`LLVM ERROR: SPARCv8 does not handle f128 in calls; pass indirectly` for `sparc-*` targets

[alexrp]

❯ zig4 build-exe empty.zig -target sparc-freestanding
LLVM ERROR: SPARCv8 does not handle f128 in calls; pass indirectly

[alexrp]

long double is 64 bits on sparc32, and 128 bits on sparc64. There is no _Float128 on sparc32 either.

I still think that this is an LLVM bug; we're producing perfectly valid IR. Just because there's no C ABI to adhere to doesn't mean that the backend should just give up on f128 in calls; it can use a bespoke calling convention for this case, as is the norm in other backends.

[alexrp]

llvm/llvm-project#41838 (comment)