[RISCV] Lower calls through PLT

This patch adds support for generating calls through the procedure
linkage table where required for a given ExternalSymbol or GlobalAddress
callee.

Differential Revision: https://reviews.llvm.org/D55304

llvm-svn: 363686

1 files changed, 14 insertions, 4 deletions

diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 363f8150340..45217f6bd1f 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -1921,11 +1921,21 @@ SDValue RISCVTargetLowering::LowerCall(CallLoweringInfo &CLI,
   // TargetGlobalAddress/TargetExternalSymbol node so that legalize won't
   // split it and then direct call can be matched by PseudoCALL.
   if (GlobalAddressSDNode *S = dyn_cast<GlobalAddressSDNode>(Callee)) {
-    Callee = DAG.getTargetGlobalAddress(S->getGlobal(), DL, PtrVT, 0,
-                                        RISCVII::MO_CALL);
+    const GlobalValue *GV = S->getGlobal();
+
+    unsigned OpFlags = RISCVII::MO_CALL;
+    if (!getTargetMachine().shouldAssumeDSOLocal(*GV->getParent(), GV))
+      OpFlags = RISCVII::MO_PLT;
+
+    Callee = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, OpFlags);
   } else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
-    Callee =
-        DAG.getTargetExternalSymbol(S->getSymbol(), PtrVT, RISCVII::MO_CALL);
+    unsigned OpFlags = RISCVII::MO_CALL;
+
+    if (!getTargetMachine().shouldAssumeDSOLocal(*MF.getFunction().getParent(),
+                                                 nullptr))
+      OpFlags = RISCVII::MO_PLT;
+
+    Callee = DAG.getTargetExternalSymbol(S->getSymbol(), PtrVT, OpFlags);
   }
 
   // The first call operand is the chain and the second is the target address.