GCC_JIT_BINARY_OP_LOGICAL_AND eager or lazy? and GCCJIT vs GNU C semantics....
Basile Starynkevitch
basile@starynkevitch.net
Thu Jan 1 00:00:00 GMT 2015
Hello David and list,
I a a bit confused by the document.... Is
GCC_JIT_BINARY_OP_LOGICAL_AND a lazy operation like in C, or is it
eager? It is documented as
Logical AND; analogous to:
(EXPR_A) && (EXPR_B)
in C.
So I guess that it is lazy. In other words, if EXPR_A is non-null,
EXPR_B is not even evaluated....
But I am not sure.... Perhaps we should state the laziness in the
documentation.
Also, do we have a ternary conditional operator, like Cond?Then:Else in
C? Apparently not
and that surprises me if GCC_JIT_BINARY_OP_LOGICAL_AND is lazy like &&
is in C.
At last, do we have a comma operator?
Or do we have a statement-expr like thing?
https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html
All these could be useful in a Scheme like client (for BEGIN in Scheme,
or PROGN in Lisp) using GCCJIT. Of course, this can be avoided by
forcing the GCCJIT client to emit much lower-level things. But in that
case, we should not even admit a function call as a gcc_jit_rvalue...
(and restrict function calls to be the last statement of basic blocks).
My implicit feeling (but I might be very wrong) is that everything which
is expressible in GNU C (this includes most GCC language extension of C)
for GCC
should be easily (and "naturally") done in GCCJIT, but perhaps I don't
understand the philosophy of GCCJIT yet.... I'm implicitly wishing that
the semantics of programs built with GCCJIT would be very close to the
semantics of GCC GNU C language (i.e. gcc -std=gnuc11....)
Then, it might be the case that we don't have any way to declare a
thread local variable, or atomic variables....
Cheers.
--
Basile STARYNKEVITCH http://starynkevitch.net/Basile/
email: basile<at>starynkevitch<dot>net mobile: +33 6 8501 2359
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*** opinions {are only mine, sont seulement les miennes} ***
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