[llvm] [Xtensa] Lower GlobalAddress/BlockAddress/JumpTable (PR #95256)

[Andrei Safronov via llvm-commits]

================
@@ -42,26 +43,48 @@ getModifierVariantKind(XtensaCP::XtensaCPModifier Modifier) {
 }
 
 void XtensaAsmPrinter::emitInstruction(const MachineInstr *MI) {
-  MCInst LoweredMI;
-  lowerToMCInst(MI, LoweredMI);
-  EmitToStreamer(*OutStreamer, LoweredMI);
+  unsigned Opc = MI->getOpcode();
+
+  switch (Opc) {
+  case Xtensa::BR_JT:
+    EmitToStreamer(
+        *OutStreamer,
+        MCInstBuilder(Xtensa::JX).addReg(MI->getOperand(0).getReg()));
+    return;
+  default:
+    MCInst LoweredMI;
+    lowerToMCInst(MI, LoweredMI);
+    EmitToStreamer(*OutStreamer, LoweredMI);
+    return;
+  }
 }
 
 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);
-
-  if (XtensaSym->isPrivateLinkage())
-    SymName = ".L" + SymName;
+  if (ACPV->isBlockAddress()) {
+    const BlockAddress *BA =
+        cast<XtensaConstantPoolConstant>(ACPV)->getBlockAddress();
+    MCSym = GetBlockAddressSymbol(BA);
+  } else if (ACPV->isJumpTable()) {
+    unsigned Idx = cast<XtensaConstantPoolJumpTable>(ACPV)->getIndex();
+    MCSym = this->GetJTISymbol(Idx, false);
+  } else {
+    assert(ACPV->isExtSymbol() && "unrecognized constant pool value");
+    XtensaConstantPoolSymbol *XtensaSym = cast<XtensaConstantPoolSymbol>(ACPV);
+    const char *SymName = XtensaSym->getSymbol();
+
+    if (XtensaSym->isPrivateLinkage()) {
+      const DataLayout &DL = getDataLayout();
+      MCSym = OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
+                                           SymName);
----------------
andreisfr wrote:

I've found that that "DL.getPrivateGlobalPrefix()" code returns appropriate prefix for Xtensa for private linkage case and such code is used for similar purposes in ARM backend and other backends. So, I used it to substitute hardcoded ".L" prefix.

https://github.com/llvm/llvm-project/pull/95256