Declare the callee saved regs

Remove the hard coded store and load of the link register
Implement ARMFrameInfo


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29727 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/ARM/ARMFrameInfo.h

@@ -0,0 +1,43 @@
+//===-- ARMTargetFrameInfo.h - Define TargetFrameInfo for ARM ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the "Instituto Nokia de Tecnologia" and
+// is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef ARM_FRAMEINFO_H
+#define ARM_FRAMEINFO_H
+
+#include "ARM.h"
+#include "llvm/Target/TargetFrameInfo.h"
+#include "llvm/Target/TargetMachine.h"
+
+namespace llvm {
+
+class ARMFrameInfo: public TargetFrameInfo {
+  std::pair<unsigned, int> LR[1];
+
+public:
+  ARMFrameInfo()
+    : TargetFrameInfo(TargetFrameInfo::StackGrowsDown, 8, 0) {
+    LR[0].first = ARM::R14;
+    LR[0].second = -4;
+  }
+
+  const std::pair<unsigned, int> *
+  getCalleeSaveSpillSlots(unsigned &NumEntries) const {
+    NumEntries = 1;
+    return &LR[0];
+  }
+};
+
+} // End llvm namespace
+
+#endif

lib/Target/ARM/ARMISelDAGToDAG.cpp

@@ -84,9 +84,8 @@ static SDOperand LowerCALL(SDOperand Op, SelectionDAG &DAG) {
   SDOperand Callee   = Op.getOperand(4);
   unsigned NumOps    = (Op.getNumOperands() - 5) / 2;
 
-  // Count how many bytes are to be pushed on the stack. Initially
-  // only the link register.
-  unsigned NumBytes = 4;
+  // Count how many bytes are to be pushed on the stack.
+  unsigned NumBytes = 0;
 
   // Add up all the space actually used.
   for (unsigned i = 4; i < NumOps; ++i)

lib/Target/ARM/ARMInstrInfo.td

@@ -61,7 +61,7 @@ let isReturn = 1 in {
   def bx: InstARM<(ops), "bx r14", [(retflag)]>;
 }
 
-let  Defs = [R0, R1, R2, R3] in {
+let  Defs = [R0, R1, R2, R3, R14] in {
   def bl: InstARM<(ops i32imm:$func, variable_ops), "bl $func", [(ARMcall tglobaladdr:$func)]>;
 }
 

lib/Target/ARM/ARMRegisterInfo.cpp

@@ -58,13 +58,21 @@ MachineInstr *ARMRegisterInfo::foldMemoryOperand(MachineInstr* MI,
 }
 
 const unsigned* ARMRegisterInfo::getCalleeSaveRegs() const {
-  static const unsigned CalleeSaveRegs[] = { 0 };
+  static const unsigned CalleeSaveRegs[] = {
+    ARM::R4,  ARM::R5, ARM::R6,  ARM::R7,
+    ARM::R8,  ARM::R9, ARM::R10, ARM::R11,
+    ARM::R14, 0
+  };
   return CalleeSaveRegs;
 }
 
 const TargetRegisterClass* const *
 ARMRegisterInfo::getCalleeSaveRegClasses() const {
-  static const TargetRegisterClass * const CalleeSaveRegClasses[] = { 0 };
+  static const TargetRegisterClass * const CalleeSaveRegClasses[] = {
+    &ARM::IntRegsRegClass, &ARM::IntRegsRegClass, &ARM::IntRegsRegClass, &ARM::IntRegsRegClass,
+    &ARM::IntRegsRegClass, &ARM::IntRegsRegClass, &ARM::IntRegsRegClass, &ARM::IntRegsRegClass,
+    &ARM::IntRegsRegClass, 0
+  };
   return CalleeSaveRegClasses;
 }
 
@@ -126,16 +134,12 @@ void ARMRegisterInfo::emitPrologue(MachineFunction &MF) const {
     // entry to the current function.  This eliminates the need for add/sub
     // brackets around call sites.
     NumBytes += MFI->getMaxCallFrameSize();
-  } else {
-    NumBytes += 4;
   }
 
   MFI->setStackSize(NumBytes);
 
   //sub sp, sp, #NumBytes
   BuildMI(MBB, MBBI, ARM::subri, 2, ARM::R13).addReg(ARM::R13).addImm(NumBytes);
-  //str lr, [sp, #NumBytes - 4]
-  BuildMI(MBB, MBBI, ARM::str, 2, ARM::R14).addImm(NumBytes - 4).addReg(ARM::R13);
 }
 
 void ARMRegisterInfo::emitEpilogue(MachineFunction &MF,
@@ -147,8 +151,6 @@ void ARMRegisterInfo::emitEpilogue(MachineFunction &MF,
   MachineFrameInfo *MFI = MF.getFrameInfo();
   int          NumBytes = (int) MFI->getStackSize();
 
-  //ldr lr, [sp]
-  BuildMI(MBB, MBBI, ARM::ldr, 2, ARM::R14).addImm(NumBytes - 4).addReg(ARM::R13);
   //add sp, sp, #NumBytes
   BuildMI(MBB, MBBI, ARM::addri, 2, ARM::R13).addReg(ARM::R13).addImm(NumBytes);
 }

lib/Target/ARM/ARMTargetMachine.cpp

@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "ARMTargetMachine.h"
+#include "ARMFrameInfo.h"
 #include "ARM.h"
 #include "llvm/Assembly/PrintModulePass.h"
 #include "llvm/Module.h"
@@ -33,7 +34,7 @@ namespace {
 ///
 ARMTargetMachine::ARMTargetMachine(const Module &M, const std::string &FS)
   : TargetMachine("ARM"), DataLayout("E-p:32:32"),
-    FrameInfo(TargetFrameInfo::StackGrowsDown, 8, -4) {
+    FrameInfo() {
 }
 
 unsigned ARMTargetMachine::getModuleMatchQuality(const Module &M) {

lib/Target/ARM/ARMTargetMachine.h

@@ -20,6 +20,7 @@
 #include "llvm/Target/TargetFrameInfo.h"
 #include "llvm/PassManager.h"
 #include "ARMInstrInfo.h"
+#include "ARMFrameInfo.h"
 
 namespace llvm {
 
@@ -28,7 +29,7 @@ class Module;
 class ARMTargetMachine : public TargetMachine {
   const TargetData DataLayout;       // Calculates type size & alignment
   ARMInstrInfo InstrInfo;
-  TargetFrameInfo FrameInfo;
+  ARMFrameInfo FrameInfo;
 public:
   ARMTargetMachine(const Module &M, const std::string &FS);