[X86] Fix the lowering of setjmp intrinsic on i386.

When the lowering of the setjmp intrinsic requires
a global base pointer to be set, make sure such pointer
gets defined by the CGBR pass.

This fixes PR26742.

llvm-svn: 262762

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index e85c04e4f7c..578f5a931fe 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -18322,6 +18322,16 @@ SDValue X86TargetLowering::LowerEH_RETURN(SDValue Op, SelectionDAG &DAG) const {
 SDValue X86TargetLowering::lowerEH_SJLJ_SETJMP(SDValue Op,
                                                SelectionDAG &DAG) const {
   SDLoc DL(Op);
+  // If the subtarget is not 64bit, we may need the global base reg
+  // after isel expand pseudo, i.e., after CGBR pass ran.
+  // Therefore, ask for the GlobalBaseReg now, so that the pass
+  // inserts the code for us in case we need it.
+  // Otherwise, we will end up in a situation where we will
+  // reference a virtual register that is not defined!
+  if (!Subtarget.is64Bit()) {
+    const X86InstrInfo *TII = Subtarget.getInstrInfo();
+    (void)TII->getGlobalBaseReg(&DAG.getMachineFunction());
+  }
   return DAG.getNode(X86ISD::EH_SJLJ_SETJMP, DL,
                      DAG.getVTList(MVT::i32, MVT::Other),
                      Op.getOperand(0), Op.getOperand(1));