Re: [BUG] lua 5.2 luai_hashnum bug with threads

[Coda Highland <chighland@...>]

On Tue, Apr 22, 2014 at 5:01 AM, Andrei <mrpuzzler@yandex.ru> wrote:
> Here's a simple, ANSI-c fix
>
> #ifndef _control87
> #define _control87 _controlfp
> #endif
>
> /*
> ** luai_hashnum is a macro to hash a lua_Number value into an integer.
> ** The hash must be deterministic and give reasonable values for
> ** both small and large values (outside the range of integers).
> */
> #define luai_hashnum(i,n) { int e, cw;  \
>    cw = _control87(0, 0);\
>    _control87(_PC_53, MCW_PC); \
>    n = l_mathop(frexp)(n, &e) * (lua_Number)(INT_MAX - DBL_MAX_EXP);  \
>    lua_number2int(i, n); i += e; \
>    _control87(cw, MCW_EM);}
>

With all due respect, that's not ANSI C. Syntactically, sure, but
_control87 is specific to x86 and isn't portable.

/s/ Adam