[SOL] Bump stack frame size

Author: jackcmay

llvm/lib/Target/BPF/BPFISelLowering.cpp

@@ -13,6 +13,7 @@
 
 #include "BPFISelLowering.h"
 #include "BPF.h"
+#include "BPFRegisterInfo.h"
 #include "BPFSubtarget.h"
 #include "BPFTargetMachine.h"
 #include "llvm/CodeGen/CallingConvLower.h"
@@ -355,7 +356,7 @@ SDValue BPFTargetLowering::LowerFormalArguments(
 
       // Arguments relative to BPF::R5
       unsigned reg = MF.addLiveIn(BPF::R5, &BPF::GPRRegClass);
-      SDValue Const = DAG.getConstant(2047 - VA.getLocMemOffset(), DL, MVT::i64);
+      SDValue Const = DAG.getConstant(FrameLength - VA.getLocMemOffset(), DL, MVT::i64);
       SDValue SDV = DAG.getCopyFromReg(Chain, DL, reg, getPointerTy(MF.getDataLayout()));
       SDV = DAG.getNode(ISD::SUB, DL, PtrVT, SDV, Const);
       SDV = DAG.getLoad(LocVT, DL, Chain, SDV, MachinePointerInfo(), 0);
@@ -466,7 +467,7 @@ SDValue BPFTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
       assert(VA.isMemLoc());
 
       EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout());
-      SDValue Const = DAG.getConstant(2047 - VA.getLocMemOffset(), CLI.DL, MVT::i64);
+      SDValue Const = DAG.getConstant(FrameLength - VA.getLocMemOffset(), CLI.DL, MVT::i64);
       SDValue PtrOff = DAG.getNode(ISD::SUB, CLI.DL, PtrVT, FramePtr, Const);
       Chain = DAG.getStore(Chain, CLI.DL, Arg, PtrOff, MachinePointerInfo());
     }

llvm/lib/Target/BPF/BPFRegisterInfo.cpp

@@ -43,13 +43,11 @@ BitVector BPFRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
 
 static void WarnSize(int Offset, MachineFunction &MF, DebugLoc& DL)
 {
-  if (Offset <= -2048) {
-      const Function &F = MF.getFunction();
-      DiagnosticInfoUnsupported DiagStackSize(F,
-          "Looks like the BPF stack limit of 2048 bytes is exceeded. "
-          "Please move large on stack variables into BPF per-cpu array map.\n",
-          DL);
-      F.getContext().diagnose(DiagStackSize);
+  int MaxOffset = -1 * FrameLength;
+  if (Offset < MaxOffset) {
+      dbgs() << "Error: Function " << MF.getFunction().getName() << " Stack offset of " << Offset
+             << " exceeded max offset of " <<  MaxOffset << " by "
+             << -(Offset - MaxOffset) << " bytes, please minimize large stack variables\n";
   }
 }
 

llvm/lib/Target/BPF/BPFRegisterInfo.h

@@ -18,6 +18,8 @@
 #define GET_REGINFO_HEADER
 #include "BPFGenRegisterInfo.inc"
 
+static const unsigned FrameLength = 4096;
+
 namespace llvm {
 
 struct BPFRegisterInfo : public BPFGenRegisterInfo {