[mips] The naming convention for private labels is ABI dependant.

[dsanders]

Summary

For N32/N64, private labels begin with '.L' but for O32 they begin with '$'.

MCAsmInfo now has an initializer function which can be used to provide information from the TargetMachine to control the assembly syntax.

[vkalintiris]

Won't we have to update the existing tests that depend on this behaviour?
I'm getting the following failures with llvm-lit:

Failing Tests (12):

LLVM :: CodeGen/Mips/analyzebranch.ll
LLVM :: CodeGen/Mips/atomic.ll
LLVM :: CodeGen/Mips/blez_bgez.ll
LLVM :: CodeGen/Mips/blockaddr.ll
LLVM :: CodeGen/Mips/fpbr.ll
LLVM :: CodeGen/Mips/llvm-ir/ashr.ll
LLVM :: CodeGen/Mips/llvm-ir/indirectbr.ll
LLVM :: CodeGen/Mips/llvm-ir/lshr.ll
LLVM :: CodeGen/Mips/llvm-ir/select.ll
LLVM :: CodeGen/Mips/llvm-ir/shl.ll
LLVM :: CodeGen/Mips/longbranch.ll
LLVM :: CodeGen/Mips/octeon.ll

Other than that it looks good to me. Please, update the existing revision if you'd like me to review the tests' changes too.

[dsanders]

Now uses the ABI instead of misusing target triples. This required the addition
of an overridable initialization function in MCAsmInfo which provides the ABI
(from the TargetMachine).

Also updated tests.

[vkalintiris]

LGTM.

lib/Target/Mips/MCTargetDesc/MipsMCAsmInfo.cpp

if ((TheTriple.getArch() == Triple::mips) ||
       (TheTriple.getArch() == Triple::mips64))
     IsLittleEndian = false;
 
   if ((TheTriple.getArch() == Triple::mips64el) ||
       (TheTriple.getArch() == Triple::mips64)) {
     PointerSize = CalleeSaveStackSlotSize = 8;
   }
 
+  // FIXME: This should depend on the ABI and rather than the triple.
+  if ((TheTriple.getArch() == Triple::mips64el) ||
+      (TheTriple.getArch() == Triple::mips64)) {
+    PrivateGlobalPrefix = ".L";
+    PrivateLabelPrefix  = ".L";
+  } else {
+    PrivateGlobalPrefix = "$";
+    PrivateLabelPrefix  = "$";
+  }
+
   AlignmentIsInBytes          = false;
   Data16bitsDirective         = "\t.2byte\t";
   Data32bitsDirective         = "\t.4byte\t";
   Data64bitsDirective         = "\t.8byte\t";
-  PrivateGlobalPrefix         = "$";
-  PrivateLabelPrefix          = "$";
   CommentString               = "#";
   ZeroDirective               = "\t.space\t";
   GPRel32Directive            = "\t.gpword\t";
   GPRel64Directive            = "\t.gpdword\t";
   UseAssignmentForEHBegin = true;
   SupportsDebugInformation = true;
   ExceptionsType = ExceptionHandling::DwarfCFI;
   DwarfRegNumForCFI = true;
 }

test/CodeGen/Mips/private_label.ll

+; RUN: llc -march=mips < %s | FileCheck -check-prefix=O32 %s
+; RUN: llc -march=mips64 -target-abi n32 < %s | FileCheck -check-prefix=N32 %s
+; RUN: llc -march=mips64 -target-abi n64 < %s | FileCheck -check-prefix=N64 %s
+
+define void @labels() nounwind  {
+entry:
+  ; O32: $func_end
+  ; N32: .Lfunc_end
+  ; N64: .Lfunc_end
+  ret void
+}