[llvm] [RISCV] Dynamically find unused register for stack protection code (PR #210992)

[Craig Topper via llvm-commits]

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@@ -71,6 +72,10 @@ class RISCVFrameLowering : public TargetFrameLowering {
 
   bool enableShrinkWrapping(const MachineFunction &MF) const override;
 
+  Register findScratchNonCalleeSaveRegister(
+      MachineBasicBlock *MBB, Register PreferredReg,
+      Register DontUseReg = RISCV::NoRegister) const;
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topperc wrote:

It's useful. There are other patches that have replaced some like 191d70f2f52d9cd38e0c57f8319b466eff1ac023 or 62791b43774615b24d565130c8c3f1e6e5145dd8

https://github.com/llvm/llvm-project/pull/210992