[llvm] [X86][GlobalISel] Support fp80 for G_FPTRUNC and G_FPEXT (PR #141611)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

> We intentionally omit s32->s64 and s64->s32 variants of stores and loads for X87 because during legalization we can't determine whether it is a floating point store or an integer one.


But you shouldn't need this? The FP-ness should be encoded in the load/store directly. i.e. are we missing FP ext load and store?

https://github.com/llvm/llvm-project/pull/141611