[llvm] [RISCV] Unify vsetvli compatibility logic in forward and backwards passes (PR #71657)

[Luke Lau via llvm-commits]

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@@ -51,11 +51,10 @@ define <32 x i32> @insertelt_v32i32_0(<32 x i32> %a, i32 %y) {
 define <32 x i32> @insertelt_v32i32_4(<32 x i32> %a, i32 %y) {
 ; CHECK-LABEL: insertelt_v32i32_4:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    li a1, 32
-; CHECK-NEXT:    vsetvli zero, a1, e32, m1, ta, ma
-; CHECK-NEXT:    vmv.s.x v16, a0
 ; CHECK-NEXT:    vsetivli zero, 5, e32, m2, tu, ma
+; CHECK-NEXT:    vmv.s.x v16, a0
 ; CHECK-NEXT:    vslideup.vi v8, v16, 4
+; CHECK-NEXT:    li a0, 32
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lukel97 wrote:

It must be from the old AVL which was removed. We can probably do some basic DCE here

https://github.com/llvm/llvm-project/pull/71657