[llvm] [AMDGPU] Use immediates for stack accesses in chain funcs (PR #71913)

[Nicolai Hähnle via llvm-commits]

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@@ -1799,10 +1798,11 @@ static bool frameTriviallyRequiresSP(const MachineFrameInfo &MFI) {
 bool SIFrameLowering::hasFP(const MachineFunction &MF) const {
   const MachineFrameInfo &MFI = MF.getFrameInfo();
 
-  // For entry functions we can use an immediate offset in most cases, so the
-  // presence of calls doesn't imply we need a distinct frame pointer.
+  // For entry & chain functions we can use an immediate offset in most cases,
+  // so the presence of calls doesn't imply we need a distinct frame pointer.
   if (MFI.hasCalls() &&
-      !MF.getInfo<SIMachineFunctionInfo>()->isEntryFunction()) {
+      !MF.getInfo<SIMachineFunctionInfo>()->isEntryFunction() &&
+      !MF.getInfo<SIMachineFunctionInfo>()->isChainFunction()) {
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nhaehnle wrote:

I'd say it's not worth it unless we find a good name for it. `isBottomOfStackFunction`? Not too fond of that, to be honest, but at least it captures the meaning.

https://github.com/llvm/llvm-project/pull/71913