[llvm-commits] [llvm] r90240 - in /llvm/trunk: include/llvm/CodeGen/LiveVariables.h lib/CodeGen/LiveVariables.cpp lib/CodeGen/PHIElimination.cpp lib/CodeGen/PHIElimination.h
Jakob Stoklund Olesen
stoklund at 2pi.dk
Tue Dec 1 09:13:32 PST 2009
Author: stoklund
Date: Tue Dec 1 11:13:31 2009
New Revision: 90240
URL: http://llvm.org/viewvc/llvm-project?rev=90240&view=rev
Log:
Move PHIElimination::isLiveOut method to LiveVariables.
We want LiveVariables clients to use methods rather than accessing the
getVarInfo data structure directly. That way it will be possible to change the
LiveVariables representation.
Modified:
llvm/trunk/include/llvm/CodeGen/LiveVariables.h
llvm/trunk/lib/CodeGen/LiveVariables.cpp
llvm/trunk/lib/CodeGen/PHIElimination.cpp
llvm/trunk/lib/CodeGen/PHIElimination.h
Modified: llvm/trunk/include/llvm/CodeGen/LiveVariables.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/LiveVariables.h?rev=90240&r1=90239&r2=90240&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/LiveVariables.h (original)
+++ llvm/trunk/include/llvm/CodeGen/LiveVariables.h Tue Dec 1 11:13:31 2009
@@ -283,6 +283,11 @@
return getVarInfo(Reg).isLiveIn(MBB, Reg, *MRI);
}
+ /// isLiveOut - Determine if Reg is live out from MBB, when not considering
+ /// PHI nodes. This means that Reg is either killed by a successor block or
+ /// passed through one.
+ bool isLiveOut(unsigned Reg, const MachineBasicBlock &MBB);
+
/// addNewBlock - Add a new basic block BB between DomBB and SuccBB. All
/// variables that are live out of DomBB and live into SuccBB will be marked
/// as passing live through BB. This method assumes that the machine code is
Modified: llvm/trunk/lib/CodeGen/LiveVariables.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LiveVariables.cpp?rev=90240&r1=90239&r2=90240&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LiveVariables.cpp (original)
+++ llvm/trunk/lib/CodeGen/LiveVariables.cpp Tue Dec 1 11:13:31 2009
@@ -720,6 +720,51 @@
return findKill(&MBB);
}
+bool LiveVariables::isLiveOut(unsigned Reg, const MachineBasicBlock &MBB) {
+ LiveVariables::VarInfo &VI = getVarInfo(Reg);
+
+ // Loop over all of the successors of the basic block, checking to see if
+ // the value is either live in the block, or if it is killed in the block.
+ std::vector<MachineBasicBlock*> OpSuccBlocks;
+ for (MachineBasicBlock::const_succ_iterator SI = MBB.succ_begin(),
+ E = MBB.succ_end(); SI != E; ++SI) {
+ MachineBasicBlock *SuccMBB = *SI;
+
+ // Is it alive in this successor?
+ unsigned SuccIdx = SuccMBB->getNumber();
+ if (VI.AliveBlocks.test(SuccIdx))
+ return true;
+ OpSuccBlocks.push_back(SuccMBB);
+ }
+
+ // Check to see if this value is live because there is a use in a successor
+ // that kills it.
+ switch (OpSuccBlocks.size()) {
+ case 1: {
+ MachineBasicBlock *SuccMBB = OpSuccBlocks[0];
+ for (unsigned i = 0, e = VI.Kills.size(); i != e; ++i)
+ if (VI.Kills[i]->getParent() == SuccMBB)
+ return true;
+ break;
+ }
+ case 2: {
+ MachineBasicBlock *SuccMBB1 = OpSuccBlocks[0], *SuccMBB2 = OpSuccBlocks[1];
+ for (unsigned i = 0, e = VI.Kills.size(); i != e; ++i)
+ if (VI.Kills[i]->getParent() == SuccMBB1 ||
+ VI.Kills[i]->getParent() == SuccMBB2)
+ return true;
+ break;
+ }
+ default:
+ std::sort(OpSuccBlocks.begin(), OpSuccBlocks.end());
+ for (unsigned i = 0, e = VI.Kills.size(); i != e; ++i)
+ if (std::binary_search(OpSuccBlocks.begin(), OpSuccBlocks.end(),
+ VI.Kills[i]->getParent()))
+ return true;
+ }
+ return false;
+}
+
/// addNewBlock - Add a new basic block BB as an empty succcessor to DomBB. All
/// variables that are live out of DomBB will be marked as passing live through
/// BB.
Modified: llvm/trunk/lib/CodeGen/PHIElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PHIElimination.cpp?rev=90240&r1=90239&r2=90240&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PHIElimination.cpp (original)
+++ llvm/trunk/lib/CodeGen/PHIElimination.cpp Tue Dec 1 11:13:31 2009
@@ -287,7 +287,7 @@
// Okay, if we now know that the value is not live out of the block, we can
// add a kill marker in this block saying that it kills the incoming value!
- if (!ValueIsUsed && !isLiveOut(SrcReg, opBlock, *LV)) {
+ if (!ValueIsUsed && !LV->isLiveOut(SrcReg, opBlock)) {
// In our final twist, we have to decide which instruction kills the
// register. In most cases this is the copy, however, the first
// terminator instruction at the end of the block may also use the value.
@@ -353,59 +353,13 @@
// We break edges when registers are live out from the predecessor block
// (not considering PHI nodes). If the register is live in to this block
// anyway, we would gain nothing from splitting.
- if (!LV.isLiveIn(Reg, MBB) && isLiveOut(Reg, *PreMBB, LV))
+ if (!LV.isLiveIn(Reg, MBB) && LV.isLiveOut(Reg, *PreMBB))
SplitCriticalEdge(PreMBB, &MBB);
}
}
return true;
}
-bool llvm::PHIElimination::isLiveOut(unsigned Reg, const MachineBasicBlock &MBB,
- LiveVariables &LV) {
- LiveVariables::VarInfo &VI = LV.getVarInfo(Reg);
-
- // Loop over all of the successors of the basic block, checking to see if
- // the value is either live in the block, or if it is killed in the block.
- std::vector<MachineBasicBlock*> OpSuccBlocks;
- for (MachineBasicBlock::const_succ_iterator SI = MBB.succ_begin(),
- E = MBB.succ_end(); SI != E; ++SI) {
- MachineBasicBlock *SuccMBB = *SI;
-
- // Is it alive in this successor?
- unsigned SuccIdx = SuccMBB->getNumber();
- if (VI.AliveBlocks.test(SuccIdx))
- return true;
- OpSuccBlocks.push_back(SuccMBB);
- }
-
- // Check to see if this value is live because there is a use in a successor
- // that kills it.
- switch (OpSuccBlocks.size()) {
- case 1: {
- MachineBasicBlock *SuccMBB = OpSuccBlocks[0];
- for (unsigned i = 0, e = VI.Kills.size(); i != e; ++i)
- if (VI.Kills[i]->getParent() == SuccMBB)
- return true;
- break;
- }
- case 2: {
- MachineBasicBlock *SuccMBB1 = OpSuccBlocks[0], *SuccMBB2 = OpSuccBlocks[1];
- for (unsigned i = 0, e = VI.Kills.size(); i != e; ++i)
- if (VI.Kills[i]->getParent() == SuccMBB1 ||
- VI.Kills[i]->getParent() == SuccMBB2)
- return true;
- break;
- }
- default:
- std::sort(OpSuccBlocks.begin(), OpSuccBlocks.end());
- for (unsigned i = 0, e = VI.Kills.size(); i != e; ++i)
- if (std::binary_search(OpSuccBlocks.begin(), OpSuccBlocks.end(),
- VI.Kills[i]->getParent()))
- return true;
- }
- return false;
-}
-
MachineBasicBlock *PHIElimination::SplitCriticalEdge(MachineBasicBlock *A,
MachineBasicBlock *B) {
assert(A && B && "Missing MBB end point");
Modified: llvm/trunk/lib/CodeGen/PHIElimination.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PHIElimination.h?rev=90240&r1=90239&r2=90240&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PHIElimination.h (original)
+++ llvm/trunk/lib/CodeGen/PHIElimination.h Tue Dec 1 11:13:31 2009
@@ -93,12 +93,6 @@
bool SplitPHIEdges(MachineFunction &MF, MachineBasicBlock &MBB,
LiveVariables &LV);
- /// isLiveOut - Determine if Reg is live out from MBB, when not
- /// considering PHI nodes. This means that Reg is either killed by
- /// a successor block or passed through one.
- bool isLiveOut(unsigned Reg, const MachineBasicBlock &MBB,
- LiveVariables &LV);
-
/// SplitCriticalEdge - Split a critical edge from A to B by
/// inserting a new MBB. Update branches in A and PHI instructions
/// in B. Return the new block.
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