[MC] Rename TLSCALL as it's not ARM specific

[davide]

Summary

MCSymbolRefExpr variant kind for TLSCALL is prefixed with _ARM_ since it was originally implemented.
I'm currently implementing the X86_64 version(s) described here http://www.fsfla.org/~lxoliva/writeups/TLS/RFC-TLSDESC-x86.txt and noticed that the assembler for both of them is:

symbol@TLSCALL(%register)

I think it makes sense to rename VK_ARM_TLSCALL to VK_TLSCALL (this may also be true for TLSDESC) and implement the correct semantic action in the machine-dependent code. Any objections?

[davide]

This is the first step to fix https://llvm.org/bugs/show_bug.cgi?id=16814

[rengolin]

No objections from me, if the semantics are identical on all targets. AFAIK, they are, so... LGTM.

[• rafael]

LGTM. Thanks

include/llvm/MC/MCExpr.h

enum VariantKind : uint16_t {
     VK_NTPOFF,
     VK_GOTNTPOFF,
     VK_PLT,
     VK_TLSGD,
     VK_TLSLD,
     VK_TLSLDM,
     VK_TPOFF,
     VK_DTPOFF,
+    VK_TLSCALL,   // symbol(tlscall)
     VK_TLVP,      // Mach-O thread local variable relocations
     VK_TLVPPAGE,
     VK_TLVPPAGEOFF,
     VK_PAGE,
     VK_PAGEOFF,
     VK_GOTPAGE,
     VK_GOTPAGEOFF,
     VK_SECREL,
     VK_SIZE,      // symbol@SIZE
     VK_WEAKREF,   // The link between the symbols in .weakref foo, bar
 
     VK_ARM_NONE,
     VK_ARM_GOT_PREL,
     VK_ARM_TARGET1,
     VK_ARM_TARGET2,
     VK_ARM_PREL31,
     VK_ARM_SBREL,          // symbol(sbrel)
     VK_ARM_TLSLDO,         // symbol(tlsldo)
-    VK_ARM_TLSCALL,        // symbol(tlscall)
     VK_ARM_TLSDESC,        // symbol(tlsdesc)
     VK_ARM_TLSDESCSEQ,
 
     VK_PPC_LO,             // symbol@l
     VK_PPC_HI,             // symbol@h
     VK_PPC_HA,             // symbol@ha
     VK_PPC_HIGHER,         // symbol@higher
     VK_PPC_HIGHERA,        // symbol@highera

lib/MC/MCExpr.cpp

StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) {
   case VK_NTPOFF: return "NTPOFF";
   case VK_GOTNTPOFF: return "GOTNTPOFF";
   case VK_PLT: return "PLT";
   case VK_TLSGD: return "TLSGD";
   case VK_TLSLD: return "TLSLD";
   case VK_TLSLDM: return "TLSLDM";
   case VK_TPOFF: return "TPOFF";
   case VK_TPREL: return "TPREL";
+  case VK_TLSCALL: return "tlscall";
   case VK_TLVP: return "TLVP";
   case VK_TLVPPAGE: return "TLVPPAGE";
   case VK_TLVPPAGEOFF: return "TLVPPAGEOFF";
   case VK_PAGE: return "PAGE";
   case VK_PAGEOFF: return "PAGEOFF";
   case VK_GOTPAGE: return "GOTPAGE";
   case VK_GOTPAGEOFF: return "GOTPAGEOFF";
   case VK_SECREL: return "SECREL32";
   case VK_SIZE: return "SIZE";
   case VK_WEAKREF: return "WEAKREF";
   case VK_ARM_NONE: return "none";
   case VK_ARM_GOT_PREL: return "GOT_PREL";
   case VK_ARM_TARGET1: return "target1";
   case VK_ARM_TARGET2: return "target2";
   case VK_ARM_PREL31: return "prel31";
   case VK_ARM_SBREL: return "sbrel";
   case VK_ARM_TLSLDO: return "tlsldo";
-  case VK_ARM_TLSCALL: return "tlscall";
   case VK_ARM_TLSDESC: return "tlsdesc";
   case VK_ARM_TLSDESCSEQ: return "tlsdescseq";
   case VK_PPC_LO: return "l";
   case VK_PPC_HI: return "h";
   case VK_PPC_HA: return "ha";
   case VK_PPC_HIGHER: return "higher";
   case VK_PPC_HIGHERA: return "highera";
   case VK_PPC_HIGHEST: return "highest";
return StringSwitch<VariantKind>(Name.lower())
     .Case("gotoff", VK_GOTOFF)
     .Case("gotrel", VK_GOTREL)
     .Case("gotpcrel", VK_GOTPCREL)
     .Case("gottpoff", VK_GOTTPOFF)
     .Case("indntpoff", VK_INDNTPOFF)
     .Case("ntpoff", VK_NTPOFF)
     .Case("gotntpoff", VK_GOTNTPOFF)
     .Case("plt", VK_PLT)
+    .Case("tlscall", VK_TLSCALL)
     .Case("tlsgd", VK_TLSGD)
     .Case("tlsld", VK_TLSLD)
     .Case("tlsldm", VK_TLSLDM)
     .Case("tpoff", VK_TPOFF)
     .Case("tprel", VK_TPREL)
     .Case("tlvp", VK_TLVP)
     .Case("tlvppage", VK_TLVPPAGE)
     .Case("tlvppageoff", VK_TLVPPAGEOFF)
return StringSwitch<VariantKind>(Name.lower())
     .Case("pcrel", VK_Hexagon_PCREL)
     .Case("none", VK_ARM_NONE)
     .Case("got_prel", VK_ARM_GOT_PREL)
     .Case("target1", VK_ARM_TARGET1)
     .Case("target2", VK_ARM_TARGET2)
     .Case("prel31", VK_ARM_PREL31)
     .Case("sbrel", VK_ARM_SBREL)
     .Case("tlsldo", VK_ARM_TLSLDO)
-    .Case("tlscall", VK_ARM_TLSCALL)
     .Case("tlsdesc", VK_ARM_TLSDESC)
     .Default(VK_Invalid);
 }
 
 void MCSymbolRefExpr::printVariantKind(raw_ostream &OS) const {
   if (UseParensForSymbolVariant)
     OS << '(' << MCSymbolRefExpr::getVariantKindName(getKind()) << ')';
   else

lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp

unsigned ARMAsmBackend::adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
   case ARM::fixup_arm_uncondbranch:
   case ARM::fixup_arm_uncondbl:
   case ARM::fixup_arm_condbl:
   case ARM::fixup_arm_blx:
     // These values don't encode the low two bits since they're always zero.
     // Offset by 8 just as above.
     if (const MCSymbolRefExpr *SRE =
             dyn_cast<MCSymbolRefExpr>(Fixup.getValue()))
-      if (SRE->getKind() == MCSymbolRefExpr::VK_ARM_TLSCALL)
+      if (SRE->getKind() == MCSymbolRefExpr::VK_TLSCALL)
         return 0;
     return 0xffffff & ((Value - 8) >> 2);
   case ARM::fixup_t2_uncondbranch: {
     Value = Value - 4;
     Value >>= 1; // Low bit is not encoded.
 
     uint32_t out = 0;
     bool I = Value & 0x800000;
case ARM::fixup_arm_thumb_blx: {
     //
     //   BLX: xxxxxSIIIIIIIIII xxJxJIIIIIIIIII0
     //
     // Note that the halfwords are stored high first, low second; so we need
     // to transpose the fixup value here to map properly.
     uint32_t offset = (Value - 2) >> 2;
     if (const MCSymbolRefExpr *SRE =
             dyn_cast<MCSymbolRefExpr>(Fixup.getValue()))
-      if (SRE->getKind() == MCSymbolRefExpr::VK_ARM_TLSCALL)
+      if (SRE->getKind() == MCSymbolRefExpr::VK_TLSCALL)
         offset = 0;
     uint32_t signBit = (offset & 0x400000) >> 22;
     uint32_t I1Bit = (offset & 0x200000) >> 21;
     uint32_t J1Bit = (I1Bit ^ 0x1) ^ signBit;
     uint32_t I2Bit = (offset & 0x100000) >> 20;
     uint32_t J2Bit = (I2Bit ^ 0x1) ^ signBit;
     uint32_t imm10HBits = (offset & 0xFFC00) >> 10;
     uint32_t imm10LBits = (offset & 0x3FF);

lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp

case FK_Data_4:
       }
       break;
     case ARM::fixup_arm_blx:
     case ARM::fixup_arm_uncondbl:
       switch (Modifier) {
       case MCSymbolRefExpr::VK_PLT:
         Type = ELF::R_ARM_CALL;
         break;
-      case MCSymbolRefExpr::VK_ARM_TLSCALL:
+      case MCSymbolRefExpr::VK_TLSCALL:
         Type = ELF::R_ARM_TLS_CALL;
         break;
       default:
         Type = ELF::R_ARM_CALL;
         break;
       }
       break;
     case ARM::fixup_arm_condbl:
case ARM::fixup_t2_movt_hi16:
       Type = ELF::R_ARM_THM_MOVT_PREL;
       break;
     case ARM::fixup_t2_movw_lo16:
       Type = ELF::R_ARM_THM_MOVW_PREL_NC;
       break;
     case ARM::fixup_arm_thumb_bl:
     case ARM::fixup_arm_thumb_blx:
       switch (Modifier) {
-      case MCSymbolRefExpr::VK_ARM_TLSCALL:
+      case MCSymbolRefExpr::VK_TLSCALL:
         Type = ELF::R_ARM_THM_TLS_CALL;
         break;
       default:
         Type = ELF::R_ARM_THM_CALL;
         break;
       }
       break;
     }
case FK_Data_4:
         Type = ELF::R_ARM_PREL31;
         break;
       case MCSymbolRefExpr::VK_ARM_SBREL:
         Type = ELF::R_ARM_SBREL32;
         break;
       case MCSymbolRefExpr::VK_ARM_TLSLDO:
         Type = ELF::R_ARM_TLS_LDO32;
         break;
-      case MCSymbolRefExpr::VK_ARM_TLSCALL:
+      case MCSymbolRefExpr::VK_TLSCALL:
         Type = ELF::R_ARM_TLS_CALL;
         break;
       case MCSymbolRefExpr::VK_ARM_TLSDESC:
         Type = ELF::R_ARM_TLS_GOTDESC;
         break;
       case MCSymbolRefExpr::VK_ARM_TLSDESCSEQ:
         Type = ELF::R_ARM_TLS_DESCSEQ;
         break;