How to ask gcc to reset an asm inline input value? %0
in the following example is not reset to 42
after the first loop. So when i = 1, %0
value is still 0
.
for (int i = 0; i < N; ++i)
asm("label: substract_immediate_value %0,%0,1;"
"compare_immediate_value %0,0;"
"branch_not_equal label"
: /* no outputs */
: /* input */ "r" (42));
I've not tried this, but it looks right:
for (int i = 0; i < N; ++i)
{
int n = 42;
asm("label: substract_immediate_value %0,%0,1;"
"compare_immediate_value %0,0;"
"branch_not_equal label"
: "+r" (n));
}
I presume this is a simplified example, because I can't imagine why you wouldn't just code that in C. Indeed, it's a no-op.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.