Revamp the SjLj "dispatch setup" intrinsic.

It needed to be moved closer to the setjmp statement, because the code directly
after the setjmp needs to know about values that are on the stack. Also, the
'bitcast' of the function context was causing a dead load. This wouldn't be too
horrible, except that at -O0 it wasn't optimized out, and because it wasn't
using the correct base pointer (if there is a VLA), it would try to access a
value from a garbage address.
<rdar://problem/9130540>

llvm-svn: 128873

llvm/include/llvm/Intrinsics.td

@@ -307,7 +307,7 @@ let Properties = [IntrNoMem] in {
   def int_eh_sjlj_lsda    : Intrinsic<[llvm_ptr_ty]>;
   def int_eh_sjlj_callsite: Intrinsic<[], [llvm_i32_ty]>;
 }
-def int_eh_sjlj_dispatch_setup : Intrinsic<[], [llvm_ptr_ty]>;
+def int_eh_sjlj_dispatch_setup : Intrinsic<[], []>;
 def int_eh_sjlj_setjmp  : Intrinsic<[llvm_i32_ty], [llvm_ptr_ty]>;
 def int_eh_sjlj_longjmp : Intrinsic<[], [llvm_ptr_ty]>;
 

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -4403,7 +4403,7 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) {
   }
   case Intrinsic::eh_sjlj_dispatch_setup: {
     DAG.setRoot(DAG.getNode(ISD::EH_SJLJ_DISPATCHSETUP, dl, MVT::Other,
-                            getRoot(), getValue(I.getArgOperand(0))));
+                            getRoot()));
     return 0;
   }
 

llvm/lib/CodeGen/SjLjEHPrepare.cpp

@@ -442,14 +442,6 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) {
   BasicBlock *DispatchBlock =
     BasicBlock::Create(F.getContext(), "eh.sjlj.setjmp.catch", &F);
 
-  // Add a call to dispatch_setup at the start of the dispatch block. This is
-  // expanded to any target-specific setup that needs to be done.
-  Value *SetupArg =
-    CastInst::Create(Instruction::BitCast, FunctionContext,
-                     Type::getInt8PtrTy(F.getContext()), "",
-                     DispatchBlock);
-  CallInst::Create(DispatchSetupFn, SetupArg, "", DispatchBlock);
-
   // Insert a load of the callsite in the dispatch block, and a switch on its
   // value.  By default, we go to a block that just does an unwind (which is the
   // correct action for a standard call).
@@ -524,6 +516,11 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) {
   Value *DispatchVal = CallInst::Create(BuiltinSetjmpFn, SetjmpArg,
                                         "dispatch",
                                         EntryBB->getTerminator());
+
+  // Add a call to dispatch_setup after the setjmp call. This is expanded to any
+  // target-specific setup that needs to be done.
+  CallInst::Create(DispatchSetupFn, "", EntryBB->getTerminator());
+
   // check the return value of the setjmp. non-zero goes to dispatcher.
   Value *IsNormal = new ICmpInst(EntryBB->getTerminator(),
                                  ICmpInst::ICMP_EQ, DispatchVal, Zero,

llvm/lib/Target/ARM/ARMISelLowering.cpp

@@ -2113,7 +2113,7 @@ ARMTargetLowering::LowerEH_SJLJ_DISPATCHSETUP(SDValue Op, SelectionDAG &DAG)
   const {
   DebugLoc dl = Op.getDebugLoc();
   return DAG.getNode(ARMISD::EH_SJLJ_DISPATCHSETUP, dl, MVT::Other,
-                     Op.getOperand(0), Op.getOperand(1));
+                     Op.getOperand(0));
 }
 
 SDValue

llvm/lib/Target/ARM/ARMInstrInfo.td

@@ -58,7 +58,7 @@ def SDT_ARMEH_SJLJ_Setjmp : SDTypeProfile<1, 2, [SDTCisInt<0>, SDTCisPtrTy<1>,
                                                  SDTCisInt<2>]>;
 def SDT_ARMEH_SJLJ_Longjmp: SDTypeProfile<0, 2, [SDTCisPtrTy<0>, SDTCisInt<1>]>;
 
-def SDT_ARMEH_SJLJ_DispatchSetup: SDTypeProfile<0, 1, [SDTCisPtrTy<0>]>;
+def SDT_ARMEH_SJLJ_DispatchSetup: SDTypeProfile<0, 0, []>;
 
 def SDT_ARMMEMBARRIER     : SDTypeProfile<0, 1, [SDTCisInt<0>]>;
 
@@ -3777,8 +3777,8 @@ def Int_eh_sjlj_longjmp : PseudoInst<(outs), (ins GPR:$src, GPR:$scratch),
 // that need the instruction size).
 let isBarrier = 1, hasSideEffects = 1 in
 def Int_eh_sjlj_dispatchsetup :
- PseudoInst<(outs), (ins GPR:$src), NoItinerary,
-            [(ARMeh_sjlj_dispatchsetup GPR:$src)]>,
+ PseudoInst<(outs), (ins), NoItinerary,
+            [(ARMeh_sjlj_dispatchsetup)]>,
               Requires<[IsDarwin]>;
 
 //===----------------------------------------------------------------------===//