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Use std::bitset for SubtargetFeatures.

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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
This commit is contained in:
Michael Kuperstein
2015-05-26 10:47:10 +00:00
parent 02fc0b1d64
commit db0712f986
38 changed files with 1074 additions and 1022 deletions
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23
llvm/lib/MC/SubtargetFeature.cpp
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@@ -151,12 +151,12 @@ std::string SubtargetFeatures::getString() const {
/// feature, set it.
///
static
void SetImpliedBits(uint64_t &Bits, const SubtargetFeatureKV *FeatureEntry,
void SetImpliedBits(FeatureBitset &Bits, const SubtargetFeatureKV *FeatureEntry,
ArrayRef<SubtargetFeatureKV> FeatureTable) {
for (auto &FE : FeatureTable) {
if (FeatureEntry->Value == FE.Value) continue;
if (FeatureEntry->Implies & FE.Value) {
if ((FeatureEntry->Implies & FE.Value).any()) {
Bits |= FE.Value;
SetImpliedBits(Bits, &FE, FeatureTable);
}
@@ -167,12 +167,13 @@ void SetImpliedBits(uint64_t &Bits, const SubtargetFeatureKV *FeatureEntry,
/// feature, clear it.
///
static
void ClearImpliedBits(uint64_t &Bits, const SubtargetFeatureKV *FeatureEntry,
void ClearImpliedBits(FeatureBitset &Bits,
const SubtargetFeatureKV *FeatureEntry,
ArrayRef<SubtargetFeatureKV> FeatureTable) {
for (auto &FE : FeatureTable) {
if (FeatureEntry->Value == FE.Value) continue;
if (FE.Implies & FeatureEntry->Value) {
if ((FE.Implies & FeatureEntry->Value).any()) {
Bits &= ~FE.Value;
ClearImpliedBits(Bits, &FE, FeatureTable);
}
@@ -181,8 +182,8 @@ void ClearImpliedBits(uint64_t &Bits, const SubtargetFeatureKV *FeatureEntry,
/// ToggleFeature - Toggle a feature and returns the newly updated feature
/// bits.
uint64_t
SubtargetFeatures::ToggleFeature(uint64_t Bits, StringRef Feature,
FeatureBitset
SubtargetFeatures::ToggleFeature(FeatureBitset Bits, StringRef Feature,
ArrayRef<SubtargetFeatureKV> FeatureTable) {
// Find feature in table.
@@ -192,7 +193,6 @@ SubtargetFeatures::ToggleFeature(uint64_t Bits, StringRef Feature,
if (FeatureEntry) {
if ((Bits & FeatureEntry->Value) == FeatureEntry->Value) {
Bits &= ~FeatureEntry->Value;
// For each feature that implies this, clear it.
ClearImpliedBits(Bits, FeatureEntry, FeatureTable);
} else {
@@ -213,13 +213,13 @@ SubtargetFeatures::ToggleFeature(uint64_t Bits, StringRef Feature,
/// getFeatureBits - Get feature bits a CPU.
///
uint64_t
FeatureBitset
SubtargetFeatures::getFeatureBits(StringRef CPU,
ArrayRef<SubtargetFeatureKV> CPUTable,
ArrayRef<SubtargetFeatureKV> FeatureTable) {
if (CPUTable.empty() || FeatureTable.empty())
return 0;
return FeatureBitset();
#ifndef NDEBUG
for (size_t i = 1, e = CPUTable.size(); i != e; ++i) {
@@ -231,7 +231,8 @@ SubtargetFeatures::getFeatureBits(StringRef CPU,
"CPU features table is not sorted");
}
#endif
uint64_t Bits = 0; // Resulting bits
// Resulting bits
FeatureBitset Bits;
// Check if help is needed
if (CPU == "help")
@@ -248,7 +249,7 @@ SubtargetFeatures::getFeatureBits(StringRef CPU,
// Set the feature implied by this CPU feature, if any.
for (auto &FE : FeatureTable) {
if (CPUEntry->Value & FE.Value)
if ((CPUEntry->Value & FE.Value).any())
SetImpliedBits(Bits, &FE, FeatureTable);
}
} else {