Summary:
TableGen interprets braces ('{}') in the asm string of instruction aliases as
variants but when defining aliases with literal braces they have to be escaped
to prevent them being removed.
Braces are escaped with '\\', for example:
def FooBraces : InstAlias<"foo \\{$imm\\}", (foo IntOperand:$imm)>;
Although when TableGen is emitting the assembly writer (-gen-asm-writer)
the AsmString that gets emitted is:
AsmString = "foo \{$\x01\}";
In c/c++ braces don't need to be escaped which causes compilation
warnings:
warning: use of non-standard escape character '\{' [-Wpedantic]
This patch fixes the issue by unescaping the flattened alias asm string
in the asm writer, by replacing '\{\}' with '{}'.
Reviewed By: hfinkel
Differential Revision: https://reviews.llvm.org/D79991
For context, the proposed RISC-V bit manipulation extension has a subset
of instructions which require one of two SubtargetFeatures to be
enabled, 'zbb' or 'zbp', and there is no defined feature which both of
these can imply to use as a constraint either (see comments in D65649).
AssemblerPredicates allow multiple SubtargetFeatures to be declared in
the "AssemblerCondString" field, separated by commas, and this means
that the two features must both be enabled. There is no equivalent to
say that _either_ feature X or feature Y must be enabled, short of
creating a dummy SubtargetFeature for this purpose and having features X
and Y imply the new feature.
To solve the case where X or Y is needed without adding a new feature,
and to better match a typical TableGen style, this replaces the existing
"AssemblerCondString" with a dag "AssemblerCondDag" which represents the
same information. Two operators are defined for use with
AssemblerCondDag, "all_of", which matches the current behaviour, and
"any_of", which adds the new proposed ORing features functionality.
This was originally proposed in the RFC at
http://lists.llvm.org/pipermail/llvm-dev/2020-February/139138.html
Changes to all current backends are mechanical to support the replaced
functionality, and are NFCI.
At this stage, it is illegal to combine features with ands and ors in a
single AssemblerCondDag. I suspect this case is sufficiently rare that
adding more complex changes to support it are unnecessary.
Differential Revision: https://reviews.llvm.org/D74338
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
This changes the generated (Instr|Asm|Reg|Regclass)Name tables from this
form:
extern const char HexagonInstrNameData[] = {
/* 0 */ 'G', '_', 'F', 'L', 'O', 'G', '1', '0', 0,
/* 9 */ 'E', 'N', 'D', 'L', 'O', 'O', 'P', '0', 0,
/* 18 */ 'V', '6', '_', 'v', 'd', 'd', '0', 0,
/* 26 */ 'P', 'S', '_', 'v', 'd', 'd', '0', 0,
[...]
};
...to this:
extern const char HexagonInstrNameData[] = {
/* 0 */ "G_FLOG10\0"
/* 9 */ "ENDLOOP0\0"
/* 18 */ "V6_vdd0\0"
/* 26 */ "PS_vdd0\0"
[...]
};
This should make debugging and exploration a lot easier for mortals,
while providing a significant compile-time reduction for common compilers.
To avoid issues with low implementation limits, this is disabled by
default for visual studio.
To force output one way or the other, pass
`--long-string-literals=<bool>` to `tablegen`
Reviewers: mstorsjo, rnk
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D73044
A variation of this patch was originally committed in ce23515f5ab011 and
then reverted in e464b31c due to build failures.
This changes the generated (Instr|Asm|Reg|Regclass)Name tables from this
form:
extern const char HexagonInstrNameData[] = {
/* 0 */ 'G', '_', 'F', 'L', 'O', 'G', '1', '0', 0,
/* 9 */ 'E', 'N', 'D', 'L', 'O', 'O', 'P', '0', 0,
/* 18 */ 'V', '6', '_', 'v', 'd', 'd', '0', 0,
/* 26 */ 'P', 'S', '_', 'v', 'd', 'd', '0', 0,
[...]
};
...to this:
extern const char HexagonInstrNameData[] = {
/* 0 */ "G_FLOG10\0"
/* 9 */ "ENDLOOP0\0"
/* 18 */ "V6_vdd0\0"
/* 26 */ "PS_vdd0\0"
[...]
};
This should make debugging and exploration a lot easier for mortals,
while providing a significant compile-time reduction for common compilers.
To avoid issues with low implementation limits, this is disabled by
default for visual studio or when cross-compiling.
To force output one way or the other, pass
`--long-string-literals=<bool>` to `tablegen`
Reviewers: mstorsjo, rnk
Subscribers: llvm-commit
Differential Revision: https://reviews.llvm.org/D73044
Before this change, the *InstPrinter.cpp files of each target where some
of the slowest objects to compile in all of LLVM. See this snippet produced by
ClangBuildAnalyzer:
https://reviews.llvm.org/P8171$96
Search for "InstPrinter", and see that it shows up in a few places.
Tablegen was emitting a large switch containing a sequence of operand checks,
each of which created many conditions and many BBs. Register allocation and
jump threading both did not scale well with such a large repetitive sequence of
basic blocks.
So, this change essentially turns those control flow structures into
data. The previous structure looked like:
switch (Opc) {
case TGT::ADD:
// check alias 1
if (MI->getOperandCount() == N && // check num opnds
MI->getOperand(0).isReg() && // check opnd 0
...
MI->getOperand(1).isImm() && // check opnd 1
AsmString = "foo";
break;
}
// check alias 2
if (...)
...
return false;
The new structure looks like:
OpToPatterns: Sorted table of opcodes mapping to pattern indices.
\->
Patterns: List of patterns. Previous table points to subrange of
patterns to match.
\->
Conds: The if conditions above encoded as a kind and 32-bit value.
See MCInstPrinter.cpp for the details of how the new data structures are
interpreted.
Here are some before and after metrics.
Time to compile AArch64InstPrinter.cpp:
0m29.062s vs. 0m2.203s
size of the obj:
3.9M vs. 676K
size of clang.exe:
97M vs. 96M
I have not benchmarked disassembly performance, but typically
disassemblers are bottlenecked on IO and string processing, not alias
matching, so I'm not sure it's interesting enough to be worth doing.
Reviewers: RKSimon, andreadb, xbolva00, craig.topper
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D70650
Summary:
While working with DagInit's, it's often the case that you expect the
operator to be a reference to a def. This patch adds a wrapper for this
common case to reduce the amount of boilerplate callers need to duplicate
repeatedly.
getOperatorAsDef() returns the record if the DagInit has an operator that is
a DefInit. Otherwise, it prints a fatal error.
There's only a few pre-existing examples in LLVM at the moment and I've
left a few instances of the code this simplifies as they had more specific
error messages than the generic one this produces. I'm going to be using
this a fair bit in my subsequent patches.
Reviewers: bogner, volkan, nhaehnle
Reviewed By: nhaehnle
Subscribers: nhaehnle, hiraditya, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, lenary, s.egerton, pzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68424
llvm-svn: 374101
The --disassembler-options, or -M, are used to customize
the disassembler and affect its output.
The two implemented options allow selecting register names on ARM:
* With -Mreg-names-raw, the disassembler uses rNN for all registers.
* With -Mreg-names-std it prints sp, lr and pc for r13, r14 and r15,
which is the default behavior of llvm-objdump.
Differential Revision: https://reviews.llvm.org/D57680
llvm-svn: 354870
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
When you define an instruction alias as a subclass of InstAlias, you
specify all the MC operands for the instruction it expands to, except
for operands that are tied to a previous one, which you leave out in
the expectation that the Tablegen output code will fill them in
automatically.
But the code in Tablegen's AsmWriter backend that skips over a tied
operand was doing it using 'if' instead of 'while', because it wasn't
expecting to find two tied operands in sequence.
So if an instruction updates a pair of registers in place, so that its
MC representation has two input operands tied to the output ones (for
example, Arm's UMLAL instruction), then any alias which wants to
expand to a special case of that instruction is likely to fail to
match, because the indices of subsequent operands will be off by one
in the generated printAliasInstr function.
This patch re-indents some existing code, so it's clearest when
viewed as a diff with whitespace changes ignored.
Reviewers: fhahn, rengolin, sdesmalen, atanasyan, asb, jholewinski, t.p.northover, kparzysz, craig.topper, stoklund
Reviewed By: rengolin
Subscribers: javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D53816
llvm-svn: 349141
Unlike CodeGenInstruction, CodeGenInstAlias was flatting asm strings in its constructor. For instructions it was the users responsibility to flatten the string.
AsmMatcherEmitter didn't know this and treated them the same. This caused double flattening of InstAliases. This is mostly harmless unless the desired assembly string contains curly braces. The second flattening wouldn't know to ignore these and would remove the curly braces. And for variant 1 it would remove the contents of them as well.
To mitigate this, this patch makes removes the flattening from the CodeGenIntAlias constructor and modifies AsmWriterEmitter to account for the flattening not having been done.
llvm-svn: 334919
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
llvm-svn: 332240
Summary:
This patch fixes an issue so that the right alias is printed when the instruction has tied operands. It checks the number of operands in the resulting instruction as opposed to the alias, and then skips over tied operands that should not be printed in the alias.
This allows to generate the preferred assembly syntax for the AArch64 'ins' instruction, which should always be displayed as 'mov' according to the ARM Architecture Reference Manual. Several unit tests have changed as a result, but only to reflect the preferred disassembly. Some other InstAlias patterns (movk/bic/orr) needed a slight adjustment to stop them becoming the default and breaking other unit tests.
Please note that the patch is mostly the same as https://reviews.llvm.org/D29219 which was reverted because of an issue found when running TableGen with the Address Sanitizer. That issue has been addressed in this iteration of the patch.
Reviewers: rengolin, stoklund, huntergr, SjoerdMeijer, rovka
Reviewed By: rengolin, SjoerdMeijer
Subscribers: fhahn, aemerson, javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D40030
llvm-svn: 318650
Some alias instructions are printed with an extra space after the tab
character. Fix this by skipping that space when the tab character is printed
so that the instructions are aligned with the rest of the code.
Patch by Milos Stojanovic.
Differential Revision: https://reviews.llvm.org/D35946
llvm-svn: 318059
Internally both these methods just return the result of getValue on either a StringInit or a CodeInit object. In both cases this returns a StringRef pointing to a string allocated in the BumpPtrAllocator so its not going anywhere. So we can just pass that StringRef along.
This is a fairly naive patch that targets just the build failures caused by this change. There's additional work that can be done to avoid creating std::string at call sites that still think getValueAsString returns a std::string. I'll try to clean those up in future patches.
Differential Revision: https://reviews.llvm.org/D33710
llvm-svn: 304325
Inside an alias group, when ordering instruction aliases, we rely
on the priority field to sort them.
When the priority is not set or more generally when there is a tie between
two aliases, we used to rely on the lexicographic order. However, this
order can change for the anonymous records when more instruction, intrinsic,
etc. are inserted.
For instance, given two anonymous records r1 and r2 with respective name
A_999 and A_1000, their lexicography order will be r2 then r1. Now, if
an instruction is added before them, their name will become respectively
A_1000 and A_1001, thus the lexicography order will be r1 then r2, i.e.,
it changed.
If that happens in an alias group, the assembly output would prefer a
different alias for no apparent good reasons.
A way to fix that is to use proper priority for all aliases, but we
can also make the tie breaker comparison smarter and use a deterministic
ordering. This is what this patch does.
llvm-svn: 294695
This patch checks the number of operands in the resulting
instruction instead of just the alias, then skips over
tied operands when generating the printing method.
This allows us to generate the preferred assembly syntax
for the AArch64 'ins' instruction, which should always be
displayed as 'mov' according to the ARMARM.
Several unit tests have changed as a result, but only to
reflect the preferred disassembly.
Some other InstAlias patterns (movk/bic/orr) needed a
slight adjustment to stop them becoming the default
and breaking other unit tests.
Patch by Graham Hunter.
Differential Revision: https://reviews.llvm.org/D29219
llvm-svn: 294437
will appear after a blank. This assumption does not hold in the ARM
target.
Patch by: Roger Ferrer Ibanez
Differential Revision: http://reviews.llvm.org/D20234
llvm-svn: 271666
consider the Predicates attached to InstAlias when generating printAliasInstr.
This forces users of printAliasInstr to check those predicates beforehand.
This commit adds them in the condition set of the IAPrinter object.
Patch by: Roger Ferrer Ibanez
Differential Revision: http://reviews.llvm.org/D20233
llvm-svn: 271665
Adds the corresponding CodeGenInstruction number to each AsmWriterInst. Then write all the operand uniqueing loops using the AsmWriterInst array and indices. Then use the CodeGenInstruction index to fill out the OpCodeInfo array.
llvm-svn: 258005
