[PATCH v3 2/2] RISC-V: Better support for long instructions (assembler)
Tsukasa OI
research_trasio@irq.a4lg.com
Fri Nov 25 02:17:24 GMT 2022
From: Tsukasa OI <research_trasio@irq.a4lg.com>
Commit bb996692bd96 ("RISC-V/gas: allow generating up to 176-bit
instructions with .insn") tried to start supporting long instructions but
it was insufficient.
1. It heavily depended on the bignum internals (radix of 2^16),
2. It generates "value conflicts with instruction length" even if a big
number instruction encoding does not exceed its expected length,
3. Because long opcode was handled separately (from struct riscv_cl_insn),
some information like DWARF line number correspondence was missing and
To solve these problems, this commit:
1. Handles bignum (and its encodings) precisely and
2. Incorporates long opcode handling into regular instruction handling.
gas/ChangeLog:
* config/tc-riscv.c (struct riscv_cl_insn): Add long opcode field.
(create_insn) Clear long opcode marker.
(install_insn) Install longer opcode as well.
(s_riscv_insn) Likewise.
(riscv_ip_hardcode): Make big number handling stricter. Length and
the value conflicts only if the bignum size exceeds the expected
maximum length.
* testsuite/gas/riscv/insn.s: Add testcases such that big number
handling is required.
* testsuite/gas/riscv/insn.d: Likewise.
* testsuite/gas/riscv/insn-na.d: Likewise.
* testsuite/gas/riscv/insn-dwarf.d: Likewise.
---
gas/config/tc-riscv.c | 38 ++++++++++++++++++++++------
gas/testsuite/gas/riscv/insn-dwarf.d | 10 +++++++-
gas/testsuite/gas/riscv/insn-na.d | 8 ++++++
gas/testsuite/gas/riscv/insn.d | 22 ++++++++++++++++
gas/testsuite/gas/riscv/insn.s | 9 +++++++
5 files changed, 78 insertions(+), 9 deletions(-)
diff --git a/gas/config/tc-riscv.c b/gas/config/tc-riscv.c
index 019545171f5e..2237062d8b45 100644
--- a/gas/config/tc-riscv.c
+++ b/gas/config/tc-riscv.c
@@ -45,6 +45,9 @@ struct riscv_cl_insn
/* The encoded instruction bits. */
insn_t insn_opcode;
+ /* The long encoded instruction bits ([0] is non-zero if used). */
+ char insn_long_opcode[RISCV_MAX_INSN_LEN];
+
/* The frag that contains the instruction. */
struct frag *frag;
@@ -714,6 +717,7 @@ create_insn (struct riscv_cl_insn *insn, const struct riscv_opcode *mo)
{
insn->insn_mo = mo;
insn->insn_opcode = mo->match;
+ insn->insn_long_opcode[0] = 0; /* Long insn has non-zero value. */
insn->frag = NULL;
insn->where = 0;
insn->fixp = NULL;
@@ -725,7 +729,10 @@ static void
install_insn (const struct riscv_cl_insn *insn)
{
char *f = insn->frag->fr_literal + insn->where;
- number_to_chars_littleendian (f, insn->insn_opcode, insn_length (insn));
+ if (insn->insn_long_opcode[0] != 0)
+ memcpy (f, insn->insn_long_opcode, insn_length (insn));
+ else
+ number_to_chars_littleendian (f, insn->insn_opcode, insn_length (insn));
}
/* Move INSN to offset WHERE in FRAG. Adjust the fixups accordingly
@@ -3481,7 +3488,9 @@ riscv_ip_hardcode (char *str,
values[num++] = (insn_t) imm_expr->X_add_number;
break;
case O_big:
- values[num++] = generic_bignum[0];
+ /* Extract lower 32-bits of a big number.
+ Assume that generic_bignum_to_int32 work on such number. */
+ values[num++] = (insn_t) generic_bignum_to_int32 ();
break;
default:
/* The first value isn't constant, so it should be
@@ -3508,12 +3517,25 @@ riscv_ip_hardcode (char *str,
if (imm_expr->X_op == O_big)
{
- if (bytes != imm_expr->X_add_number * CHARS_PER_LITTLENUM)
+ unsigned int llen = 0;
+ for (LITTLENUM_TYPE lval = generic_bignum[imm_expr->X_add_number - 1];
+ lval != 0; llen++)
+ lval >>= BITS_PER_CHAR;
+ unsigned int repr_bytes
+ = (imm_expr->X_add_number - 1) * CHARS_PER_LITTLENUM + llen;
+ if (bytes < repr_bytes)
return _("value conflicts with instruction length");
- char *f = frag_more (bytes);
- for (num = 0; num < imm_expr->X_add_number; ++num)
- number_to_chars_littleendian (f + num * CHARS_PER_LITTLENUM,
- generic_bignum[num], CHARS_PER_LITTLENUM);
+ for (num = 0; num < imm_expr->X_add_number - 1; ++num)
+ number_to_chars_littleendian (
+ ip->insn_long_opcode + num * CHARS_PER_LITTLENUM,
+ generic_bignum[num],
+ CHARS_PER_LITTLENUM);
+ if (llen != 0)
+ number_to_chars_littleendian (
+ ip->insn_long_opcode + num * CHARS_PER_LITTLENUM,
+ generic_bignum[num],
+ llen);
+ memset(ip->insn_long_opcode + repr_bytes, 0, bytes - repr_bytes);
return NULL;
}
@@ -4590,7 +4612,7 @@ s_riscv_insn (int x ATTRIBUTE_UNUSED)
else
as_bad ("%s `%s'", error.msg, error.statement);
}
- else if (imm_expr.X_op != O_big)
+ else
{
gas_assert (insn.insn_mo->pinfo != INSN_MACRO);
append_insn (&insn, &imm_expr, imm_reloc);
diff --git a/gas/testsuite/gas/riscv/insn-dwarf.d b/gas/testsuite/gas/riscv/insn-dwarf.d
index 89dc8d58ff09..b8bd42dff18c 100644
--- a/gas/testsuite/gas/riscv/insn-dwarf.d
+++ b/gas/testsuite/gas/riscv/insn-dwarf.d
@@ -74,5 +74,13 @@ insn.s +69 +0xf6.*
insn.s +70 +0xfe.*
insn.s +71 +0x108.*
insn.s +72 +0x114.*
-insn.s +- +0x12a
+insn.s +74 +0x12a.*
+insn.s +75 +0x134.*
+insn.s +76 +0x13e.*
+insn.s +77 +0x154.*
+insn.s +78 +0x16a.*
+insn.s +79 +0x180.*
+insn.s +80 +0x196.*
+insn.s +81 +0x1ac.*
+insn.s +- +0x1c2
#pass
diff --git a/gas/testsuite/gas/riscv/insn-na.d b/gas/testsuite/gas/riscv/insn-na.d
index 66dce71ebc21..6928ba9ba0f2 100644
--- a/gas/testsuite/gas/riscv/insn-na.d
+++ b/gas/testsuite/gas/riscv/insn-na.d
@@ -73,3 +73,11 @@ Disassembly of section .text:
[^:]+:[ ]+007f 0000 0000 0000 0000[ ]+[._a-z].*
[^:]+:[ ]+0000107f 00000000 00000000[ ]+[._a-z].*
[^:]+:[ ]+607f 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000[ ]+[._a-z].*
+[^:]+:[ ]+007f 0000 0000 0000 8000[ ]+\.byte[ ]+0x7f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80
+[^:]+:[ ]+007f 0000 0000 0000 8000[ ]+\.byte[ ]+0x7f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80
+[^:]+:[ ]+607f 89ab 4567 0123 3210 7654 ba98 fedc 0000 0000 0000[ ]+\.byte[ ]+0x7f, 0x60, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+[^:]+:[ ]+607f 89ab 4567 0123 3210 7654 ba98 fedc 0000 0000 0000[ ]+\.byte[ ]+0x7f, 0x60, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+[^:]+:[ ]+607f 33cc 55aa cdef 89ab 4567 0123 3210 7654 ba98 00dc[ ]+\.byte[ ]+0x7f, 0x60, 0xcc, 0x33, 0xaa, 0x55, 0xef, 0xcd, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0x00
+[^:]+:[ ]+607f 33cc 55aa cdef 89ab 4567 0123 3210 7654 ba98 00dc[ ]+\.byte[ ]+0x7f, 0x60, 0xcc, 0x33, 0xaa, 0x55, 0xef, 0xcd, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0x00
+[^:]+:[ ]+607f 33cc 55aa cdef 89ab 4567 0123 3210 7654 ba98 fedc[ ]+\.byte[ ]+0x7f, 0x60, 0xcc, 0x33, 0xaa, 0x55, 0xef, 0xcd, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe
+[^:]+:[ ]+607f 33cc 55aa cdef 89ab 4567 0123 3210 7654 ba98 fedc[ ]+\.byte[ ]+0x7f, 0x60, 0xcc, 0x33, 0xaa, 0x55, 0xef, 0xcd, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe
diff --git a/gas/testsuite/gas/riscv/insn.d b/gas/testsuite/gas/riscv/insn.d
index 2e5d35b39702..b25bc35553fd 100644
--- a/gas/testsuite/gas/riscv/insn.d
+++ b/gas/testsuite/gas/riscv/insn.d
@@ -92,3 +92,25 @@ Disassembly of section .text:
[^:]+:[ ]+607f 0000 0000 0000[ ]+[._a-z].*
[^:]+:[ ]+0000 0000 0000 0000 ?
[^:]+:[ ]+0000 0000 0000 ?
+[^:]+:[ ]+007f 0000 0000 0000[ ]+\.byte[ ]+0x7f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80
+[^:]+:[ ]+8000 ?
+[^:]+:[ ]+007f 0000 0000 0000[ ]+\.byte[ ]+0x7f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80
+[^:]+:[ ]+8000 ?
+[^:]+:[ ]+607f 89ab 4567 0123[ ]+\.byte[ ]+0x7f, 0x60, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+[^:]+:[ ]+3210 7654 ba98 fedc ?
+[^:]+:[ ]+0000 0000 0000 ?
+[^:]+:[ ]+607f 89ab 4567 0123[ ]+\.byte[ ]+0x7f, 0x60, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+[^:]+:[ ]+3210 7654 ba98 fedc ?
+[^:]+:[ ]+0000 0000 0000 ?
+[^:]+:[ ]+607f 33cc 55aa cdef[ ]+\.byte[ ]+0x7f, 0x60, 0xcc, 0x33, 0xaa, 0x55, 0xef, 0xcd, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0x00
+[^:]+:[ ]+89ab 4567 0123 3210 ?
+[^:]+:[ ]+7654 ba98 00dc ?
+[^:]+:[ ]+607f 33cc 55aa cdef[ ]+\.byte[ ]+0x7f, 0x60, 0xcc, 0x33, 0xaa, 0x55, 0xef, 0xcd, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0x00
+[^:]+:[ ]+89ab 4567 0123 3210 ?
+[^:]+:[ ]+7654 ba98 00dc ?
+[^:]+:[ ]+607f 33cc 55aa cdef[ ]+\.byte[ ]+0x7f, 0x60, 0xcc, 0x33, 0xaa, 0x55, 0xef, 0xcd, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe
+[^:]+:[ ]+89ab 4567 0123 3210 ?
+[^:]+:[ ]+7654 ba98 fedc ?
+[^:]+:[ ]+607f 33cc 55aa cdef[ ]+\.byte[ ]+0x7f, 0x60, 0xcc, 0x33, 0xaa, 0x55, 0xef, 0xcd, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe
+[^:]+:[ ]+89ab 4567 0123 3210 ?
+[^:]+:[ ]+7654 ba98 fedc ?
diff --git a/gas/testsuite/gas/riscv/insn.s b/gas/testsuite/gas/riscv/insn.s
index 94f62fe5672e..48db59b14e88 100644
--- a/gas/testsuite/gas/riscv/insn.s
+++ b/gas/testsuite/gas/riscv/insn.s
@@ -70,3 +70,12 @@ target:
.insn 10, 0x007f
.insn 12, 0x107f
.insn 22, 0x607f
+
+ .insn 0x8000000000000000007f
+ .insn 10, 0x8000000000000000007f
+ .insn 0x000000000000fedcba98765432100123456789ab607f
+ .insn 22, 0x000000000000fedcba98765432100123456789ab607f
+ .insn 0x00dcba98765432100123456789abcdef55aa33cc607f
+ .insn 22, 0x00dcba98765432100123456789abcdef55aa33cc607f
+ .insn 0xfedcba98765432100123456789abcdef55aa33cc607f
+ .insn 22, 0xfedcba98765432100123456789abcdef55aa33cc607f
--
2.38.1
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