- Change MachineInstr::isIdenticalTo to take a new option that determines whether it should skip checking defs or at least virtual register defs. This subsumes part of the TargetInstrInfo::isIdentical functionality.

- 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

5 files changed, 34 insertions, 38 deletions

diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 5f1bfff1c0..cba93f14a0 100644
--- 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 bb80cd67ce..0361694d66 100644
--- 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 a0fccabdb5..e9e998f81d 100644
--- 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 ae84da8af2..8e537d8b62 100644
--- 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 0d9d4a755b..e095acc409 100644
--- 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