In the legacy space, if both the 66 prefix and REX.W=1 are present, the
REX.W=1 takes precedence and makes OSIZE=64b. EVEX map 4 inherits this
convention, with EVEX.pp=01 and EVEX.W playing the roles of the 66
prefix and REX.W. So if EVEX.pp=00, the OSIZE can only be 64b or 32b,
depending on whether EVEX.W=1 or not. But if EVEX.pp=01, then OSIZE is
either 64b or 16b depending on whether EVEX.W=1 or not.
Since `raw_string_ostream` doesn't own the string buffer, it is
desirable (in terms of memory safety) for users to directly reference
the string buffer rather than use `raw_string_ostream::str()`.
Work towards TODO item to remove `raw_string_ostream::str()`.
PUSH2 and POP2 are two new instructions for (respectively)
pushing/popping 2 GPRs at a time to/from
the stack. The opcodes of PUSH2 and POP2 are those of “PUSH r/m” and
“POP r/m” from legacy map 0, but we
require ModRM.Mod = 3 in order to disallow memory operand.
The 1-bit Push-Pop Acceleration hint described in #73092 applies to
PUSH2/POP2 too, then we have PUSH2P/POP2P.
For AT&T syntax, PUSH2[P] pushes the registers from right to left onto
the stack. POP2[P] pops the stack to registers from right to left. Intel
syntax has the opposite order - from left to right.
The assembly syntax is aligned with GCC & binutils
https://gcc.gnu.org/pipermail/gcc-patches/2023-November/637718.html
JMPABS is a 64-bit only ISA extension, and acts as a near-direct branch
with an absolute target. The 64-bit immediate operand is treated an as
absolute effective address, which is subject to canonicality checks. It
is in legacy map 0 and requires REX2 prefix with `REX2.M0=0` and
`REX2.W=0`. All other REX2 payload bits are ignored.
blog: https://kanrobert.github.io/rfc/All-about-APX-JMPABS/
This patch
1. Extends `ExplicitVEXPrefix` to `ExplicitOpPrefix` for instrcutions
requires explicit `REX2` or `EVEX`
2. Adds `ATTR_REX2` and `IC_64BIT_REX2` to put `JMPABS` , `MOV EAX,
moffs32` in different tables to avoid opcode conflict
NOTE:
1. `ExplicitREX2Prefix` can be reused by the following PUSHP/POPP
instructions.
2. `ExplicitEVEXPrefix` will be used by the instructions promoted to
EVEX space for EGPR.
`llvm` and downstream internal callers no longer use `array_lengthof`, so drop
the include everywhere.
Differential Revision: https://reviews.llvm.org/D133600
LLVM contains a helpful function for getting the size of a C-style
array: `llvm::array_lengthof`. This is useful prior to C++17, but not as
helpful for C++17 or later: `std::size` already has support for C-style
arrays.
Change call sites to use `std::size` instead.
Differential Revision: https://reviews.llvm.org/D133429
This reverts the functional changes of D103427 but keeps its tests, and
and reimplements the functionality by reusing the existing 32-bit
MASKMOVDQU and VMASKMOVDQU instructions as suggested by skan in review.
These instructions were previously predicated on Not64BitMode. This
reimplementation restores the disassembly of a class of instructions,
which will see a test added in followup patch D122449.
These instructions are in 64-bit mode special cased in
X86MCInstLower::Lower, because we use flags with one meaning for subtly
different things: we have an AdSize32 class which indicates both that
the instruction needs a 0x67 prefix and that the text form of the
instruction implies a 0x67 prefix. These instructions are special in
needing a 0x67 prefix but having a text form that does *not* imply a
0x67 prefix, so we encode this in MCInst as an instruction that has an
explicit address size override.
Note that originally VMASKMOVDQU64 was special cased to be excluded from
disassembly, as we cannot distinguish between VMASKMOVDQU and
VMASKMOVDQU64 and rely on the fact that these are indistinguishable, or
close enough to it, at the MCInst level that it does not matter which we
use. Because VMASKMOVDQU now receives special casing, even though it
does not make a difference in the current implementation, as a
precaution VMASKMOVDQU is excluded from disassembly rather than
VMASKMOVDQU64.
Reviewed By: RKSimon, skan
Differential Revision: https://reviews.llvm.org/D122540
Based on the output of include-what-you-use.
It's an utility directory, so no much impact on other code areas.
clang++ -E -Iinclude -I../llvm/include ../llvm/utils/TableGen/*.cpp -std=c++14 -fno-rtti -fno-exceptions | wc -l
before: 4327274
after: 4316190
Related discourse thread: https://llvm.discourse.group/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D118466
This reverts commit ef8206320769ad31422a803a0d6de6077fd231d2.
- It conflicts with the existing llvm::size in STLExtras, which will now
never be called.
- Calling it without llvm:: breaks C++17 compat
The maskmovdqu instruction is an odd one: it has a 32-bit and a 64-bit
variant, the former using EDI, the latter RDI, but the use of the
register is implicit. In 64-bit mode, a 0x67 prefix can be used to get
the version using EDI, but there is no way to express this in
assembly in a single instruction, the only way is with an explicit
addr32.
This change adds support for the instruction. When generating assembly
text, that explicit addr32 will be added. When not generating assembly
text, it will be kept as a single instruction and will be emitted with
that 0x67 prefix. When parsing assembly text, it will be re-parsed as
ADDR32 followed by MASKMOVDQU64, which still results in the correct
bytes when converted to machine code.
The same applies to vmaskmovdqu as well.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D103427
In x86Disassembler{OneByte,TwoByte,...}Codes,
"/* EmptyTable */" is very common. Omitting it saves lots of space.
Also, there is no need to display a table entry in multiple lines.
It is also common that the whole OpcodeDecision is { MODRM_ONEENTRY, 0}.
Make use of zero-initialization.
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
llvm-svn: 369013
Merging the two bits shrinks the context table from 16384 bytes to 8192 bytes.
Remove the ATTRIBUTE_BITS macro and just create an enum directly. Then fix the ATTR_max define to be 8192 to reflect the table size so we stop hardcoding it separately.
llvm-svn: 363330
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
