[llvm] [Xtensa] Implement base CallConvention. (PR #83280)

[Matt Arsenault via llvm-commits]

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@@ -25,12 +29,193 @@
 
 using namespace llvm;
 
+static MCSymbolRefExpr::VariantKind
+getModifierVariantKind(XtensaCP::XtensaCPModifier Modifier) {
+  switch (Modifier) {
+  case XtensaCP::no_modifier:
+    return MCSymbolRefExpr::VK_None;
+  case XtensaCP::TPOFF:
+    return MCSymbolRefExpr::VK_TPOFF;
+  }
+  report_fatal_error("Invalid XtensaCPModifier!");
+}
+
 void XtensaAsmPrinter::emitInstruction(const MachineInstr *MI) {
   MCInst LoweredMI;
   lowerToMCInst(MI, LoweredMI);
   EmitToStreamer(*OutStreamer, LoweredMI);
 }
 
+void XtensaAsmPrinter::emitMachineConstantPoolValue(
+    MachineConstantPoolValue *MCPV) {
+  XtensaConstantPoolValue *ACPV = static_cast<XtensaConstantPoolValue *>(MCPV);
+  MCSymbol *MCSym;
+
+  assert(ACPV->isExtSymbol() && "unrecognized constant pool value");
+
+  XtensaConstantPoolSymbol *XtensaSym = cast<XtensaConstantPoolSymbol>(ACPV);
+  const char *Sym = XtensaSym->getSymbol();
+  std::string SymName(Sym);
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arsenm wrote:

SmallString + svector_ostream? 

https://github.com/llvm/llvm-project/pull/83280