Use the "isCompare" machine instruction attribute instead of calling the

relatively expensive comparison analyzer on each instruction. Also rename the
comparison analyzer method to something more in line with what it actually does.

This pass is will eventually be folded into the Machine CSE pass.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110539 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 16 insertions, 15 deletions

diff --git a/lib/CodeGen/OptimizeCmps.cpp b/lib/CodeGen/OptimizeCmps.cpp
index 5b524cd..209c8b9 100644
--- a/lib/CodeGen/OptimizeCmps.cpp
+++ b/lib/CodeGen/OptimizeCmps.cpp
@@ -72,9 +72,8 @@ bool OptimizeCmps::OptimizeCmpInstr(MachineInstr *MI, MachineBasicBlock *MBB) {
   // physical register, we can try to optimize it.
   unsigned SrcReg;
   int CmpValue;
-  if (!TII->isCompareInstr(MI, SrcReg, CmpValue) ||
-      TargetRegisterInfo::isPhysicalRegister(SrcReg) ||
-      CmpValue != 0)
+  if (!TII->AnalyzeCompare(MI, SrcReg, CmpValue) ||
+      TargetRegisterInfo::isPhysicalRegister(SrcReg) || CmpValue != 0)
     return false;
 
   MachineRegisterInfo::def_iterator DI = MRI->def_begin(SrcReg);
@@ -83,7 +82,7 @@ bool OptimizeCmps::OptimizeCmpInstr(MachineInstr *MI, MachineBasicBlock *MBB) {
     return false;
 
   // Attempt to convert the defining instruction to set the "zero" flag.
-  if (TII->convertToSetZeroFlag(&*DI, MI)) {
+  if (TII->ConvertToSetZeroFlag(&*DI, MI)) {
     ++NumEliminated;
     return true;
   }
@@ -104,7 +103,8 @@ bool OptimizeCmps::runOnMachineFunction(MachineFunction &MF) {
     for (MachineBasicBlock::iterator
            MII = MBB->begin(), ME = MBB->end(); MII != ME; ) {
       MachineInstr *MI = &*MII++;
-      Changed |= OptimizeCmpInstr(MI, MBB);
+      if (MI->getDesc().isCompare())
+        Changed |= OptimizeCmpInstr(MI, MBB);
     }
   }
 
diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp
index 68e35ed..7e1c84e 100644
--- a/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -1355,7 +1355,7 @@ bool llvm::rewriteARMFrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
 }
 
 bool ARMBaseInstrInfo::
-isCompareInstr(const MachineInstr *MI, unsigned &SrcReg, int &CmpValue) const {
+AnalyzeCompare(const MachineInstr *MI, unsigned &SrcReg, int &CmpValue) const {
   switch (MI->getOpcode()) {
   default: break;
   case ARM::t2CMPri:
@@ -1368,10 +1368,10 @@ isCompareInstr(const MachineInstr *MI, unsigned &SrcReg, int &CmpValue) const {
   return false;
 }
 
-/// convertToSetZeroFlag - Convert the instruction to set the "zero" flag so
+/// ConvertToSetZeroFlag - Convert the instruction to set the "zero" flag so
 /// that we can remove a "comparison with zero".
 bool ARMBaseInstrInfo::
-convertToSetZeroFlag(MachineInstr *MI, MachineInstr *CmpInstr) const {
+ConvertToSetZeroFlag(MachineInstr *MI, MachineInstr *CmpInstr) const {
   // Conservatively refuse to convert an instruction which isn't in the same BB
   // as the comparison.
   if (MI->getParent() != CmpInstr->getParent())
diff --git a/lib/Target/ARM/ARMBaseInstrInfo.h b/lib/Target/ARM/ARMBaseInstrInfo.h
index 4f1c453..2547ad1 100644
--- a/lib/Target/ARM/ARMBaseInstrInfo.h
+++ b/lib/Target/ARM/ARMBaseInstrInfo.h
@@ -337,15 +337,15 @@ public:
     return NumInstrs && NumInstrs == 1;
   }
 
-  /// isCompareInstr - If the machine instruction is a comparison instruction,
-  /// then return true. Also return the source register in SrcReg and the value
-  /// it compares against in CmpValue.
-  virtual bool isCompareInstr(const MachineInstr *MI, unsigned &SrcReg,
+  /// AnalyzeCompare - For a comparison instruction, return the source register
+  /// in SrcReg and the value it compares against in CmpValue. Return true if
+  /// the comparison instruction can be analyzed.
+  virtual bool AnalyzeCompare(const MachineInstr *MI, unsigned &SrcReg,
                               int &CmpValue) const;
 
-  /// convertToSetZeroFlag - Convert the instruction to set the zero flag so
+  /// ConvertToSetZeroFlag - Convert the instruction to set the zero flag so
   /// that we can remove a "comparison with zero".
-  virtual bool convertToSetZeroFlag(MachineInstr *Instr,
+  virtual bool ConvertToSetZeroFlag(MachineInstr *Instr,
                                     MachineInstr *CmpInstr) const;
 };
 
diff --git a/lib/Target/ARM/ARMInstrThumb2.td b/lib/Target/ARM/ARMInstrThumb2.td
index 4ec71c4..a73aefc 100644
--- a/lib/Target/ARM/ARMInstrThumb2.td
+++ b/lib/Target/ARM/ARMInstrThumb2.td
@@ -2155,11 +2155,12 @@ def : T2Pat<(or (and rGPR:$src1, 0xFFFF0000),
 //===----------------------------------------------------------------------===//
 //  Comparison Instructions...
 //
-
+let isCompare = 1 in {
 defm t2CMP  : T2I_cmp_irs<0b1101, "cmp",
                           BinOpFrag<(ARMcmp node:$LHS, node:$RHS)>>;
 defm t2CMPz : T2I_cmp_irs<0b1101, "cmp",
                           BinOpFrag<(ARMcmpZ node:$LHS, node:$RHS)>>;
+}
 
 //FIXME: Disable CMN, as CCodes are backwards from compare expectations
 //       Compare-to-zero still works out, just not the relationals