t)(mask) << (shift)))
while (*p)
switch (c = *p++)
{
case 'C': /* RVC */
switch (c = *p++)
{
case 'a': used_bits |= ENCODE_RVC_J_IMM (-1U); break;
case 'c': break; /* RS1, constrained to equal sp */
case 'i': used_bits |= ENCODE_RVC_SIMM3(-1U); break;
case 'j': used_bits |= ENCODE_RVC_IMM (-1U); break;
case 'o': used_bits |= ENCODE_RVC_IMM (-1U); break;
case 'k': used_bits |= ENCODE_RVC_LW_IMM (-1U); break;
case 'l': used_bits |= ENCODE_RVC_LD_IMM (-1U); break;
case 'm': used_bits |= ENCODE_RVC_LWSP_IMM (-1U); break;
case 'n': used_bits |= ENCODE_RVC_LDSP_IMM (-1U); break;
case 'p': used_bits |= ENCODE_RVC_B_IMM (-1U); break;
case 's': USE_BITS (OP_MASK_CRS1S, OP_SH_CRS1S); break;
case 't': USE_BITS (OP_MASK_CRS2S, OP_SH_CRS2S); break;
case 'u': used_bits |= ENCODE_RVC_IMM (-1U); break;
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 '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 'N': used_bits |= ENCODE_RVC_SDSP_IMM (-1U); break;
case 'U': break; /* RS1, constrained to equal RD */
case 'V': USE_BITS (OP_MASK_CRS2, OP_SH_CRS2); break;
case '<': used_bits |= ENCODE_RVC_IMM (-1U); break;
case '>': used_bits |= ENCODE_RVC_IMM (-1U); break;
case 'T': USE_BITS (OP_MASK_CRS2, OP_SH_CRS2); break;
case 'D': USE_BITS (OP_MASK_CRS2S, OP_SH_CRS2S); break;
default:
as_bad (_("internal: bad RISC-V opcode (unknown operand type `C%c'): %s %s"),
c, opc->name, opc->args);
return FALSE;
}
break;
case ',': break;
case '(': break;
case ')': break;
case '<': USE_BITS (OP_MASK_SHAMTW, OP_SH_SHAMTW); break;
case '>': USE_BITS (OP_MASK_SHAMT, OP_SH_SHAMT); break;
case 'A': break;
case 'D': USE_BITS (OP_MASK_RD, OP_SH_RD); break;
case 'Z': USE_BITS (OP_MASK_RS1, OP_SH_RS1); break;
case 'E': USE_BITS (OP_MASK_CSR, OP_SH_CSR); break;
case 'I': break;
case 'R': USE_BITS (OP_MASK_RS3, OP_SH_RS3); break;
case 'S': USE_BITS (OP_MASK_RS1, OP_SH_RS1); break;
case 'U': USE_BITS (OP_MASK_RS1, OP_SH_RS1); /* fallthru */
case 'T': USE_BITS (OP_MASK_RS2, OP_SH_RS2); break;
case 'd': USE_BITS (OP_MASK_RD, OP_SH_RD); break;
case 'm': USE_BITS (OP_MASK_RM, OP_SH_RM); break;
case 's': USE_BITS (OP_MASK_RS1, OP_SH_RS1); break;
case 't': USE_BITS (OP_MASK_RS2, OP_SH_RS2); break;
case 'P': USE_BITS (OP_MASK_PRED, OP_SH_PRED); break;
case 'Q': USE_BITS (OP_MASK_SUCC, OP_SH_SUCC); break;
case 'o':
case 'j': used_bits |= ENCODE_ITYPE_IMM (-1U); break;
case 'a': used_bits |= ENCODE_UJTYPE_IMM (-1U); break;
case 'p': used_bits |= ENCODE_SBTYPE_IMM (-1U); break;
case 'q': used_bits |= ENCODE_STYPE_IMM (-1U); break;
case 'u': used_bits |= ENCODE_UTYPE_IMM (-1U); break;
case '[': break;
case ']': break;
case '0': break;
default:
as_bad (_("internal: bad RISC-V opcode "
"(unknown operand type `%c'): %s %s"),
c, opc->name, opc->args);
return FALSE;
}
#undef USE_BITS
if (used_bits != required_bits)
{
as_bad (_("internal: bad RISC-V opcode (bits 0x%lx undefined): %s %s"),
~(unsigned long)(used_bits & required_bits),
opc->name, opc->args);
return FALSE;
}
return TRUE;
}
struct percent_op_match
{
const char *str;
bfd_reloc_code_real_type reloc;
};
/* This function is called once, at assembler startup time. It should set up
all the tables, etc. that the MD part of the assembler will need. */
void
md_begin (void)
{
int i = 0;
unsigned long mach = xlen == 64 ? bfd_mach_riscv64 : bfd_mach_riscv32;
if (! bfd_set_arch_mach (stdoutput, bfd_arch_riscv, mach))
as_warn (_("Could not set architecture and machine"));
op_hash = hash_new ();
while (riscv_opcodes[i].name)
{
const char *name = riscv_opcodes[i].name;
const char *hash_error =
hash_insert (op_hash, name, (void *) &riscv_opcodes[i]);
if (hash_error)
{
fprintf (stderr, _("internal error: can't hash `%s': %s\n"),
riscv_opcodes[i].name, hash_error);
/* Probably a memory allocation problem? Give up now. */
as_fatal (_("Broken assembler. No assembly attempted."));
}
do
{
if (riscv_opcodes[i].pinfo != INSN_MACRO)
{
if (!validate_riscv_insn (&riscv_opcodes[i]))
as_fatal (_("Broken assembler. No assembly attempted."));
}
++i;
}
while (riscv_opcodes[i].name && !strcmp (riscv_opcodes[i].name, name));
}
reg_names_hash = hash_new ();
hash_reg_names (RCLASS_GPR, riscv_gpr_names_numeric, NGPR);
hash_reg_names (RCLASS_GPR, riscv_gpr_names_abi, NGPR);
hash_reg_names (RCLASS_FPR, riscv_fpr_names_numeric, NFPR);
hash_reg_names (RCLASS_FPR, riscv_fpr_names_abi, NFPR);
#define DECLARE_CSR(name, num) hash_reg_name (RCLASS_CSR, #name, num);
#include "opcode/riscv-opc.h"
#undef DECLARE_CSR
/* Set the default alignment for the text section. */
record_alignment (text_section, riscv_opts.rvc ? 1 : 2);
}
static insn_t
riscv_apply_const_reloc (bfd_reloc_code_real_type reloc_type, bfd_vma value)
{
switch (reloc_type)
{
case BFD_RELOC_32:
return value;
case BFD_RELOC_RISCV_HI20:
return ENCODE_UTYPE_IMM (RISCV_CONST_HIGH_PART (value));
case BFD_RELOC_RISCV_LO12_S:
return ENCODE_STYPE_IMM (value);
case BFD_RELOC_RISCV_LO12_I:
return ENCODE_ITYPE_IMM (value);
default:
abort ();
}
}
/* Output an instruction. IP is the instruction information.
ADDRESS_EXPR is an operand of the instruction to be used with
RELOC_TYPE. */
static void
append_insn (struct riscv_cl_insn *ip, expressionS *address_expr,
bfd_reloc_code_real_type reloc_type)
{
dwarf2_emit_insn (0);
if (reloc_type != BFD_RELOC_UNUSED)
{
reloc_howto_type *howto;
gas_assert (address_expr);
if (reloc_type == BFD_RELOC_12_PCREL
|| reloc_type == BFD_RELOC_RISCV_JMP)
{
int j = reloc_type == BFD_RELOC_RISCV_JMP;
int best_case = riscv_insn_length (ip->insn_opcode);
unsigned worst_case = relaxed_branch_length (NULL, NULL, 0);
add_relaxed_insn (ip, worst_case, best_case,
RELAX_BRANCH_ENCODE (j, best_case == 2, worst_case),
address_expr->X_add_symbol,
address_expr->X_add_number);
return;
}
else
{
howto = bfd_reloc_type_lookup (stdoutput, reloc_type);
if (howto == NULL)
as_bad (_("Unsupported RISC-V relocation number %d"), reloc_type);
ip->fixp = fix_new_exp (ip->frag, ip->where,
bfd_get_reloc_size (howto),
address_expr, FALSE, reloc_type);
ip->fixp->fx_tcbit = riscv_opts.relax;
}
}
add_fixed_insn (ip);
install_insn (ip);
}
/* Build an instruction created by a macro expansion. This is passed
a pointer to the count of instructions created so far, an
expression, the name of the instruction to build, an operand format
string, and corresponding arguments. */
static void
macro_build (expressionS *ep, const char *name, const char *fmt, ...)
{
const struct riscv_opcode *mo;
struct riscv_cl_insn insn;
bfd_reloc_code_real_type r;
va_list args;
va_start (args, fmt);
r = BFD_RELOC_UNUSED;
mo = (struct riscv_opcode *) hash_find (op_hash, name);
gas_assert (mo);
/* Find a non-RVC variant of the instruction. append_insn will compress
it if possible. */
while (riscv_insn_length (mo->match) < 4)
mo++;
gas_assert (strcmp (name, mo->name) == 0);
create_insn (&insn, mo);
for (;;)
{
switch (*fmt++)
{
case 'd':
INSERT_OPERAND (RD, insn, va_arg (args, int));
continue;
case 's':
INSERT_OPERAND (RS1, insn, va_arg (args, int));
continue;
case 't':
INSERT_OPERAND (RS2, insn, va_arg (args, int));
continue;
case '>':
INSERT_OPERAND (SHAMT, insn, va_arg (args, int));
continue;
case 'j':
case 'u':
case 'q':
gas_assert (ep != NULL);
r = va_arg (args, int);
continue;
case '\0':
break;
case ',':
continue;
default:
as_fatal (_("internal error: invalid macro"));
}
break;
}
va_end (args);
gas_assert (r == BFD_RELOC_UNUSED ? ep == NULL : ep != NULL);
append_insn (&insn, ep, r);
}
/* Sign-extend 32-bit mode constants that have bit 31 set and all higher bits
unset. */
static void
normalize_constant_expr (expressionS *ex)
{
if (xlen > 32)
return;
if ((ex->X_op == O_constant || ex->X_op == O_symbol)
&& IS_ZEXT_32BIT_NUM (ex->X_add_number))
ex->X_add_number = (((ex->X_add_number & 0xffffffff) ^ 0x80000000)
- 0x80000000);
}
/* Fail if an expression is not a constant. */
static void
check_absolute_expr (struct riscv_cl_insn *ip, expressionS *ex)
{
if (ex->X_op == O_big)
as_bad (_("unsupported large constant"));
else if (ex->X_op != O_constant)
as_bad (_("Instruction %s requires absolute expression"),
ip->insn_mo->name);
normalize_constant_expr (ex);
}
static symbolS *
make_internal_label (void)
{
return (symbolS *) local_symbol_make (FAKE_LABEL_NAME, now_seg,
(valueT) frag_now_fix (), frag_now);
}
/* Load an entry from the GOT. */
static void
pcrel_access (int destreg, int tempreg, expressionS *ep,
const char *lo_insn, const char *lo_pattern,
bfd_reloc_code_real_type hi_reloc,
bfd_reloc_code_real_type lo_reloc)
{
expressionS ep2;
ep2.X_op = O_symbol;
ep2.X_add_symbol = make_internal_label ();
ep2.X_add_number = 0;
macro_build (ep, "auipc", "d,u", tempreg, hi_reloc);
macro_build (&ep2, lo_insn, lo_pattern, destreg, tempreg, lo_reloc);
}
static void
pcrel_load (int destreg, int tempreg, expressionS *ep, const char *lo_insn,
bfd_reloc_code_real_type hi_reloc,
bfd_reloc_code_real_type lo_reloc)
{
pcrel_access (destreg, tempreg, ep, lo_insn, "d,s,j", hi_reloc, lo_reloc);
}
static void
pcrel_store (int srcreg, int tempreg, expressionS *ep, const char *lo_insn,
bfd_reloc_code_real_type hi_reloc,
bfd_reloc_code_real_type lo_reloc)
{
pcrel_access (srcreg, tempreg, ep, lo_insn, "t,s,q", hi_reloc, lo_reloc);
}
/* PC-relative function call using AUIPC/JALR, relaxed to JAL. */
static void
riscv_call (int destreg, int tempreg, expressionS *ep,
bfd_reloc_code_real_type reloc)
{
macro_build (ep, "auipc", "d,u", tempreg, reloc);
macro_build (NULL, "jalr", "d,s", destreg, tempreg);
}
/* Load an integer constant into a register. */
static void
load_const (int reg, expressionS *ep)
{
int shift = RISCV_IMM_BITS;
expressionS upper = *ep, lower = *ep;
lower.X_add_number = (int32_t) ep->X_add_number << (32-shift) >> (32-shift);
upper.X_add_number -= lower.X_add_number;
if (ep->X_op != O_constant)
{
as_bad (_("unsupported large constant"));
return;
}
if (xlen > 32 && !IS_SEXT_32BIT_NUM (ep->X_add_number))
{
/* Reduce to a signed 32-bit constant using SLLI and ADDI. */
while (((upper.X_add_number >> shift) & 1) == 0)
shift++;
upper.X_add_number = (int64_t) upper.X_add_number >> shift;
load_const (reg, &upper);
macro_build (NULL, "slli", "d,s,>", reg, reg, shift);
if (lower.X_add_number != 0)
macro_build (&lower, "addi", "d,s,j", reg, reg, BFD_RELOC_RISCV_LO12_I);
}
else
{
/* Simply emit LUI and/or ADDI to build a 32-bit signed constant. */
int hi_reg = 0;
if (upper.X_add_number != 0)
{
macro_build (ep, "lui", "d,u", reg, BFD_RELOC_RISCV_HI20);
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);
}
}
/* Expand RISC-V assembly macros into one or more instructions. */
static void
macro (struct riscv_cl_insn *ip, expressionS *imm_expr,
bfd_reloc_code_real_type *imm_reloc)
{
int rd = (ip->insn_opcode >> OP_SH_RD) & OP_MASK_RD;
int rs1 = (ip->insn_opcode >> OP_SH_RS1) & OP_MASK_RS1;
int rs2 = (ip->insn_opcode >> OP_SH_RS2) & OP_MASK_RS2;
int mask = ip->insn_mo->mask;
switch (mask)
{
case M_LI:
load_const (rd, imm_expr);
break;
case M_LA:
case M_LLA:
/* Load the address of a symbol into a register. */
if (!IS_SEXT_32BIT_NUM (imm_expr->X_add_number))
as_bad (_("offset too large"));
if (imm_expr->X_op == O_constant)
load_const (rd, imm_expr);
else if (riscv_opts.pic && mask == M_LA) /* Global PIC symbol */
pcrel_load (rd, rd, imm_expr, LOAD_ADDRESS_INSN,
BFD_RELOC_RISCV_GOT_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
else /* Local PIC symbol, or any non-PIC symbol */
pcrel_load (rd, rd, imm_expr, "addi",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
break;
case M_LA_TLS_GD:
pcrel_load (rd, rd, imm_expr, "addi",
BFD_RELOC_RISCV_TLS_GD_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
break;
case M_LA_TLS_IE:
pcrel_load (rd, rd, imm_expr, LOAD_ADDRESS_INSN,
BFD_RELOC_RISCV_TLS_GOT_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
break;
case M_LB:
pcrel_load (rd, rd, imm_expr, "lb",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
break;
case M_LBU:
pcrel_load (rd, rd, imm_expr, "lbu",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
break;
case M_LH:
pcrel_load (rd, rd, imm_expr, "lh",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
break;
case M_LHU:
pcrel_load (rd, rd, imm_expr, "lhu",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
break;
case M_LW:
pcrel_load (rd, rd, imm_expr, "lw",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
break;
case M_LWU:
pcrel_load (rd, rd, imm_expr, "lwu",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
break;
case M_LD:
pcrel_load (rd, rd, imm_expr, "ld",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
break;
case M_FLW:
pcrel_load (rd, rs1, imm_expr, "flw",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
break;
case M_FLD:
pcrel_load (rd, rs1, imm_expr, "fld",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_I);
break;
case M_SB:
pcrel_store (rs2, rs1, imm_expr, "sb",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_S);
break;
case M_SH:
pcrel_store (rs2, rs1, imm_expr, "sh",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_S);
break;
case M_SW:
pcrel_store (rs2, rs1, imm_expr, "sw",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_S);
break;
case M_SD:
pcrel_store (rs2, rs1, imm_expr, "sd",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_S);
break;
case M_FSW:
pcrel_store (rs2, rs1, imm_expr, "fsw",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_S);
break;
case M_FSD:
pcrel_store (rs2, rs1, imm_expr, "fsd",
BFD_RELOC_RISCV_PCREL_HI20, BFD_RELOC_RISCV_PCREL_LO12_S);
break;
case M_CALL:
riscv_call (rd, rs1, imm_expr, *imm_reloc);
break;
default:
as_bad (_("Macro %s not implemented"), ip->insn_mo->name);
break;
}
}
static const struct percent_op_match percent_op_utype[] =
{
{"%tprel_hi", BFD_RELOC_RISCV_TPREL_HI20},
{"%pcrel_hi", BFD_RELOC_RISCV_PCREL_HI20},
{"%tls_ie_pcrel_hi", BFD_RELOC_RISCV_TLS_GOT_HI20},
{"%tls_gd_pcrel_hi", BFD_RELOC_RISCV_TLS_GD_HI20},
{"%hi", BFD_RELOC_RISCV_HI20},
{0, 0}
};
static const struct percent_op_match percent_op_itype[] =
{
{"%lo", BFD_RELOC_RISCV_LO12_I},
{"%tprel_lo", BFD_RELOC_RISCV_TPREL_LO12_I},
{"%pcrel_lo", BFD_RELOC_RISCV_PCREL_LO12_I},
{0, 0}
};
static const struct percent_op_match percent_op_stype[] =
{
{"%lo", BFD_RELOC_RISCV_LO12_S},
{"%tprel_lo", BFD_RELOC_RISCV_TPREL_LO12_S},
{"%pcrel_lo", BFD_RELOC_RISCV_PCREL_LO12_S},
{0, 0}
};
static const struct percent_op_match percent_op_rtype[] =
{
{"%tprel_add", BFD_RELOC_RISCV_TPREL_ADD},
{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. */
static bfd_boolean
parse_relocation (char **str, bfd_reloc_code_real_type *reloc,
const struct percent_op_match *percent_op)
{
for ( ; percent_op->str; percent_op++)
if (strncasecmp (*str, percent_op->str, strlen (percent_op->str)) == 0)
{
int len = strlen (percent_op->str);
if (!ISSPACE ((*str)[len]) && (*str)[len] != '(')
continue;
*str += strlen (percent_op->str);
*reloc = percent_op->reloc;
/* Check whether the output BFD supports this relocation.
If not, issue an error and fall back on something safe. */
if (*reloc != BFD_RELOC_UNUSED
&& !bfd_reloc_type_lookup (stdoutput, *reloc))
{
as_bad ("relocation %s isn't supported by the current ABI",
percent_op->str);
*reloc = BFD_RELOC_UNUSED;
}
return TRUE;
}
return FALSE;
}
static void
my_getExpression (expressionS *ep, char *str)
{
char *save_in;
save_in = input_line_pointer;
input_line_pointer = str;
expression (ep);
expr_end = input_line_pointer;
input_line_pointer = save_in;
}
/* Parse string STR as a 16-bit relocatable operand. Store the
expression in *EP and the relocation, if any, in RELOC.
Return the number of relocation operators used (0 or 1).
On exit, EXPR_END points to the first character after the expression. */
static size_t
my_getSmallExpression (expressionS *ep, bfd_reloc_code_real_type *reloc,
char *str, const struct percent_op_match *percent_op)
{
size_t reloc_index;
unsigned crux_depth, str_depth, regno;
char *crux;
/* First, check for integer registers. */
if (reg_lookup (&str, RCLASS_GPR, &regno))
{
ep->X_op = O_register;
ep->X_add_number = regno;
return 0;
}
/* Search for the start of the main expression.
End the loop with CRUX pointing to the start
of the main expression and with CRUX_DEPTH containing the number
of open brackets at that point. */
reloc_index = -1;
str_depth = 0;
do
{
reloc_index++;
crux = str;
crux_depth = str_depth;
/* Skip over whitespace and brackets, keeping count of the number
of brackets. */
while (*str == ' ' || *str == '\t' || *str == '(')
if (*str++ == '(')
str_depth++;
}
while (*str == '%'
&& reloc_index < 1
&& parse_relocation (&str, reloc, percent_op));
my_getExpression (ep, crux);
str = expr_end;
/* Match every open bracket. */
while (crux_depth > 0 && (*str == ')' || *str == ' ' || *str == '\t'))
if (*str++ == ')')
crux_depth--;
if (crux_depth > 0)
as_bad ("unclosed '('");
expr_end = str;
return reloc_index;
}
/* This routine assembles an instruction into its binary format. As a
side effect, it sets the global variable imm_reloc to the type of
relocation to do if one of the operands is an address expression. */
static const char *
riscv_ip (char *str, struct riscv_cl_insn *ip, expressionS *imm_expr,
bfd_reloc_code_real_type *imm_reloc)
{
char *s;
const char *args;
char c = 0;
struct riscv_opcode *insn;
char *argsStart;
unsigned int regno;
char save_c = 0;
int argnum;
const struct percent_op_match *p;
const char *error = "unrecognized opcode";
/* Parse the name of the instruction. Terminate the string if whitespace
is found so that hash_find only sees the name part of the string. */
for (s = str; *s != '\0'; ++s)
if (ISSPACE (*s))
{
save_c = *s;
*s++ = '\0';
break;
}
insn = (struct riscv_opcode *) hash_find (op_hash, str);
argsStart = s;
for ( ; insn && insn->name && strcmp (insn->name, str) == 0; insn++)
{
if (!riscv_subset_supports (insn->subset))
continue;
create_insn (ip, insn);
argnum = 1;
imm_expr->X_op = O_absent;
*imm_reloc = BFD_RELOC_UNUSED;
p = percent_op_itype;
for (args = insn->args;; ++args)
{
s += strspn (s, " \t");
switch (*args)
{
case '\0': /* End of args. */
if (insn->pinfo != INSN_MACRO)
{
if (!insn->match_func (insn, ip->insn_opcode))
break;
if (riscv_insn_length (insn->match) == 2 && !riscv_opts.rvc)
break;
}
if (*s != '\0')
break;
/* Successful assembly. */
error = NULL;
goto out;
case 'C': /* RVC */
switch (*++args)
{
case 's': /* RS1 x8-x15 */
if (!reg_lookup (&s, RCLASS_GPR, &regno)
|| !(regno >= 8 && regno <= 15))
break;
INSERT_OPERAND (CRS1S, *ip, regno % 8);
continue;
case 'w': /* RS1 x8-x15, constrained to equal RD x8-x15. */
if (!reg_lookup (&s, RCLASS_GPR, &regno)
|| EXTRACT_OPERAND (CRS1S, ip->insn_opcode) + 8 != regno)
break;
continue;
case 't': /* RS2 x8-x15 */
if (!reg_lookup (&s, RCLASS_GPR, &regno)
|| !(regno >= 8 && regno <= 15))
break;
INSERT_OPERAND (CRS2S, *ip, regno % 8);
continue;
case 'x': /* RS2 x8-x15, constrained to equal RD x8-x15. */
if (!reg_lookup (&s, RCLASS_GPR, &regno)
|| EXTRACT_OPERAND (CRS2S, ip->insn_opcode) + 8 != regno)
break;
continue;
case 'U': /* RS1, constrained to equal RD. */
if (!reg_lookup (&s, RCLASS_GPR, &regno)
|| EXTRACT_OPERAND (RD, ip->insn_opcode) != regno)
break;
continue;
case 'V': /* RS2 */
if (!reg_lookup (&s, RCLASS_GPR, &regno))
break;
INSERT_OPERAND (CRS2, *ip, regno);
continue;
case 'c': /* RS1, constrained to equal sp. */
if (!reg_lookup (&s, RCLASS_GPR, &regno)
|| regno != X_SP)
break;
continue;
case '>':
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)
break;
ip->insn_opcode |= ENCODE_RVC_IMM (imm_expr->X_add_number);
rvc_imm_done:
s = expr_end;
imm_expr->X_op = O_absent;
continue;
case '<':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
|| !VALID_RVC_IMM (imm_expr->X_add_number)
|| imm_expr->X_add_number <= 0
|| imm_expr->X_add_number >= 32)
break;
ip->insn_opcode |= ENCODE_RVC_IMM (imm_expr->X_add_number);
goto rvc_imm_done;
case 'i':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
|| imm_expr->X_add_number == 0
|| !VALID_RVC_SIMM3 (imm_expr->X_add_number))
break;
ip->insn_opcode |= ENCODE_RVC_SIMM3 (imm_expr->X_add_number);
goto rvc_imm_done;
case 'j':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
|| imm_expr->X_add_number == 0
|| !VALID_RVC_IMM (imm_expr->X_add_number))
break;
ip->insn_opcode |= ENCODE_RVC_IMM (imm_expr->X_add_number);
goto rvc_imm_done;
case 'k':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
|| !VALID_RVC_LW_IMM (imm_expr->X_add_number))
break;
ip->insn_opcode |= ENCODE_RVC_LW_IMM (imm_expr->X_add_number);
goto rvc_imm_done;
case 'l':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
|| !VALID_RVC_LD_IMM (imm_expr->X_add_number))
break;
ip->insn_opcode |= ENCODE_RVC_LD_IMM (imm_expr->X_add_number);
goto rvc_imm_done;
case 'm':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
|| !VALID_RVC_LWSP_IMM (imm_expr->X_add_number))
break;
ip->insn_opcode |=
ENCODE_RVC_LWSP_IMM (imm_expr->X_add_number);
goto rvc_imm_done;
case 'n':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
|| !VALID_RVC_LDSP_IMM (imm_expr->X_add_number))
break;
ip->insn_opcode |=
ENCODE_RVC_LDSP_IMM (imm_expr->X_add_number);
goto rvc_imm_done;
case 'o':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
|| !VALID_RVC_IMM (imm_expr->X_add_number))
break;
ip->insn_opcode |= ENCODE_RVC_IMM (imm_expr->X_add_number);
goto rvc_imm_done;
case 'K':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
|| !VALID_RVC_ADDI4SPN_IMM (imm_expr->X_add_number)
|| imm_expr->X_add_number == 0)
break;
ip->insn_opcode |=
ENCODE_RVC_ADDI4SPN_IMM (imm_expr->X_add_number);
goto rvc_imm_done;
case 'L':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
|| !VALID_RVC_ADDI16SP_IMM (imm_expr->X_add_number)
|| imm_expr->X_add_number == 0)
break;
ip->insn_opcode |=
ENCODE_RVC_ADDI16SP_IMM (imm_expr->X_add_number);
goto rvc_imm_done;
case 'M':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
|| !VALID_RVC_SWSP_IMM (imm_expr->X_add_number))
break;
ip->insn_opcode |=
ENCODE_RVC_SWSP_IMM (imm_expr->X_add_number);
goto rvc_imm_done;
case 'N':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| imm_expr->X_op != O_constant
|| !VALID_RVC_SDSP_IMM (imm_expr->X_add_number))
break;
ip->insn_opcode |=
ENCODE_RVC_SDSP_IMM (imm_expr->X_add_number);
goto rvc_imm_done;
case 'u':
p = percent_op_utype;
if (my_getSmallExpression (imm_expr, imm_reloc, s, p))
break;
rvc_lui:
if (imm_expr->X_op != O_constant
|| imm_expr->X_add_number <= 0
|| imm_expr->X_add_number >= RISCV_BIGIMM_REACH
|| (imm_expr->X_add_number >= RISCV_RVC_IMM_REACH / 2
&& (imm_expr->X_add_number <
RISCV_BIGIMM_REACH - RISCV_RVC_IMM_REACH / 2)))
break;
ip->insn_opcode |= ENCODE_RVC_IMM (imm_expr->X_add_number);
goto rvc_imm_done;
case 'v':
if (my_getSmallExpression (imm_expr, imm_reloc, s, p)
|| (imm_expr->X_add_number & (RISCV_IMM_REACH - 1))
|| ((int32_t)imm_expr->X_add_number
!= imm_expr->X_add_number))
break;
imm_expr->X_add_number =
((uint32_t) imm_expr->X_add_number) >> RISCV_IMM_BITS;
goto rvc_lui;
case 'p':
goto branch;
case 'a':
goto jump;
case 'D': /* Floating-point RS2 x8-x15. */
if (!reg_lookup (&s, RCLASS_FPR, &regno)
|| !(regno >= 8 && regno <= 15))
break;
INSERT_OPERAND (CRS2S, *ip, regno % 8);
continue;
case 'T': /* Floating-point RS2. */
if (!reg_lookup (&s, RCLASS_FPR, &regno))
break;
INSERT_OPERAND (CRS2, *ip, regno);
continue;
default:
as_bad (_("bad RVC field specifier 'C%c'\n"), *args);
}
break;
case ',':
++argnum;
if (*s++ == *args)
continue;
s--;
break;
case '(':
case ')':
case '[':
case ']':
if (*s++ == *args)
continue;
break;
case '<': /* Shift amount, 0 - 31. */
my_getExpression (imm_expr, s);
check_absolute_expr (ip, imm_expr);
if ((unsigned long) imm_expr->X_add_number > 31)
as_bad (_("Improper shift amount (%lu)"),
(unsigned long) imm_expr->X_add_number);
INSERT_OPERAND (SHAMTW, *ip, imm_expr->X_add_number);
imm_expr->X_op = O_absent;
s = expr_end;
continue;
case '>': /* Shift amount, 0 - (XLEN-1). */
my_getExpression (imm_expr, s);
check_absolute_expr (ip, imm_expr);
if ((unsigned long) imm_expr->X_add_number >= xlen)
as_bad (_("Improper shift amount (%lu)"),
(unsigned long) imm_expr->X_add_number);
INSERT_OPERAND (SHAMT, *ip, imm_expr->X_add_number);
imm_expr->X_op = O_absent;
s = expr_end;
continue;
case 'Z': /* CSRRxI immediate. */
my_getExpression (imm_expr, s);
check_absolute_expr (ip, imm_expr);
if ((unsigned long) imm_expr->X_add_number > 31)
as_bad (_("Improper CSRxI immediate (%lu)"),
(unsigned long) imm_expr->X_add_number);
INSERT_OPERAND (RS1, *ip, imm_expr->X_add_number);
imm_expr->X_op = O_absent;
s = expr_end;
continue;
case 'E': /* Control register. */
if (reg_lookup (&s, RCLASS_CSR, &regno))
INSERT_OPERAND (CSR, *ip, regno);
else
{
my_getExpression (imm_expr, s);
check_absolute_expr (ip, imm_expr);
if ((unsigned long) imm_expr->X_add_number > 0xfff)
as_bad (_("Improper CSR address (%lu)"),
(unsigned long) imm_expr->X_add_number);
INSERT_OPERAND (CSR, *ip, imm_expr->X_add_number);
imm_expr->X_op = O_absent;
s = expr_end;
}
continue;
case 'm': /* Rounding mode. */
if (arg_lookup (&s, riscv_rm, ARRAY_SIZE (riscv_rm), &regno))
{
INSERT_OPERAND (RM, *ip, regno);
continue;
}
break;
case 'P':
case 'Q': /* Fence predecessor/successor. */
if (arg_lookup (&s, riscv_pred_succ, ARRAY_SIZE (riscv_pred_succ),
&regno))
{
if (*args == 'P')
INSERT_OPERAND (PRED, *ip, regno);
else
INSERT_OPERAND (SUCC, *ip, regno);
continue;
}
break;
case 'd': /* Destination register. */
case 's': /* Source register. */
case 't': /* Target register. */
if (reg_lookup (&s, RCLASS_GPR, &regno))
{
c = *args;
if (*s == ' ')
++s;
/* Now that we have assembled one operand, we use the args
string to figure out where it goes in the instruction. */
switch (c)
{
case 's':
INSERT_OPERAND (RS1, *ip, regno);
break;
case 'd':
INSERT_OPERAND (RD, *ip, regno);
break;
case 't':
INSERT_OPERAND (RS2, *ip, regno);
break;
}
continue;
}
break;
case 'D': /* Floating point rd. */
case 'S': /* Floating point rs1. */
case 'T': /* Floating point rs2. */
case 'U': /* Floating point rs1 and rs2. */
case 'R': /* Floating point rs3. */
if (reg_lookup (&s, RCLASS_FPR, &regno))
{
c = *args;
if (*s == ' ')
++s;
switch (c)
{
case 'D':
INSERT_OPERAND (RD, *ip, regno);
break;
case 'S':
INSERT_OPERAND (RS1, *ip, regno);
break;
case 'U':
INSERT_OPERAND (RS1, *ip, regno);
/* fallthru */
case 'T':
INSERT_OPERAND (RS2, *ip, regno);
break;
case 'R':
INSERT_OPERAND (RS3, *ip, regno);
break;
}
continue;
}
break;
case 'I':
my_getExpression (imm_expr, s);
if (imm_expr->X_op != O_big
&& imm_expr->X_op != O_constant)
break;
normalize_constant_expr (imm_expr);
s = expr_end;
continue;
case 'A':
my_getExpression (imm_expr, s);
normalize_constant_expr (imm_expr);
/* The 'A' format specifier must be a symbol. */
if (imm_expr->X_op != O_symbol)
break;
*imm_reloc = BFD_RELOC_32;
s = expr_end;
continue;
case 'j': /* Sign-extended immediate. */
*imm_reloc = BFD_RELOC_RISCV_LO12_I;
p = percent_op_itype;
goto alu_op;
case 'q': /* Store displacement. */
p = percent_op_stype;
*imm_reloc = BFD_RELOC_RISCV_LO12_S;
goto load_store;
case 'o': /* Load displacement. */
p = percent_op_itype;
*imm_reloc = BFD_RELOC_RISCV_LO12_I;
goto load_store;
case '0': /* AMO "displacement," which must be zero. */
p = percent_op_rtype;
*imm_reloc = BFD_RELOC_UNUSED;
load_store:
/* Check whether there is only a single bracketed expression
left. If so, it must be the base register and the
constant must be zero. */
imm_expr->X_op = O_constant;
imm_expr->X_add_number = 0;
if (*s == '(' && strchr (s + 1, '(') == 0)
continue;
alu_op:
/* If this value won't fit into a 16 bit offset, then go
find a macro that will generate the 32 bit offset
code pattern. */
if (!my_getSmallExpression (imm_expr, imm_reloc, s, p))
{
normalize_constant_expr (imm_expr);
if (imm_expr->X_op != O_constant
|| (*args == '0' && imm_expr->X_add_number != 0)
|| imm_expr->X_add_number >= (signed)RISCV_IMM_REACH/2
|| imm_expr->X_add_number < -(signed)RISCV_IMM_REACH/2)
break;
}
s = expr_end;
continue;
case 'p': /* PC-relative offset. */
branch:
*imm_reloc = BFD_RELOC_12_PCREL;
my_getExpression (imm_expr, s);
s = expr_end;
continue;
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 (imm_expr->X_add_number < 0
|| imm_expr->X_add_number >= (signed)RISCV_BIGIMM_REACH)
as_bad (_("lui expression not in range 0..1048575"));
*imm_reloc = BFD_RELOC_RISCV_HI20;
imm_expr->X_add_number <<= RISCV_IMM_BITS;
}
s = expr_end;
continue;
case 'a': /* 20-bit PC-relative offset. */
jump:
my_getExpression (imm_expr, s);
s = expr_end;
*imm_reloc = BFD_RELOC_RISCV_JMP;
continue;
case 'c':
my_getExpression (imm_expr, s);
s = expr_end;
if (strcmp (s, "@plt") == 0)
{
*imm_reloc = BFD_RELOC_RISCV_CALL_PLT;
s += 4;
}
else
*imm_reloc = BFD_RELOC_RISCV_CALL;
continue;
default:
as_fatal (_("internal error: bad argument type %c"), *args);
}
break;
}
s = argsStart;
error = _("illegal operands");
}
out:
/* Restore the character we might have clobbered above. */
if (save_c)
*(argsStart - 1) = save_c;
return error;
}
void
md_assemble (char *str)
{
struct riscv_cl_insn insn;
expressionS imm_expr;
bfd_reloc_code_real_type imm_reloc = BFD_RELOC_UNUSED;
const char *error = riscv_ip (str, &insn, &imm_expr, &imm_reloc);
if (error)
{
as_bad ("%s `%s'", error, str);
return;
}
if (insn.insn_mo->pinfo == INSN_MACRO)
macro (&insn, &imm_expr, &imm_reloc);
else
append_insn (&insn, &imm_expr, imm_reloc);
}
const char *
md_atof (int type, char *litP, int *sizeP)
{
return ieee_md_atof (type, litP, sizeP, TARGET_BYTES_BIG_ENDIAN);
}
void
md_number_to_chars (char *buf, valueT val, int n)
{
number_to_chars_littleendian (buf, val, n);
}
const char *md_shortopts = "O::g::G:";
enum options
{
OPTION_MARCH = OPTION_MD_BASE,
OPTION_PIC,
OPTION_NO_PIC,
OPTION_MABI,
OPTION_END_OF_ENUM
};
struct option md_longopts[] =
{
{"march", required_argument, NULL, OPTION_MARCH},
{"fPIC", no_argument, NULL, OPTION_PIC},
{"fpic", no_argument, NULL, OPTION_PIC},
{"fno-pic", no_argument, NULL, OPTION_NO_PIC},
{"mabi", required_argument, NULL, OPTION_MABI},
{NULL, no_argument, NULL, 0}
};
size_t md_longopts_size = sizeof (md_longopts);
enum float_abi {
FLOAT_ABI_DEFAULT = -1,
FLOAT_ABI_SOFT,
FLOAT_ABI_SINGLE,
FLOAT_ABI_DOUBLE,
FLOAT_ABI_QUAD
};
static enum float_abi float_abi = FLOAT_ABI_DEFAULT;
static void
riscv_set_abi (unsigned new_xlen, enum float_abi new_float_abi)
{
abi_xlen = new_xlen;
float_abi = new_float_abi;
}
int
md_parse_option (int c, const char *arg)
{
switch (c)
{
case OPTION_MARCH:
riscv_set_arch (arg);
break;
case OPTION_NO_PIC:
riscv_opts.pic = FALSE;
break;
case OPTION_PIC:
riscv_opts.pic = TRUE;
break;
case OPTION_MABI:
if (strcmp (arg, "ilp32") == 0)
riscv_set_abi (32, FLOAT_ABI_SOFT);
else if (strcmp (arg, "ilp32f") == 0)
riscv_set_abi (32, FLOAT_ABI_SINGLE);
else if (strcmp (arg, "ilp32d") == 0)
riscv_set_abi (32, FLOAT_ABI_DOUBLE);
else if (strcmp (arg, "ilp32q") == 0)
riscv_set_abi (32, FLOAT_ABI_QUAD);
else if (strcmp (arg, "lp64") == 0)
riscv_set_abi (64, FLOAT_ABI_SOFT);
else if (strcmp (arg, "lp64f") == 0)
riscv_set_abi (64, FLOAT_ABI_SINGLE);
else if (strcmp (arg, "lp64d") == 0)
riscv_set_abi (64, FLOAT_ABI_DOUBLE);
else if (strcmp (arg, "lp64q") == 0)
riscv_set_abi (64, FLOAT_ABI_QUAD);
else
return 0;
break;
default:
return 0;
}
return 1;
}
void
riscv_after_parse_args (void)
{
if (xlen == 0)
{
if (strcmp (default_arch, "riscv32") == 0)
xlen = 32;
else if (strcmp (default_arch, "riscv64") == 0)
xlen = 64;
else
as_bad ("unknown default architecture `%s'", default_arch);
}
if (riscv_subsets == 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");
/* Infer ABI from ISA if not specified on command line. */
if (abi_xlen == 0)
abi_xlen = xlen;
else if (abi_xlen > xlen)
as_bad ("can't have %d-bit ABI on %d-bit ISA", abi_xlen, xlen);
else if (abi_xlen < xlen)
as_bad ("%d-bit ABI not yet supported on %d-bit ISA", abi_xlen, xlen);
if (float_abi == FLOAT_ABI_DEFAULT)
{
struct riscv_subset *subset;
/* Assume soft-float unless D extension is present. */
float_abi = FLOAT_ABI_SOFT;
for (subset = riscv_subsets; subset != NULL; subset = subset->next)
{
if (strcasecmp (subset->name, "D") == 0)
float_abi = FLOAT_ABI_DOUBLE;
if (strcasecmp (subset->name, "Q") == 0)
float_abi = FLOAT_ABI_QUAD;
}
}
/* 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));
}
long
md_pcrel_from (fixS *fixP)
{
return fixP->fx_where + fixP->fx_frag->fr_address;
}
/* Apply a fixup to the object file. */
void
md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
{
unsigned int subtype;
bfd_byte *buf = (bfd_byte *) (fixP->fx_frag->fr_literal + fixP->fx_where);
bfd_boolean relaxable = FALSE;
offsetT loc;
segT sub_segment;
/* Remember value for tc_gen_reloc. */
fixP->fx_addnumber = *valP;
switch (fixP->fx_r_type)
{
case BFD_RELOC_RISCV_HI20:
case BFD_RELOC_RISCV_LO12_I:
case BFD_RELOC_RISCV_LO12_S:
bfd_putl32 (riscv_apply_const_reloc (fixP->fx_r_type, *valP)
| bfd_getl32 (buf), buf);
if (fixP->fx_addsy == NULL)
fixP->fx_done = TRUE;
relaxable = TRUE;
break;
case BFD_RELOC_RISCV_GOT_HI20:
case BFD_RELOC_RISCV_PCREL_HI20:
case BFD_RELOC_RISCV_ADD8:
case BFD_RELOC_RISCV_ADD16:
case BFD_RELOC_RISCV_ADD32:
case BFD_RELOC_RISCV_ADD64:
case BFD_RELOC_RISCV_SUB6:
case BFD_RELOC_RISCV_SUB8:
case BFD_RELOC_RISCV_SUB16:
case BFD_RELOC_RISCV_SUB32:
case BFD_RELOC_RISCV_SUB64:
case BFD_RELOC_RISCV_RELAX:
break;
case BFD_RELOC_RISCV_TPREL_HI20:
case BFD_RELOC_RISCV_TPREL_LO12_I:
case BFD_RELOC_RISCV_TPREL_LO12_S:
case BFD_RELOC_RISCV_TPREL_ADD:
relaxable = TRUE;
/* Fall through. */
case BFD_RELOC_RISCV_TLS_GOT_HI20:
case BFD_RELOC_RISCV_TLS_GD_HI20:
case BFD_RELOC_RISCV_TLS_DTPREL32:
case BFD_RELOC_RISCV_TLS_DTPREL64:
if (fixP->fx_addsy != NULL)
S_SET_THREAD_LOCAL (fixP->fx_addsy);
else
as_bad_where (fixP->fx_file, fixP->fx_line,
_("TLS relocation against a constant"));
break;
case BFD_RELOC_32:
/* Use pc-relative relocation for FDE initial location.
The symbol address in .eh_frame may be adjusted in
_bfd_elf_discard_section_eh_frame, and the content of
.eh_frame will be adjusted in _bfd_elf_write_section_eh_frame.
Therefore, we cannot insert a relocation whose addend symbol is
in .eh_frame. Othrewise, the value may be adjusted twice.*/
if (fixP->fx_addsy && fixP->fx_subsy
&& (sub_segment = S_GET_SEGMENT (fixP->fx_subsy))
&& strcmp (sub_segment->name, ".eh_frame") == 0
&& S_GET_VALUE (fixP->fx_subsy)
== fixP->fx_frag->fr_address + fixP->fx_where)
{
fixP->fx_r_type = BFD_RELOC_RISCV_32_PCREL;
fixP->fx_subsy = NULL;
break;
}
/* Fall through. */
case BFD_RELOC_64:
case BFD_RELOC_16:
case BFD_RELOC_8:
case BFD_RELOC_RISCV_CFA:
if (fixP->fx_addsy && fixP->fx_subsy)
{
fixP->fx_next = xmemdup (fixP, sizeof (*fixP), sizeof (*fixP));
fixP->fx_next->fx_addsy = fixP->fx_subsy;
fixP->fx_next->fx_subsy = NULL;
fixP->fx_next->fx_offset = 0;
fixP->fx_subsy = NULL;
switch (fixP->fx_r_type)
{
case BFD_RELOC_64:
fixP->fx_r_type = BFD_RELOC_RISCV_ADD64;
fixP->fx_next->fx_r_type = BFD_RELOC_RISCV_SUB64;
break;
case BFD_RELOC_32:
fixP->fx_r_type = BFD_RELOC_RISCV_ADD32;
fixP->fx_next->fx_r_type = BFD_RELOC_RISCV_SUB32;
break;
case BFD_RELOC_16:
fixP->fx_r_type = BFD_RELOC_RISCV_ADD16;
fixP->fx_next->fx_r_type = BFD_RELOC_RISCV_SUB16;
break;
case BFD_RELOC_8:
fixP->fx_r_type = BFD_RELOC_RISCV_ADD8;
fixP->fx_next->fx_r_type = BFD_RELOC_RISCV_SUB8;
break;
case BFD_RELOC_RISCV_CFA:
/* Load the byte to get the subtype. */
subtype = bfd_get_8 (NULL, &((fragS *) (fixP->fx_frag->fr_opcode))->fr_literal[fixP->fx_where]);
loc = fixP->fx_frag->fr_fix - (subtype & 7);
switch (subtype)
{
case DW_CFA_advance_loc1:
fixP->fx_where = loc + 1;
fixP->fx_next->fx_where = loc + 1;
fixP->fx_r_type = BFD_RELOC_RISCV_SET8;
fixP->fx_next->fx_r_type = BFD_RELOC_RISCV_SUB8;
break;
case DW_CFA_advance_loc2:
fixP->fx_size = 2;
fixP->fx_next->fx_size = 2;
fixP->fx_where = loc + 1;
fixP->fx_next->fx_where = loc + 1;
fixP->fx_r_type = BFD_RELOC_RISCV_SET16;
fixP->fx_next->fx_r_type = BFD_RELOC_RISCV_SUB16;
break;
case DW_CFA_advance_loc4:
fixP->fx_size = 4;
fixP->fx_next->fx_size = 4;
fixP->fx_where = loc;
fixP->fx_next->fx_where = loc;
fixP->fx_r_type = BFD_RELOC_RISCV_SET32;
fixP->fx_next->fx_r_type = BFD_RELOC_RISCV_SUB32;
break;
default:
if (subtype < 0x80 && (subtype & 0x40))
{
/* DW_CFA_advance_loc */
fixP->fx_frag = (fragS *) fixP->fx_frag->fr_opcode;
fixP->fx_next->fx_frag = fixP->fx_frag;
fixP->fx_r_type = BFD_RELOC_RISCV_SET6;
fixP->fx_next->fx_r_type = BFD_RELOC_RISCV_SUB6;
}
else
as_fatal (_("internal error: bad CFA value #%d"), subtype);
break;
}
break;
default:
/* This case is unreachable. */
abort ();
}
}
/* Fall through. */
case BFD_RELOC_RVA:
/* If we are deleting this reloc entry, we must fill in the
value now. This can happen if we have a .word which is not
resolved when it appears but is later defined. */
if (fixP->fx_addsy == NULL)
{
gas_assert (fixP->fx_size <= sizeof (valueT));
md_number_to_chars ((char *) buf, *valP, fixP->fx_size);
fixP->fx_done = 1;
}
break;
case BFD_RELOC_RISCV_JMP:
if (fixP->fx_addsy)
{
/* Fill in a tentative value to improve objdump readability. */
bfd_vma target = S_GET_VALUE (fixP->fx_addsy) + *valP;
bfd_vma delta = target - md_pcrel_from (fixP);
bfd_putl32 (bfd_getl32 (buf) | ENCODE_UJTYPE_IMM (delta), buf);
}
break;
case BFD_RELOC_12_PCREL:
if (fixP->fx_addsy)
{
/* Fill in a tentative value to improve objdump readability. */
bfd_vma target = S_GET_VALUE (fixP->fx_addsy) + *valP;
bfd_vma delta = target - md_pcrel_from (fixP);
bfd_putl32 (bfd_getl32 (buf) | ENCODE_SBTYPE_IMM (delta), buf);
}
break;
case BFD_RELOC_RISCV_RVC_BRANCH:
if (fixP->fx_addsy)
{
/* Fill in a tentative value to improve objdump readability. */
bfd_vma target = S_GET_VALUE (fixP->fx_addsy) + *valP;
bfd_vma delta = target - md_pcrel_from (fixP);
bfd_putl16 (bfd_getl16 (buf) | ENCODE_RVC_B_IMM (delta), buf);
}
break;
case BFD_RELOC_RISCV_RVC_JUMP:
if (fixP->fx_addsy)
{
/* Fill in a tentative value to improve objdump readability. */
bfd_vma target = S_GET_VALUE (fixP->fx_addsy) + *valP;
bfd_vma delta = target - md_pcrel_from (fixP);
bfd_putl16 (bfd_getl16 (buf) | ENCODE_RVC_J_IMM (delta), buf);
}
break;
case BFD_RELOC_RISCV_CALL:
case BFD_RELOC_RISCV_CALL_PLT:
relaxable = TRUE;
break;
case BFD_RELOC_RISCV_PCREL_LO12_S:
case BFD_RELOC_RISCV_PCREL_LO12_I:
case BFD_RELOC_RISCV_ALIGN:
break;
default:
/* We ignore generic BFD relocations we don't know about. */
if (bfd_reloc_type_lookup (stdoutput, fixP->fx_r_type) != NULL)
as_fatal (_("internal error: bad relocation #%d"), fixP->fx_r_type);
}
if (fixP->fx_subsy != NULL)
as_bad_where (fixP->fx_file, fixP->fx_line,
_("unsupported symbol subtraction"));
/* Add an R_RISCV_RELAX reloc if the reloc is relaxable. */
if (relaxable && fixP->fx_tcbit && fixP->fx_addsy != NULL)
{
fixP->fx_next = xmemdup (fixP, sizeof (*fixP), sizeof (*fixP));
fixP->fx_next->fx_addsy = fixP->fx_next->fx_subsy = NULL;
fixP->fx_next->fx_r_type = BFD_RELOC_RISCV_RELAX;
}
}
/* Because the value of .cfi_remember_state may changed after relaxation,
we insert a fix to relocate it again in link-time. */
void
riscv_pre_output_hook (void)
{
const frchainS *frch;
const asection *s;
for (s = stdoutput->sections; s; s = s->next)
for (frch = seg_info (s)->frchainP; frch; frch = frch->frch_next)
{
fragS *frag;
for (frag = frch->frch_root; frag; frag = frag->fr_next)
{
if (frag->fr_type == rs_cfa)
{
expressionS exp;
symbolS *add_symbol = frag->fr_symbol->sy_value.X_add_symbol;
symbolS *op_symbol = frag->fr_symbol->sy_value.X_op_symbol;
exp.X_op = O_subtract;
exp.X_add_symbol = add_symbol;
exp.X_add_number = 0;
exp.X_op_symbol = op_symbol;
fix_new_exp (frag, (int) frag->fr_offset, 1, &exp, 0,
BFD_RELOC_RISCV_CFA);
}
}
}
}
/* This structure is used to hold a stack of .option values. */
struct riscv_option_stack
{
struct riscv_option_stack *next;
struct riscv_set_options options;
};
static struct riscv_option_stack *riscv_opts_stack;
/* Handle the .option pseudo-op. */
static void
s_riscv_option (int x ATTRIBUTE_UNUSED)
{
char *name = input_line_pointer, ch;
while (!is_end_of_line[(unsigned char) *input_line_pointer])
++input_line_pointer;
ch = *input_line_pointer;
*input_line_pointer = '\0';
if (strcmp (name, "rvc") == 0)
riscv_set_rvc (TRUE);
else if (strcmp (name, "norvc") == 0)
riscv_set_rvc (FALSE);
else if (strcmp (name, "pic") == 0)
riscv_opts.pic = TRUE;
else if (strcmp (name, "nopic") == 0)
riscv_opts.pic = FALSE;
else if (strcmp (name, "relax") == 0)
riscv_opts.relax = TRUE;
else if (strcmp (name, "norelax") == 0)
riscv_opts.relax = FALSE;
else if (strcmp (name, "push") == 0)
{
struct riscv_option_stack *s;
s = (struct riscv_option_stack *) xmalloc (sizeof *s);
s->next = riscv_opts_stack;
s->options = riscv_opts;
riscv_opts_stack = s;
}
else if (strcmp (name, "pop") == 0)
{
struct riscv_option_stack *s;
s = riscv_opts_stack;
if (s == NULL)
as_bad (_(".option pop with no .option push"));
else
{
riscv_opts = s->options;
riscv_opts_stack = s->next;
free (s);
}
}
else
{
as_warn (_("Unrecognized .option directive: %s\n"), name);
}
*input_line_pointer = ch;
demand_empty_rest_of_line ();
}
/* Handle the .dtprelword and .dtpreldword pseudo-ops. They generate
a 32-bit or 64-bit DTP-relative relocation (BYTES says which) for
use in DWARF debug information. */
static void
s_dtprel (int bytes)
{
expressionS ex;
char *p;
expression (&ex);
if (ex.X_op != O_symbol)
{
as_bad (_("Unsupported use of %s"), (bytes == 8
? ".dtpreldword"
: ".dtprelword"));
ignore_rest_of_line ();
}
p = frag_more (bytes);
md_number_to_chars (p, 0, bytes);
fix_new_exp (frag_now, p - frag_now->fr_literal, bytes, &ex, FALSE,
(bytes == 8
? BFD_RELOC_RISCV_TLS_DTPREL64
: BFD_RELOC_RISCV_TLS_DTPREL32));
demand_empty_rest_of_line ();
}
/* Handle the .bss pseudo-op. */
static void
s_bss (int ignore ATTRIBUTE_UNUSED)
{
subseg_set (bss_section, 0);
demand_empty_rest_of_line ();
}
static void
riscv_make_nops (char *buf, bfd_vma bytes)
{
bfd_vma i = 0;
/* RISC-V instructions cannot begin or end on odd addresses, so this case
means we are not within a valid instruction sequence. It is thus safe
to use a zero byte, even though that is not a valid instruction. */
if (bytes % 2 == 1)
buf[i++] = 0;
/* Use at most one 2-byte NOP. */
if ((bytes - i) % 4 == 2)
{
md_number_to_chars (buf + i, RVC_NOP, 2);
i += 2;
}
/* Fill the remainder with 4-byte NOPs. */
for ( ; i < bytes; i += 4)
md_number_to_chars (buf + i, RISCV_NOP, 4);
}
/* Called from md_do_align. Used to create an alignment frag in a
code section by emitting a worst-case NOP sequence that the linker
will later relax to the correct number of NOPs. We can't compute
the correct alignment now because of other linker relaxations. */
bfd_boolean
riscv_frag_align_code (int n)
{
bfd_vma bytes = (bfd_vma) 1 << n;
bfd_vma min_text_alignment_order = riscv_opts.rvc ? 1 : 2;
bfd_vma min_text_alignment = (bfd_vma) 1 << min_text_alignment_order;
/* First, get back to minimal alignment. */
frag_align_code (min_text_alignment_order, 0);
/* When not relaxing, riscv_handle_align handles code alignment. */
if (!riscv_opts.relax)
return FALSE;
if (bytes > min_text_alignment)
{
bfd_vma worst_case_bytes = bytes - min_text_alignment;
char *nops = frag_more (worst_case_bytes);
expressionS ex;
ex.X_op = O_constant;
ex.X_add_number = worst_case_bytes;
riscv_make_nops (nops, worst_case_bytes);
fix_new_exp (frag_now, nops - frag_now->fr_literal, 0,
&ex, FALSE, BFD_RELOC_RISCV_ALIGN);
}
return TRUE;
}
/* Implement HANDLE_ALIGN. */
void
riscv_handle_align (fragS *fragP)
{
switch (fragP->fr_type)
{
case rs_align_code:
/* When relaxing, riscv_frag_align_code handles code alignment. */
if (!riscv_opts.relax)
{
bfd_signed_vma count = fragP->fr_next->fr_address
- fragP->fr_address - fragP->fr_fix;
if (count <= 0)
break;
count &= MAX_MEM_FOR_RS_ALIGN_CODE;
riscv_make_nops (fragP->fr_literal + fragP->fr_fix, count);
fragP->fr_var = count;
}
break;
default:
break;
}
}
int
md_estimate_size_before_relax (fragS *fragp, asection *segtype)
{
return (fragp->fr_var = relaxed_branch_length (fragp, segtype, FALSE));
}
/* Translate internal representation of relocation info to BFD target
format. */
arelent *
tc_gen_reloc (asection *section ATTRIBUTE_UNUSED, fixS *fixp)
{
arelent *reloc = (arelent *) xmalloc (sizeof (arelent));
reloc->sym_ptr_ptr = (asymbol **) xmalloc (sizeof (asymbol *));
*reloc->sym_ptr_ptr = symbol_get_bfdsym (fixp->fx_addsy);
reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;
reloc->addend = fixp->fx_addnumber;
reloc->howto = bfd_reloc_type_lookup (stdoutput, fixp->fx_r_type);
if (reloc->howto == NULL)
{
if ((fixp->fx_r_type == BFD_RELOC_16 || fixp->fx_r_type == BFD_RELOC_8)
&& fixp->fx_addsy != NULL && fixp->fx_subsy != NULL)
{
/* We don't have R_RISCV_8/16, but for this special case,
we can use R_RISCV_ADD8/16 with R_RISCV_SUB8/16. */
return reloc;
}
as_bad_where (fixp->fx_file, fixp->fx_line,
_("cannot represent %s relocation in object file"),
bfd_get_reloc_code_name (fixp->fx_r_type));
return NULL;
}
return reloc;
}
int
riscv_relax_frag (asection *sec, fragS *fragp, long stretch ATTRIBUTE_UNUSED)
{
if (RELAX_BRANCH_P (fragp->fr_subtype))
{
offsetT old_var = fragp->fr_var;
fragp->fr_var = relaxed_branch_length (fragp, sec, TRUE);
return fragp->fr_var - old_var;
}
return 0;
}
/* Expand far branches to multi-instruction sequences. */
static void
md_convert_frag_branch (fragS *fragp)
{
bfd_byte *buf;
expressionS exp;
fixS *fixp;
insn_t insn;
int rs1, reloc;
buf = (bfd_byte *)fragp->fr_literal + fragp->fr_fix;
exp.X_op = O_symbol;
exp.X_add_symbol = fragp->fr_symbol;
exp.X_add_number = fragp->fr_offset;
gas_assert (fragp->fr_var == RELAX_BRANCH_LENGTH (fragp->fr_subtype));
if (RELAX_BRANCH_RVC (fragp->fr_subtype))
{
switch (RELAX_BRANCH_LENGTH (fragp->fr_subtype))
{
case 8:
case 4:
/* Expand the RVC branch into a RISC-V one. */
insn = bfd_getl16 (buf);
rs1 = 8 + ((insn >> OP_SH_CRS1S) & OP_MASK_CRS1S);
if ((insn & MASK_C_J) == MATCH_C_J)
insn = MATCH_JAL;
else if ((insn & MASK_C_JAL) == MATCH_C_JAL)
insn = MATCH_JAL | (X_RA << OP_SH_RD);
else if ((insn & MASK_C_BEQZ) == MATCH_C_BEQZ)
insn = MATCH_BEQ | (rs1 << OP_SH_RS1);
else if ((insn & MASK_C_BNEZ) == MATCH_C_BNEZ)
insn = MATCH_BNE | (rs1 << OP_SH_RS1);
else
abort ();
bfd_putl32 (insn, buf);
break;
case 6:
/* Invert the branch condition. Branch over the jump. */
insn = bfd_getl16 (buf);
insn ^= MATCH_C_BEQZ ^ MATCH_C_BNEZ;
insn |= ENCODE_RVC_B_IMM (6);
bfd_putl16 (insn, buf);
buf += 2;
goto jump;
case 2:
/* Just keep the RVC branch. */
reloc = RELAX_BRANCH_UNCOND (fragp->fr_subtype)
? BFD_RELOC_RISCV_RVC_JUMP : BFD_RELOC_RISCV_RVC_BRANCH;
fixp = fix_new_exp (fragp, buf - (bfd_byte *)fragp->fr_literal,
2, &exp, FALSE, reloc);
buf += 2;
goto done;
default:
abort ();
}
}
switch (RELAX_BRANCH_LENGTH (fragp->fr_subtype))
{
case 8:
gas_assert (!RELAX_BRANCH_UNCOND (fragp->fr_subtype));
/* Invert the branch condition. Branch over the jump. */
insn = bfd_getl32 (buf);
insn ^= MATCH_BEQ ^ MATCH_BNE;
insn |= ENCODE_SBTYPE_IMM (8);
md_number_to_chars ((char *) buf, insn, 4);
buf += 4;
jump:
/* Jump to the target. */
fixp = fix_new_exp (fragp, buf - (bfd_byte *)fragp->fr_literal,
4, &exp, FALSE, BFD_RELOC_RISCV_JMP);
md_number_to_chars ((char *) buf, MATCH_JAL, 4);
buf += 4;
break;
case 4:
reloc = RELAX_BRANCH_UNCOND (fragp->fr_subtype)
? BFD_RELOC_RISCV_JMP : BFD_RELOC_12_PCREL;
fixp = fix_new_exp (fragp, buf - (bfd_byte *)fragp->fr_literal,
4, &exp, FALSE, reloc);
buf += 4;
break;
default:
abort ();
}
done:
fixp->fx_file = fragp->fr_file;
fixp->fx_line = fragp->fr_line;
gas_assert (buf == (bfd_byte *)fragp->fr_literal
+ fragp->fr_fix + fragp->fr_var);
fragp->fr_fix += fragp->fr_var;
}
/* Relax a machine dependent frag. This returns the amount by which
the current size of the frag should change. */
void
md_convert_frag (bfd *abfd ATTRIBUTE_UNUSED, segT asec ATTRIBUTE_UNUSED,
fragS *fragp)
{
gas_assert (RELAX_BRANCH_P (fragp->fr_subtype));
md_convert_frag_branch (fragp);
}
void
md_show_usage (FILE *stream)
{
fprintf (stream, _("\
RISC-V options:\n\
-fpic generate position-independent code\n\
-fno-pic don't generate position-independent code (default)\n\
-march=ISA set the RISC-V architecture\n\
-mabi=ABI set the RISC-V ABI\n\
"));
}
/* Standard calling conventions leave the CFA at SP on entry. */
void
riscv_cfi_frame_initial_instructions (void)
{
cfi_add_CFA_def_cfa_register (X_SP);
}
int
tc_riscv_regname_to_dw2regnum (char *regname)
{
int reg;
if ((reg = reg_lookup_internal (regname, RCLASS_GPR)) >= 0)
return reg;
if ((reg = reg_lookup_internal (regname, RCLASS_FPR)) >= 0)
return reg + 32;
as_bad (_("unknown register `%s'"), regname);
return -1;
}
void
riscv_elf_final_processing (void)
{
elf_elfheader (stdoutput)->e_flags |= elf_flags;
}
/* Parse the .sleb128 and .uleb128 pseudos. Only allow constant expressions,
since these directives break relaxation when used with symbol deltas. */
static void
s_riscv_leb128 (int sign)
{
expressionS exp;
char *save_in = input_line_pointer;
expression (&exp);
if (exp.X_op != O_constant)
as_bad (_("non-constant .%cleb128 is not supported"), sign ? 's' : 'u');
demand_empty_rest_of_line ();
input_line_pointer = save_in;
return s_leb128 (sign);
}
/* Pseudo-op table. */
static const pseudo_typeS riscv_pseudo_table[] =
{
/* RISC-V-specific pseudo-ops. */
{"option", s_riscv_option, 0},
{"half", cons, 2},
{"word", cons, 4},
{"dword", cons, 8},
{"dtprelword", s_dtprel, 4},
{"dtpreldword", s_dtprel, 8},
{"bss", s_bss, 0},
{"uleb128", s_riscv_leb128, 0},
{"sleb128", s_riscv_leb128, 1},
{ NULL, NULL, 0 },
};
void
riscv_pop_insert (void)
{
extern void pop_insert (const pseudo_typeS *);
pop_insert (riscv_pseudo_table);
}
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