[PATCH] D106857: [RISCV] Teach VSETVLI insertion to merge the unused VSETVLI with the one need to be insert after it.

[Jianjian Guan via Phabricator via llvm-commits]

jacquesguan added inline comments.


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Comment at: llvm/test/CodeGen/RISCV/rvv/vsetvli-insert.ll:12
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    vsetvli a0, a0, e64, m1, ta, mu
+; CHECK-NEXT:    vfadd.vv v8, v8, v9
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craig.topper wrote:
> What if a0 is used by another instruction or a pointer increment? This changes VLMAX which changes where AVL gets clipped, potentially breaking the other uses.
A new condition added for checking if is a virtual register.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D106857/new/

https://reviews.llvm.org/D106857