[llvm] [GlobalISel][ARM] Legalization of G_CONSTANT using constant pool (PR #98308)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> AArch64 legalizes all constants:

> https://github.com/llvm/llvm-project/blob/ee5d572718f7bb07f89b69df393b28a89033a5ca/llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp#L2598
> 
> Why should ARM deviate from that model?

They are not trying to achieve the same result. AArch64 does not use a constant pool, and ARM does. The constant pool expansion can be shared to generic code, and is a higher level transform than belongs in selection.

https://github.com/llvm/llvm-project/pull/98308