Revert "[NVPTX] Disable parens for identifiers starting with '$'"

This reverts commit 78d70a1c97.

Failed on Mips32:
https://lab.llvm.org/buildbot#builders/109/builds/36628

   # CHECK: # fixup A - offset: 0, value: ($tmp0), kind: fixup_Mips_26
   <stdin>:580:2: note: possible intended match here
   # fixup A - offset: 0, value: $tmp0, kind: fixup_Mips_26

llvm/include/llvm/MC/MCAsmInfo.h

@@ -478,10 +478,6 @@ protected:
   /// For example, foo(plt) instead of foo@plt.  Defaults to false.
   bool UseParensForSymbolVariant = false;
 
-  /// True if the target uses parens for symbol names starting with
-  /// '$' character to distinguish them from absolute names.
-  bool UseParensForDollarSignNames = true;
-
   /// True if the target supports flags in ".loc" directive, false if only
   /// location is allowed.
   bool SupportsExtendedDwarfLocDirective = true;
@@ -793,9 +789,6 @@ public:
   bool doDwarfFDESymbolsUseAbsDiff() const { return DwarfFDESymbolsUseAbsDiff; }
   bool useDwarfRegNumForCFI() const { return DwarfRegNumForCFI; }
   bool useParensForSymbolVariant() const { return UseParensForSymbolVariant; }
-  bool useParensForDollarSignNames() const {
-    return UseParensForDollarSignNames;
-  }
   bool supportsExtendedDwarfLocDirective() const {
     return SupportsExtendedDwarfLocDirective;
   }

llvm/lib/MC/MCExpr.cpp

@@ -75,9 +75,8 @@ void MCExpr::print(raw_ostream &OS, const MCAsmInfo *MAI, bool InParens) const {
     const MCSymbol &Sym = SRE.getSymbol();
     // Parenthesize names that start with $ so that they don't look like
     // absolute names.
-    bool UseParens = MAI && MAI->useParensForDollarSignNames() && !InParens &&
-                     !Sym.getName().empty() && Sym.getName()[0] == '$';
-
+    bool UseParens =
+        !InParens && !Sym.getName().empty() && Sym.getName()[0] == '$';
     if (UseParens) {
       OS << '(';
       Sym.print(OS, MAI);

llvm/lib/Target/NVPTX/MCTargetDesc/NVPTXMCAsmInfo.cpp

@@ -54,8 +54,4 @@ NVPTXMCAsmInfo::NVPTXMCAsmInfo(const Triple &TheTriple,
   GlobalDirective = "\t// .globl\t";
 
   UseIntegratedAssembler = false;
-
-  // Avoid using parens for identifiers starting with $ - ptxas does
-  // not expect them.
-  UseParensForDollarSignNames = false;
 }

llvm/test/CodeGen/NVPTX/no-extra-parens.ll

@@ -1,14 +0,0 @@
-; RUN: llc < %s -march=nvptx64 -mcpu=sm_20 | FileCheck %s
-
-; ptxas has no special meaning for '$' character, so it should be used
-; without parens.
-
-@"$str" = private addrspace(1) constant [4 x i8] c"str\00"
-
-declare void @str2(i8* %str)
-define void @str1() {
-entry:
-;; CHECK: mov.u64 %rd{{[0-9]+}}, $str;
-  tail call void @str2(i8* getelementptr ([4 x i8], [4 x i8]* addrspacecast ([4 x i8] addrspace(1)* @"$str" to [4 x i8]*), i64 0, i64 0))
-  ret void
-}