Cranelift: Inconsistent results from scalar_to_vector #10906
Description
.clif Test Case
test optimize
set opt_level=none
set preserve_frame_pointers=true
set enable_multi_ret_implicit_sret=true
target x86_64
function %main() -> i16x8 fast {
const0 = 0x560af419d25ee4ab70b6b8ba64146998
block0:
v3 = iconst.i8 66
v4 = iconst.i16 0x6342
v9 = f64const 0x1.3ebf9685e6a16p-2
v10 = vconst.i8x16 const0
v11 = vconst.i16x8 const0
v12 = vconst.i32x4 const0
v13 = vconst.f32x4 const0
v14 = vconst.i64x2 const0
v15 = vconst.f64x2 const0
jump block2
block2:
v23 = scalar_to_vector.i16x8 v4
return v23
}
; print: %main()
Steps to Reproduce
clif-util run -v ./test1.clif
Results
%main() -> 0x00000000000000000000000000006342
Then add a return value v9.
test optimize
set opt_level=none
set preserve_frame_pointers=true
set enable_multi_ret_implicit_sret=true
target x86_64
function %main() -> f64, i16x8 fast {
const0 = 0x560af419d25ee4ab70b6b8ba64146998
block0:
v3 = iconst.i8 66
v4 = iconst.i16 0x6342
v9 = f64const 0x1.3ebf9685e6a16p-2
v10 = vconst.i8x16 const0
v11 = vconst.i16x8 const0
v12 = vconst.i32x4 const0
v13 = vconst.f32x4 const0
v14 = vconst.i64x2 const0
v15 = vconst.f64x2 const0
jump block2
block2:
v23 = scalar_to_vector.i16x8 v4
return v9, v23
}
; print: %main()
Sometimes the result is [0x1.3ebf9685e6a16p-2, 0x00000000000000000000000000006342],
and other times it’s [0x1.3ebf9685e6a16p-2, 0x000000000000000100000000ffff6342].
Why does this inconsistency happen?