From ce48c1de828688b34cf5c2038fde23368a0a45f4 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Wed, 2 Jun 2010 12:39:06 +0000
Subject: [PATCH] Remove uses of getCalleeSavedRegClasses from outside the
 backends and removes the virtual declaration. With that out of the way I
 should be able to cleanup one backend at a time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105321 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Target/TargetRegisterInfo.h |  9 ++++-----
 lib/CodeGen/PrologEpilogInserter.cpp     | 10 +++-------
 lib/Target/TargetRegisterInfo.cpp        | 19 +++++++++++++++++++
 3 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/include/llvm/Target/TargetRegisterInfo.h b/include/llvm/Target/TargetRegisterInfo.h
index 45d27aad392..a2493fddd8b 100644
--- a/include/llvm/Target/TargetRegisterInfo.h
+++ b/include/llvm/Target/TargetRegisterInfo.h
@@ -319,6 +319,10 @@ public:
   virtual const TargetRegisterClass *
     getPhysicalRegisterRegClass(unsigned Reg, EVT VT = MVT::Other) const;
 
+  /// getMinimalPhysRegClass - Returns the Register Class of a physical
+  /// register of the given type.
+  const TargetRegisterClass * getMinimalPhysRegClass(unsigned Reg) const;
+
   /// getAllocatableSet - Returns a bitset indexed by register number
   /// indicating if a register is allocatable or not. If a register class is
   /// specified, returns the subset for the class.
@@ -438,11 +442,6 @@ public:
   virtual const unsigned* getCalleeSavedRegs(const MachineFunction *MF = 0)
                                                                       const = 0;
 
-  /// getCalleeSavedRegClasses - Return a null-terminated list of the preferred
-  /// register classes to spill each callee saved register with.  The order and
-  /// length of this list match the getCalleeSaveRegs() list.
-  virtual const TargetRegisterClass* const *getCalleeSavedRegClasses(
-                                            const MachineFunction *MF) const =0;
 
   /// getReservedRegs - Returns a bitset indexed by physical register number
   /// indicating if a register is a special register that has particular uses
diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp
index e778024c6a3..d73383e71ff 100644
--- a/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/lib/CodeGen/PrologEpilogInserter.cpp
@@ -202,22 +202,18 @@ void PEI::calculateCalleeSavedRegisters(MachineFunction &Fn) {
   if (Fn.getFunction()->hasFnAttr(Attribute::Naked))
     return;
 
-  // Figure out which *callee saved* registers are modified by the current
-  // function, thus needing to be saved and restored in the prolog/epilog.
-  const TargetRegisterClass * const *CSRegClasses =
-    RegInfo->getCalleeSavedRegClasses(&Fn);
-
   std::vector<CalleeSavedInfo> CSI;
   for (unsigned i = 0; CSRegs[i]; ++i) {
     unsigned Reg = CSRegs[i];
+    const TargetRegisterClass *RC = RegInfo->getMinimalPhysRegClass(Reg);
     if (Fn.getRegInfo().isPhysRegUsed(Reg)) {
       // If the reg is modified, save it!
-      CSI.push_back(CalleeSavedInfo(Reg, CSRegClasses[i]));
+      CSI.push_back(CalleeSavedInfo(Reg, RC));
     } else {
       for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg);
            *AliasSet; ++AliasSet) {  // Check alias registers too.
         if (Fn.getRegInfo().isPhysRegUsed(*AliasSet)) {
-          CSI.push_back(CalleeSavedInfo(Reg, CSRegClasses[i]));
+          CSI.push_back(CalleeSavedInfo(Reg, RC));
           break;
         }
       }
diff --git a/lib/Target/TargetRegisterInfo.cpp b/lib/Target/TargetRegisterInfo.cpp
index dcc5f610e6d..32299f6c7e0 100644
--- a/lib/Target/TargetRegisterInfo.cpp
+++ b/lib/Target/TargetRegisterInfo.cpp
@@ -60,6 +60,25 @@ TargetRegisterInfo::getPhysicalRegisterRegClass(unsigned reg, EVT VT) const {
   return BestRC;
 }
 
+/// getMinimalPhysRegClass - Returns the Register Class of a physical
+/// register of the given type.
+const TargetRegisterClass *
+TargetRegisterInfo::getMinimalPhysRegClass(unsigned reg) const {
+  assert(isPhysicalRegister(reg) && "reg must be a physical register");
+
+  // Pick the most sub register class of the right type that contains
+  // this physreg.
+  const TargetRegisterClass* BestRC = 0;
+  for (regclass_iterator I = regclass_begin(), E = regclass_end(); I != E; ++I){
+    const TargetRegisterClass* RC = *I;
+    if (RC->contains(reg) && (!BestRC || BestRC->hasSubClass(RC)))
+      BestRC = RC;
+  }
+
+  assert(BestRC && "Couldn't find the register class");
+  return BestRC;
+}
+
 /// getAllocatableSetForRC - Toggle the bits that represent allocatable
 /// registers for the specific register class.
 static void getAllocatableSetForRC(const MachineFunction &MF,