Fix PR5367. QPR_8 is the super regclass of DPR_8 and SPR_8.

[oota-llvm.git] / lib / Target / ARM / ARMBaseRegisterInfo.cpp

diff --git a/lib/Target/ARM/ARMBaseRegisterInfo.cpp b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
index 3de83af8344751f44e571e960c54d953b3ce2f49..c1c531c9376bb7e56c0f01b8f3b376fffd61af13 100644 (file)
--- a/lib/Target/ARM/ARMBaseRegisterInfo.cpp
+++ b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
@@ -265,16 +265,25 @@ ARMBaseRegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A,
   case 4:
     // S sub-registers.
     if (A->getSize() == 8) {
+      if (B == &ARM::SPR_8RegClass)
+        return &ARM::DPR_8RegClass;
+      assert(B == &ARM::SPRRegClass && "Expecting SPR register class!");
       if (A == &ARM::DPR_8RegClass)
         return A;
       return &ARM::DPR_VFP2RegClass;
     }
 
     assert(A->getSize() == 16 && "Expecting a Q register class!");
+    if (B == &ARM::SPR_8RegClass)
+      return &ARM::QPR_8RegClass;
     return &ARM::QPR_VFP2RegClass;
   case 5:
   case 6:
     // D sub-registers.
+    if (B == &ARM::DPR_VFP2RegClass)
+      return &ARM::QPR_VFP2RegClass;
+    if (B == &ARM::DPR_8RegClass)
+      return &ARM::QPR_8RegClass;
     return A;
   }
   return 0;
@@ -467,11 +476,7 @@ ARMBaseRegisterInfo::UpdateRegAllocHint(unsigned Reg, unsigned NewReg,
 }
 
 static unsigned calculateMaxStackAlignment(const MachineFrameInfo *FFI) {
-  // FIXME: For now, force at least 128-bit alignment. This will push the
-  // nightly tester harder for making sure things work correctly. When
-  // we're ready to enable this for real, this goes back to starting at zero.
-  unsigned MaxAlign = 16;
-//  unsigned MaxAlign = 0;
+  unsigned MaxAlign = 0;
 
   for (int i = FFI->getObjectIndexBegin(),
          e = FFI->getObjectIndexEnd(); i != e; ++i) {
@@ -504,14 +509,12 @@ needsStackRealignment(const MachineFunction &MF) const {
   if (!ARMDynamicStackAlign)
     return false;
 
-  // FIXME: To force more brutal testing, realign whether we need to or not.
-  // Change this to be more selective when we turn it on for real, of course.
   const MachineFrameInfo *MFI = MF.getFrameInfo();
   const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
-//  unsigned StackAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
+  unsigned StackAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
   return (RealignStack &&
           !AFI->isThumb1OnlyFunction() &&
-//          (MFI->getMaxAlignment() > StackAlign) &&
+          (MFI->getMaxAlignment() > StackAlign) &&
           !MFI->hasVarSizedObjects());
 }
 
@@ -1121,6 +1124,7 @@ ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   unsigned FrameReg = ARM::SP;
   int FrameIndex = MI.getOperand(i).getIndex();
   int Offset = MFI->getObjectOffset(FrameIndex) + MFI->getStackSize() + SPAdj;
+  bool isFixed = MFI->isFixedObjectIndex(FrameIndex);
 
   // When doing dynamic stack realignment, all of these need to change(?)
   if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
@@ -1133,7 +1137,7 @@ ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
     // When dynamically realigning the stack, use the frame pointer for
     // parameters, and the stack pointer for locals.
     assert (hasFP(MF) && "dynamic stack realignment without a FP!");
-    if (FrameIndex < 0) {
+    if (isFixed) {
       FrameReg = getFrameRegister(MF);
       Offset -= AFI->getFramePtrSpillOffset();
       // When referencing from the frame pointer, stack pointer adjustments
@@ -1142,13 +1146,22 @@ ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
     }
   } else if (hasFP(MF) && AFI->hasStackFrame()) {
     assert(SPAdj == 0 && "Unexpected stack offset!");
-    // Use frame pointer to reference fixed objects unless this is a
-    // frameless function.
-    FrameReg = getFrameRegister(MF);
-    Offset -= AFI->getFramePtrSpillOffset();
+    if (isFixed || MFI->hasVarSizedObjects()) {
+      // Use frame pointer to reference fixed objects unless this is a
+      // frameless function.
+      FrameReg = getFrameRegister(MF);
+      Offset -= AFI->getFramePtrSpillOffset();
+    } else if (AFI->isThumb2Function()) {
+      // In Thumb2 mode, the negative offset is very limited.
+      int FPOffset = Offset - AFI->getFramePtrSpillOffset();
+      if (FPOffset >= -255 && FPOffset < 0) {
+        FrameReg = getFrameRegister(MF);
+        Offset = FPOffset;
+      }
+    }
   }
 
-  // modify MI as necessary to handle as much of 'Offset' as possible
+  // Modify MI as necessary to handle as much of 'Offset' as possible
   bool Done = false;
   if (!AFI->isThumbFunction())
     Done = rewriteARMFrameIndex(MI, i, FrameReg, Offset, TII);