On Thu, May 16, 2013 at 11:56 PM, Xi Wang <xi.wang@xxxxxxxxx> wrote:
> Consider the following function.
>
> static _Bool foo(int x) { return x; }
>
> Currently sparse emits:
>
> scast.1 %r2 <- (32) %arg1
> ret.1 %r2
>
> This is incorrect since bool requires a zero test.
>
> setne.32 %r2 <- %arg1, $0
> ret.1 %r2
>
> This patch adds zero testing for bool in cast_to().
>
> Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx>
Acked-by: Pekka Enberg <penberg@xxxxxxxxxx>
> ---
> evaluate.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/evaluate.c b/evaluate.c
> index d9c767f..a090028 100644
> --- a/evaluate.c
> +++ b/evaluate.c
> @@ -272,6 +272,18 @@ static struct expression * cast_to(struct expression *old, struct symbol *type)
> if (old->ctype != &null_ctype && is_same_type(old, type))
> return old;
>
> + /* bool requires a zero test */
> + if (is_bool_type(type)) {
> + expr = alloc_expression(old->pos, EXPR_COMPARE);
> + expr->op = SPECIAL_NOTEQUAL;
> + expr->ctype = type;
> + expr->left = old;
> + expr->right = alloc_expression(old->pos, EXPR_VALUE);
> + expr->right->ctype = old->ctype;
> + expr->right->value = 0;
> + return expr;
> + }
> +
> /*
> * See if we can simplify the op. Move the cast down.
> */
> --
> 1.8.1.2
>
> --
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