[llvm] [RISCV] Rematerialize vmv.v.i (PR #107550)

[Philip Reames via llvm-commits]

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@@ -519,6 +519,7 @@ define void @vselect_legalize_regression(<vscale x 16 x double> %a, <vscale x 16
 ; CHECK-NEXT:    vmv.v.i v24, 0
 ; CHECK-NEXT:    vmerge.vvm v16, v24, v16, v0
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preames wrote:

Any idea why we're not turning this into a vmerge.vim with a negated mask?  That would radically reduce register pressure and work, and be net equal in terms of instructions.  

https://github.com/llvm/llvm-project/pull/107550