[llvm] [RISCV] Check for null LIS before trying to move AVL in canMutatePriorConfig. (PR #196673)

[Pengcheng Wang via llvm-commits]

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@@ -7,8 +7,8 @@ define <2 x double> @fixed_length(<2 x double> %a, <2 x double> %b) nounwind {
 ; CHECK:       # %bb.0: # %entry
 ; CHECK-NEXT:    vsetivli zero, 2, e64, m1, ta, ma
 ; CHECK-NEXT:    vmv1r.v v10, v9
-; CHECK-NEXT:    # kill: def $v11 killed $v10
-; CHECK-NEXT:    # kill: def $v9 killed $v8
+; CHECK-NEXT:    # kill: def $v11 killed $v10 killed $vtype
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wangpc-pp wrote:

By the way, why is vtype killed after this change?

https://github.com/llvm/llvm-project/pull/196673