Add register class hack that needs to go away, but makes it more obvious

that it needs to go away.  Use loadRegFromStackSlot where possible.

Also, remember to update the value map.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111883 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index fbe4126b2f870c03e5d64c6503af42031246914e..2247b8549e01ae5ac5164524a24142da68b16c9d 100644 (file)
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -58,6 +58,9 @@ class ARMFastISel : public FastISel {
   const TargetInstrInfo &TII;
   const TargetLowering &TLI;
   const ARMFunctionInfo *AFI;
+  
+  // FIXME: Remove this and replace it with queries.
+  const TargetRegisterClass *FixedRC;
 
   public:
     explicit ARMFastISel(FunctionLoweringInfo &funcInfo) 
@@ -67,6 +70,7 @@ class ARMFastISel : public FastISel {
       TLI(*TM.getTargetLowering()) {
       Subtarget = &TM.getSubtarget<ARMSubtarget>();
       AFI = funcInfo.MF->getInfo<ARMFunctionInfo>();
+      FixedRC = ARM::GPRRegisterClass;
     }
 
     // Code from FastISel.cpp.
@@ -109,6 +113,7 @@ class ARMFastISel : public FastISel {
 
     // Utility routines.
   private:
+    bool ARMLoadAlloca(const Instruction *I);
     bool ARMComputeRegOffset(const Value *Obj, unsigned &Reg, int &Offset);
     
     bool DefinesOptionalPredicate(MachineInstr *MI, bool *CPSR);
@@ -340,22 +345,14 @@ bool ARMFastISel::ARMComputeRegOffset(const Value *Obj, unsigned &Reg,
     //errs() << "Failing Opcode is: " << *Op1 << "\n";
     break;
     case Instruction::Alloca: {
-      // Do static allocas.
-      const AllocaInst *A = cast<AllocaInst>(Obj);
-      DenseMap<const AllocaInst*, int>::iterator SI =
-        FuncInfo.StaticAllocaMap.find(A);
-      if (SI != FuncInfo.StaticAllocaMap.end())
-        Offset =
-          TM.getRegisterInfo()->getFrameIndexReference(*FuncInfo.MF,
-                                                       SI->second, Reg);
-      else
-        return false;
-      return true;
+      assert(false && "Alloca should have been handled earlier!");
+      return false;
     }
   }
   
   if (const GlobalValue *GV = dyn_cast<GlobalValue>(Obj)) {
     //errs() << "Failing GV is: " << GV << "\n";
+    (void)GV;
     return false;
   }
   
@@ -364,12 +361,37 @@ bool ARMFastISel::ARMComputeRegOffset(const Value *Obj, unsigned &Reg,
   return Reg != 0;  
 }
 
+bool ARMFastISel::ARMLoadAlloca(const Instruction *I) {
+  Value *Op0 = I->getOperand(0);
+
+  // Verify it's an alloca.
+  const Instruction *Inst = dyn_cast<Instruction>(Op0);
+  if (!Inst || Inst->getOpcode() != Instruction::Alloca) return false;
+
+  const AllocaInst *AI = cast<AllocaInst>(Op0);
+  DenseMap<const AllocaInst*, int>::iterator SI =
+    FuncInfo.StaticAllocaMap.find(AI);
+    
+  if (SI != FuncInfo.StaticAllocaMap.end()) {
+    unsigned ResultReg = createResultReg(FixedRC);
+    TII.loadRegFromStackSlot(*FuncInfo.MBB, *FuncInfo.InsertPt,
+                              ResultReg, SI->second, FixedRC,
+                              TM.getRegisterInfo());
+    UpdateValueMap(I, ResultReg);
+    return true;
+  }
+  
+  return false;
+}
+
 bool ARMFastISel::ARMSelectLoad(const Instruction *I) {
   // Our register and offset with innocuous defaults.
   unsigned Reg = 0;
   int Offset = 0;
   
   // TODO: Think about using loadRegFromStackSlot() here when we can.
+  if (ARMLoadAlloca(I))
+    return true;
   
   // See if we can handle this as Reg + Offset
   if (!ARMComputeRegOffset(I->getOperand(0), Reg, Offset))
@@ -393,10 +415,11 @@ bool ARMFastISel::ARMSelectLoad(const Instruction *I) {
   } 
   
   // FIXME: There is more than one register class in the world...
-  unsigned ResultReg = createResultReg(ARM::GPRRegisterClass);
+  unsigned ResultReg = createResultReg(FixedRC);
   AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
                           TII.get(ARM::LDR), ResultReg)
                   .addImm(0).addReg(Reg).addImm(Offset));
+  UpdateValueMap(I, ResultReg);
         
   return true;
 }