[llvm-commits] CVS: llvm/include/llvm/CodeGen/LiveVariables.h
Bill Wendling
isanbard at gmail.com
Tue Oct 3 00:20:36 PDT 2006
Changes in directory llvm/include/llvm/CodeGen:
LiveVariables.h updated: 1.29 -> 1.30
---
Log message:
Fix for PR929: http://llvm.org/PR929 . The PHI nodes were being gone through for each instruction
in a successor block for every block...resulting in some O(N^k) algorithm
which wasn't very good for performance. Calculating this information up
front and keeping it in a map made it much faster.
---
Diffs of the changes: (+11 -1)
LiveVariables.h | 12 +++++++++++-
1 files changed, 11 insertions(+), 1 deletion(-)
Index: llvm/include/llvm/CodeGen/LiveVariables.h
diff -u llvm/include/llvm/CodeGen/LiveVariables.h:1.29 llvm/include/llvm/CodeGen/LiveVariables.h:1.30
--- llvm/include/llvm/CodeGen/LiveVariables.h:1.29 Sat Sep 2 19:05:09 2006
+++ llvm/include/llvm/CodeGen/LiveVariables.h Tue Oct 3 02:20:20 2006
@@ -39,7 +39,7 @@
class LiveVariables : public MachineFunctionPass {
public:
/// VarInfo - This represents the regions where a virtual register is live in
- /// the program. We represent this with three difference pieces of
+ /// the program. We represent this with three different pieces of
/// information: the instruction that uniquely defines the value, the set of
/// blocks the instruction is live into and live out of, and the set of
/// non-phi instructions that are the last users of the value.
@@ -136,9 +136,19 @@
MachineInstr **PhysRegInfo;
bool *PhysRegUsed;
+ typedef std::map<const MachineBasicBlock*,
+ std::vector<unsigned> > PHIVarInfoMap;
+
+ PHIVarInfoMap PHIVarInfo;
+
void HandlePhysRegUse(unsigned Reg, MachineInstr *MI);
void HandlePhysRegDef(unsigned Reg, MachineInstr *MI);
+ /// analyzePHINodes - Gather information about the PHI nodes in here. In
+ /// particular, we want to map the variable information of a virtual
+ /// register which is used in a PHI node. We map that to the BB the vreg
+ /// is coming from.
+ void analyzePHINodes(const MachineFunction& Fn);
public:
virtual bool runOnMachineFunction(MachineFunction &MF);
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