[llvm] [X86] Lower mathlib call ldexp into scalef when avx512 is enabled (PR #69710)

[Simon Pilgrim via llvm-commits]

================
@@ -2405,6 +2405,15 @@ X86TargetLowering::X86TargetLowering(const X86TargetMachine &TM,
     setOperationAction(ISD::STRICT_UINT_TO_FP, MVT::i128, Custom);
   }
 
+  if (Subtarget.hasAVX512()) {
+    for (MVT VT : { MVT::f16, MVT::f32, MVT::f64, MVT::v4f32, MVT::v2f64 })
----------------
RKSimon wrote:

Are we sure this is right? I'd expect MVT::v4f32, MVT::v2f64, MVT::v8f32, MVT::v4f64 to be the VLX cases. 

https://github.com/llvm/llvm-project/pull/69710