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[TableGen][DecoderEmitter] Remove redundant variable (NFC) (#154880)

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`NumFiltered` is the number of elements in all vectors in a map.
It is ever compared to 1, which is equivalent to checking if the map
contains exactly one vector with exactly one element.
This commit is contained in:
Sergei Barannikov 2025-08-22 07:42:06 +03:00 committed by GitHub
parent 586a7131d3
commit 6a7ade03d1
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GPG Key ID: B5690EEEBB952194
1 changed files with 8 additions and 12 deletions
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20
llvm/utils/TableGen/DecoderEmitter.cpp
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@ -403,26 +403,25 @@ protected:
// A filter chooser for encodings that contain some '?' in the filtered range. // A filter chooser for encodings that contain some '?' in the filtered range.
std::unique_ptr<const FilterChooser> VariableFC; std::unique_ptr<const FilterChooser> VariableFC;
// Number of instructions which fall under FilteredInstructions category.
unsigned NumFiltered;
public: public:
Filter(Filter &&f); Filter(Filter &&f);
Filter(const FilterChooser &owner, unsigned startBit, unsigned numBits); Filter(const FilterChooser &owner, unsigned startBit, unsigned numBits);
~Filter() = default; ~Filter() = default;
unsigned getNumFiltered() const { return NumFiltered; } bool hasSingleFilteredID() const {
return FilteredIDs.size() == 1 && FilteredIDs.begin()->second.size() == 1;
}
unsigned getSingletonEncodingID() const { unsigned getSingletonEncodingID() const {
assert(NumFiltered == 1); assert(hasSingleFilteredID());
return FilteredIDs.begin()->second.front(); return FilteredIDs.begin()->second.front();
} }
// Return the filter chooser for the group of instructions without constant // Return the filter chooser for the group of instructions without constant
// segment values. // segment values.
const FilterChooser &getVariableFC() const { const FilterChooser &getVariableFC() const {
assert(NumFiltered == 1 && FilterChooserMap.empty()); assert(hasSingleFilteredID() && FilterChooserMap.empty());
return *VariableFC; return *VariableFC;
} }
@ -617,14 +616,12 @@ Filter::Filter(Filter &&f)
FilteredIDs(std::move(f.FilteredIDs)), FilteredIDs(std::move(f.FilteredIDs)),
VariableIDs(std::move(f.VariableIDs)), VariableIDs(std::move(f.VariableIDs)),
FilterChooserMap(std::move(f.FilterChooserMap)), FilterChooserMap(std::move(f.FilterChooserMap)),
VariableFC(std::move(f.VariableFC)), NumFiltered(f.NumFiltered) {} VariableFC(std::move(f.VariableFC)) {}
Filter::Filter(const FilterChooser &owner, unsigned startBit, unsigned numBits) Filter::Filter(const FilterChooser &owner, unsigned startBit, unsigned numBits)
: Owner(owner), StartBit(startBit), NumBits(numBits) { : Owner(owner), StartBit(startBit), NumBits(numBits) {
assert(StartBit + NumBits - 1 < Owner.BitWidth); assert(StartBit + NumBits - 1 < Owner.BitWidth);
NumFiltered = 0;
for (unsigned EncodingID : Owner.EncodingIDs) { for (unsigned EncodingID : Owner.EncodingIDs) {
// Populates the insn given the uid. // Populates the insn given the uid.
KnownBits EncodingBits = Owner.getMandatoryEncodingBits(EncodingID); KnownBits EncodingBits = Owner.getMandatoryEncodingBits(EncodingID);
@ -636,7 +633,6 @@ Filter::Filter(const FilterChooser &owner, unsigned startBit, unsigned numBits)
// The encoding bits are well-known. Lets add the uid of the // The encoding bits are well-known. Lets add the uid of the
// instruction into the bucket keyed off the constant field value. // instruction into the bucket keyed off the constant field value.
FilteredIDs[FieldBits.getConstant().getZExtValue()].push_back(EncodingID); FilteredIDs[FieldBits.getConstant().getZExtValue()].push_back(EncodingID);
++NumFiltered;
} else { } else {
// Some of the encoding bit(s) are unspecified. This contributes to // Some of the encoding bit(s) are unspecified. This contributes to
// one additional member of "Variable" instructions. // one additional member of "Variable" instructions.
@ -668,7 +664,7 @@ void Filter::recurse() {
// No need to recurse for a singleton filtered instruction. // No need to recurse for a singleton filtered instruction.
// See also Filter::emit*(). // See also Filter::emit*().
if (getNumFiltered() == 1) { if (hasSingleFilteredID()) {
assert(VariableFC && "Shouldn't have created a filter for one encoding!"); assert(VariableFC && "Shouldn't have created a filter for one encoding!");
return; return;
} }
@ -1716,7 +1712,7 @@ void FilterChooser::emitTableEntries(DecoderTableInfo &TableInfo) const {
} }
// Use the best filter to do the decoding! // Use the best filter to do the decoding!
if (BestFilter->getNumFiltered() == 1) if (BestFilter->hasSingleFilteredID())
emitSingletonTableEntry(TableInfo, *BestFilter); emitSingletonTableEntry(TableInfo, *BestFilter);
else else
BestFilter->emitTableEntry(TableInfo); BestFilter->emitTableEntry(TableInfo);