[llvm] [Mips] Fix compiler crash when returning fp128 after calling a functi… (PR #117525)

[Nikita Popov via llvm-commits]

https://github.com/nikic requested changes to this pull request.

I looked into this in more detail, and as far as I understand, the problem here is a confusion between the call return type and the function return type in CanLowerReturn. This function is used both for function returns and call return values, and we analyze the wrong one. This needs to be fixed by analyzing the correct type. Adding additional registers will change the actual calling convention to no longer use sret demotion.

https://github.com/llvm/llvm-project/pull/117525