[Bug tree-optimization/69196] code size regression with jump threading at -O2
sebastian.huber@embedded-brains.de
gcc-bugzilla@gcc.gnu.org
Mon Jan 11 09:41:00 GMT 2016
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69196
--- Comment #4 from Sebastian Huber <sebastian.huber@embedded-brains.de> ---
I did a very rough check to see which code is faster on the PSIM/GDB simulator
using the following input data:
void printk(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vprintk(fmt, ap);
va_end(ap);
}
void test(void)
{
char *s = "x";
printk("abc%sx%ix%cx%lu\n", s, 0, 'c', 1UL);
}
GCC 4.9: 311 time units
GCC 6: 316 time units
I guess its quite difficult to determine if this target independent code size
increase is actually a regression in general. At least in this particular
function with this particular input data on this particular target/simulator
the code size is nearly doubled and the execution is slightly slower.
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