The extend instruction is for loading narrower data types into wider
data types, eg, single element into 2, 3, or 4 element types, with a
small set of extension schemes: 0, 1, -1, copy (for 1->any and 2 -> 4).
Possibly most importantly, it works with unaligned data.
Progress towards #30
It currently fails for two reasons:
- call's mode selection is incorrect (never updated from when there was
only the one call instruction and the mode was encoded in operand c)
- return should automatically restore the stack pointer to the value it
had on entry to the function, thus allowing local values stored on
the stack to be safely returned.
Does not include string concatenation because I don't feel like messing
with zone init, but all the other operators are tested (currently
failing due to bool convention)
They currently fail because for vector values, gcc casts the view, not
the value, so vec4 cast to ivec4 simply views the bits as int rather
than doing the actual conversion.
* / % %% + -
As a bonus, includes partial tests for a few extra operators. Several
things are broken at this stage, but uncommitted code is already
working.
They even found a bug in the addressing mode functions :) (I'd forgotten
that I wanted signed offsets from the pointer and thus forgot to cast
st->b to short in order to get the sign extension)
