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.
This patch adds the permission model enhancement and memory
attribute index enhancement features and their corresponding
system registers in AArch64 assembler.
Permission Indirection Extension (FEAT_S1PIE, FEAT_S2PIE)
Permission Overlay Extension (FEAT_S1POE, FEAT_S2POE)
Memory Attribute Index Enhancement (FEAT_AIE)
Extension to Translation Control Registers (FEAT_TCR2)
These features are available by default from Armv9.4-A architecture.
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.
This patch adds features to the Statistical Profiling Extension,
identified as FEAT_SPEv1p4, FEAT_SPE_FDS, and FEAT_SPE_CRR, which
are enabled by default from Armv9.4-A.
Also adds support for system register "pmsdsfr_el1".
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).
This patch adds a mechanism for system register name alias detection
to register-matching mechanisms.
A new `F_REG_ALIAS' flag is added to the set of register flags and
used to label which entries in aarch64_sys_regs[] correspond to
aliases (and thus which CPENC values are non-unique in this array).
Where this is used is, for example, in `aarch64_print_operand' where,
in the case of system register decoding, the aarch64_sys_regs[] array
is iterated through until a match in CPENC value is made and the first
match accepted. If insufficient care is given in the ordering of
system registers in this array, the alias is encountered before the
"real" register and used incorrectly as the register name in the
disassembled output.
With this flag and the new `aarch64_sys_reg_alias_p' test, search
candidates corresponding to aliases can be conveniently skipped over.
One concrete example of where this is useful is with the
`trcextinselr0' system register. It was initially placed in the
system register list before `trcextinselr', in contrast to a more
natural alphabetical order.
include/ChangeLog:
* opcode/aarch64.h: add `aarch64_sys_reg_alias_p' prototype.
opcodes/ChangeLog:
* aarch64-opc.c (aarch64_sys_reg_alias_p): New.
(aarch64_print_operand): add aarch64_sys_reg_alias_p check.
(aarch64_sys_regs): Add F_REG_ALIAS flag to "trcextinselr"
entry.
* aarch64-opc.h (F_REG_ALIAS): New.
Following on from the previous patch to make the feature macros take
a word number, this one increases the number of flag words from 1 to 2.
The patch uses some dummy features to push the number of features
over 64. The intention is that these should be reused by real
features rather than kept as-is.
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 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.
There are two instruction formats here:
- SQCVT, SQCVTU and UQCVT, which operate on lists of two or
four registers.
- SQCVTN, SQCVTUN and UQCVTN, which operate on lists of
four registers.
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.
This patch adds the SME2 multi-register forms of F{MAX,MIN}{,NM}
and {S,U}{MAX,MIN}. SQDMULH, SRSHL and URSHL have the same form
as SMAX etc., so the patch adds them too.
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.
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.
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.
SVE register lists were classified as SVE_REG, since there had been
no particular reason to separate them out. However, some SME2
instructions have tied register list operands, and so we need to
distinguish registers and register lists when checking whether two
operands match.
Also, the register list operands used a general error message,
even though we already have a dedicated error code for register
lists that are the wrong length.
libopcodes currently reports out-of-range registers as a general
AARCH64_OPDE_OTHER_ERROR. However, this means that each register
range needs its own hard-coded string, which is a bit cumbersome
if the range is determined programmatically. This patch therefore
adds a dedicated error type for out-of-range errors.
SME2 has many instructions that take a list of SVE registers.
There are often multiple forms, with different forms taking
different numbers of registers.
This means that if, after a successful parse and qualifier match,
we find that the number of registers does not match the opcode entry,
the associated error should have a lower priority/severity than other
errors reported at the same stage. For example, if there are 2-register
and 4-register forms of an instruction, and if the assembly code uses
the 2-register form with an out-of-range value, the out-of-range value
error against the 2-register instruction should have a higher priority
than the "wrong number of registers" error against the 4-register
instruction.
This is tested by the main SME2 patches, but seemed worth splitting out.
This patch moves the range checks on ZA vector select offsets from
gas to libopcodes. Doing the checks there means that the error
messages contain the expected range. It also fits in better
with the error severity scheme, which becomes important later.
(This is because out-of-range indices are treated as more severe than
syntax errors, on the basis that parsing must have succeeded if we get
to the point of checking the completed opcode.)
The patch also adds a new check_za_access function for checking
ZA accesses. That's a bit over the top for one offset check, but the
function becomes more complex with later patches.
sme-9-illegal.s checked for an invalid .q suffix using:
psel p1, p15, p3.q[w15]
but this is doubly invalid because it misses the immediate part
of the index. The patch keeps that test but adds another with
a zero index, so that .q is the only thing wrong.
The aarch64-tbl.h change includes neatening up the backslash
positions.
A later patch moves the range checking for ZA vector select
offsets from gas to libopcodes. That in turn requires the
immediate field to be big enough to support all parsed values.
This shouldn't be a particularly size-sensitive structure,
so there should be no memory problems with doing this.
za_tile_vector is also used for indexing ZA as a whole, rather than
just for indexing tiles. The former is more common than the latter
in SME2, so this patch generalises the name to "indexed_za".
The patch also names the associated structure, so that later patches
can reuse it during parsing.
This patch makes all SME instructions use F_STRICT, so that qualifiers
have to be provided explicitly rather than being inferred from other
operands. The main change is to move the qualifier setting from the
operand-level decoders to the opcode level.
This is one step towards consolidating the ZA parsing code and
extending it to handle SME2.
Most extension flags are named after the associated architectural
FEAT_* flags, but sme-i64 and sme-f64 were exceptions. This patch
adds sme-i16i64 and sme-f64f64 aliases, but keeps the old names too
for compatibility.
The newer update-copyright.py fixes file encoding too, removing cr/lf
on binutils/bfdtest2.c and ld/testsuite/ld-cygwin/exe-export.exp, and
embedded cr in binutils/testsuite/binutils-all/ar.exp string match.
This commit enables disassembler styling for AArch64. After this
commit it is possible to have objdump style AArch64 disassembler
output (using --disassembler-color option). Once the required GDB
patches are merged, GDB will also style the disassembler output.
The changes to support styling are mostly split between two files
opcodes/aarch64-dis.c and opcodes/aarch64-opc.c.
The entry point for the AArch64 disassembler can be found in
aarch64-dis.c, this file handles printing the instruction mnemonics,
and assembler directives (e.g. '.byte', '.word', etc). Some operands,
mostly relating to assembler directives are also printed from this
file. This commit changes all of this to pass through suitable
styling information.
However, for most "normal" instructions, the instruction operands are
printed using a two step process. From aarch64-dis.c, in the
print_operands function, the function aarch64_print_operand is called,
this function is in aarch64-opc.c, and converts an instruction operand
into a string. Then, back in print_operands (aarch64-dis.c), the
operand string is printed.
Unfortunately, the string returned by aarch64_print_operand can be
quite complex, it will include syntax elements, like '[' and ']', in
addition to register names and immediate values. In some cases, a
single operand will expand into what will appear (to the user) as
multiple operands separated with a ','.
This makes the task of styling more complex, all these different
components need to by styled differently, so we need to get the
styling information out of aarch64_print_operand in some way.
The solution that I propose here is similar to the solution that I
used for the i386 disassembler.
Currently, aarch64_print_operand uses snprintf to write the operand
text into a buffer provided by the caller.
What I propose is that we pass an extra argument to the
aarch64_print_operand function, this argument will be a structure, the
structure contains a callback function and some state.
When aarch64_print_operand needs to format part of its output this can
be done by using the callback function within the new structure, this
callback returns a string with special embedded markers that indicate
which mode should be used for each piece of text. Back in
aarch64-dis.c we can spot these special style markers and use this to
split the disassembler output up and apply the correct style to each
piece.
To make aarch64-opc.c clearer a series of new static functions have
been added, e.g. 'style_reg', 'style_imm', etc. Each of these
functions formats a piece of text in a different style, 'register' and
'immediate' in this case.
Here's an example taken from aarch64-opc.c of the new functions in
use:
snprintf (buf, size, "[%s, %s]!",
style_reg (styler, base),
style_imm (styler, "#%d", opnd->addr.offset.imm));
The aarch64_print_operand function is also called from the assembler
to aid in printing diagnostic messages. Right now I have no plans to
add styling to the assembler output, and so, the callback function
used in the assembler ignores the styling information and just returns
an plain string.
I've used the source files in gas/testsuite/gas/aarch64/ for testing,
and have manually gone through and checked that the styling looks
reasonable, however, I'm not an AArch64 expert, so it is possible that
the odd piece is styled incorrectly. Please point out any mistakes
I've made.
With objdump disassembler color turned off, there should be no change
in the output after this commit.
