[llvm] [RISCV] Handled the uimm9 offset while FrameIndex folding. (PR #149303)

[Craig Topper via llvm-commits]

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@@ -573,6 +573,9 @@ bool RISCVRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
     int64_t Val = Offset.getFixed();
     int64_t Lo12 = SignExtend64<12>(Val);
     unsigned Opc = MI.getOpcode();
+    int64_t Imm9Val = SignExtend64<9>(Val);
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topperc wrote:

We can't sign extend the value to 9 bits. We need to check that the raw `Val` is uimm9.

https://github.com/llvm/llvm-project/pull/149303