[Bug]Failed to compile the AES-GCM with feature +soft-float: LLVM ERROR: Do not know how to split the result of this operator!

[yaoxin-jing]

I try to use AES-GCM in the rust kernel development environment (no-std). But after I add the following to Cargo.toml [dependencies]:

getrandom = { version = "0.2", features = ["rdrand"] }
aes-gcm = "0.10.1"

I got the following error

   Compiling aes-gcm v0.10.1
   Compiling enum_dispatch v0.3.8 (https://github.com/QuarkContainer/enum_dispatch_clone.git#db1abae3)
   Compiling qkernel v0.6.0 (/home/yaoxin/Project/master-thesis-quark/qkernel)
LLVM ERROR: Do not know how to split the result of this operator!

error: could not compile `qkernel`
make[1]: *** [makefile:28: kernel] Error 101
make[1]: Leaving directory '/home/yaoxin/Project/master-thesis-quark/qkernel'
make: *** [makefile:5: release] Error 2

I use cmd CARGO_TARGET_DIR=../target cargo xbuild --target x86_64-qkernel.json
to compile to code. And here is the x86_64-qkernel.json:

{
  "llvm-target": "x86_64-unknown-none",
  "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128",
  "linker-flavor": "gcc",
  "target-endian": "little",
  "target-pointer-width": "64",
  "target-c-int-width": "32",
  "arch": "x86_64",
  "os": "none",
  "disable-redzone": true,
  "features": "-mmx,-sse,-avx,+soft-float",
  "frame-pointer": "always"
}

[yaoxin-jing]

@tarcieri @warner @fjarri @vladikoff Could you please take a look? Many thanks

[newpavlov]

It looks like an LLVM issue (I think we had a similar issue recently...). Have you tried to compile aes? If it fails with the same error, then this issue should go to the block ciphers repository.

As a temporary workaround, try to compile your project with the aes_force_soft configuration flag.

[yaoxin-jing]

It looks like an LLVM issue (I think we had a similar issue recently...). Have you tried to compile aes? If it fails with the same error, then this issue should go to the block ciphers repository.

As a temporary workaround, try to compile your project with the aes_force_soft configuration flag.

I tried to compile aes with my project. It also shows the same error LLVM ERROR: Do not know how to split the result of this operator!.

The workaround works for aes crate. But it doesn't work for aes-gcm.

Here is how I compile my project with the [aes_force_soft]

RUSTFLAGS="--cfg aes_force_soft" CARGO_TARGET_DIR=../target cargo xbuild --target x86_64-qkernel.json 

[newpavlov]

You also need to enable the polyval_force_soft configuration flag.

[yaoxin-jing]

You also need to enable the polyval_force_soft configuration flag.

Many thanks, compiling the code with RUSTFLAGS="--cfg aes_force_soft --cfg polyval_force_soft" fixed the issue