Convert the last use of getPhysicalRegisterRegClass and remove it.

AggressiveAntiDepBreaker should not be using getPhysicalRegisterRegClass. An
instruction might be using a register that can only be replaced with one from
a subclass of getPhysicalRegisterRegClass.

With this patch we use getMinimalPhysRegClass. This is correct, but
conservative. We should check the uses of the register and select the
largest register class that can be used in all of them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108122 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Target/TargetRegisterInfo.h b/include/llvm/Target/TargetRegisterInfo.h
index ca458c57a9a83af2ef1093c0c753ed975a55ad1c..f6ac2b7b1a8faafd1f76cbd978eb804297ce2c2d 100644 (file)
--- a/include/llvm/Target/TargetRegisterInfo.h
+++ b/include/llvm/Target/TargetRegisterInfo.h
@@ -318,12 +318,6 @@ public:
     return Reg >= FirstVirtualRegister;
   }
 
-  /// getPhysicalRegisterRegClass - Returns the Register Class of a physical
-  /// register of the given type. If type is EVT::Other, then just return any
-  /// register class the register belongs to.
-  const TargetRegisterClass *
-    getPhysicalRegisterRegClass(unsigned Reg, EVT VT = MVT::Other) const;
-
   /// getMinimalPhysRegClass - Returns the Register Class of a physical
   /// register of the given type, picking the most sub register class of
   /// the right type that contains this physreg.

diff --git a/lib/CodeGen/AggressiveAntiDepBreaker.cpp b/lib/CodeGen/AggressiveAntiDepBreaker.cpp
index 7d923b1258e44f65311c370bf61744716ad7e246..a7189acc3fecd37adb9011ab791d94ea2283a87e 100644 (file)
--- a/lib/CodeGen/AggressiveAntiDepBreaker.cpp
+++ b/lib/CodeGen/AggressiveAntiDepBreaker.cpp
@@ -626,8 +626,12 @@ bool AggressiveAntiDepBreaker::FindSuitableFreeRegisters(
   // order. If that register is available, and the corresponding
   // registers are available for the other group subregisters, then we
   // can use those registers to rename.
+
+  // FIXME: Using getMinimalPhysRegClass is very conservative. We should
+  // check every use of the register and find the largest register class
+  // that can be used in all of them.
   const TargetRegisterClass *SuperRC =
-    TRI->getPhysicalRegisterRegClass(SuperReg, MVT::Other);
+    TRI->getMinimalPhysRegClass(SuperReg, MVT::Other);
 
   const TargetRegisterClass::iterator RB = SuperRC->allocation_order_begin(MF);
   const TargetRegisterClass::iterator RE = SuperRC->allocation_order_end(MF);

diff --git a/lib/Target/TargetRegisterInfo.cpp b/lib/Target/TargetRegisterInfo.cpp
index 65898243d0a22551db06dbf559387e76bc8eb05a..49bfad54136d3a039e1526e24a93edbbc1581a8a 100644 (file)
--- a/lib/Target/TargetRegisterInfo.cpp
+++ b/lib/Target/TargetRegisterInfo.cpp
@@ -39,27 +39,6 @@ TargetRegisterInfo::TargetRegisterInfo(const TargetRegisterDesc *D, unsigned NR,
 
 TargetRegisterInfo::~TargetRegisterInfo() {}
 
-/// getPhysicalRegisterRegClass - Returns the Register Class of a physical
-/// register of the given type. If type is EVT::Other, then just return any
-/// register class the register belongs to.
-const TargetRegisterClass *
-TargetRegisterInfo::getPhysicalRegisterRegClass(unsigned reg, EVT VT) const {
-  assert(isPhysicalRegister(reg) && "reg must be a physical register");
-
-  // Pick the most super 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 ((VT == MVT::Other || RC->hasType(VT)) && RC->contains(reg) &&
-        (!BestRC || BestRC->hasSuperClass(RC)))
-      BestRC = RC;
-  }
-
-  assert(BestRC && "Couldn't find the register class");
-  return BestRC;
-}
-
 /// getMinimalPhysRegClass - Returns the Register Class of a physical
 /// register of the given type, picking the most sub register class of
 /// the right type that contains this physreg.