The former two are unused anyway. And having such constants isn't very
helpful either, when they live in a place where updating the register
table wouldn't even allow noticing the need to adjust these constants.
st(1) ... st(7) will never be looked up in the hash table, so there's no
point inserting the entries. It's also not really necessary to do a 2nd
hash lookup after parsing the register number, nor is there a real
reason for having both st and st(0) entries. Plus we can easily do away
with the need for st to be first in the table.
Now that all base opcodes are only at most 2 bytes in size, shrink its
template field to just as much. By also shrinking extension_opcode and
operands to just what they really need, we can free up an entire 32-bit
slot (plus 4 left bits past the bitfields themselves).
At present this alters sizeof(struct insn_template) only for 32-bit
builds. In 64-bit builds it instead leaves a padding hole that will
allow to buffer future growth of other fields (opcode_modifier,
cpu_flags, operand_types[]).
In the majority of cases we can easily determine the length from the
encoding, irrespective of whether a prefix is specified there as well.
We further don't even need to record the value in the table entries, as
it's easy enough to determine it (without any guesswork, unless an insn
with major opcode 00 appeared that requires a 2nd opcode byte to be
specified explicitly) when installing the chosen template for further
processing.
Should an encoding appear which
- has a major opcode byte of 66, F3, or F2,
- requires a 2nd opcode byte to be specified explicitly,
- doesn't have a mandatory prefix
we'd need to convert all templates presently encoding a mandatory prefix
this way to the Prefix_0X<nn> model to eliminate the respective guessing
i386-gen does.
This is in preparation of opcode_length going away as a field in the
templates. Identify pseudo prefixes by a base opcode of zero instead:
No real prefix has an opcode of zero. This at the same time allows
dropping a curious special case from i386-gen.
Since most attributes are identical for all pseudo prefixes, take the
opportunity and also template them.
In preparation to use PREFIX_0X<nn> attributes also in VEX/XOP/EVEX
encoding templates, renumber the pseudo-enumerators such that their
values can then also be used directly in the respective prefix bit
fields.
Commit 8b65b8953a ("x86: Remove the prefix byte from non-VEX/EVEX
base_opcode") used the opcodeprefix field for two distinct purposes. In
preparation of having VEX/XOP/EVEX and non-VEX templates become similar
in the representatioon of both encoding space and opcode prefixes, split
the field to have a separate one holding an insn's opcode space.
RepPrefixOk, HLEPrefixOk, and NoTrackPrefixOk can't be specified
together, so can share an enum-like field. IsLockable can be inferred
from HLE setting and hence only needs specifying when neither of them
is present.
Rename VexOpcode to OpcodePrefix so that OpcodePrefix can be used for
regular encoding prefix.
gas/
* config/tc-i386.c (build_vex_prefix): Replace vexopcode with
opcodeprefix.
(build_evex_prefix): Likewise.
(is_any_vex_encoding): Don't check vexopcode.
(output_insn): Handle opcodeprefix.
opcodes/
* i386-gen.c (opcode_modifiers): Replace VexOpcode with
OpcodePrefix.
* i386-opc.h (VexOpcode): Renamed to ...
(OpcodePrefix): This.
(PREFIX_NONE): New.
(PREFIX_0X66): Likewise.
(PREFIX_0XF2): Likewise.
(PREFIX_0XF3): Likewise.
* i386-opc.tbl (Prefix_0X66): New.
(Prefix_0XF2): Likewise.
(Prefix_0XF3): Likewise.
Replace VexOpcode= with OpcodePrefix=. Use Prefix_0X66 on xorpd.
Use Prefix_0XF3 on cvtdq2pd. Use Prefix_0XF2 on cvtpd2dq.
* i386-tbl.h: Regenerated.
We check register-only source operand to decide if two source operands of
VEX encoded instructions should be swapped. But source operands in AMX
instructions with two source operands swapped are all register-only
operand. Add SwapSources to indicate two source operands should be
swapped.
gas/
* config/tc-i386.c (build_modrm_byte): Check vexswapsources to
swap two source operands.
opcodes/
* i386-gen.c (opcode_modifiers): Add VexSwapSources.
* i386-opc.h (VexSwapSources): New.
(i386_opcode_modifier): Add vexswapsources.
* i386-opc.tbl: Add VexSwapSources to BMI2 and BMI instructions
with two source operands swapped.
* i386-tbl.h: Regenerated.
Rename VecSIB to SIB to support Intel Advanced Matrix Extensions which
introduces instructions with a mandatory SIB byte which isn't a vector
SIB (VSIB).
gas/
* config/tc-i386.c (check_VecOperands): Replace vecsib with sib.
Replace VecSIB128, VecSIB256 and VecSIB512 with VECSIB128,
VECSIB256 and VECSIB512, respectively.
(build_modrm_byte): Replace vecsib with sib.
opcodes/
* i386-gen.c (opcode_modifiers): Replace VecSIB with SIB.
(VecSIB128): Renamed to ...
(VECSIB128): This.
(VecSIB256): Renamed to ...
(VECSIB256): This.
(VecSIB512): Renamed to ...
(VECSIB512): This.
(VecSIB): Renamed to ...
(SIB): This.
(i386_opcode_modifier): Replace vecsib with sib.
* i386-opc.tbl (VexSIB128): New.
(VecSIB256): Likewise.
(VecSIB512): Likewise.
Replace VecSIB=1, VecSIB=2 and VecSIB=3 with VexSIB128, VecSIB256
and VecSIB512, respectively.
Register aliases (created e.g. via .set) check their target register at
the time of creation of the alias. While this makes sense, it's not
enough: The underlying register must also be "visible" at the time of
use. Wrong use of such aliases would lead to internal errors in e.g.
add_prefix() or build_modrm_byte().
Split the checking part of parse_real_register() into a new helper
function and use it also from the latter part of parse_register() (at
the same time replacing a minor open coded part of it).
Since parse_register() returning NULL already has a meaning, a fake new
"bad register" indicator gets added, which all callers need to check
for.
It is almost entirely redundant with Size64, and the sole case (CRC32)
where direct replacement isn't possible can easily be taken care of in
another way.
AMD ABM has 2 instructions: popcnt and lzcnt. ABM CPUID feature bit has
been reused for lzcnt and a POPCNT CPUID feature bit is added for popcnt
which used to be the part of SSE4.2. This patch removes CpuABM and adds
CpuPOPCNT. It changes ABM to enable both lzcnt and popcnt, changes SSE4.2
to also enable popcnt.
gas/
* config/tc-i386.c (cpu_arch): Add .popcnt.
* doc/c-i386.texi: Remove abm and .abm. Add popcnt and .popcnt.
Add a tab before @samp{.sse4a}.
opcodes/
* i386-gen.c (cpu_flag_init): Replace CpuABM with
CpuLZCNT|CpuPOPCNT. Add CpuPOPCNT to CPU_SSE4_2_FLAGS. Add
CPU_POPCNT_FLAGS.
(cpu_flags): Remove CpuABM. Add CpuPOPCNT.
* i386-opc.h (CpuABM): Removed.
(CpuPOPCNT): New.
(i386_cpu_flags): Remove cpuabm. Add cpupopcnt.
* i386-opc.tbl: Replace CpuABM|CpuSSE4_2 with CpuPOPCNT on
popcnt. Remove CpuABM from lzcnt.
* i386-init.h: Regenerated.
* i386-tbl.h: Likewise.
Commit d835a58baa disabled sysenter/sysenter in 64-bit mode by
default. By default, assembler should accept common, Intel64 only
and AMD64 ISAs since there are no conflicts.
gas/
PR gas/25516
* config/tc-i386.c (intel64): Renamed to ...
(isa64): This.
(match_template): Accept Intel64 only instruction by default.
(i386_displacement): Updated.
(md_parse_option): Updated.
* c-i386.texi: Update -mamd64/-mintel64 documentation.
* testsuite/gas/i386/i386.exp: Run x86-64-sysenter. Pass
-mamd64 to x86-64-sysenter-amd.
* testsuite/gas/i386/x86-64-sysenter.d: New file.
opcodes/
PR gas/25516
* i386-gen.c (opcode_modifiers): Replace AMD64 and Intel64
with ISA64.
* i386-opc.h (AMD64): Removed.
(Intel64): Likewose.
(AMD64): New.
(INTEL64): Likewise.
(INTEL64ONLY): Likewise.
(i386_opcode_modifier): Replace amd64 and intel64 with isa64.
* i386-opc.tbl (Amd64): New.
(Intel64): Likewise.
(Intel64Only): Likewise.
Replace AMD64 with Amd64. Update sysenter/sysenter with
Cpu64 and Intel64Only. Remove AMD64 from sysenter/sysenter.
* i386-tbl.h: Regenerated.
... instead of an operand one. Which operand it applies to can be
determined from other operand properties, but as it turns out the only
place it is actually used at doesn't even need further qualification.
EsSeg (a per-operand bit) is used with IsString (a per-insn attribute)
only. Extend the attribute to 2 bits, thus allowing to encode
- not a string insn,
- string insn with neither operand requiring use of %es:,
- string insn with 1st operand requiring use of %es:,
- string insn with 2nd operand requiring use of %es:,
which covers all possible cases, allowing to drop EsSeg.
The (transient) need to comment out the OTUnused #define did uncover an
oversight in the earlier OTMax -> OTNum conversion, which is being taken
care of here.
Drop the remaining instances left in place by commit c3949f432f ("x86:
limit ImmExt abuse), now that we have a way to specify specific GPRs.
Take the opportunity and also introduce proper 16-bit forms of
applicable SVME insns as well as 1-operand forms of CLZERO.
Special register "class" instances can't be combined with one another
(neither in templates nor in register entries), and hence it is not a
good use of resources (memory as well as execution time) to represent
them as individual bits of a bit field.
Furthermore the generalization becoming possible will allow
improvements to the handling of insns accepting only individual
registers as their operands.
Many operand types, in particular the various kinds of registers, can't
be combined with one another (neither in templates nor in register
entries), and hence it is not a good use of resources (memory as well as
execution time) to represent them as individual bits of a bit field.
The flag is used to indicate opcodes which can be switched between byte
and word/dword/qword forms (in a "canonical" way). Obviously it's quite
odd then to see it on insns not allowing for byte operands in the first
place. As a result the opcode bytes need to be adjusted accordingly,
which includes comparisons done in optimize_encoding().
To make re-introduction of such issues less likely have i386-gen
diagnose it (in a generally non-fatal way for now).
This was supposed to also be removed by c48dadc9a8 ('x86: drop "mem"
operand type attribute'). It's odd enough that this hasn't caused
build issues, considering the careful use of OTunused (apparently to
avoid "missing initializer" warnings).
To avoid such happening again introduce compile time consistency
checks.
... instead of an operand type bit: It's an insn property, not an
operand one. There's just one actual change to be made to the
templates: Most are now required to have the (unswapped) destination go
into ModR/M.rm, so VMOVD template needs its opcode adjusted accordingly
and its operands swapped. {,V}MOVS{S,D}, otoh, are left alone in this
regard, as otherwise generated code would differ from what we've been
producing so far (which I don't think is wanted).
Take the opportunity and add a missing IgnoreSize to pextrb (leading to
an error in 16-bit mode), and take the liberty to once again drop stray
IgnoreSize attributes from lines changed and neighboring related ones.
