[SOL] Push stack args to the bottom of the stack

anza-xyz · Aug 19, 2024 · 37daba6 · 37daba6
1 parent e084e41
commit 37daba6
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Showing 2 changed files with 6 additions and 9 deletions.
diff --git a/llvm/lib/Target/BPF/BPFISelLowering.cpp b/llvm/lib/Target/BPF/BPFISelLowering.cpp
@@ -388,7 +388,7 @@ SDValue BPFTargetLowering::LowerFormalArguments(
 
       // Arguments relative to BPF::R5
       unsigned reg = MF.addLiveIn(BPF::R5, &BPF::GPRRegClass);
-      SDValue Const = DAG.getConstant(VA.getLocMemOffset() + 8, DL, MVT::i64);
+      SDValue Const = DAG.getConstant(2047 - 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);
@@ -488,7 +488,7 @@ SDValue BPFTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   if (HasStackArgs) {
     SDValue FramePtr = DAG.getCopyFromReg(Chain, CLI.DL, BPF::R10, getPointerTy(MF.getDataLayout()));
 
-    // Stack arguments have to walked in reverse order by inserting
+    // Stack arguments have to be walked in reverse order by inserting
     // chained stores, this ensures their order is not changed by the scheduler
     // and that the push instruction sequence generated is correct, otherwise they
     // can be freely intermixed.
@@ -500,7 +500,7 @@ SDValue BPFTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
       assert(VA.isMemLoc());
 
       EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout());
-      SDValue Const = DAG.getConstant(VA.getLocMemOffset() + 8, CLI.DL, MVT::i64);
+      SDValue Const = DAG.getConstant(2047 - 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());
     }

diff --git a/llvm/lib/Target/BPF/BPFRegisterInfo.cpp b/llvm/lib/Target/BPF/BPFRegisterInfo.cpp
@@ -51,12 +51,9 @@ 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 is exceeded. "
-          "Please move large on stack variables into BPF per-cpu array map. For "
-          "non-kernel uses, the stack can be increased using -mllvm "
-          "-bpf-stack-size.\n",
+      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);
   }