[llvm] [RISCV] Support postRA vsetvl insertion pass (PR #70549)

[Philip Reames via llvm-commits]

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@@ -35,10 +35,10 @@ define <512 x i8> @single_source(<512 x i8> %a) {
 ; CHECK-NEXT:    vslidedown.vi v16, v16, 4
 ; CHECK-NEXT:    li a0, 466
 ; CHECK-NEXT:    li a1, 465
+; CHECK-NEXT:    lbu a2, 1012(sp)
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preames wrote:

This is a slight regression - it's the same push back heuristic I raised previously.  Non blocking, but this would be good to address.  

https://github.com/llvm/llvm-project/pull/70549