so that subclasses can provide the appropriate MCAsmInfo to print
MCExpr objects.
At present, llvm/utils/TableGen/AsmMatcherEmitter.cpp constucts a
generic MCAsmInfo.
GNU Assembler supports symbol reassignment via .set, .equ, or =.
However, LLVM's integrated assembler only allows reassignment for
MCConstantExpr cases, as it struggles with scenarios like:
```
.data
.set x, 0
.long x // reference the first instance
x = .-.data
.long x // reference the second instance
.set x,.-.data
.long x // reference the third instance
```
Between two assignments binds, we cannot ensure that a reference binds
to the earlier assignment. We use MCSymbol::IsUsed and other conditions
to reject potentially unsafe reassignments, but certain MCConstantExpr
uses could be unsafe as well.
This patch enables reassignment by cloning the symbol upon reassignment
and updating the symbol table. Existing references to the original
symbol remain unchanged, and the original symbol is excluded from the
emitted symbol table.
These are identified by misc-include-cleaner. I've filtered out those
that break builds. Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.
Matches ML.EXE by translating "ret" instructions inside a `PROC FAR` to "retf", and automatically prepending a `push cs` to all near calls to a `PROC FAR`.
Due to the known limitations of .set reassignment (see
https://sourceware.org/PR288), we use diagnostics to reject patterns
that could lead to errors (ae7ac010594f693fdf7b3ab879e196428d961e75 2009-06)).
This code gets refined multiple times, see:
* 9b4a824217f1fe23f83045afe7521acb791bc2d0 (2010-05) `IsUsedInExpr`
* 46c79ef1132607aead144dfda0f26aa8b065214f (2010-11) renamed `IsUsedInExpr` to `IsUsed`
The related `SetUsed` bit seems unnecessary nowadays.
https://reviews.llvm.org/D24047 added `IsAtStartOfStatement` to
MCAsmLexer, while its subclass AsmLexer had a variable of the same name.
The assignment in `UnLex` is unnecessary, which is now removed.
60b403e75cd25a0c76aaaf4e6b176923acf49443 (2019) named the result
`parseStatement` `Parsed`. `HasError` is a clearer name.
A relocation expression might be used in an immediate operand or a
memory offset. https://reviews.llvm.org/D23110 , which intended to
generalize chained relocation operators (%hi(%neg(%gp_rel(x)))),
inappropriated introduced intrusive changes to the generic code. This
patch drops the intrusive changes and significantly simplifies the code.
The new style is similar to pre-D23110 but much cleaner.
Some weird expressions allowed by gas are not supported for simplicity,
e.g. "%lo foo", "(%lo(foo))", "%lo(foo)+1".
"(%lo(foo))", while previously parsed, is not used in practice.
"%lo(foo)+1" and "%lo(2*4)+foo" were previously parsed but would lead to
an error anyway as the expression is not relocatable
(`evaluateSymbolicAdd` does not fold the Add when RefKind are
different).
This call was made unsafe recently, but was not fixed in
db48f1a1764023f8efeb055e343b967d1eb37d19 (the commit that fixed the
parallel code in AsmParser.cpp).
Fixes#123189
These specify that the value of the given register in the previous frame
is the CFA plus some offset. This isn't very common but can be necessary
if the original value is normally reconstructed from the stack/frame
pointer instead of being saved on the stack and reloaded from there.
It is almost always simpler to use {} instead of std::nullopt to
initialize an empty ArrayRef. This patch changes all occurrences I could
find in LLVM itself. In future the ArrayRef(std::nullopt_t) constructor
could be deprecated or removed.
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 comment to remove `raw_string_ostream::str()`.
Previously, a symbol insertion requires (at least) three hash table
operations:
- Lookup/create entry in Symbols (main symbol table)
- Lookup NextUniqueID to deduplicate identical temporary labels
- Add entry to UsedNames, which is also used to serve as storage for the
symbol name in the MCSymbol.
All three lookups are done with the same name, so combining these into a
single table reduces the number of lookups to one. Thus, a pointer to a
symbol table entry can be passed to createSymbol to avoid a duplicate
lookup of the same name.
The new symbol table entry value is placed in a separate header to avoid
including MCContext in MCSymbol or vice versa.
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
This finishes the work of replacing OperandMatchResultTy with
ParseStatus, started in D154101.
As a drive-by change, rename some RegNo variables to just Reg
(a leftover from the days when RegNo had 'unsigned' type).
Conventionally, parsing methods return false on success and true on
error. However, directive parsing methods need a third state: the
directive is not target specific. AsmParser::parseStatement detected
this case by using a fragile heuristic: if the target parser did not
consume any tokens, the directive is assumed to be not target-specific.
Some targets fail to follow the convention: they return success after
emitting an error or do not consume the entire line and return failure
on successful parsing. This was partially worked around by checking for
pending errors in parseStatement.
This patch tries to improve the situation by introducing parseDirective
method that returns ParseStatus -- three-state class. The new method
should eventually replace the old one returning bool.
ParseStatus is intentionally implicitly constructible from bool to allow
uses like `return Error(Loc, "message")`. It also has a potential to
replace OperandMatchResulTy as it is more convenient to use due to the
implicit construction from bool and more type safe.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D154101
to help debug and report better diagnostics for functions like
relaxDwarfCallFrameFragment (D153167).
In MCStreamer, some emitCFI* functions already take a SMLoc argument. Add a
SMLoc argument to the remaining functions that generate a MCCFIInstruction.
These codes deleted are dead code, we never go into it.
1. In AggressiveAntiDepBreaker.cpp, have assert AntiDepReg != 0.
2. IfConversion.cpp, Kind can only be one unique value, so isFalse && isRev
can never be true.
3. DAGCombiner.cpp, at line 3675, we have considered the condition like
```
// fold (sub x, c) -> (add x, -c)
if (N1C) {
return DAG.getNode(ISD::ADD, DL, VT, N0,
DAG.getConstant(-N1C->getAPIntValue(), DL, VT));
}
```
4. ScheduleDAGSDNodes.cpp, we have Latency > 1 at line 663
5. MasmParser.cpp, code exists in a switch-case block which decided by
the value FirstTokenKind, at line 1621, FirstTokenKind could only be
one of AsmToken::Dollar, AsmToken::At and AsmToken::Identifier.
Reviewed By: skan
Differential Revision: https://reviews.llvm.org/D148610
Summary: For functions that accept an rvalue reference type
parameter, use move to avoid copying the parameter.
These were found when implementing CppCoreGuideline F.18 in
clang-tidy.
Committed on behalf of ccotter (Chris Cotter)
Reviewers: Michael137 thieta
Differential Revision: https://reviews.llvm.org/D142825
'{', '}' and (conditionally) '*' were allowed at the start of a
statement. This behavior was copied from AsmParser, where they were
added to support Hexagon bundles (braces) and BFP memory instructions
(the star).
MASM dialect is x86-specific and does not allow these symbols to be
used at the beginning of an instruction.
Worth noting that '{' is a valid first character in AT&T syntax
(e.g. "{vex} vpmadd52huq ..."); MASM variant is to omit the braces.
Reviewed By: epastor
Differential Revision: https://reviews.llvm.org/D142321
The new methods return a range for easier iteration. Use them everywhere
instead of getImplicitUses, getNumImplicitUses, getImplicitDefs and
getNumImplicitDefs. A future patch will remove the old methods.
In some use cases the new methods are less efficient because they always
have to scan the whole uses/defs array to count its length, but that
will be fixed in a future patch by storing the number of implicit
uses/defs explicitly in MCInstrDesc. At that point there will be no need
to 0-terminate the arrays.
Differential Revision: https://reviews.llvm.org/D142215
Change MCInstrDesc::operands to return an ArrayRef so we can easily use
it everywhere instead of the (IMHO ugly) opInfo_begin and opInfo_end.
A future patch will remove opInfo_begin and opInfo_end.
Also use it instead of raw access to the OpInfo pointer. A future patch
will remove this pointer.
Differential Revision: https://reviews.llvm.org/D142213
