[llvm] [RISCV] Add stack clash vector support (PR #119458)

[Craig Topper via llvm-commits]

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@@ -914,6 +966,20 @@ void RISCVFrameLowering::emitPrologue(MachineFunction &MF,
             .addImm(ShiftAmount)
             .setMIFlag(MachineInstr::FrameSetup);
       }
+      if (NeedProbe) {
+        // Do a probe if the align + size allocated just passed the probe size
+        // and was not yet probed.
+        uint64_t AllocatedStack = SecondSPAdjustAmount + RVVStackSize;
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topperc wrote:

RVVStackSize is relative to vscale. Does this addition make sense?

https://github.com/llvm/llvm-project/pull/119458