- Change MachineInstr::isIdenticalTo to take a new option that determines whether...

- Eliminate TargetInstrInfo::isIdentical and replace it with produceSameValue. In the default case, produceSameValue just checks whether two machine instructions are identical (except for virtual register defs). But targets may override it to check for unusual cases (e.g. ARM pic loads from constant pools).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97628 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h
index a8a8f6ff55a6787b10be5dcebcd88955e8425bc5..66be26c950a77fd856d59501b9bfec1a80fbb789 100644 (file)
--- a/include/llvm/CodeGen/MachineInstr.h
+++ b/include/llvm/CodeGen/MachineInstr.h
@@ -179,17 +179,16 @@ public:
     return MemRefsEnd - MemRefs == 1;
   }
 
+  enum MICheckType {
+    CheckDefs,      // Check all operands for equality
+    IgnoreDefs,     // Ignore all definitions
+    IgnoreVRegDefs  // Ignore virtual register definitions
+  };
+
   /// isIdenticalTo - Return true if this instruction is identical to (same
   /// opcode and same operands as) the specified instruction.
-  bool isIdenticalTo(const MachineInstr *Other) const {
-    if (Other->getOpcode() != getOpcode() ||
-        Other->getNumOperands() != getNumOperands())
-      return false;
-    for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
-      if (!getOperand(i).isIdenticalTo(Other->getOperand(i)))
-        return false;
-    return true;
-  }
+  bool isIdenticalTo(const MachineInstr *Other,
+                     MICheckType Check = CheckDefs) const;
 
   /// removeFromParent - This method unlinks 'this' from the containing basic
   /// block, and returns it, but does not delete it.

diff --git a/include/llvm/Target/TargetInstrInfo.h b/include/llvm/Target/TargetInstrInfo.h
index d95e4e8acdef2e13508587364b9215cc6536f2f8..4b26beb82cef283ce39be804dfa3881c4ab46095 100644 (file)
--- a/include/llvm/Target/TargetInstrInfo.h
+++ b/include/llvm/Target/TargetInstrInfo.h
@@ -19,14 +19,14 @@
 
 namespace llvm {
 
-class MCAsmInfo;
-class TargetRegisterClass;
-class TargetRegisterInfo;
-class LiveVariables;
 class CalleeSavedInfo;
+class LiveVariables;
+class MCAsmInfo;
+class MachineMemOperand;
 class SDNode;
 class SelectionDAG;
-class MachineMemOperand;
+class TargetRegisterClass;
+class TargetRegisterInfo;
 
 template<class T> class SmallVectorImpl;
 
@@ -243,13 +243,11 @@ public:
   virtual bool findCommutedOpIndices(MachineInstr *MI, unsigned &SrcOpIdx1,
                                      unsigned &SrcOpIdx2) const = 0;
 
-  /// isIdentical - Return true if two instructions are identical. This differs
-  /// from MachineInstr::isIdenticalTo() in that it does not require the
-  /// virtual destination registers to be the same. This is used by MachineLICM
-  /// and other MI passes to perform CSE.
-  virtual bool isIdentical(const MachineInstr *MI,
-                           const MachineInstr *Other,
-                           const MachineRegisterInfo *MRI) const = 0;
+  /// produceSameValue - Return true if two machine instructions would produce
+  /// identical values. By default, this is only true when the two instructions
+  /// are deemed identical except for defs.
+  virtual bool produceSameValue(const MachineInstr *MI0,
+                                const MachineInstr *MI1) const = 0;
 
   /// AnalyzeBranch - Analyze the branching code at the end of MBB, returning
   /// true if it cannot be understood (e.g. it's a switch dispatch or isn't
@@ -560,10 +558,8 @@ public:
                              const TargetRegisterInfo *TRI) const;
   virtual MachineInstr *duplicate(MachineInstr *Orig,
                                   MachineFunction &MF) const;
-  virtual bool isIdentical(const MachineInstr *MI,
-                           const MachineInstr *Other,
-                           const MachineRegisterInfo *MRI) const;
-
+  virtual bool produceSameValue(const MachineInstr *MI0,
+                                const MachineInstr *MI1) const;
   virtual unsigned GetFunctionSizeInBytes(const MachineFunction &MF) const;
 };
 

diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 5f1bfff1c0c9942dc1701fb4d423597554e02b1b..cba93f14a0bb0812773602d7739cd16bd60de055 100644 (file)
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -18,6 +18,7 @@
 #include "llvm/Type.h"
 #include "llvm/Value.h"
 #include "llvm/Assembly/Writer.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
@@ -701,6 +702,28 @@ void MachineInstr::addMemOperand(MachineFunction &MF,
   MemRefsEnd = NewMemRefsEnd;
 }
 
+bool MachineInstr::isIdenticalTo(const MachineInstr *Other,
+                                 MICheckType Check) const {
+    if (Other->getOpcode() != getOpcode() ||
+        Other->getNumOperands() != getNumOperands())
+      return false;
+    for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+      const MachineOperand &MO = getOperand(i);
+      const MachineOperand &OMO = Other->getOperand(i);
+      if (Check != CheckDefs && MO.isReg() && MO.isDef()) {
+        if (Check == IgnoreDefs)
+          continue;
+        // Check == IgnoreVRegDefs
+        if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()) ||
+            TargetRegisterInfo::isPhysicalRegister(OMO.getReg()))
+          if (MO.getReg() != OMO.getReg())
+            return false;
+      } else if (!MO.isIdenticalTo(OMO))
+        return false;
+    }
+    return true;
+}
+
 /// removeFromParent - This method unlinks 'this' from the containing basic
 /// block, and returns it, but does not delete it.
 MachineInstr *MachineInstr::removeFromParent() {

diff --git a/lib/CodeGen/MachineLICM.cpp b/lib/CodeGen/MachineLICM.cpp
index bb80cd67ce51e7663dac237bb0152bb5356c8389..0361694d663699ca3d043faf68af5fd7463e06ac 100644 (file)
--- a/lib/CodeGen/MachineLICM.cpp
+++ b/lib/CodeGen/MachineLICM.cpp
@@ -445,7 +445,7 @@ MachineLICM::LookForDuplicate(const MachineInstr *MI,
                               std::vector<const MachineInstr*> &PrevMIs) {
   for (unsigned i = 0, e = PrevMIs.size(); i != e; ++i) {
     const MachineInstr *PrevMI = PrevMIs[i];
-    if (TII->isIdentical(MI, PrevMI, RegInfo))
+    if (TII->produceSameValue(MI, PrevMI))
       return PrevMI;
   }
   return 0;

diff --git a/lib/CodeGen/TargetInstrInfoImpl.cpp b/lib/CodeGen/TargetInstrInfoImpl.cpp
index a0fccabdb5af26eb89caf2d5aab30c8d4b2de6dd..e9e998f81d55fcdc49cdc75c5151d56ea39f7519 100644 (file)
--- a/lib/CodeGen/TargetInstrInfoImpl.cpp
+++ b/lib/CodeGen/TargetInstrInfoImpl.cpp
@@ -150,6 +150,11 @@ void TargetInstrInfoImpl::reMaterialize(MachineBasicBlock &MBB,
   MBB.insert(I, MI);
 }
 
+bool TargetInstrInfoImpl::produceSameValue(const MachineInstr *MI0,
+                                           const MachineInstr *MI1) const {
+  return MI0->isIdenticalTo(MI1, MachineInstr::IgnoreVRegDefs);
+}
+
 MachineInstr *TargetInstrInfoImpl::duplicate(MachineInstr *Orig,
                                              MachineFunction &MF) const {
   assert(!Orig->getDesc().isNotDuplicable() &&
@@ -157,37 +162,6 @@ MachineInstr *TargetInstrInfoImpl::duplicate(MachineInstr *Orig,
   return MF.CloneMachineInstr(Orig);
 }
 
-bool
-TargetInstrInfoImpl::isIdentical(const MachineInstr *MI,
-                                 const MachineInstr *Other,
-                                 const MachineRegisterInfo *MRI) const {
-  if (MI->getOpcode() != Other->getOpcode() ||
-      MI->getNumOperands() != Other->getNumOperands())
-    return false;
-
-  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
-    const MachineOperand &MO = MI->getOperand(i);
-    const MachineOperand &OMO = Other->getOperand(i);
-    if (MO.isReg() && MO.isDef()) {
-      assert(OMO.isReg() && OMO.isDef());
-      unsigned Reg = MO.getReg();
-      if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
-        if (Reg != OMO.getReg())
-          return false;
-      } else if (MRI->getRegClass(MO.getReg()) !=
-                 MRI->getRegClass(OMO.getReg()))
-        return false;
-
-      continue;
-    }
-
-    if (!MO.isIdenticalTo(OMO))
-      return false;
-  }
-
-  return true;
-}
-
 unsigned
 TargetInstrInfoImpl::GetFunctionSizeInBytes(const MachineFunction &MF) const {
   unsigned FnSize = 0;

diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp
index ae84da8af24a6ab353b3125d84c9af8cff583a6e..8e537d8b6280139fceef86004ebc3562b80290d7 100644 (file)
--- a/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -1037,9 +1037,8 @@ ARMBaseInstrInfo::duplicate(MachineInstr *Orig, MachineFunction &MF) const {
   return MI;
 }
 
-bool ARMBaseInstrInfo::isIdentical(const MachineInstr *MI0,
-                                  const MachineInstr *MI1,
-                                  const MachineRegisterInfo *MRI) const {
+bool ARMBaseInstrInfo::produceSameValue(const MachineInstr *MI0,
+                                        const MachineInstr *MI1) const {
   int Opcode = MI0->getOpcode();
   if (Opcode == ARM::t2LDRpci ||
       Opcode == ARM::t2LDRpci_pic ||
@@ -1068,7 +1067,7 @@ bool ARMBaseInstrInfo::isIdentical(const MachineInstr *MI0,
     return ACPV0->hasSameValue(ACPV1);
   }
 
-  return TargetInstrInfoImpl::isIdentical(MI0, MI1, MRI);
+  return MI0->isIdenticalTo(MI1, MachineInstr::IgnoreVRegDefs);
 }
 
 /// getInstrPredicate - If instruction is predicated, returns its predicate

diff --git a/lib/Target/ARM/ARMBaseInstrInfo.h b/lib/Target/ARM/ARMBaseInstrInfo.h
index 0d9d4a755b2bf6b5edec6f086be7cefa2c707595..e095acc409b6b9a1f0d73a2811066269dcb8ceb2 100644 (file)
--- a/lib/Target/ARM/ARMBaseInstrInfo.h
+++ b/lib/Target/ARM/ARMBaseInstrInfo.h
@@ -289,8 +289,8 @@ public:
 
   MachineInstr *duplicate(MachineInstr *Orig, MachineFunction &MF) const;
 
-  virtual bool isIdentical(const MachineInstr *MI, const MachineInstr *Other,
-                           const MachineRegisterInfo *MRI) const;
+  virtual bool produceSameValue(const MachineInstr *MI0,
+                                const MachineInstr *MI1) const;
 };
 
 static inline