[llvm] Spill/restore FP/BP around instructions in which they are clobbered (PR #81048)

[via llvm-commits]

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@@ -1587,3 +1600,115 @@ void PEI::replaceFrameIndices(MachineBasicBlock *BB, MachineFunction &MF,
       ++I;
   }
 }
+
+static bool accessFrameBasePointer(const MachineInstr &MI, Register FP,
+                                   Register BP, bool &AccessFP, bool &AccessBP,
+                                   const TargetRegisterInfo *TRI) {
+  AccessFP = AccessBP = false;
+  if (FP) {
+    if (MI.findRegisterUseOperandIdx(FP, TRI, false) != -1 ||
+        MI.findRegisterDefOperandIdx(FP, TRI, false, true) != -1)
+      AccessFP = true;
+  }
+  if (BP) {
+    if (MI.findRegisterUseOperandIdx(BP, TRI, false) != -1 ||
+        MI.findRegisterDefOperandIdx(BP, TRI, false, true) != -1)
+      AccessBP = true;
+  }
+  return AccessFP || AccessBP;
+}
+
+/// If a function uses base pointer and the base pointer is clobbered by inline
+/// asm, RA doesn't detect this case, and after the inline asm, the base pointer
+/// cotains garbage value.
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zmodem wrote:

nit: contains

https://github.com/llvm/llvm-project/pull/81048