Incorrect Handling of SIMD v128 Return Value

[Q1IQ]

Subject of the issue

iwasm fails to handle v128 return values correctly

Test case

program.wasm.txt

Your environment

• os: Ubuntu 20.04
• cpu: amd64
• WAMR version: iwasm 1.2.3
• command: iwasm --interp ./program.wasm

Steps to reproduce

Run the following wasm module:

(module
  (memory 1)
  (func $return_v128 (result v128)
    (v128.const i32x4 0x00000004 0x34567890 0x66666666 0x77777777)
 )
  (export "main" (func $return_v128))
)

Observed output:

iwasm --interp  -f main ./program.wasm
Segmentation fault (core dumped)

Expected behavior

The v128 value should be returned correctly, like it can correctly process i32.

(module
  (memory 1)
  (func $func1 (result i32)
    i32.const 1234
 )
  (export "main" (func $func1))
)

iwasm --interp  -f main program.wasm
0x1234:i32

[lum1n0us]

@Q1IQ SIMD on interp is currently in development. You may want to try again using the development branch. dev/simd_for_interp

@Zzzabiyaka @loganek Just FYI.

[Zzzabiyaka]

Hi
Just fyi I would expect this branch to be merge-ready in January

[lum1n0us]

iwasm --fast-jit ./program.wasm

SIMD is not supported on the fast-jit. Only llvm-jit and aot support SIMD opcodes.

[Q1IQ]

interp should at least output a hint like "unsupported opcode" similar to fast-jit, instead of directly segmentation fault.

$ iwasm --fast-jit  -f  main ./program.wasm
fast jit compilation failed: Error: unsupported opcode
Exception: failed to compile fast jit function
fast jit compilation failed: Error: unsupported opcode
failed to compile fast jit function 0
$ iwasm --interp  -f main./program.wasm
Segmentation fault (core dumped)

[Zzzabiyaka]

interp should at least output a hint like "unsupported opcode" similar to fast-jit, instead of directly segmentation fault.

$ iwasm --fast-jit  -f  main ./program.wasm

fast jit compilation failed: Error: unsupported opcode

Exception: failed to compile fast jit function

fast jit compilation failed: Error: unsupported opcode

failed to compile fast jit function 0

$ iwasm --interp  -f main./program.wasm

Segmentation fault (core dumped)

I think for fast interp it might not be needed right now given we expect to deliver simd there in about a month or so

For classic interp maybe it'd be helpful

[lum1n0us]

Please re-try with latest commit, like 04f1071.

if with

(module
  (memory 1)
  (func $return_v128 (result v128)
    (v128.const i32x4 0x00000004 0x34567890 0x66666666 0x77777777)
 )
  (export "main" (func $return_v128))
)

->

$ /workspaces/wasm-micro-runtime/product-mini/platforms/linux/build/iwasm --interp  -f main case1.wasm 
Exception: unsupported opcode

if with

(module
  (memory 1)
  (func $func1 (result i32)
    i32.const 1234
 )
  (export "main" (func $func1))
)

->

$ /workspaces/wasm-micro-runtime/product-mini/platforms/linux/build/iwasm --interp  -f main case2.wasm 
Exception: unsupported opcode