[llvm-commits] [llvm] r97663 - in /llvm/trunk: include/llvm/CodeGen/MachineRegisterInfo.h lib/CodeGen/MachineRegisterInfo.cpp lib/CodeGen/TwoAddressInstructionPass.cpp

[Evan Cheng]

Author: evancheng
Date: Wed Mar  3 15:18:38 2010
New Revision: 97663

URL: http://llvm.org/viewvc/llvm-project?rev=97663&view=rev
Log:
Add MachineRegisterInfo::hasOneUse and hasOneNonDBGUse.

Modified:
    llvm/trunk/include/llvm/CodeGen/MachineRegisterInfo.h
    llvm/trunk/lib/CodeGen/MachineRegisterInfo.cpp
    llvm/trunk/lib/CodeGen/TwoAddressInstructionPass.cpp

Modified: llvm/trunk/include/llvm/CodeGen/MachineRegisterInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/MachineRegisterInfo.h?rev=97663&r1=97662&r2=97663&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/MachineRegisterInfo.h (original)
+++ llvm/trunk/include/llvm/CodeGen/MachineRegisterInfo.h Wed Mar  3 15:18:38 2010
@@ -115,6 +115,10 @@
   /// register.
   bool use_empty(unsigned RegNo) const { return use_begin(RegNo) == use_end(); }
 
+  /// hasOneUse - Return true if there is exactly one instruction using the
+  /// specified register.
+  bool hasOneUse(unsigned RegNo) const;
+
   /// use_nodbg_iterator/use_nodbg_begin/use_nodbg_end - Walk all uses of the
   /// specified register, skipping those marked as Debug.
   typedef defusechain_iterator<true,false,true> use_nodbg_iterator;
@@ -129,6 +133,10 @@
     return use_nodbg_begin(RegNo) == use_nodbg_end();
   }
 
+  /// hasOneNonDBGUse - Return true if there is exactly one non-Debug
+  /// instruction using the specified register.
+  bool hasOneNonDBGUse(unsigned RegNo) const;
+
   /// replaceRegWith - Replace all instances of FromReg with ToReg in the
   /// machine function.  This is like llvm-level X->replaceAllUsesWith(Y),
   /// except that it also changes any definitions of the register as well.

Modified: llvm/trunk/lib/CodeGen/MachineRegisterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineRegisterInfo.cpp?rev=97663&r1=97662&r2=97663&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineRegisterInfo.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineRegisterInfo.cpp Wed Mar  3 15:18:38 2010
@@ -116,6 +116,19 @@
   return 0;
 }
 
+bool MachineRegisterInfo::hasOneUse(unsigned RegNo) const {
+  use_iterator UI = use_begin(RegNo);
+  if (UI == use_end())
+    return false;
+  return ++UI == use_end();
+}
+
+bool MachineRegisterInfo::hasOneNonDBGUse(unsigned RegNo) const {
+  use_nodbg_iterator UI = use_nodbg_begin(RegNo);
+  if (UI == use_nodbg_end())
+    return false;
+  return ++UI == use_nodbg_end();
+}
 
 #ifndef NDEBUG
 void MachineRegisterInfo::dumpUses(unsigned Reg) const {

Modified: llvm/trunk/lib/CodeGen/TwoAddressInstructionPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/TwoAddressInstructionPass.cpp?rev=97663&r1=97662&r2=97663&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/TwoAddressInstructionPass.cpp (original)
+++ llvm/trunk/lib/CodeGen/TwoAddressInstructionPass.cpp Wed Mar  3 15:18:38 2010
@@ -454,13 +454,10 @@
                                      const TargetInstrInfo *TII,
                                      bool &IsCopy,
                                      unsigned &DstReg, bool &IsDstPhys) {
-  MachineRegisterInfo::use_nodbg_iterator UI = MRI->use_nodbg_begin(Reg);
-  if (UI == MRI->use_nodbg_end())
-    return 0;
-  MachineInstr &UseMI = *UI;
-  if (++UI != MRI->use_nodbg_end())
-    // More than one use.
+  if (!MRI->hasOneNonDBGUse(Reg))
+    // None or more than one use.
     return 0;
+  MachineInstr &UseMI = *MRI->use_nodbg_begin(Reg);
   if (UseMI.getParent() != MBB)
     return 0;
   unsigned SrcReg;