[llvm] [AArch64][GlobalISel] Fix lowering of i64->f32 itofp. (PR #132703)

[Matt Arsenault via llvm-commits]

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@@ -7609,6 +7609,22 @@ LegalizerHelper::lowerU64ToF64BitFloatOps(MachineInstr &MI) {
   return Legalized;
 }
 
+/// i64->fp16 itofp can be lowered to i64->f64,f64->f32,f32->f16. We cannot
+/// convert fpround f64->f16 without double-rounding, so we manually perform the
+/// lowering here where we know it is valid.
+static LegalizerHelper::LegalizeResult
+loweri64tof16ITOFP(MachineInstr &MI, Register Dst, LLT DstTy, Register Src,
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arsenm wrote:

Why is this under lower and not narrow scalar? 

https://github.com/llvm/llvm-project/pull/132703