[llvm-branch-commits] [llvm] [clang] [SPARC] Prefer RDPC over CALL to implement GETPCX for 64-bit target (PR #77196)

[via llvm-branch-commits]

================
@@ -234,8 +244,15 @@ void SparcAsmPrinter::LowerGETPCXAndEmitMCInsts(const MachineInstr *MI,
   //   add <MO>, %o7, <MO>
 
   OutStreamer->emitLabel(StartLabel);
-  MCOperand Callee =  createPCXCallOP(EndLabel, OutContext);
-  EmitCall(*OutStreamer, Callee, STI);
+  if (!STI.getTargetTriple().isSPARC64() ||
+      STI.hasFeature(Sparc::TuneSlowRDPC)) {
+    MCOperand Callee = createPCXCallOP(EndLabel, OutContext);
+    EmitCall(*OutStreamer, Callee, STI);
+  } else {
+    // TODO make it possible to store PC in other registers
+    // so that leaf function optimization becomes possible.
----------------
koachan wrote:

I'm not sure how hard would that be, especially given that there seems to be a couple places where the %o7-as-output assumption is being made... so we need to clean all of those up first, I think?

https://github.com/llvm/llvm-project/pull/77196