[llvm] [RISCV] Use LMUL=1 for vmv_s_x_vl with non-undef passthru (PR #66659)

[Philip Reames via llvm-commits]

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@@ -810,9 +810,10 @@ for.end:                                          ; preds = %for.body
 define <vscale x 4 x i32> @cross_block_mutate(<vscale x 4 x i32> %a, <vscale x 4 x i32> %b,
 ; CHECK-LABEL: cross_block_mutate:
 ; CHECK:       # %bb.0: # %entry
-; CHECK-NEXT:    vsetivli a0, 6, e32, m2, tu, ma
+; CHECK-NEXT:    vsetivli a0, 6, e16, m1, ta, ma
+; CHECK-NEXT:    vsetvli a1, zero, e32, m1, tu, ma
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preames wrote:

Here's another instance of a forced VL toggle.

https://github.com/llvm/llvm-project/pull/66659