Make the following changes in MipsISelLowering.cpp:

- Stop creating stack frame objects needed for saving $gp.
- Insert a node that copies the global pointer register to register $gp
  before the call node. This will ensure $gp is valid at the entry of the
  called function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156692 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index d5cc7478081f2fd63601563d190cbe01f9ee3529..a8b738b1111540797ce88940e0a98998c8d817fc 100644 (file)
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -2455,11 +2455,6 @@ MipsTargetLowering::LowerCall(SDValue InChain, SDValue Callee,
   Chain = CallSeqStart = DAG.getCALLSEQ_START(InChain, NextStackOffsetVal);
   ByValChain = InChain;
 
-  // If this is the first call, create a stack frame object that points to
-  // a location to which .cprestore saves $gp.
-  if (IsO32 && IsPIC && MipsFI->globalBaseRegFixed() && !MipsFI->getGPFI())
-    MipsFI->setGPFI(MFI->CreateFixedObject(4, 0, true));
-
   // Get the frame index of the stack frame object that points to the location
   // of dynamically allocated area on the stack.
   int DynAllocFI = MipsFI->getDynAllocFI();
@@ -2482,9 +2477,6 @@ MipsTargetLowering::LowerCall(SDValue InChain, SDValue Callee,
     NextStackOffset = (NextStackOffset + StackAlignment - 1) /
                       StackAlignment * StackAlignment;
 
-    if (MipsFI->needGPSaveRestore())
-      MFI->setObjectOffset(MipsFI->getGPFI(), NextStackOffset);
-
     MFI->setObjectOffset(DynAllocFI, NextStackOffset);
   }
 
@@ -2656,6 +2648,14 @@ MipsTargetLowering::LowerCall(SDValue InChain, SDValue Callee,
     Callee = DAG.getRegister(T9Reg, getPointerTy());
   }
 
+  // Insert node "GP copy globalreg" before call to function.
+  // Lazy-binding stubs require GP to point to the GOT.
+  if (IsPICCall) {
+    unsigned GPReg = IsN64 ? Mips::GP_64 : Mips::GP;
+    EVT Ty = IsN64 ? MVT::i64 : MVT::i32;
+    RegsToPass.push_back(std::make_pair(GPReg, GetGlobalReg(DAG, Ty)));
+  }
+
   // Build a sequence of copy-to-reg nodes chained together with token
   // chain and flag operands which copy the outgoing args into registers.
   // The InFlag in necessary since all emitted instructions must be