On some architectures such as Arm and X86 the encoding for a nop may
change depending on the subtarget in operation at the time of
encoding. This change replaces the per module MCSubtargetInfo retained
by the targets AsmBackend in favour of passing through the local
MCSubtargetInfo in operation at the time.
On Arm using the architectural NOP instruction can have a performance
benefit on some implementations.
For Arm I've deleted the copy of the AsmBackend's MCSubtargetInfo to
limit the chances of this causing problems in the future. I've not
done this for other targets such as X86 as there is more frequent use
of the MCSubtargetInfo and it looks to be for stable properties that
we would not expect to vary per function.
This change required threading STI through MCNopsFragment and
MCBoundaryAlignFragment.
I've attempted to take into account the in tree experimental backends.
Differential Revision: https://reviews.llvm.org/D45962
In preparation for passing the MCSubtargetInfo (STI) through to writeNops
so that it can use the STI in operation at the time, we need to record the
STI in operation when a MCAlignFragment may write nops as padding. The
STI is currently unused, a further patch will pass it through to
writeNops.
There are many places that can create an MCAlignFragment, in most cases
we can find out the STI in operation at the time. In a few places this
isn't possible as we are in initialisation or finalisation, or are
emitting constant pools. When possible I've tried to find the most
appropriate existing fragment to obtain the STI from, when none is
available use the per module STI.
For constant pools we don't actually need to use EmitCodeAlign as the
constant pools are data anyway so falling through into it via an
executable NOP is no better than falling through into data padding.
This is a prerequisite for D45962 which uses the STI to emit the
appropriate NOP for the STI. Which can differ per fragment.
Note that involves an interface change to InitSections. It is now
called initSections and requires a SubtargetInfo as a parameter.
Differential Revision: https://reviews.llvm.org/D45961
ML64.EXE applies implicit RIP-relative addressing only to memory references that include a named-variable reference.
Reviewed By: mstorsjo
Differential Revision: https://reviews.llvm.org/D105372
This is a mechanical change. This actually also renames the
similarly named methods in the SmallString class, however these
methods don't seem to be used outside of the llvm subproject, so
this doesn't break building of the rest of the monorepo.
Handle "short" in a case-insensitive fashion in MASM.
Required to correctly parse z_Windows_NT-586_asm.asm from the OpenMP runtime.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D104195
Did not correctly handle "jecxz short <address>".
Discovered while working on LLVM-ML; shows up in z_Windows_NT-586_asm.asm from the OpenMP runtime
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D104194
`X86AsmParser::ParseIntelExpression` has a while loop. In the body,
calls to MCAsmLexer::UnLex can force a reallocation in the MCAsmLexer's
`CurToken` SmallVector, invalidating saved references to
`MCAsmLexer::getTok()`.
`const MCAsmToken &Tok` is such a saved reference, and this moves it
from outside the while loop to inside the body, fixing a
use-after-realloc.
`Tok` will still be reused across calls to `Lex()`, each of which
effectively destroys and constructs the pointed-to token. I'm a bit
skeptical of this usage pattern, but it seems broadly used in the
X86AsmParser (and others) so I'm leaving it alone (for now).
Somehow this bug was exposed by https://reviews.llvm.org/D94739,
resulting in test failures in dot-operator related tests in
llvm/test/tools/llvm-ml. I suspect the exposure path is related to
optimizer changes from splitting up the grow operation, but I haven't
dug all the way in. Regardless, there are already tests in tree that
cover this; they might fail consistently if we added ASan
instrumentation to SmallVector.
Differential Revision: https://reviews.llvm.org/D95112
X86 allows for the "addr32" and "addr16" address size override prefixes.
Also, these and the segment override prefixes should be recognized as
valid prefixes.
Differential Revision: https://reviews.llvm.org/D94726
For MASM syntax, the prefixes are not enclosed in braces.
The assembly code should like:
"evex vcvtps2pd xmm0, xmm1"
Differential Revision: https://reviews.llvm.org/D90441
MASM interprets strings in expression contexts as integers expressed in big-endian base-256, treating each character as its ASCII representation.
This completely eliminates the need to special-case single-character strings.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D90788
Allow single-quoted strings and double-quoted character values, as well as doubled-quote escaping.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89731
This patch mainly made the following changes:
1. Support AVX-VNNI instructions;
2. Introduce ExplicitVEXPrefix flag so that vpdpbusd/vpdpbusds/vpdpbusds/vpdpbusds instructions only use vex-encoding when user explicity add {vex} prefix.
Differential Revision: https://reviews.llvm.org/D89105
For now, we lost the encoding information if we using inline assembly.
The encoding for the inline assembly will keep default even if we add
the vex/evex prefix.
Differential Revision: https://reviews.llvm.org/D90009
PR47632
This allows MC to match `data32 ...` as one instruction instead of two (data32 without insn + insn).
The compatibility with GNU as improves: `data32 ljmp` will be matched as ljmpl.
`data32 lgdt 4(%eax)` will be matched as `lgdtl` (prefixes: 0x67 0x66, instead
of 0x66 0x67).
GNU as supports many other `data32 *w` as `*l`. We currently just hard code
`data32 callw` and `data32 ljmpw`. Generalizing the suffix replacement is
tricky and requires a think about the "bwlq" appending suffix rules in MatchAndEmitATTInstruction.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D88772
MASM allows arbitrary whitespace around the Intel dot operator, especially when used for struct field lookup
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D88450
Add support for .radix directive, and radix specifiers [yY] (binary), [oOqQ] (octal), and [tT] (decimal).
Also, when lexing MASM integers, require radix specifier; MASM requires that all literals without a radix specifier be treated as in the default radix. (e.g., 0100 = 100)
Relanding D87400, now with fewer ms-inline-asm tests broken!
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D88337
Used by kexec-tools (PR46942)
In GNU as, tc-i386.c:output_jump uses 4-byte immediate if a data32 prefix is present.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D88137
Add support for .radix directive, and radix specifiers [yY] (binary), [oOqQ] (octal), and [tT] (decimal).
Also, when lexing MASM integers, require radix specifier; MASM requires that all literals without a radix specifier be treated as in the default radix. (e.g., 0100 = 100)
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D87400
This is an older syntax than the {disp32} and {disp8} pseudo
prefixes that were added a few weeks ago. We can reuse most of
the support for that to support .d32 and .d8 as well.
These prefixes should override the default behavior and force a larger immediate size. I don't believe gas issues any warning if you use {disp8} when a 32-bit displacement is already required. And this patch doesn't either.
This completes the {disp8} and {disp32} support from PR46650.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D84793
Similar to what was recently done to ParseATTOperand. Make
ParseIntelOperand directly responsible for adding to the operand
vector instead of returning the operand. Return a bool for error.
Remove ErrorOperand since it is no longer used.
We parse .arch so that some `.arch i386; .code32` code can assemble. It seems
that X86AsmParser does not do a good job tracking what features are needed to
assemble instructions. GNU as's x86 port supports a very wide range of .arch
operands. Ignore the operand for now.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D84900
Continue the change made to ParseATTOperand to take the vector by
reference. Let ParseMemOperand add its memory operand to the
vector and just return true/false to indicate error.
A '*' after the segment is equivalent to a '*' before the segment register. To make the AsmMatcher table work we need to place the '*' token into the operand vector before the full memory operand. To accomplish this I've modified some portions of operand parsing to expose the operand vector to ParseATTOperand so that the token can be pushed to the vector after parsing the segment register and before creating the memory operand using that segment register.
Fixes PR46879
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D84895
By default we pick a 1 byte displacement and let relaxation enlarge it if necessary. The GNU assembler supports a pseudo prefix to basically pre-relax the instruction the larger size.
I plan to add {disp8} and {disp32} support for memory operands in another patch which is why I've included the parsing code and enum for {disp8} pseudo prefix as well.
Reviewed By: echristo
Differential Revision: https://reviews.llvm.org/D84709
Summary:
Add support for MASM STRUCT casting field accessors: (<TYPE> PTR <value>).<field>
Since these are operands, we add them to X86AsmParser. If/when we extend MASM support to other architectures (e.g., ARM), we will need similar changes there as well.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D83346
Xiang1 Zhang