Long live the exception handling!
This patch fills the last necessary bits to enable exceptions
handling in LLVM. Currently only on x86-32/linux.
In fact, this patch adds necessary intrinsics (and their lowering) which
represent really weird target-specific gcc builtins used inside unwinder.
After corresponding llvm-gcc patch will land (easy) exceptions should be
more or less workable. However, exceptions handling support should not be
thought as 'finished': I expect many small and not so small glitches
everywhere.
llvm-svn: 39855
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 3bf2b9f..37dea79 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -42,6 +42,8 @@
X86ScalarSSE = Subtarget->hasSSE2();
X86StackPtr = Subtarget->is64Bit() ? X86::RSP : X86::ESP;
+ RegInfo = TM.getRegisterInfo();
+
// Set up the TargetLowering object.
// X86 is weird, it always uses i8 for shift amounts and setcc results.
@@ -197,6 +199,9 @@
}
// X86 ret instruction may pop stack.
setOperationAction(ISD::RET , MVT::Other, Custom);
+ if (!Subtarget->is64Bit())
+ setOperationAction(ISD::EH_RETURN , MVT::Other, Custom);
+
// Darwin ABI issue.
setOperationAction(ISD::ConstantPool , MVT::i32 , Custom);
setOperationAction(ISD::JumpTable , MVT::i32 , Custom);
@@ -4226,6 +4231,39 @@
DAG.getConstant(4, getPointerTy()));
}
+SDOperand X86TargetLowering::LowerFRAME_TO_ARGS_OFFSET(SDOperand Op,
+ SelectionDAG &DAG) {
+ // Is not yet supported on x86-64
+ if (Subtarget->is64Bit())
+ return SDOperand();
+
+ return DAG.getConstant(8, getPointerTy());
+}
+
+SDOperand X86TargetLowering::LowerEH_RETURN(SDOperand Op, SelectionDAG &DAG)
+{
+ assert(!Subtarget->is64Bit() &&
+ "Lowering of eh_return builtin is not supported yet on x86-64");
+
+ MachineFunction &MF = DAG.getMachineFunction();
+ SDOperand Chain = Op.getOperand(0);
+ SDOperand Offset = Op.getOperand(1);
+ SDOperand Handler = Op.getOperand(2);
+
+ SDOperand Frame = DAG.getRegister(RegInfo->getFrameRegister(MF),
+ getPointerTy());
+
+ SDOperand StoreAddr = DAG.getNode(ISD::SUB, getPointerTy(), Frame,
+ DAG.getConstant(-4UL, getPointerTy()));
+ StoreAddr = DAG.getNode(ISD::ADD, getPointerTy(), StoreAddr, Offset);
+ Chain = DAG.getStore(Chain, Handler, StoreAddr, NULL, 0);
+ Chain = DAG.getCopyToReg(Chain, X86::ECX, StoreAddr);
+ MF.addLiveOut(X86::ECX);
+
+ return DAG.getNode(X86ISD::EH_RETURN, MVT::Other,
+ Chain, DAG.getRegister(X86::ECX, getPointerTy()));
+}
+
/// LowerOperation - Provide custom lowering hooks for some operations.
///
SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
@@ -4263,7 +4301,10 @@
case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG);
case ISD::RETURNADDR: return LowerRETURNADDR(Op, DAG);
case ISD::FRAMEADDR: return LowerFRAMEADDR(Op, DAG);
+ case ISD::FRAME_TO_ARGS_OFFSET:
+ return LowerFRAME_TO_ARGS_OFFSET(Op, DAG);
case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
+ case ISD::EH_RETURN: return LowerEH_RETURN(Op, DAG);
}
return SDOperand();
}
@@ -4311,6 +4352,7 @@
case X86ISD::FRCP: return "X86ISD::FRCP";
case X86ISD::TLSADDR: return "X86ISD::TLSADDR";
case X86ISD::THREAD_POINTER: return "X86ISD::THREAD_POINTER";
+ case X86ISD::EH_RETURN: return "X86ISD::EH_RETURN";
}
}