Split the init.trampoline intrinsic, which currently combines GCC's

init.trampoline and adjust.trampoline intrinsics, into two intrinsics
like in GCC.  While having one combined intrinsic is tempting, it is
not natural because typically the trampoline initialization needs to
be done in one function, and the result of adjust trampoline is needed
in a different (nested) function.  To get around this llvm-gcc hacks the
nested function lowering code to insert an additional parent variable
holding the adjust.trampoline result that can be accessed from the child
function.  Dragonegg doesn't have the luxury of tweaking GCC code, so it
stored the result of adjust.trampoline in the memory GCC set aside for
the trampoline itself (this is always available in the child function),
and set up some new memory (using an alloca) to hold the trampoline.
Unfortunately this breaks Go which allocates trampoline memory on the
heap and wants to use it even after the parent has exited (!).  Rather
than doing even more hacks to get Go working, it seemed best to just use
two intrinsics like in GCC.  Patch mostly by Sanjoy Das.

llvm-svn: 139140

1 files changed, 13 insertions, 9 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index be94b08e75a..39e6c2412f6 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -211,7 +211,8 @@ PPCTargetLowering::PPCTargetLowering(PPCTargetMachine &TM)
   setOperationAction(ISD::TRAP, MVT::Other, Legal);
 
   // TRAMPOLINE is custom lowered.
-  setOperationAction(ISD::TRAMPOLINE, MVT::Other, Custom);
+  setOperationAction(ISD::INIT_TRAMPOLINE, MVT::Other, Custom);
+  setOperationAction(ISD::ADJUST_TRAMPOLINE, MVT::Other, Custom);
 
   // VASTART needs to be custom lowered to use the VarArgsFrameIndex
   setOperationAction(ISD::VASTART           , MVT::Other, Custom);
@@ -1373,8 +1374,13 @@ SDValue PPCTargetLowering::LowerVAARG(SDValue Op, SelectionDAG &DAG,
   return DAG.getLoad(VT, dl, InChain, Result, MachinePointerInfo(), false, false, 0);
 }
 
-SDValue PPCTargetLowering::LowerTRAMPOLINE(SDValue Op,
-                                           SelectionDAG &DAG) const {
+SDValue PPCTargetLowering::LowerADJUST_TRAMPOLINE(SDValue Op,
+                                                  SelectionDAG &DAG) const {
+  return Op.getOperand(0);
+}
+
+SDValue PPCTargetLowering::LowerINIT_TRAMPOLINE(SDValue Op,
+                                                SelectionDAG &DAG) const {
   SDValue Chain = Op.getOperand(0);
   SDValue Trmp = Op.getOperand(1); // trampoline
   SDValue FPtr = Op.getOperand(2); // nested function
@@ -1403,16 +1409,13 @@ SDValue PPCTargetLowering::LowerTRAMPOLINE(SDValue Op,
 
   // Lower to a call to __trampoline_setup(Trmp, TrampSize, FPtr, ctx_reg)
   std::pair<SDValue, SDValue> CallResult =
-    LowerCallTo(Chain, Op.getValueType().getTypeForEVT(*DAG.getContext()),
+    LowerCallTo(Chain, Type::getVoidTy(*DAG.getContext()),
                 false, false, false, false, 0, CallingConv::C, false,
                 /*isReturnValueUsed=*/true,
                 DAG.getExternalSymbol("__trampoline_setup", PtrVT),
                 Args, DAG, dl);
 
-  SDValue Ops[] =
-    { CallResult.first, CallResult.second };
-
-  return DAG.getMergeValues(Ops, 2, dl);
+  return CallResult.second;
 }
 
 SDValue PPCTargetLowering::LowerVASTART(SDValue Op, SelectionDAG &DAG,
@@ -4499,7 +4502,8 @@ SDValue PPCTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
   case ISD::GlobalTLSAddress:   llvm_unreachable("TLS not implemented for PPC");
   case ISD::JumpTable:          return LowerJumpTable(Op, DAG);
   case ISD::SETCC:              return LowerSETCC(Op, DAG);
-  case ISD::TRAMPOLINE:         return LowerTRAMPOLINE(Op, DAG);
+  case ISD::INIT_TRAMPOLINE:    return LowerINIT_TRAMPOLINE(Op, DAG);
+  case ISD::ADJUST_TRAMPOLINE:  return LowerADJUST_TRAMPOLINE(Op, DAG);
   case ISD::VASTART:
     return LowerVASTART(Op, DAG, PPCSubTarget);