Re: LOADF vs LOADK

[Bas Groothedde <lua@...>]

> Dear,
> I was looking at the opcodes from lua-5.4.0-rc1 using "luac -l", and 
> the simple code below
>
> local v1 = 1
> local v2 = 1.
> local v3 = 1.0
> local v4 = 1.01
>
> is translated to
>
> 1 [1] VARARGPREP 0
> 2 [1] LOADI     0 1
> 3 [2] LOADF     1 1
> 4 [3] LOADF     2 1
> 5 [4] LOADK     3 0 ; 1.01
>
> So, why "1." and "1.0" use LOADF but "1.01" uses LOADK?

I think that is caused by the fact LOADF loads the value from the sBx 
argument, an integer. In lvm.c, you can see it simply casting sBx as an 
int to a lua_Number:

vmcase(OP_LOADF) {
  int b = GETARG_sBx(i);
  setfltvalue(s2v(ra), cast_num(b));
  vmbreak;
}

So I would assume only floating point numbers with an integer value can 
be stored in LOADF instructions in the current implementation.

~Bas
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