[llvm-commits] [llvm] r72426 - in /llvm/trunk: include/llvm/CodeGen/LiveVariables.h lib/CodeGen/LiveIntervalAnalysis.cpp lib/CodeGen/LiveVariables.cpp lib/CodeGen/PHIElimination.cpp
Jeffrey Yasskin
jyasskin at google.com
Tue May 26 11:27:15 PDT 2009
Author: jyasskin
Date: Tue May 26 13:27:15 2009
New Revision: 72426
URL: http://llvm.org/viewvc/llvm-project?rev=72426&view=rev
Log:
LiveVariables::VarInfo contains an AliveBlocks BitVector, which has as many
entries as there are basic blocks in the function. LiveVariables::getVarInfo
creates a VarInfo struct for every register in the function, leading to
quadratic space use. This patch changes the BitVector to a SparseBitVector,
which doesn't help the worst-case memory use but does reduce the actual use in
very long functions with short-lived variables.
Modified:
llvm/trunk/include/llvm/CodeGen/LiveVariables.h
llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp
llvm/trunk/lib/CodeGen/LiveVariables.cpp
llvm/trunk/lib/CodeGen/PHIElimination.cpp
Modified: llvm/trunk/include/llvm/CodeGen/LiveVariables.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/LiveVariables.h?rev=72426&r1=72425&r2=72426&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/LiveVariables.h (original)
+++ llvm/trunk/include/llvm/CodeGen/LiveVariables.h Tue May 26 13:27:15 2009
@@ -33,6 +33,7 @@
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/SparseBitVector.h"
namespace llvm {
@@ -75,7 +76,7 @@
/// through. This is a bit set which uses the basic block number as an
/// index.
///
- BitVector AliveBlocks;
+ SparseBitVector<> AliveBlocks;
/// NumUses - Number of uses of this register across the entire function.
///
Modified: llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp?rev=72426&r1=72425&r2=72426&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp (original)
+++ llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp Tue May 26 13:27:15 2009
@@ -422,7 +422,7 @@
// If the kill happens after the definition, we have an intra-block
// live range.
if (killIdx > defIndex) {
- assert(vi.AliveBlocks.none() &&
+ assert(vi.AliveBlocks.empty() &&
"Shouldn't be alive across any blocks!");
LiveRange LR(defIndex, killIdx, ValNo);
interval.addRange(LR);
@@ -443,10 +443,10 @@
// Iterate over all of the blocks that the variable is completely
// live in, adding [insrtIndex(begin), instrIndex(end)+4) to the
// live interval.
- for (int i = vi.AliveBlocks.find_first(); i != -1;
- i = vi.AliveBlocks.find_next(i)) {
- LiveRange LR(getMBBStartIdx(i),
- getMBBEndIdx(i)+1, // MBB ends at -1.
+ for (SparseBitVector<>::iterator I = vi.AliveBlocks.begin(),
+ E = vi.AliveBlocks.end(); I != E; ++I) {
+ LiveRange LR(getMBBStartIdx(*I),
+ getMBBEndIdx(*I)+1, // MBB ends at -1.
ValNo);
interval.addRange(LR);
DOUT << " +" << LR;
Modified: llvm/trunk/lib/CodeGen/LiveVariables.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LiveVariables.cpp?rev=72426&r1=72425&r2=72426&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LiveVariables.cpp (original)
+++ llvm/trunk/lib/CodeGen/LiveVariables.cpp Tue May 26 13:27:15 2009
@@ -52,8 +52,9 @@
void LiveVariables::VarInfo::dump() const {
cerr << " Alive in blocks: ";
- for (int i = AliveBlocks.find_first(); i != -1; i = AliveBlocks.find_next(i))
- cerr << i << ", ";
+ for (SparseBitVector<>::iterator I = AliveBlocks.begin(),
+ E = AliveBlocks.end(); I != E; ++I)
+ cerr << *I << ", ";
cerr << "\n Killed by:";
if (Kills.empty())
cerr << " No instructions.\n";
@@ -75,9 +76,7 @@
else
VirtRegInfo.resize(2*VirtRegInfo.size());
}
- VarInfo &VI = VirtRegInfo[RegIdx];
- VI.AliveBlocks.resize(MF->getNumBlockIDs());
- return VI;
+ return VirtRegInfo[RegIdx];
}
void LiveVariables::MarkVirtRegAliveInBlock(VarInfo& VRInfo,
@@ -96,11 +95,11 @@
if (MBB == DefBlock) return; // Terminate recursion
- if (VRInfo.AliveBlocks[BBNum])
+ if (VRInfo.AliveBlocks.test(BBNum))
return; // We already know the block is live
// Mark the variable known alive in this bb
- VRInfo.AliveBlocks[BBNum] = true;
+ VRInfo.AliveBlocks.set(BBNum);
for (MachineBasicBlock::const_pred_reverse_iterator PI = MBB->pred_rbegin(),
E = MBB->pred_rend(); PI != E; ++PI)
@@ -163,7 +162,7 @@
// Add a new kill entry for this basic block. If this virtual register is
// already marked as alive in this basic block, that means it is alive in at
// least one of the successor blocks, it's not a kill.
- if (!VRInfo.AliveBlocks[BBNum])
+ if (!VRInfo.AliveBlocks.test(BBNum))
VRInfo.Kills.push_back(MI);
// Update all dominating blocks to mark them as "known live".
@@ -175,7 +174,7 @@
void LiveVariables::HandleVirtRegDef(unsigned Reg, MachineInstr *MI) {
VarInfo &VRInfo = getVarInfo(Reg);
- if (VRInfo.AliveBlocks.none())
+ if (VRInfo.AliveBlocks.empty())
// If vr is not alive in any block, then defaults to dead.
VRInfo.Kills.push_back(MI);
}
Modified: llvm/trunk/lib/CodeGen/PHIElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PHIElimination.cpp?rev=72426&r1=72425&r2=72426&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PHIElimination.cpp (original)
+++ llvm/trunk/lib/CodeGen/PHIElimination.cpp Tue May 26 13:27:15 2009
@@ -334,8 +334,7 @@
// Is it alive in this successor?
unsigned SuccIdx = SuccMBB->getNumber();
- if (SuccIdx < InRegVI.AliveBlocks.size() &&
- InRegVI.AliveBlocks[SuccIdx]) {
+ if (InRegVI.AliveBlocks.test(SuccIdx)) {
ValueIsLive = true;
break;
}
@@ -407,8 +406,7 @@
// This vreg no longer lives all of the way through opBlock.
unsigned opBlockNum = opBlock.getNumber();
- if (opBlockNum < InRegVI.AliveBlocks.size())
- InRegVI.AliveBlocks[opBlockNum] = false;
+ InRegVI.AliveBlocks.reset(opBlockNum);
}
}
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