[llvm] [AMDGPU] Recover direct callees from called globals (PR #192199)

[Shilei Tian via llvm-commits]

================
@@ -59,6 +59,21 @@ static const Function *getCalleeFunction(const MachineOperand &Op) {
   return cast<Function>(Op.getGlobal()->stripPointerCastsAndAliases());
 }
 
+static const Function *getCalleeFunction(const MachineFunction &MF,
+                                         const MachineInstr &MI,
+                                         const SIInstrInfo &TII) {
+  if (MachineFunction::CalledGlobalInfo CGI = MF.tryGetCalledGlobal(&MI);
----------------
shiltian wrote:

IMHO, this conditional statement's readability is not really good. I'd just write it as something like:

```
MachineFunction::CalledGlobalInfo CGI = MF.tryGetCalledGlobal(&MI);
if (CGI.Callee) {
  if (const auto *F = dyn_cast<Function>(CGI.Callee->stripPointerCastsAndAliases()))
    return F;
}
...
```

https://github.com/llvm/llvm-project/pull/192199