With the addition of 128-bit system registers to the Arm architecture
starting with Armv9.4-a, a mechanism for manipulating their contents
is introduced with the `msrr' and `mrrs' instruction pair.
These move values from one such 128-bit system register into a pair of
contiguous general-purpose registers and vice-versa, as for example:
msrr ttlb0_el1, x0, x1
mrrs x0, x1, ttlb0_el1
This patch adds the necessary support for these instructions, adding
checks for system-register width by defining a new operand type in the
form of `AARCH64_OPND_SYSREG128' and the `aarch64_sys_reg_128bit_p'
predicate, responsible for checking whether the requested system
register table entry is marked as implemented in the 128-bit mode via
the F_REG_128 flag.
The addition of 128-bit page table descriptors and, with it, the
addition of 128-bit system registers for these means that special
"invalidate translation table entry" instructions are needed to cope
with the new 128-bit model. This is introduced with the `tlbpi'
instruction, implemented here.
While CRn and CRm fields in the SYSP instruction are 4-bit wide and
are thus able to accommodate values in the range 0-15, the
specifications for the SYSP instructions limit their ranges to 8-9 for
CRm and 0-7 in the case of CRn.
This led to the need to signal in some way to the operand parser that
a given operand is under special restrictions regarding its use. This
is done via the new `F_OPD_NARROW' flag, indicating a narrowing in the
range of operand values for fields in the instruction tagged with the
flag.
The flag is then used in `parse_operands' when the instruction is
assembled, but needs not be taken into consideration during
disassembly.
Two of the instructions added by the `+d128' architectural extension
add the flexibility to have two optional operands. Prior to the
addition of the `tlbip' and `sysp' instructions, no mnemonic allowed
more than one such optional operand.
With `tlbip' as an example, some TLBIP instruction names do not allow
for any optional operands, while others allow for both to be optional.
In the latter case, it is possible that either the second operand
alone is omitted or both operands are omitted.
Therefore, a considerable degree of flexibility needed to be added to
the way operands were parsed. It was, however, possible to achieve
this with relatively few changes to existing code.
it is noteworthy that opcode flags specifying the optional operand
number are non-orthogonal. For example, we have:
#define F_OPD1_OPT (2 << 12) : 0b10 << 12
#define F_OPD2_OPT (3 << 12) : 0b11 << 12
such that by virtue of the observation that
(F_OPD1_OPT | F_OPD2_OPT) == F_OPD2_OPT
it is impossible to mark both operands 1 and 2 as optional for an
instruction and it is assumed that a maximum of 1 operand can ever be
optional. This is not overly-problematic given that, for optional
pairs, the second optional operand is always found immediately after
the first. Thus, it suffices for us to flag that there is a second
optional operand. With this fact, we can infer its position in the
mnemonic from the position of the first (e.g. if the second operand in
the mnemonic is optional, we know the third is too). We therefore
define the `F_OPD_PAIR_OPT' flag and calculate its position in the
mnemonic from the value encoded by the `F_OPD<n>_OPT' flag.
Another observation is that there is a tight coupling between default
values assigned to the two registers when one (or both) are omitted
from the mnemonic. Namely, if Xt1 has a value of 0x1f (the zero
register is specified), Xt2 defaults to the same value, otherwise Xt2
will be assigned Xt + 1. This meant that where you have default value
validation, in checking the second optional operand's value, it is
also necessary to look at the value assigned to the
previously-processed operand value before deciding its validity. Thus
`process_omitted_operand' needs not only access to its `operand'
argument, but also to the global `inst' struct.
Analysis of the allowed operand values for `sysp' and `tlbip' reveals
a significant departure from the allowed behavior for operand register
pairs (hitherto labeled AARCH64_OPND_PAIRREG) observed for other
insns in this category.
For instructions `casp', `mrrs' and `msrr' the register pair must
always start at an even index and the second register in the pair is
the index + 1. This precludes the use of xzr as the first register,
given it corresponds to register number 31.
This is different in the case of `sysp' and `tlbip', however. These
allow the use of xzr and, where the first operand in the pair is
omitted, this is the default value assigned to it. When this
operand is assigned xzr, it is expected that the second operand will
likewise take on a value of xzr.
These two instructions therefore "break" two rules of register pairs:
* The first of the two registers is odd-numbered.
* The index of the second register is equal to that of the first,
and not n+1.
To allow for this departure from hitherto standard behavior, we
extend the functionality of the assembler by defining an extension of
the AARCH64_OPND_PAIRREG, called AARCH64_OPND_PAIRREG_OR_XZR.
It is used in defining `sysp' and `tlbip' and allows
`operand_general_constraint_met_p' to allow the pair to both take on
the value of xzr.
Indicating the presence of the Armv9.4-a features concerning 128-bit
Page Table Descriptors, 128-bit System Registers and Instructions,
the "+d128" architectural extension flag is added to the list of
possible -march options in Binutils, together with the necessary macro
for encoding d128 instructions.
The comment looks bogus (perhaps simply stale, perhaps wrongly copied
from Arm in the first place), and there are also no other precautions
against subsections being used on ELF with .bss. It also doesn't look
to be a good idea to override the custom handlers that ELF and COFF
have (afaict doing so further broke .previous on ELF).
As to the mapping state update - such also doesn't appear to be done
for other section switching, so its original purpose was at best
questionable as well.
Adds two new external authors to etc/update-copyright.py to cover
bfd/ax_tls.m4, and adds gprofng to dirs handled automatically, then
updates copyright messages as follows:
1) Update cgen/utils.scm emitted copyrights.
2) Run "etc/update-copyright.py --this-year" with an extra external
author I haven't committed, 'Kalray SA.', to cover gas testsuite
files (which should have their copyright message removed).
3) Build with --enable-maintainer-mode --enable-cgen-maint=yes.
4) Check out */po/*.pot which we don't update frequently.
This patch add supports for FEAT_SPECRES2 "Enhanced speculation
restriction instructions" adding the "cosp" instruction.
This is mandatory v8.9-a/v9.4-a and optional v8.0-a+/v9.0-a+. It is
enabled by the +predres2 march flag.
Hi,
This patch adds support for the Cortex-X3 CPU to binutils.
Gas regression testing for aarch64-none-linux-gnu target and found no regressions.
Ok for binutils-master? I don't have commit access so I need someone to commit on my behalf.
Regards,
Matthieu.
This patch also adds support for:
1. FEAT_RASv2 feature and "ERXGSR_EL1" system register.
RASv2 feature is enabled by passing +rasv2 to -march
(eg: -march=armv8-a+rasv2).
2. FEAT_SCTLR2 and following system registers.
SCTLR2_EL1, SCTLR2_EL12, SCTLR2_EL2 and SCTLR2_EL3.
3. FEAT_FGT2 and following system registers.
HDFGRTR2_EL2, HDFGWTR2_EL2, HFGRTR2_EL2, HFGWTR2_EL2
4. FEAT_PFAR and following system registers.
PFAR_EL1, PFAR_EL2 and PFAR_EL12.
FEAT_RASv2, FEAT_SCTLR2, FEAT_FGT2 and FEAT_PFAR features are by default
enabled from Armv9.4-A architecture.
This patch also adds support for two read only system registers
id_aa64mmfr3_el1 and id_aa64mmfr4_el1, which are available from
Armv8-A Architecture.
Enable the `+lse128' feature modifier which, together with new
internal feature flags, enables LSE128 instructions, which are
represented via the new `_LSE128_INSN' macro.
gas/ChangeLog:
* config/tc-aarch64.c (aarch64_features): Add new "lse128"
entry.
include/ChangeLog:
* include/opcode/aarch64.h (enum aarch64_feature_bit): New
AARCH64_FEATURE_LSE128 feature bit.
(enum aarch64_insn_class): New lse128_atomic instruction class.
opcodes/ChangeLog:
* opcodes/aarch64-tbl.h (aarch64_feature_lse128): New.
(LSE128): Likewise.
(_LSE128_INSN): Likewise.
Given the particular encoding of the LSE128 instructions, create the
necessary shared input+output operand register description and
handling in the code to allow for the encoding of the LSE128 128-bit
atomic operations.
gas/ChangeLog:
* config/tc-aarch64.c (parse_operands):
include/ChangeLog:
* opcode/aarch64.h (enum aarch64_opnd):
opcodes/ChangeLog:
* aarch64-opc.c (fields):
(aarch64_print_operand):
* aarch64-opc.h (enum aarch64_field_kind):
* aarch64-tbl.h (AARCH64_OPERANDS):
Add Binutils support for system registers associated with the
Translation Hardening Extension (THE).
In doing so, we also add core feature support for THE, enabling its
associated feature flag and implementing the necessary
feature-checking machinery.
Regression tested on aarch64-linux-gnu, no regressions.
gas/ChangeLog:
* config/tc-aarch64.c (aarch64_features): Add "+the" feature modifier.
* doc/c-aarch64.texi (AArch64 Extensions): Update
documentation for `the' option.
* testsuite/gas/aarch64/sysreg-8.s: Add tests for `the'
associated system registers.
* testsuite/gas/aarch64/sysreg-8.d: Likewise.
include/ChangeLog:
* opcode/aarch64.h (enum aarch64_feature_bit): Add
AARCH64_FEATURE_THE.
opcode/ChangeLog:
* aarch64-opc.c (aarch64_sys_ins_reg_supported_p): Add `the'
system register check support.
* aarch64-sys-regs.def: Add `rcwmask_el1' and `rcwsmask_el1'
* aarch64-tbl.h: Define `THE' preprocessor macro.
This patch adds support for Guarded control stack data synchronization
instruction (GCSB DSYNC). This instruction is allocated to existing
HINT space and uses the HINT number 19 and to match this an entry is
added to the aarch64_hint_options array.
This patch adds for Guarded Control Stack Extension (GCS) extension. GCS feature is
optional from Armv9.4-A architecture and enabled by passing +gcs option to -march
(eg: -march=armv9.4-a+gcs) or using ".arch_extension gcs" directive in the assembly file.
Also this patch adds support for GCS instructions gcspushx, gcspopcx, gcspopx,
gcsss1, gcsss2, gcspushm, gcspopm, gcsstr and gcssttr.
This patch adds support for Check Feature Status Extension (CHK) which
is mandatory from Armv8.0-A. Also this patch supports "chkfeat" instruction
(hint #40).
The AArch64 feature-flag code is currently limited to a maximum
of 64 features. This patch reworks it so that the limit can be
increased more easily. The basic idea is:
(1) Turn the ARM_FEATURE_FOO macros into an enum, with the enum
counting bit positions.
(2) Make the feature-list macros take an array index argument
(currently always 0). The macros then return the
aarch64_feature_set contents for that array index.
An N-element array would then be initialised as:
{ MACRO (0), ..., MACRO (N - 1) }
(3) Provide convenience macros for initialising an
aarch64_feature_set for:
- a single feature
- a list of individual features
- an architecture version
- an architecture version + a list of additional features
(2) and (3) use the preprocessor to generate static initialisers.
The main restriction was that uses of the same preprocessor macro
cannot be nested. So if a macro wants to do something for N individual
arguments, it needs to use a chain of N macros to do it. There then
needs to be a way of deriving N, as a preprocessor token suitable for
pasting.
The easiest way of doing that was to precede each list of features
by the number of features in the list. So an aarch64_feature_set
initialiser for three features A, B and C would be written:
AARCH64_FEATURES (3, A, B, C)
This scheme makes it difficult to keep AARCH64_FEATURE_CRYPTO as a
synonym for SHA2+AES, so the patch expands the former to the latter.
Historically, flags and variables relating to architectural revisions
for the A-profile architecture omitted the trailing `A' such that, for
example, assembling for `-march=armv8.4-a' set the `AARCH64_ARCH_V8_4'
flag in the assembler.
This leads to some ambiguity, since Binutils also targets the
R-profile Arm architecture. Therefore, it seems prudent to have
everything associated with the A-profile cores end in `A' and likewise
`R' for the R-profile. Referring back to the example above, the flag
set for `-march=armv8.4-a' is better characterized if labeled
`AARCH64_ARCH_V8_4A'.
The only exception to the rule of appending `A' to variables is found
in the handling of the `AARCH64_FEATURE_V8' macro, as it is the
baseline from which ALL processors derive and should therefore be left
unchanged.
In reflecting the `ARM' architectural nomenclature choices, where we
have `ARM_ARCH_V8A' and `ARM_ARCH_V8R', the choice is made to not have
an underscore separating the numerical revision number and the
A/R-profile indicator suffix. This has meant that renaming of
R-profile related flags and variables was warranted, thus going from
`.*_[vV]8_[rR]' to `.*_[vV]8[rR]'.
Finally, this is more in line with conventions within GCC and adds consistency
across the toolchain.
gas/ChangeLog:
* gas/config/tc-aarch64.c:
(aarch64_cpus): Reference to arch feature macros updated.
(aarch64_archs): Likewise.
include/ChangeLog:
* include/opcode/aarch64.h:
(AARCH64_FEATURE_V8A): Updated name: V8_A -> V8A.
(AARCH64_FEATURE_V8_1A): A-suffix added.
(AARCH64_FEATURE_V8_2A): Likewise.
(AARCH64_FEATURE_V8_3A): Likewise.
(AARCH64_FEATURE_V8_4A): Likewise.
(AARCH64_FEATURE_V8_5A): Likewise.
(AARCH64_FEATURE_V8_6A): Likewise.
(AARCH64_FEATURE_V8_7A): Likewise.
(AARCH64_FEATURE_V8_8A):Likewise.
(AARCH64_FEATURE_V9A): Likewise.
(AARCH64_FEATURE_V8R): Updated name: V8_R -> V8R.
(AARCH64_ARCH_V8A_FEATURES): Updated name: V8_A -> V8A.
(AARCH64_ARCH_V8_1A_FEATURES): A-suffix added.
(AARCH64_ARCH_V8_2A_FEATURES): Likewise.
(AARCH64_ARCH_V8_3A_FEATURES): Likewise.
(AARCH64_ARCH_V8_4A_FEATURES): Likewise.
(AARCH64_ARCH_V8_5A_FEATURES): Likewise.
(AARCH64_ARCH_V8_6A_FEATURES): Likewise.
(AARCH64_ARCH_V8_7A_FEATURES): Likewise.
(AARCH64_ARCH_V8_8A_FEATURES): Likewise.
(AARCH64_ARCH_V9A_FEATURES): Likewise.
(AARCH64_ARCH_V9_1A_FEATURES): Likewise.
(AARCH64_ARCH_V9_2A_FEATURES): Likewise.
(AARCH64_ARCH_V9_3A_FEATURES): Likewise.
(AARCH64_ARCH_V8A): Updated name: V8_A -> V8A.
(AARCH64_ARCH_V8_1A): A-suffix added.
(AARCH64_ARCH_V8_2A): Likewise.
(AARCH64_ARCH_V8_3A): Likewise.
(AARCH64_ARCH_V8_4A): Likewise.
(AARCH64_ARCH_V8_5A): Likewise.
(AARCH64_ARCH_V8_6A): Likewise.
(AARCH64_ARCH_V8_7A): Likewise.
(AARCH64_ARCH_V8_8A): Likewise.
(AARCH64_ARCH_V9A): Likewise.
(AARCH64_ARCH_V9_1A): Likewise.
(AARCH64_ARCH_V9_2A): Likewise.
(AARCH64_ARCH_V9_3A): Likewise.
(AARCH64_ARCH_V8_R): Updated name: V8_R -> V8R.
opcodes/ChangeLog:
* opcodes/aarch64-opc.c (SR_V8A): Updated name: V8_A -> V8A.
(SR_V8_1A): A-suffix added.
(SR_V8_2A): Likewise.
(SR_V8_3A): Likewise.
(SR_V8_4A): Likewise.
(SR_V8_6A): Likewise.
(SR_V8_7A): Likewise.
(SR_V8_8A): Likewise.
(aarch64_sys_regs): Reference to arch feature macros updated.
(aarch64_pstatefields): Reference to arch feature macros updated.
(aarch64_sys_ins_reg_supported_p): Reference to arch feature macros
updated.
* opcodes/aarch64-tbl.h:
(aarch64_feature_v8_2a): a-suffix added.
(aarch64_feature_v8_3a): Likewise.
(aarch64_feature_fp_v8_3a): Likewise.
(aarch64_feature_v8_4a): Likewise.
(aarch64_feature_fp_16_v8_2a): Likewise.
(aarch64_feature_v8_5a): Likewise.
(aarch64_feature_v8_6a): Likewise.
(aarch64_feature_v8_7a): Likewise.
(aarch64_feature_v8r): Updated name: v8_r-> v8r.
(ARMV8R): Updated name: V8_R-> V8R.
(ARMV8_2A): A-suffix added.
(ARMV8_3A): Likewise.
(FP_V8_3A): Likewise.
(ARMV8_4A): Likewise.
(FP_F16_V8_2A): Likewise.
(ARMV8_5): Likewise.
(ARMV8_6A): Likewise.
(ARMV8_6A_SVE): Likewise.
(ARMV8_7A): Likewise.
(V8_2A_INSN): `A' added to macro symbol.
(V8_3A_INSN): Likewise.
(V8_4A_INSN): Likewise.
(FP16_V8_2A_INSN): Likewise.
(V8_5A_INSN): Likewise.
(V8_6A_INSN): Likewise.
(V8_7A_INSN): Likewise.
(V8R_INSN): Updated name: V8_R-> V8R.
This patch adds support for the Cortex-A720 CPU to binutils.
bfd/ChangeLog:
* cpu-aarch64.c: Add Cortex-A720.
gas/ChangeLog:
* NEWS: Update docs.
* config/tc-aarch64.c: Add Cortex-A720.
* doc/c-aarch64.texi: Update docs.
* testsuite/gas/aarch64/cpu-cortex-a720.d: New test.
This patch adds support for the Cortex-A520 CPU to gas.
No regressions on aarch64-none-elf.
gas/ChangeLog:
* NEWS: Update docs.
* config/tc-aarch64.c: Add Cortex-A520.
* doc/c-aarch64.texi: Update docs.
tc-aarch64.c:1473:27: runtime error: left shift of 7 by 30 places
cannot be represented in type 'int'.
* config/tc-aarch64.c (parse_vector_reg_list): Avoid UB left
shift.
This patch adds the RPRFM (range prefetch) instruction.
It was introduced as part of SME2, but it belongs to the
prefetch hint space and so doesn't require any specific
ISA flags.
The aarch64_rprfmop_array initialiser (deliberately) only
fills in the leading non-null elements.
This patch adds the SVE FDOT, SDOT and UDOT instructions,
which are available when FEAT_SME2 is implemented. The patch
also reorders the existing SVE_Zm3_22_INDEX to keep the
operands numerically sorted.
There are two instruction formats here:
- SQRSHR, SQRSHRU and UQRSHR, which operate on lists of two
or four registers.
- SQRSHRN, SQRSHRUN and UQRSHRN, which operate on lists of
four registers.
These are the first SME2 instructions to have immediate operands.
The patch makes sure that, when parsing SME2 instructions with
immediate operands, the new predicate-as-counter registers are
parsed as registers rather than as #-less immediates.
SMLALL, SMLSLL, UMLALL and UMLSLL have the same format.
USMLALL and SUMLALL allow the same operand types as those
instructions, except that SUMLALL does not have the multi-vector
x multi-vector forms (which would be redundant with USMLALL).
The {BF,F,S,U}MLAL and {BF,F,S,U}MLSL instructions share the same
encoding. They are the first instance of a ZA (as opposed to ZA tile)
operand having a range of offsets. As with ZA tiles, the expected
range size is encoded in the operand-specific data field.
Add support for the SME2 ADD. SUB, FADD and FSUB instructions.
SUB and FSUB have the same form as ADD and FADD, except that
ADD also has a 2-operand accumulating form.
The 64-bit ADD/SUB instructions require FEAT_SME_I16I64 and the
64-bit FADD/FSUB instructions require FEAT_SME_F64F64.
These are the first instructions to have tied register list
operands, as opposed to tied single registers.
The parse_operands change prevents unsuffixed Z registers (width==-1)
from being treated as though they had an Advanced SIMD-style suffix
(.4s etc.). It means that:
Error: expected element type rather than vector type at operand 2 -- `add za\.s\[w8,0\],{z0-z1}'
becomes:
Error: missing type suffix at operand 2 -- `add za\.s\[w8,0\],{z0-z1}'
SME2 adds lookup table instructions for quantisation. They use
a new lookup table register called ZT0.
LUTI2 takes an unsuffixed SVE vector index of the form Zn[<imm>],
which is the first time that this syntax has been used.
Implementation-wise, the main things to note here are:
- the WHILE* instructions have forms that return a pair of predicate
registers. This is the first time that we've had lists of predicate
registers, and they wrap around after register 15 rather than after
register 31.
- the predicate-as-counter WHILE* instructions have a fourth operand
that specifies the vector length. We can treat this as an enumeration,
except that immediate values aren't allowed.
- PEXT takes an unsuffixed predicate index of the form PN<n>[<imm>].
This is the first instance of a vector/predicate index having
no suffix.
SME2 adds LD1 and ST1 variants for lists of 2 and 4 registers.
The registers can be consecutive or strided. In the strided case,
2-register lists have a stride of 8, starting at register x0xxx.
4-register lists have a stride of 4, starting at register x00xx.
The instructions are predicated on a predicate-as-counter register in
the range pn8-pn15. Although we already had register fields with upper
bounds of 7 and 15, this is the first plain register operand to have a
nonzero lower bound. The patch uses the operand-specific data field
to record the minimum value, rather than having separate inserters
and extractors for each lower bound. This in turn required adding
an extra bit to the field.
SME2 defines new MOVA instructions for moving multiple registers
to and from ZA. As with SME, the instructions are also available
through MOV aliases.
One notable feature of these instructions (and many other SME2
instructions) is that some register lists must start at a multiple
of the list's size. The patch uses the general error "start register
out of range" when this constraint isn't met, rather than an error
specifically about multiples. This ensures that the error is
consistent between these simple consecutive lists and later
strided lists, for which the requirements aren't a simple multiple.
SME2 adds a new format for the existing SVE predicate registers:
predicates as counters rather than predicates as masks. In assembly
code, operands that interpret predicates as counters are written
pn<N> rather than p<N>.
This patch adds support for these registers and extends some
existing instructions to support them. Since the new forms
are just a programmer convenience, there's no need to make them
more restrictive than the earlier predicate-as-mask forms.
Some SME2 instructions operate on a range of consecutive ZA vectors.
This is indicated by syntax such as:
za[<Wv>, <imml>:<immh>]
Like with the earlier vgx2 and vgx4 support, we get better error
messages if the parser allows all ZA indices to have a range.
We can then reject invalid cases during constraint checking.
Many SME2 instructions operate on groups of 2 or 4 ZA vectors.
This is indicated by adding a "vgx2" or "vgx4" group size to the
ZA index. The group size is optional in assembly but preferred
for disassembly.
There is not a binary distinction between mnemonics that have
group sizes and mnemonics that don't, nor between mnemonics that
take vgx2 and mnemonics that take vgx4. We therefore get better
error messages if we allow any ZA index to have a group size
during parsing, and wait until constraint checking to reject
invalid sizes.
A quirk of the way errors are reported means that if an instruction
is wrong both in its qualifiers and its use of a group size, we'll
print suggested alternative instructions that also have an incorrect
group size. But that's a general property that also applies to
things like out-of-range immediates. It's also not obviously the
wrong thing to do. We need to be relatively confident that we're
looking at the right opcode before reporting detailed operand-specific
errors, so doing qualifier checking first seems resonable.
SME2 adds various new fields that are similar to
AARCH64_OPND_SME_ZA_array, but are distinguished by the size of
their offset fields. This patch adds _off4 to the name of the
field that we already have.
Until now, binutils has supported register ranges such
as { v0.4s - v3.4s } as an unofficial shorthand for
{ v0.4s, v1.4s, v2.4s, v3.4s }. The SME2 ISA embraces this form
and makes it the preferred disassembly. It also embraces wrapped
lists such as { z31.s - z2.s }, which is something that binutils
didn't previously allow.
The range form was already binutils's preferred disassembly for 3- and
4-register lists. This patch prefers it for 2-register lists too.
The patch also adds support for wrap-around.
SME2 has instructions that accept strided register lists,
such as { z0.s, z4.s, z8.s, z12.s }. The purpose of this
patch is to extend binutils to support such lists.
The parsing code already had (unused) support for strides of 2.
The idea here is instead to accept all strides during parsing
and reject invalid strides during constraint checking.
The SME2 instructions that accept strided operands also have
non-strided forms. The errors about invalid strides therefore
take a bitmask of acceptable strides, which allows multiple
possibilities to be summed up in a single message.
I've tried to update all code that handles register lists.
In GAS, the vector and predicate registers are identified by
REG_TYPE_VN, REG_TYPE_ZN and REG_TYPE_PN. This "N" is obviously
a placeholder for the register number. However, we don't use that
convention for integer and FP registers, and (more importantly)
SME2 adds "predicate-as-counter" registers that are denoted PN.
This patch therefore drops the "N" suffix from the existing
registers. The main hitch is that Z was also used for the
zero register in things like R_Z, but using ZR seems more
consistent with the SP-based names.
Quite a lot of SME2 instructions have an opcode bit that selects
between 32-bit and 64-bit forms of an instruction, with the 32-bit
forms being part of base SME2 and with the 64-bit forms being part
of an optional extension. It's nevertheless useful to have a single
opcode entry for both forms since (a) that matches the ISA definition
and (b) it tends to improve error reporting.
This patch therefore adds a libopcodes function called
aarch64_cpu_supports_inst_p that tests whether the target
supports a particular instruction. In future it will depend
on internal libopcodes routines.
There are three main kinds of error reported during parsing,
in increasing order of priority:
- AARCH64_OPDE_RECOVERABLE (register seen instead of immediate)
- AARCH64_OPDE_SYNTAX_ERROR
- AARCH64_OPDE_FATAL_SYNTAX_ERROR
This priority makes sense when comparing errors reported against the
same operand. But if we get to operand 3 (say) and see a register
instead of an immediate, that's likely to be a better match than
something that fails with a syntax error at operand 1.
The idea of this patch is to prioritise parsing-related errors
based on operand index first, then by error code. Post-parsing
errors still win over parsing errors, and their relative priorities
don't change.
If an instruction has invalid qualifiers, GAS would report the
error against the final opcode entry that got to the qualifier-
checking stage. It seems better to report the error against
the opcode entry that had the closest match, just like we
pick the closest match within an opcode entry for the
"did you mean this?" message.
This patch adds the number of invalid operands as an
argument to AARCH64_OPDE_INVALID_VARIANT and then picks the
AARCH64_OPDE_INVALID_VARIANT with the lowest argument.
The error for invalid register lists had the form:
invalid number of registers in the list; N registers are expected at operand M -- `insn'
This seems a bit verbose. Also, the "bracketing" is really:
(invalid number of registers in the list; N registers are expected) at operand M
but the semicolon works against that.
This patch goes for slightly shorter messages, setting a template
that later patches can use for more complex cases.
