averello/swift-mirror
1
0
Fork 0
mirror of https://github.com/apple/swift.git synced 2025-12-21 12:14:44 +01:00
Code Issues Packages Projects Releases Wiki Activity

Use a SmallBitVector instead of BitVector in DSE. I observed that most functions

Browse Source 
do not have over 64 locations which makes SmallBitVector a more suitable choice
than BitVector.

I see a ~10% drop in compilation time in DSE. i.e. 1430ms to 1270ms (2.2% to 2.0% of
overall compilation time).
This commit is contained in:
Xin Tong
2015-12-26 12:30:46 -08:00
parent e9b8bb855b
commit 173fc871ff
1 changed files with 15 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

30
lib/SILOptimizer/Transforms/DeadStoreElimination.cpp
View File

@@ -178,33 +178,33 @@ public:
/// A bit vector for which the ith bit represents the ith LSLocation in
/// LocationVault. If the bit is set, then the location currently has an
/// upward visible store at the end of the basic block.
llvm::BitVector BBWriteSetOut;
llvm::SmallBitVector BBWriteSetOut;
/// A bit vector for which the ith bit represents the ith LSLocation in
/// LocationVault. If the bit is set, then the location currently has an
/// upward visible store in middle of the basic block.
llvm::BitVector BBWriteSetMid;
llvm::SmallBitVector BBWriteSetMid;
/// A bit vector for which the ith bit represents the ith LSLocation in
/// LocationVault. If a bit in the vector is set, then the location has an
/// upward visible store at the beginning of the basic block.
llvm::BitVector BBWriteSetIn;
llvm::SmallBitVector BBWriteSetIn;
/// A bit vector for which the ith bit represents the ith LSLocation in
/// LocationVault. If the bit is set, then the current basic block
/// generates an upward visible store.
llvm::BitVector BBGenSet;
llvm::SmallBitVector BBGenSet;
/// A bit vector for which the ith bit represents the ith LSLocation in
/// LocationVault. If the bit is set, then the current basic block
/// kills an upward visible store.
llvm::BitVector BBKillSet;
llvm::SmallBitVector BBKillSet;
/// A bit vector to keep the maximum number of stores that can reach the
/// beginning of the basic block. If a bit is set, that means there is
/// potentially a upward visible store to the location at the beginning
/// of the basic block.
llvm::BitVector BBMaxStoreSet;
llvm::SmallBitVector BBMaxStoreSet;
/// The dead stores in the current basic block.
llvm::DenseSet<SILInstruction *> DeadStores;
@@ -231,17 +231,17 @@ public:
/// Check whether the BBWriteSetIn has changed. If it does, we need to rerun
/// the data flow on this block's predecessors to reach fixed point.
bool updateBBWriteSetIn(llvm::BitVector &X);
bool updateBBWriteSetIn(llvm::SmallBitVector &X);
/// Functions to manipulate the write set.
void startTrackingLocation(llvm::BitVector &BV, unsigned bit);
void stopTrackingLocation(llvm::BitVector &BV, unsigned bit);
bool isTrackingLocation(llvm::BitVector &BV, unsigned bit);
void startTrackingLocation(llvm::SmallBitVector &BV, unsigned bit);
void stopTrackingLocation(llvm::SmallBitVector &BV, unsigned bit);
bool isTrackingLocation(llvm::SmallBitVector &BV, unsigned bit);
};
} // end anonymous namespace
bool BlockState::updateBBWriteSetIn(llvm::BitVector &X) {
bool BlockState::updateBBWriteSetIn(llvm::SmallBitVector &X) {
bool Changed = (BBWriteSetIn != X);
if (!Changed)
return Changed;
@@ -249,15 +249,15 @@ bool BlockState::updateBBWriteSetIn(llvm::BitVector &X) {
return Changed;
}
void BlockState::startTrackingLocation(llvm::BitVector &BV, unsigned i) {
void BlockState::startTrackingLocation(llvm::SmallBitVector &BV, unsigned i) {
BV.set(i);
}
void BlockState::stopTrackingLocation(llvm::BitVector &BV, unsigned i) {
void BlockState::stopTrackingLocation(llvm::SmallBitVector &BV, unsigned i) {
BV.reset(i);
}
bool BlockState::isTrackingLocation(llvm::BitVector &BV, unsigned i) {
bool BlockState::isTrackingLocation(llvm::SmallBitVector &BV, unsigned i) {
return BV.test(i);
}
@@ -746,7 +746,7 @@ void DSEContext::processWrite(SILInstruction *I, BlockState *S, SILValue Val,
bool Dead = true;
LSLocationList Locs;
LSLocation::expand(L, Mod, Locs, TE);
llvm::BitVector V(Locs.size());
llvm::SmallBitVector V(Locs.size());
// Are we computing max store set.
if (isComputeMaxStoreSet(Kind)) {