fix an arm codegen bug (the same as PR4482 on ppc) where available_externally

symbols were not getting stubs.  While I'm at it, add a big testcase for
stub generation to make sure I don't break anything.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75737 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 73 insertions, 7 deletions

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index a9ef392..22743dd 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -935,8 +935,7 @@ SDValue ARMTargetLowering::LowerCALL(SDValue Op, SelectionDAG &DAG) {
   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
     GlobalValue *GV = G->getGlobal();
     isDirect = true;
-    bool isExt = (GV->isDeclaration() || GV->hasWeakLinkage() ||
-                  GV->hasLinkOnceLinkage());
+    bool isExt = GV->isDeclaration() || GV->isWeakForLinker();
     bool isStub = (isExt && Subtarget->isTargetDarwin()) &&
                    getTargetMachine().getRelocationModel() != Reloc::Static;
     isARMFunc = !Subtarget->isThumb() || isStub;
@@ -1179,7 +1178,7 @@ ARMTargetLowering::LowerToTLSExecModels(GlobalAddressSDNode *GA,
   // Get the Thread Pointer
   SDValue ThreadPointer = DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
 
-  if (GV->isDeclaration()){
+  if (GV->isDeclaration()) {
     // initial exec model
     unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
     ARMConstantPoolValue *CPV =
@@ -1254,7 +1253,7 @@ SDValue ARMTargetLowering::LowerGlobalAddressELF(SDValue Op,
 static bool GVIsIndirectSymbol(GlobalValue *GV, Reloc::Model RelocM) {
   // If symbol visibility is hidden, the extra load is not needed if
   // the symbol is definitely defined in the current translation unit.
-  bool isDecl = GV->isDeclaration() && !GV->hasNotBeenReadFromBitcode();
+  bool isDecl = GV->isDeclaration() || GV->hasAvailableExternallyLinkage();
   if (GV->hasHiddenVisibility() && (!isDecl && !GV->hasCommonLinkage()))
     return false;
   return RelocM != Reloc::Static && (isDecl || GV->isWeakForLinker());
diff --git a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
index a62ec45..758488e 100644
--- a/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
+++ b/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
@@ -346,8 +346,7 @@ void ARMAsmPrinter::printOperand(const MachineInstr *MI, int OpNum,
     bool isCallOp = Modifier && !strcmp(Modifier, "call");
     GlobalValue *GV = MO.getGlobal();
     std::string Name = Mang->getMangledName(GV);
-    bool isExt = (GV->isDeclaration() || GV->hasWeakLinkage() ||
-                  GV->hasLinkOnceLinkage());
+    bool isExt = GV->isDeclaration() || GV->isWeakForLinker();
     if (isExt && isCallOp && Subtarget->isTargetDarwin() &&
         TM.getRelocationModel() != Reloc::Static) {
       printSuffixedName(Name, "$stub");
@@ -1185,6 +1184,7 @@ bool ARMAsmPrinter::doFinalization(Module &M) {
   if (Subtarget->isTargetDarwin()) {
     SwitchToDataSection("");
 
+    O << '\n';
     // Output stubs for dynamically-linked functions
     for (StringSet<>::iterator I = FnStubs.begin(), E = FnStubs.end();
          I != E; ++I) {
@@ -1227,7 +1227,7 @@ bool ARMAsmPrinter::doFinalization(Module &M) {
       O << "\t.indirect_symbol " << p << "\n";
       O << "\t.long\tdyld_stub_binding_helper\n";
     }
-    O << "\n";
+    O << '\n';
 
     // Output non-lazy-pointers for external and common global variables.
     if (!GVNonLazyPtrs.empty()) {
diff --git a/test/CodeGen/ARM/stubs.ll b/test/CodeGen/ARM/stubs.ll
new file mode 100644
index 0000000..7c9cc23
--- /dev/null
+++ b/test/CodeGen/ARM/stubs.ll
@@ -0,0 +1,67 @@
+; RUN: llvm-as < %s | llc -relocation-model=static | FileCheck %s -check-prefix=STATIC
+; RUN: llvm-as < %s | llc -relocation-model=pic | FileCheck %s -check-prefix=PIC
+; RUN: llvm-as < %s | llc -relocation-model=dynamic-no-pic | FileCheck %s -check-prefix=DYNAMIC
+; PR4482
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "armv6-apple-darwin2"
+
+define i32 @foo(i64 %x) nounwind {
+entry:
+; STATIC: _foo:
+; STATIC: bl _exact_log2
+; STATIC: ldmfd sp!, {r7, pc}
+; STATIC: .subsections_via_symbols
+
+; PIC: _foo:
+; PIC: bl L_exact_log2$stub
+; PIC: ldmfd sp!, {r7, pc}
+
+; DYNAMIC: _foo:
+; DYNAMIC: bl L_exact_log2$stub
+; DYNAMIC: ldmfd sp!, {r7, pc}
+
+ 	%A = call i32 @exact_log2(i64 %x)
+	ret i32 %A
+}
+
+define available_externally i32 @exact_log2(i64 %x) nounwind {
+  ret i32 4
+}
+
+
+; PIC: .section __TEXT,__picsymbolstub4,symbol_stubs,none,16
+; PIC: L_exact_log2$stub:
+; PIC: .indirect_symbol _exact_log2
+; PIC: ldr ip, L_exact_log2$slp
+; PIC: L_exact_log2$scv:
+; PIC: add ip, pc, ip
+; PIC: ldr pc, [ip, #0]
+; PIC: L_exact_log2$slp:
+; PIC: .long	L_exact_log2$lazy_ptr-(L_exact_log2$scv+8)
+
+; PIC: .lazy_symbol_pointer
+; PIC: L_exact_log2$lazy_ptr:
+; PIC: .indirect_symbol _exact_log2
+; PIC: .long	dyld_stub_binding_helper
+
+; PIC: .subsections_via_symbols
+
+
+; DYNAMIC: .section __TEXT,__symbol_stub4,symbol_stubs,none,12
+; DYNAMIC: L_exact_log2$stub:
+; DYNAMIC: .indirect_symbol _exact_log2
+; DYNAMIC: ldr ip, L_exact_log2$slp
+; DYNAMIC: ldr pc, [ip, #0]
+; DYNAMIC: L_exact_log2$slp:
+; DYNAMIC: .long	L_exact_log2$lazy_ptr
+
+; DYNAMIC: .lazy_symbol_pointer
+; DYNAMIC: L_exact_log2$lazy_ptr:
+; DYNAMIC: .indirect_symbol _exact_log2
+; DYNAMIC: .long	dyld_stub_binding_helper
+; DYNAMIC: .subsections_via_symbols
+
+
+
+
+