Mine produces the same code either way:
int
main()
{
int i=0;
if (i==0) {
i++;
}
}
gcc --version
2.95.3
.file "t1.c"
.version "01.01"
gcc2_compiled.:
.text
.align 4
.globl main
.type main,@function
main:
pushl %ebp
movl %esp,%ebp
subl $24,%esp
movl $0,-4(%ebp)
cmpl $0,-4(%ebp)
jne .L3
incl -4(%ebp)
.L3:
.L2:
movl %ebp,%esp
popl %ebp
ret
.Lfe1:
.size main,.Lfe1-main
.ident "GCC: (GNU) 2.95.3 20010315 (release)"
----- Original Message -----
From: "Folkert van Heusden" <folkert@vanheusden.com>
To: "'Ersek Laszlo'" <erseklaszlo@chello.hu>; <linux-kernel@vger.kernel.org>
Sent: Monday, November 25, 2002 4:01 PM
Subject: RE: [PATCH] rbtree
> Not trying to be negative and also really wondering this: won't
> the compiler produce the same code for:
> if (!variable)
> and
> if (variable == 0)
> ?
>
> -----Oorspronkelijk bericht-----
> Van: linux-kernel-owner@vger.kernel.org
> [mailto:linux-kernel-owner@vger.kernel.org]Namens Ersek Laszlo
> Verzonden: zondag 24 november 2002 23:41
> Aan: linux-kernel@vger.kernel.org
> Onderwerp: [PATCH] rbtree
>
>
> Hi all,
>
> this patch tries to remove those checks for 0 from
> linux-2.4.19/lib/rbtree.c which are (I think) superfluous.
>
> Laszlo Ersek
>
>
> --- linux-2.4.19/lib/rbtree.c Sat Aug 3 02:39:46 2002
> +++ linux/lib/rbtree.c Sun Nov 24 22:59:38 2002
> @@ -159,17 +159,16 @@
> if (!other->rb_right ||
> other->rb_right->rb_color == RB_BLACK)
> {
> - register rb_node_t * o_left;
> - if ((o_left = other->rb_left))
> - o_left->rb_color = RB_BLACK;
> + /* unneeded check-for-0 removed */
> + other->rb_left->rb_color = RB_BLACK;
> ...
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sat Nov 30 2002 - 22:00:13 EST