Use std::bitset for SubtargetFeatures.
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
diff --git a/llvm/lib/MC/MCInstrDesc.cpp b/llvm/lib/MC/MCInstrDesc.cpp
index 0f942cd..decc2d8 100644
--- a/llvm/lib/MC/MCInstrDesc.cpp
+++ b/llvm/lib/MC/MCInstrDesc.cpp
@@ -23,7 +23,7 @@
std::string &Info) const {
if (ComplexDeprecationInfo)
return ComplexDeprecationInfo(MI, STI, Info);
- if ((DeprecatedFeatureMask & STI.getFeatureBits()) != 0) {
+ if (DeprecatedFeature != -1 && STI.getFeatureBits()[DeprecatedFeature]) {
// FIXME: it would be nice to include the subtarget feature here.
Info = "deprecated";
return true;
diff --git a/llvm/lib/MC/MCSubtargetInfo.cpp b/llvm/lib/MC/MCSubtargetInfo.cpp
index daba321..6abdd3a 100644
--- a/llvm/lib/MC/MCSubtargetInfo.cpp
+++ b/llvm/lib/MC/MCSubtargetInfo.cpp
@@ -63,14 +63,19 @@
/// ToggleFeature - Toggle a feature and returns the re-computed feature
/// bits. This version does not change the implied bits.
-uint64_t MCSubtargetInfo::ToggleFeature(uint64_t FB) {
+FeatureBitset MCSubtargetInfo::ToggleFeature(uint64_t FB) {
+ FeatureBits.flip(FB);
+ return FeatureBits;
+}
+
+FeatureBitset MCSubtargetInfo::ToggleFeature(const FeatureBitset &FB) {
FeatureBits ^= FB;
return FeatureBits;
}
/// ToggleFeature - Toggle a feature and returns the re-computed feature
/// bits. This version will also change all implied bits.
-uint64_t MCSubtargetInfo::ToggleFeature(StringRef FS) {
+FeatureBitset MCSubtargetInfo::ToggleFeature(StringRef FS) {
SubtargetFeatures Features;
FeatureBits = Features.ToggleFeature(FeatureBits, FS, ProcFeatures);
return FeatureBits;
diff --git a/llvm/lib/MC/SubtargetFeature.cpp b/llvm/lib/MC/SubtargetFeature.cpp
index 3880d88..78006e0 100644
--- a/llvm/lib/MC/SubtargetFeature.cpp
+++ b/llvm/lib/MC/SubtargetFeature.cpp
@@ -151,12 +151,12 @@
/// 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 @@
/// 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 @@
/// 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 @@
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 @@
/// 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 @@
"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 @@
// 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 {