[llvm-commits] [llvm] r170092 - in /llvm/trunk: lib/Target/Mips/MipsISelLowering.cpp test/CodeGen/Mips/gpreg-lazy-binding.ll

[Akira Hatanaka]

Author: ahatanak
Date: Wed Dec 12 21:17:29 2012
New Revision: 170092

URL: http://llvm.org/viewvc/llvm-project?rev=170092&view=rev
Log:
[mips] Do not copy GOT address to register $gp if the function being called has
internal linkage.

Added:
    llvm/trunk/test/CodeGen/Mips/gpreg-lazy-binding.ll
Modified:
    llvm/trunk/lib/Target/Mips/MipsISelLowering.cpp

Modified: llvm/trunk/lib/Target/Mips/MipsISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Mips/MipsISelLowering.cpp?rev=170092&r1=170091&r2=170092&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Mips/MipsISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/Mips/MipsISelLowering.cpp Wed Dec 12 21:17:29 2012
@@ -2849,12 +2849,14 @@
   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
   // node so that legalize doesn't hack it.
   bool IsPICCall = (IsN64 || IsPIC); // true if calls are translated to jalr $25
-  bool GlobalOrExternal = false;
+  bool GlobalOrExternal = false, InternalLinkage = false;
   SDValue CalleeLo;
 
   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
     if (IsPICCall) {
-      if (G->getGlobal()->hasInternalLinkage())
+      InternalLinkage = G->getGlobal()->hasInternalLinkage();
+
+      if (InternalLinkage)
         Callee = getAddrLocal(Callee, DAG, HasMips64);
       else if (LargeGOT)
         Callee = getAddrGlobalLargeGOT(Callee, DAG, MipsII::MO_CALL_HI16,
@@ -2901,8 +2903,11 @@
   }
 
   // Insert node "GP copy globalreg" before call to function.
-  // Lazy-binding stubs require GP to point to the GOT.
-  if (IsPICCall) {
+  //
+  // R_MIPS_CALL* operators (emitted when non-internal functions are called
+  // in PIC mode) allow symbols to be resolved via lazy binding.
+  // The lazy binding stub requires GP to point to the GOT.
+  if (IsPICCall && !InternalLinkage) {
     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)));

Added: llvm/trunk/test/CodeGen/Mips/gpreg-lazy-binding.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Mips/gpreg-lazy-binding.ll?rev=170092&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/Mips/gpreg-lazy-binding.ll (added)
+++ llvm/trunk/test/CodeGen/Mips/gpreg-lazy-binding.ll Wed Dec 12 21:17:29 2012
@@ -0,0 +1,27 @@
+; RUN: llc -march=mipsel -disable-mips-delay-filler < %s | FileCheck %s 
+
+ at g = external global i32
+
+; CHECK:     addu  $gp
+; CHECK:     jalr  $25
+; CHECK:     nop
+; CHECK-NOT: addu  $gp
+; CHECK:     jalr  $25
+
+define void @f0() nounwind {
+entry:
+  tail call void @externalFunc() nounwind
+  tail call fastcc void @internalFunc()
+  ret void
+}
+
+declare void @externalFunc()
+
+define internal fastcc void @internalFunc() nounwind noinline {
+entry:
+  %0 = load i32* @g, align 4
+  %inc = add nsw i32 %0, 1
+  store i32 %inc, i32* @g, align 4
+  ret void
+}
+