Hello Oleg,
On Sun, Aug 18, 2013 at 6:36 AM, Oleg Endo wrote:
> On Sun, 2013-08-18 at 00:55 -0400, Asm Twiddler wrote:
>> Hello all,
>>
>> I'm not sure whether this has been posted before, but gcc creates
>> slightly inefficient code for large integers in several
Hello all,
I'm not sure whether this has been posted before, but gcc creates
slightly inefficient code for large integers in several cases:
unsigned long long val;
void example1() {
val += 0x8000ULL;
}
On x86 this results in the following assembly:
addl $0, val
adcl $32768, val+4
re
Hello all.
The current implementation produces non-optimal code for large shifts
that aren't a multiple of eight when operating on long integers (4
bytes).
All such shifts are broken down into a slow loop shift.
For example, a logical shift right by 17 will result in a loop that
takes around 7 cyc
