If a method / function returns a StringRef but the
variable is of type const std::string& a temporary string is
created (StringRef has a cast operator to std::string),
which is a suboptimal behavior.
Differential revision: https://reviews.llvm.org/D34994
Test plan: make check-all
llvm-svn: 307195
Summary:
SetVector already used DenseSet, but SmallSetVector used std::set. This
leads to surprising performance differences. Moreover, it means that
the set of key types accepted by SetVector and SmallSetVector are
quite different!
In order to make this change, we had to convert some callsites that used
SmallSetVector<std::string, N> to use SmallSetVector<CachedHashString, N>
instead.
Reviewers: timshen
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25648
llvm-svn: 284887
This is for a situation where the encoding for a register may be
different depending on the specific operand. For some instructions,
we want to apply additional restrictions beyond the encoding's
constraints.
In AMDGPU some operands are VSrc_32, using the VS_32 pseudo register
class which accept VGPRs, SGPRs, or immediates in the encoding.
Some specific instructions with the same encoding operand do not want
to allow immediates or SGPRs, but the encoding format is different
in this case than a regular VGPR_32 operand.
This allows specifying the encoding should be treated the same
without introducing yet another dummy register class.
llvm-svn: 275929
We use to have an odd difference among MapVector and SetVector. The map
used a DenseMop, but the set used a SmallSet, which in turn uses a
std::set.
I have changed SetVector to use a DenseSet. If you were depending on the
old behaviour you can pass an explicit set type or use SmallSetVector.
The common cases for needing to do it are:
* Optimizing for small sets.
* Sets for types not supported by DenseSet.
llvm-svn: 253439
After r244870 flush() will only compare two null pointers and return,
doing nothing but wasting run time. The call is not required any more
as the stream and its SmallString are always in sync.
Thanks to David Blaikie for reviewing.
llvm-svn: 244928
When FixedLenDecoder matches an input bitpattern of form [01]+ with an
instruction bitpattern of form [01?]+ (where 0/1 are static bits and ? are
mixed/variable bits) it passes the input bitpattern to a specific instruction
decoder method which then makes a final decision whether the bitpattern is a
valid instruction or not. This means the decoder must handle all possible
values of the variable bits which sometimes leads to opcode rewrites in the
decoder method when the instructions are not fully orthogonal.
The patch provides a way for the decoder method to say that when it returns
Fail it does not necessarily mean the bitpattern is invalid, but rather that
the bitpattern is definitely not an instruction that is recognized by the
decoder method. The decoder can then try to match the input bitpattern with
other possible instruction bitpatterns.
For example, this allows to solve a situation on AArch64 where the `MSR
(immediate)` instruction has form:
1101 0101 0000 0??? 0100 ???? ???1 1111
but not all values of the ? bits are allowed. The rejected values should be
handled by the `extended MSR (register)` instruction:
1101 0101 000? ???? ???? ???? ???? ????
The decoder will first try to decode an input bitpattern that matches both
bitpatterns as `MSR (immediate)` but currently this puts the decoder method of
`MSR (immediate)` into a situation when it must be able to decode all possible
values of the ? bits, i.e. it would need to rewrite the instruction to `MSR
(register)` when it is not `MSR (immediate)`.
The patch allows to specify that the decoder method cannot determine if the
instruction is valid for all variable values. The decoder method can simply
return Fail when it knows it is definitely not `MSR (immediate)`. The decoder
will then backtrack the decoding and find that it can match the input
bitpattern with the more generic `MSR (register)` bitpattern too.
Differential Revision: http://reviews.llvm.org/D7174
llvm-svn: 242274
If the type isn't trivially moveable emplace can skip a potentially
expensive move. It also saves a couple of characters.
Call sites were found with the ASTMatcher + some semi-automated cleanup.
memberCallExpr(
argumentCountIs(1), callee(methodDecl(hasName("push_back"))),
on(hasType(recordDecl(has(namedDecl(hasName("emplace_back")))))),
hasArgument(0, bindTemporaryExpr(
hasType(recordDecl(hasNonTrivialDestructor())),
has(constructExpr()))),
unless(isInTemplateInstantiation()))
No functional change intended.
llvm-svn: 238602
Previously, subtarget features were a bitfield with the underlying type being uint64_t.
Since several targets (X86 and ARM, in particular) have hit or were very close to hitting this bound, switching the features to use a bitset.
No functional change.
The first several times this was committed (e.g. r229831, r233055), it caused several buildbot failures.
Apparently the reason for most failures was both clang and gcc's inability to deal with large numbers (> 10K) of bitset constructor calls in tablegen-generated initializers of instruction info tables.
This should now be fixed.
llvm-svn: 238192
Previously, subtarget features were a bitfield with the underlying type being uint64_t.
Since several targets (X86 and ARM, in particular) have hit or were very close to hitting this bound, switching the features to use a bitset.
No functional change.
The first two times this was committed (r229831, r233055), it caused several buildbot failures.
At least some of the ARM and MIPS ones were due to gcc/binutils issues, and should now be fixed.
llvm-svn: 237234
Summary:
The loop which emits AssemblerPredicate conditions also links them together by emitting a '&&'.
If the 1st predicate is not an AssemblerPredicate, while the 2nd one is, nothing gets emitted for the 1st one, but we still emit the '&&' because of the 2nd predicate.
This generated code looks like "( && Cond2)" and is invalid.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D8294
llvm-svn: 234312
This reverts commit r233055.
It still causes buildbot failures (gcc running out of memory on several platforms, and a self-host failure on arm), although less than the previous time.
llvm-svn: 233068
Previously, subtarget features were a bitfield with the underlying type being uint64_t.
Since several targets (X86 and ARM, in particular) have hit or were very close to hitting this bound, switching the features to use a bitset.
No functional change.
The first time this was committed (r229831), it caused several buildbot failures.
At least some of the ARM ones were due to gcc/binutils issues, and should now be fixed.
Differential Revision: http://reviews.llvm.org/D8542
llvm-svn: 233055
Now that SmallString is a first-class citizen, most SmallString::str()
calls are not required. This patch removes a whole bunch of them, yet
there are lots more.
There are two use cases where str() is really needed:
1) To use one of StringRef member functions which is not available in
SmallString.
2) To convert to std::string, as StringRef implicitly converts while
SmallString do not. We may wish to change this, but it may introduce
ambiguity.
llvm-svn: 232622
Previously, subtarget features were a bitfield with the underlying type being uint64_t.
Since several targets (X86 and ARM, in particular) have hit or were very close to hitting this bound, switching the features to use a bitset.
No functional change.
Differential Revision: http://reviews.llvm.org/D7065
llvm-svn: 229831
This patch was generated by a clang tidy checker that is being open sourced.
The documentation of that checker is the following:
/// The emptiness of a container should be checked using the empty method
/// instead of the size method. It is not guaranteed that size is a
/// constant-time function, and it is generally more efficient and also shows
/// clearer intent to use empty. Furthermore some containers may implement the
/// empty method but not implement the size method. Using empty whenever
/// possible makes it easier to switch to another container in the future.
Patch by Gábor Horváth!
llvm-svn: 226161
There are currently two schemes for mapping instruction operands to
instruction-format variables for generating the instruction encoders and
decoders for the assembler and disassembler respectively: a) to map by name and
b) to map by position.
In the long run, we'd like to remove the position-based scheme and use only
name-based mapping. Unfortunately, the name-based scheme currently cannot deal
with complex operands (those with suboperands), and so we currently must use
the position-based scheme for those. On the other hand, the position-based
scheme cannot deal with (register) variables that are split into multiple
ranges. An upcoming commit to the PowerPC backend (adding VSX support) will
require this capability. While we could teach the position-based scheme to
handle that, since we'd like to move away from the position-based mapping
generally, it seems silly to teach it new tricks now. What makes more sense is
to allow for partial transitioning: use the name-based mapping when possible,
and only use the position-based scheme when necessary.
Now the problem is that mixing the two sensibly was not possible: the
position-based mapping would map based on position, but would not skip those
variables that were mapped by name. Instead, the two sets of assignments would
overlap. However, I cannot currently change the current behavior, because there
are some backends that rely on it [I think mistakenly, but I'll send a message
to llvmdev about that]. So I've added a new TableGen bit variable:
noNamedPositionallyEncodedOperands, that can be used to cause the
position-based mapping to skip variables mapped by name.
llvm-svn: 203767
Unfortunately, the PowerPC instruction definitions make heavy use of the
positional operand encoding heuristic to map operands onto bitfield variables
in the instruction definitions. Changing this to use name-based mapping is not
trivial, however, because additional infrastructure needs to be designed to
handle mapping of complex operands (with multiple suboperands) onto multiple
bitfield variables.
In the mean time, this adds support for positionally encoded operands to
FixedLenDecoderEmitter, so that we can generate a disassembler for the PowerPC
backend. To prevent an accidental reliance on this feature, and to prevent an
undesirable interaction with existing disassemblers, a backend must opt-in to
this support by setting the new decodePositionallyEncodedOperands
instruction-set bit to true.
When enabled, this iterates the variables that contribute to the instruction
encoding, just as the encoder does, and emulates the procedure the encoder uses
to map "numbered" operands to variables. The bit range for each variable is
also determined as the encoder determines them. This map is then consulted
during the decoder-generator's loop over operands to decode, allowing the
decoder to understand both position-based and name-based operand-to-variable
mappings.
As noted in the comment on the decodePositionallyEncodedOperands definition,
this support should be removed once it is no longer needed. There should be no
change to existing disassemblers.
llvm-svn: 197691
