LoongArch: Remove VK_CALL/VK_CALL_PLT and don't print %plt

`%plt` is a redundant relocation specifier: `bl %plt(foo)` is identical
to `bl foo`. Let's replace VK_CALL/VK_CALL_PLT with R_LARCH_B26 and
remove the only specifier constants.

Pull Request: llvm#138632

Author: MaskRay

llvm/lib/Target/LoongArch/AsmParser/LoongArchAsmParser.cpp

@@ -517,9 +517,7 @@ class LoongArchOperand : public MCParsedAsmOperand {
     int64_t Imm;
     LoongArchMCExpr::Specifier VK = LoongArchMCExpr::VK_None;
     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
-    bool IsValidKind =
-        VK == LoongArchMCExpr::VK_None || VK == LoongArchMCExpr::VK_CALL ||
-        VK == LoongArchMCExpr::VK_CALL_PLT || VK == ELF::R_LARCH_B26;
+    bool IsValidKind = VK == LoongArchMCExpr::VK_None || VK == ELF::R_LARCH_B26;
     return IsConstantImm
                ? isShiftedInt<26, 2>(Imm) && IsValidKind
                : LoongArchAsmParser::classifySymbolRef(getImm(), VK) &&
@@ -793,7 +791,6 @@ ParseStatus LoongArchAsmParser::parseSImm26Operand(OperandVector &Operands) {
 
   MCSymbol *Sym = getContext().getOrCreateSymbol(Identifier);
   Res = MCSymbolRefExpr::create(Sym, getContext());
-  Res = LoongArchMCExpr::create(Res, LoongArchMCExpr::VK_CALL, getContext());
   Operands.push_back(LoongArchOperand::createImm(Res, S, E));
   return ParseStatus::Success;
 }

llvm/lib/Target/LoongArch/LoongArchMCInstLower.cpp

@@ -35,10 +35,8 @@ static MCOperand lowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym,
     Kind = LoongArchMCExpr::VK_None;
     break;
   case LoongArchII::MO_CALL:
-    Kind = LoongArchMCExpr::VK_CALL;
-    break;
   case LoongArchII::MO_CALL_PLT:
-    Kind = LoongArchMCExpr::VK_CALL_PLT;
+    Kind = ELF::R_LARCH_B26;
     break;
   case LoongArchII::MO_PCREL_HI:
     Kind = ELF::R_LARCH_PCALA_HI20;

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCCodeEmitter.cpp

@@ -147,8 +147,6 @@ LoongArchMCCodeEmitter::getExprOpValue(const MCInst &MI, const MCOperand &MO,
       FixupKind = LoongArch::fixup_loongarch_b21;
       break;
     case ELF::R_LARCH_B26:
-    case LoongArchMCExpr::VK_CALL:
-    case LoongArchMCExpr::VK_CALL_PLT:
       FixupKind = LoongArch::fixup_loongarch_b26;
       break;
     case ELF::R_LARCH_ABS_HI20:

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCExpr.cpp

@@ -32,7 +32,7 @@ const LoongArchMCExpr *LoongArchMCExpr::create(const MCExpr *Expr, uint16_t S,
 
 void LoongArchMCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const {
   Specifier S = getSpecifier();
-  bool HasVariant = S != VK_None && S != VK_CALL;
+  bool HasVariant = S != VK_None && S != ELF::R_LARCH_B26;
 
   if (HasVariant)
     OS << '%' << getSpecifierName(specifier) << '(';
@@ -63,14 +63,10 @@ StringRef LoongArchMCExpr::getSpecifierName(uint16_t S) {
   switch (S) {
   default:
     llvm_unreachable("Invalid ELF symbol kind");
-  case VK_CALL_PLT:
-    return "plt";
   case ELF::R_LARCH_B16:
     return "b16";
   case ELF::R_LARCH_B21:
     return "b21";
-  case ELF::R_LARCH_B26:
-    return "b26";
   case ELF::R_LARCH_ABS_HI20:
     return "abs_hi20";
   case ELF::R_LARCH_ABS_LO12:
@@ -176,7 +172,7 @@ StringRef LoongArchMCExpr::getSpecifierName(uint16_t S) {
 
 LoongArchMCExpr::Specifier LoongArchMCExpr::parseSpecifier(StringRef name) {
   return StringSwitch<LoongArchMCExpr::Specifier>(name)
-      .Case("plt", VK_CALL_PLT)
+      .Case("plt", ELF::R_LARCH_B26)
       .Case("b16", ELF::R_LARCH_B16)
       .Case("b21", ELF::R_LARCH_B21)
       .Case("b26", ELF::R_LARCH_B26)

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCExpr.h

@@ -23,11 +23,7 @@ class StringRef;
 class LoongArchMCExpr : public MCTargetExpr {
 public:
   using Specifier = uint16_t;
-  enum {
-    VK_None,
-    VK_CALL = 1000, // larger than relocation types
-    VK_CALL_PLT,
-  };
+  enum { VK_None };
 
 private:
   const MCExpr *Expr;

llvm/test/CodeGen/LoongArch/addrspacecast.ll

@@ -24,7 +24,7 @@ define void @cast1(ptr %ptr) {
 ; LA32-NEXT:    .cfi_def_cfa_offset 16
 ; LA32-NEXT:    st.w $ra, $sp, 12 # 4-byte Folded Spill
 ; LA32-NEXT:    .cfi_offset 1, -4
-; LA32-NEXT:    bl %plt(foo)
+; LA32-NEXT:    bl foo
 ; LA32-NEXT:    ld.w $ra, $sp, 12 # 4-byte Folded Reload
 ; LA32-NEXT:    addi.w $sp, $sp, 16
 ; LA32-NEXT:    ret

llvm/test/CodeGen/LoongArch/alloca.ll

@@ -20,7 +20,7 @@ define void @simple_alloca(i32 %n) nounwind {
 ; LA32-NEXT:    bstrins.w $a0, $zero, 3, 0
 ; LA32-NEXT:    sub.w $a0, $sp, $a0
 ; LA32-NEXT:    move $sp, $a0
-; LA32-NEXT:    bl %plt(notdead)
+; LA32-NEXT:    bl notdead
 ; LA32-NEXT:    addi.w $sp, $fp, -16
 ; LA32-NEXT:    ld.w $fp, $sp, 8 # 4-byte Folded Reload
 ; LA32-NEXT:    ld.w $ra, $sp, 12 # 4-byte Folded Reload
@@ -67,7 +67,7 @@ define void @scoped_alloca(i32 %n) nounwind {
 ; LA32-NEXT:    bstrins.w $a0, $zero, 3, 0
 ; LA32-NEXT:    sub.w $a0, $sp, $a0
 ; LA32-NEXT:    move $sp, $a0
-; LA32-NEXT:    bl %plt(notdead)
+; LA32-NEXT:    bl notdead
 ; LA32-NEXT:    move $sp, $s0
 ; LA32-NEXT:    addi.w $sp, $fp, -16
 ; LA32-NEXT:    ld.w $s0, $sp, 4 # 4-byte Folded Reload
@@ -137,7 +137,7 @@ define void @alloca_callframe(i32 %n) nounwind {
 ; LA32-NEXT:    ori $a6, $zero, 7
 ; LA32-NEXT:    ori $a7, $zero, 8
 ; LA32-NEXT:    st.w $t0, $sp, 0
-; LA32-NEXT:    bl %plt(func)
+; LA32-NEXT:    bl func
 ; LA32-NEXT:    addi.w $sp, $sp, 16
 ; LA32-NEXT:    addi.w $sp, $fp, -16
 ; LA32-NEXT:    ld.w $fp, $sp, 8 # 4-byte Folded Reload

llvm/test/CodeGen/LoongArch/bnez-beqz.ll

@@ -11,7 +11,7 @@ define void @bnez_i32(i32 signext %0) nounwind {
 ; LA32-NEXT:  # %bb.1: # %f
 ; LA32-NEXT:    ret
 ; LA32-NEXT:  .LBB0_2: # %t
-; LA32-NEXT:    b %plt(bar)
+; LA32-NEXT:    b bar
 ;
 ; LA64-LABEL: bnez_i32:
 ; LA64:       # %bb.0: # %start
@@ -38,7 +38,7 @@ define void @beqz_i32(i32 signext %0) nounwind {
 ; LA32:       # %bb.0: # %start
 ; LA32-NEXT:    beqz $a0, .LBB1_2
 ; LA32-NEXT:  # %bb.1: # %t
-; LA32-NEXT:    b %plt(bar)
+; LA32-NEXT:    b bar
 ; LA32-NEXT:  .LBB1_2: # %f
 ; LA32-NEXT:    ret
 ;
@@ -70,7 +70,7 @@ define void @bnez_i64(i64 %0) nounwind {
 ; LA32-NEXT:  # %bb.1: # %f
 ; LA32-NEXT:    ret
 ; LA32-NEXT:  .LBB2_2: # %t
-; LA32-NEXT:    b %plt(bar)
+; LA32-NEXT:    b bar
 ;
 ; LA64-LABEL: bnez_i64:
 ; LA64:       # %bb.0: # %start
@@ -98,7 +98,7 @@ define void @beqz_i64(i64 %0) nounwind {
 ; LA32-NEXT:    or $a0, $a0, $a1
 ; LA32-NEXT:    beqz $a0, .LBB3_2
 ; LA32-NEXT:  # %bb.1: # %t
-; LA32-NEXT:    b %plt(bar)
+; LA32-NEXT:    b bar
 ; LA32-NEXT:  .LBB3_2: # %f
 ; LA32-NEXT:    ret
 ;

llvm/test/CodeGen/LoongArch/code-models.ll

@@ -14,7 +14,7 @@ define i32 @call_globaladdress(i32 %a) nounwind {
 ; SMALL:       # %bb.0:
 ; SMALL-NEXT:    addi.d $sp, $sp, -16
 ; SMALL-NEXT:    st.d $ra, $sp, 8 # 8-byte Folded Spill
-; SMALL-NEXT:    bl %plt(callee)
+; SMALL-NEXT:    bl callee
 ; SMALL-NEXT:    ld.d $ra, $sp, 8 # 8-byte Folded Reload
 ; SMALL-NEXT:    addi.d $sp, $sp, 16
 ; SMALL-NEXT:    ret
@@ -55,7 +55,7 @@ define void @call_external_sym(ptr %dst) {
 ; SMALL-NEXT:    .cfi_offset 1, -8
 ; SMALL-NEXT:    ori $a2, $zero, 1000
 ; SMALL-NEXT:    move $a1, $zero
-; SMALL-NEXT:    bl %plt(memset)
+; SMALL-NEXT:    bl memset
 ; SMALL-NEXT:    ld.d $ra, $sp, 8 # 8-byte Folded Reload
 ; SMALL-NEXT:    addi.d $sp, $sp, 16
 ; SMALL-NEXT:    ret
@@ -101,7 +101,7 @@ declare i32 @callee_tail(i32 %i)
 define i32 @caller_tail(i32 %i) nounwind {
 ; SMALL-LABEL: caller_tail:
 ; SMALL:       # %bb.0: # %entry
-; SMALL-NEXT:    b %plt(callee_tail)
+; SMALL-NEXT:    b callee_tail
 ;
 ; MEDIUM-LABEL: caller_tail:
 ; MEDIUM:       # %bb.0: # %entry