[llvm] [AArch64] Correct SCVTF instructions for vector input (PR #152974)

[Eli Friedman via llvm-commits]

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@@ -5520,6 +5520,11 @@ multiclass IntegerToFPSIMDScalar<bits<2> rmode, bits<3> opcode, string asm, SDPa
     let Inst{31} = 1; // 64-bit FPR flag
     let Inst{23-22} = 0b00; // 32-bit FPR flag
   }
+  def : Pat<(v1f64 (extract_subvector (v2f64 (node (v2i64 (sext (v2i32 V64:$Rn))))), (i64 0))),
+        (!cast<Instruction>(NAME # DSr) (EXTRACT_SUBREG V64:$Rn, ssub))>;
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efriedma-quic wrote:

This will match `uitofp(sext(...))`, which is not a valid transform.

https://github.com/llvm/llvm-project/pull/152974