[PATCH] D75305: [AIX] Handle LinkOnceODRLinkage and llvm.global_ctors/dtors' AppendingLinkage

[Xiangling Liao via Phabricator via llvm-commits]

Xiangling_L created this revision.
Xiangling_L added reviewers: jasonliu, sfertile, hubert.reinterpretcast, stevewan.
Xiangling_L added a project: LLVM.
Herald added subscribers: llvm-commits, jsji, kbarton, hiraditya, nemanjai.

(1)LinkOnceODRLinkage:

  emit .weak for the symbol;

(2) AppendingLinkage of `llvm.global_ctors`, `llvm.global_dtors`:
omit emitting anything from these two global arrays until we support `-qtwolink` similar behavior on AIX.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D75305

Files:
  llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
  llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
  llvm/test/CodeGen/PowerPC/aix-AppendingLinkage.ll
  llvm/test/CodeGen/PowerPC/aix-LinkOnceODRLinkage.ll


Index: llvm/test/CodeGen/PowerPC/aix-LinkOnceODRLinkage.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/PowerPC/aix-LinkOnceODRLinkage.ll
@@ -0,0 +1,13 @@
+; RUN: llc -mtriple powerpc-ibm-aix-xcoff < %s | \
+; RUN: FileCheck %s
+
+; RUN: llc -mtriple powerpc64-ibm-aix-xcoff < %s | \
+; RUN: FileCheck %s
+
+define linkonce_odr void @_Z3fooIiEvT_() {
+entry:
+  ret void
+}
+
+; CHECK: .weak   _Z3fooIiEvT_
+; CHECK: .weak   ._Z3fooIiEvT_
Index: llvm/test/CodeGen/PowerPC/aix-AppendingLinkage.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/PowerPC/aix-AppendingLinkage.ll
@@ -0,0 +1,22 @@
+; RUN: llc -mtriple powerpc-ibm-aix-xcoff < %s | \
+; RUN: FileCheck %s
+
+; RUN: llc -mtriple powerpc64-ibm-aix-xcoff < %s | \
+; RUN: FileCheck %s
+
+ at llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @foo, i8* null }]
+ at llvm.global_dtors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @bar, i8* null }]
+
+define dso_local void @foo() {
+entry:
+  ret void
+}
+
+define dso_local void @bar() {
+entry:
+  ret void
+}
+
+; CHECK-NOT: llvm.global_ctors
+; CHECK-NOT: llvm.global_dtors
+; CHECK-NOT: Should never emit it.
Index: llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
===================================================================
--- llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -1584,9 +1584,18 @@
   return PPCAsmPrinter::lowerConstant(CV);
 }
 
+static bool isSpecialLLVMGlobal(const GlobalVariable *GV) {
+  return StringSwitch<bool>(GV->getName())
+      .Cases("llvm.global_ctors", "llvm.global_dtors", true)
+      .Default(false);
+}
+
 void PPCAIXAsmPrinter::emitGlobalVariable(const GlobalVariable *GV) {
   ValidateGV(GV);
 
+  if (isSpecialLLVMGlobal(GV))
+    return;
+
   // Create the symbol, set its storage class.
   MCSymbolXCOFF *GVSym = cast<MCSymbolXCOFF>(getSymbol(GV));
   GVSym->setStorageClass(
Index: llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
===================================================================
--- llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -1946,7 +1946,10 @@
   case GlobalValue::CommonLinkage:
     return XCOFF::C_EXT;
   case GlobalValue::ExternalWeakLinkage:
+  case GlobalValue::LinkOnceODRLinkage:
     return XCOFF::C_WEAKEXT;
+  case GlobalValue::AppendingLinkage:
+    llvm_unreachable("Should never emit it.");
   default:
     report_fatal_error(
         "Unhandled linkage when mapping linkage to StorageClass.");


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