Hi all,
I wonder if anyone can spot an obvious problem with the function zero_B
below, which produces a segfault, whereas zero_A does not.
I understand that in many instances this task of converting to a bitstype
is more safety completed with high-level Julia functionality like
reinterpret or immutable wrappers. However, I'm working on a library that
works directly with data byte-fields. With this kind of coding it seems
inevitable that one runs into bugs (like the recent LLVM shift bug), but
here I was unable either to figure out my coding mistake or to find any
recent bug-reports matching this pattern.
Thanks in advance for any clues...!
Bryce
import Base.Intrinsics: box, unbox, zext_int, trunc_int
bitstype 144 UInt144
function zero_A(::Type{UInt144})
box(UInt144,zext_int(UInt144,unbox(UInt64,zero(UInt64))))
end
function zero_B(::Type{UInt144})
if sizeof(UInt144) > sizeof(UInt64)
box(UInt144,zext_int(UInt144,unbox(UInt64,zero(UInt64))))
else
box(UInt144,trunc_int(UInt144,unbox(UInt64,zero(UInt64))))
end
end
julia> zero_A(UInt144)
UInt144(0x000000000000000000000000000000000000)
julia> zero_B(UInt144)
Assertion failed: (castIsValid(op, S, Ty) && "Invalid cast!"), function
Create, file Instructions.cpp, line 2290.
signal (6): Abort trap: 6
__pthread_kill at /usr/lib/system/libsystem_kernel.dylib (unknown line)
Abort trap: 6
