[llvm-commits] [llvm] r63936 - in /llvm/trunk: include/llvm/Target/TargetInstrInfo.h lib/CodeGen/PreAllocSplitting.cpp lib/Target/X86/X86InstrInfo.cpp lib/Target/X86/X86InstrInfo.h

[Evan Cheng]

Author: evancheng
Date: Fri Feb  6 11:17:30 2009
New Revision: 63936

URL: http://llvm.org/viewvc/llvm-project?rev=63936&view=rev
Log:
Add TargetInstrInfo::isSafeToMoveRegisterClassDefs. It returns true if it's safe to move an instruction which defines a value in the register class. Replace pre-splitting specific IgnoreRegisterClassBarriers with this new hook.

Modified:
    llvm/trunk/include/llvm/Target/TargetInstrInfo.h
    llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp
    llvm/trunk/lib/Target/X86/X86InstrInfo.cpp
    llvm/trunk/lib/Target/X86/X86InstrInfo.h

Modified: llvm/trunk/include/llvm/Target/TargetInstrInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/TargetInstrInfo.h?rev=63936&r1=63935&r2=63936&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Target/TargetInstrInfo.h (original)
+++ llvm/trunk/include/llvm/Target/TargetInstrInfo.h Fri Feb  6 11:17:30 2009
@@ -427,10 +427,9 @@
     return false;
   }
 
-  /// IgnoreRegisterClassBarriers - Returns true if pre-register allocation
-  /// live interval splitting pass should ignore barriers of the specified
-  /// register class.
-  virtual bool IgnoreRegisterClassBarriers(const TargetRegisterClass *RC) const{
+  /// isSafeToMoveRegClassDefs - Return true if it's safe to move a machine
+  /// instruction that defines the specified register class.
+  virtual bool isSafeToMoveRegClassDefs(const TargetRegisterClass *RC) const {
     return true;
   }
 

Modified: llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp?rev=63936&r1=63935&r2=63936&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp (original)
+++ llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp Fri Feb  6 11:17:30 2009
@@ -1128,7 +1128,10 @@
   // by the current barrier.
   SmallVector<LiveInterval*, 8> Intervals;
   for (const TargetRegisterClass **RC = RCs; *RC; ++RC) {
-    if (TII->IgnoreRegisterClassBarriers(*RC))
+    // FIXME: If it's not safe to move any instruction that defines the barrier
+    // register class, then it means there are some special dependencies which
+    // codegen is not modelling. Ignore these barriers for now.
+    if (!TII->isSafeToMoveRegClassDefs(*RC))
       continue;
     std::vector<unsigned> &VRs = MRI->getRegClassVirtRegs(*RC);
     for (unsigned i = 0, e = VRs.size(); i != e; ++i) {

Modified: llvm/trunk/lib/Target/X86/X86InstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrInfo.cpp?rev=63936&r1=63935&r2=63936&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86InstrInfo.cpp Fri Feb  6 11:17:30 2009
@@ -2483,11 +2483,11 @@
 }
 
 bool X86InstrInfo::
-IgnoreRegisterClassBarriers(const TargetRegisterClass *RC) const {
-  // FIXME: Ignore bariers of x87 stack registers for now. We can't
+isSafeToMoveRegClassDefs(const TargetRegisterClass *RC) const {
+  // FIXME: Return false for x87 stack register classes for now. We can't
   // allow any loads of these registers before FpGet_ST0_80.
-  return RC == &X86::CCRRegClass || RC == &X86::RFP32RegClass ||
-    RC == &X86::RFP64RegClass || RC == &X86::RFP80RegClass;
+  return !(RC == &X86::CCRRegClass || RC == &X86::RFP32RegClass ||
+           RC == &X86::RFP64RegClass || RC == &X86::RFP80RegClass);
 }
 
 const TargetRegisterClass *X86InstrInfo::getPointerRegClass() const {

Modified: llvm/trunk/lib/Target/X86/X86InstrInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrInfo.h?rev=63936&r1=63935&r2=63936&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrInfo.h (original)
+++ llvm/trunk/lib/Target/X86/X86InstrInfo.h Fri Feb  6 11:17:30 2009
@@ -406,10 +406,9 @@
   virtual
   bool ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const;
 
-  /// IgnoreRegisterClassBarriers - Returns true if pre-register allocation
-  /// live interval splitting pass should ignore barriers of the specified
-  /// register class.
-  bool IgnoreRegisterClassBarriers(const TargetRegisterClass *RC) const;
+  /// isSafeToMoveRegClassDefs - Return true if it's safe to move a machine
+  /// instruction that defines the specified register class.
+  bool isSafeToMoveRegClassDefs(const TargetRegisterClass *RC) const;
 
   const TargetRegisterClass *getPointerRegClass() const;