Start thinking of stack frames

Author: LucasSte

llvm/lib/Target/SBF/SBFFrameLowering.cpp

@@ -21,20 +21,26 @@ bool SBFFrameLowering::hasFPImpl(const MachineFunction &MF) const { return true;
 
 void SBFFrameLowering::emitPrologue(MachineFunction &MF,
                                     MachineBasicBlock &MBB) const {
-  if (!MF.getSubtarget<SBFSubtarget>().getHasDynamicFrames()) {
+  const SBFSubtarget& Subtarget = MF.getSubtarget<SBFSubtarget>();
+  if (!Subtarget.getHasDynamicFrames()) {
     return;
   }
+
   MachineBasicBlock::iterator MBBI = MBB.begin();
   MachineFrameInfo &MFI = MF.getFrameInfo();
   int NumBytes = (int)MFI.getStackSize();
-  if ((NumBytes || MF.getSubtarget<SBFSubtarget>().getHasStaticSyscalls()) &&
-      MBBI != MBB.end()) {
+
+  if (NumBytes && MBBI != MBB.end()) {
     DebugLoc Dl = MBBI->getDebugLoc();
     const SBFInstrInfo &TII =
         *static_cast<const SBFInstrInfo *>(MF.getSubtarget().getInstrInfo());
+
+    if (Subtarget.isDynamicFramesV1())
+      NumBytes = -NumBytes;
+
     BuildMI(MBB, MBBI, Dl, TII.get(SBF::ADD_ri), SBF::R10)
         .addReg(SBF::R10)
-        .addImm(-NumBytes);
+        .addImm(NumBytes);
   }
 }
 

llvm/lib/Target/SBF/SBFRegisterInfo.cpp

@@ -167,13 +167,20 @@ int SBFRegisterInfo::resolveInternalFrameIndex(
 
   if (SubTarget.getHasDynamicFrames() &&
       SBFFuncInfo->containsFrameIndex(FI)) {
-    return -Offset;
+    if (SubTarget.isDynamicFramesV1())
+      return -Offset;
+
+    return Offset;
   }
 
   Offset += Imm.value_or(0);
 
   if (SubTarget.getHasDynamicFrames()) {
-    return static_cast<int>(StackSize) + Offset;
+    Offset += static_cast<int>(StackSize);
+    if (SubTarget.isDynamicFramesV1())
+      return Offset;
+
+    return -Offset;
   }
 
   return Offset;

llvm/lib/Target/SBF/SBFSubtarget.h

@@ -92,6 +92,8 @@ class SBFSubtarget : public SBFGenSubtargetInfo {
   // JMP32 support depends on ALU32 being enabled
   bool HasJmp32;
 
+  bool HasDynamicFramesV3;
+
   std::unique_ptr<CallLowering> CallLoweringInfo;
   std::unique_ptr<InstructionSelector> InstSelector;
   std::unique_ptr<LegalizerInfo> Legalizer;
@@ -110,7 +112,12 @@ class SBFSubtarget : public SBFGenSubtargetInfo {
   // subtarget options.  Definition of function is auto generated by tblgen.
   void ParseSubtargetFeatures(StringRef CPU, StringRef TuneCPU, StringRef FS);
   bool getHasAlu32() const { return HasAlu32; }
-  bool getHasDynamicFrames() const { return HasDynamicFrames; }
+  bool getHasDynamicFrames() const {
+    return HasDynamicFrames || HasDynamicFramesV3;
+  }
+  bool isDynamicFramesV1() const {
+    return HasDynamicFrames;
+  }
   bool getUseDwarfRIS() const { return UseDwarfRIS; }
   bool getDisableNeg() const { return DisableNeg; }
   bool getReverseSubImm() const { return ReverseSubImm; }

llvm/lib/Target/SBF/SBFTargetFeatures.td

@@ -55,6 +55,9 @@ def FeatureAbiV2 : SubtargetFeature<"abi-v2", "IsAbiV2",
 def FeatureJmp32 : SubtargetFeature<"jmp-32", "HasJmp32", "true",
                                                 "Enable the JMP32 instruction class">;
 
+def FeatureDynamicFramesV3 : SubtargetFeature<"dynamic-frames-v3", "HasDynamicFramesV3", "true",
+                                            "Enable dynamic frames in SBPFv3">;
+
 class Proc<string Name, list<SubtargetFeature> Features>
  : Processor<Name, NoItineraries, Features>;