LoongArchMCCodeEmitter: Set PCRel at fixup creation

Avoid reliance on the MCAssembler::evaluateFixup workaround that checks
MCFixupKindInfo::FKF_IsPCRel. Additionally, standardize how fixups are
appended. This helper will facilitate future fixup data structure
optimizations.

Author: MaskRay

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

@@ -57,9 +57,9 @@ MCFixupKindInfo LoongArchAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
       // LoongArchFixupKinds.h.
       //
       // {name, offset, bits, flags}
-      {"fixup_loongarch_b16", 10, 16, MCFixupKindInfo::FKF_IsPCRel},
-      {"fixup_loongarch_b21", 0, 26, MCFixupKindInfo::FKF_IsPCRel},
-      {"fixup_loongarch_b26", 0, 26, MCFixupKindInfo::FKF_IsPCRel},
+      {"fixup_loongarch_b16", 10, 16, 0},
+      {"fixup_loongarch_b21", 0, 26, 0},
+      {"fixup_loongarch_b26", 0, 26, 0},
       {"fixup_loongarch_abs_hi20", 5, 20, 0},
       {"fixup_loongarch_abs_lo12", 10, 12, 0},
       {"fixup_loongarch_abs64_lo20", 5, 20, 0},

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

@@ -97,6 +97,18 @@ class LoongArchMCCodeEmitter : public MCCodeEmitter {
 };
 } // end namespace
 
+static void addFixup(SmallVectorImpl<MCFixup> &Fixups, uint32_t Offset,
+                     const MCExpr *Value, uint16_t Kind) {
+  bool PCRel = false;
+  switch (Kind) {
+  case LoongArch::fixup_loongarch_b16:
+  case LoongArch::fixup_loongarch_b21:
+  case LoongArch::fixup_loongarch_b26:
+    PCRel = true;
+  }
+  Fixups.push_back(MCFixup::create(Offset, Value, Kind, PCRel));
+}
+
 unsigned
 LoongArchMCCodeEmitter::getMachineOpValue(const MCInst &MI, const MCOperand &MO,
                                           SmallVectorImpl<MCFixup> &Fixups,
@@ -195,7 +207,7 @@ LoongArchMCCodeEmitter::getExprOpValue(const MCInst &MI, const MCOperand &MO,
   assert(FixupKind != LoongArch::fixup_loongarch_invalid &&
          "Unhandled expression!");
 
-  Fixups.push_back(MCFixup::create(0, Expr, MCFixupKind(FixupKind)));
+  addFixup(Fixups, 0, Expr, FixupKind);
   // If linker relaxation is enabled and supported by this relocation, set
   // a bit so that if fixup is unresolved, a R_LARCH_RELAX relocation will be
   // appended.
@@ -248,7 +260,7 @@ void LoongArchMCCodeEmitter::expandAddTPRel(const MCInst &MI,
          "Expected %le_add_r relocation on TP-relative symbol");
 
   // Emit the correct %le_add_r relocation for the symbol.
-  Fixups.push_back(MCFixup::create(0, Expr, ELF::R_LARCH_TLS_LE_ADD_R));
+  addFixup(Fixups, 0, Expr, ELF::R_LARCH_TLS_LE_ADD_R);
   if (STI.hasFeature(LoongArch::FeatureRelax))
     Fixups.back().setLinkerRelaxable();