APX assembly syntax recommendations:
https://cdrdv2.intel.com/v1/dl/getContent/817241
NOTE:
The change in llvm/tools/llvm-exegesis/lib/X86/Target.cpp is for test
LLVM ::
tools/llvm-exegesis/X86/latency/latency-SETCCr-cond-codes-sweep.s
For `SETcc`, llvm-exegesis would randomly choose 1 other instruction to
test with `SETcc`, after selecting the instruction, llvm-exegesis would
check if the operand is initialized and valid, if not
`randomizeTargetMCOperand` would choose a value for invalid operand, it
misses support for condition code operand, which cause the flaky failure
after `CCMP` supported.
llvm-exegesis can choose `CCMP` without specifying ccmp feature b/c it
use `MCSubtarget` and only16/32/64 bit is considered.
llvm-exegesis doesn't choose other instructions b/c requirement in
`hasAliasingRegistersThrough`: the instruction should use GPR (defined
by `SETcc`) and define `EFLAGS` (used by `SETcc`).
The mnemonic of CMPCCXADD is `cmp${cond}xadd` and the condition code
is in the middle of mnemonic. When generating the function name for
CMPCCXADD, the substring `xadd` should be kept.
Before this patch, the name is `isCMPCC`. After this patch, the name
is `isCMPCCXADD`.
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.
Movdir64b is special for its mem operand, 67 prefex can not only modify its add size,
so it's mem base and index reg should be the same type as source reg, such as
movdir64b (%rdx), rcx, and could not be movdir64b (%edx), rcx.
Now llvm-mc can encode the asm 'movdir64b (%edx), rcx' but the result is the same as
'movdir64b (%edx), ecx', which offend users' intention, while gcc will object this
action and give a warning.
I add 3 new mem descriptions to let llvm-mc to report the same error.
Reviewed By: skan, craig.topper
Differential Revision: https://reviews.llvm.org/D145893
Set Size appropriately in operand definitions and query it for dumping memory
operand size table `getMemOperandSize` (follow-up use D126116) and
`X86Disassembler::getMemOperandSize`.
Excerpt from a produced `getMemOperandSize` table for X86:
```
static int getMemOperandSize(int OpType) {
switch (OpType) {
default: return 0;
case OpTypes::i8mem:
case OpTypes::i8mem_NOREX:
return 8;
case OpTypes::f16mem:
case OpTypes::i16mem:
return 16;
case OpTypes::f32mem:
case OpTypes::i32mem:
return 32;
...
```
Reviewed By: skan, pengfei
Differential Revision: https://reviews.llvm.org/D127787
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
1. Add comments to explain why we set `isAsmParserOnly` for XACQUIRE and XRELEASE
2. Check `X86Inst` in the constructor of `RecognizableInstrBase` so that
we can avoid the case where one of it's field is not initialized but
accessed by user. (e.g. in X86EVEX2VEXTablesEmitter.cpp)
3. Move `Rec` from `RecognizableInstrBase` to `RecognizableInstr` to reduce
size of `RecognizableInstrBase`
4. Remove out-of-date comments for shouldBeEmitted() (filter() was removed)
5. Add a basic field `IsAsmParserOnly` and remove the field
`ShouldBeEmitted` b/c we can deduce it w/ little overhead
In fact, an instruction can not be emitted to disassemble table when
`isAsmParserOnly` is true, so `isAsmParserOnly=true` implies
`ShouldBeEmitted=false`.
We check `isAsmParserOnly` in X86FoldTablesEmitter.cpp at a early stage
b/c none of them is foldable.
This change fixes the code violations flagged in AMD compute CodeQL scan -
Query Description: "Comparisons between types of different widths in a loop condition can cause the loop to behave unexpectedly."
Differential Revision: https://reviews.llvm.org/D120355
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 is also a bug. The VK[1/2/4/8/16]PAIR here should be VK[1/2/4/8/16]Pair which has its
custom PrintMethod and ParserMatchClass. However we don't have any instructions using vvvv
and ModR/M.REG field so this issue is not exposed.
Differential Revision: https://reviews.llvm.org/D109564
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
These are documented as using modrm byte of 0xe8, 0xf0, and 0xf8
respectively. But hardware ignore bits 2:0. So 0xe9-0xef is treated
the same as 0xe8. Similar for the other two.
Fixing this required adding 8 new formats to the X86 instructions
to convey this information. Could have gotten away with 3, but
adding all 8 made for a more logical conversion from format to
modrm encoding.
I renumbered the format encodings to keep the register modrm
formats grouped together.
isPrefix was added to support the patches to align branches.
it relies on a switch over instruction names.
This moves those opcodes to a new format so the information is
tablegen and we can just check for a specific value in some bits
in TSFlags instead.
I've left the other function in place for now so that the
existing patches in phabricator will still work. I'll work with
the owner to get them migrated.
