Would out-of-order execution produce the same out-of-order order over, say, 10 executions?
The clock() results between GCC and TCC are similar. But the ASM looks fairly different. I'm still not seeing rsqrt or sqrt instructions even after specifying short floats throughout and using sqrtf(), with or without -O0, for whatever that's worth. But the speed of the 1/sqrtf() increased quite a bit from 1/sqrt(). gepr@cormac:~/lang/c$ ./gcc.out 1/sqrt() took 0.076633 s Q_rsqrt() took 0.473007 s gepr@cormac:~/lang/c$ ./tcc.out 1/sqrt() took 0.078259 s Q_rsqrt() took 0.46164 s On 1/8/21 8:46 AM, Stephen Taylor wrote: > Because the hardware environment has changed, and the tradeoffs on > integer and floating-point arithmetic are different. (Like it says in the > Wikipedia article.) Out of order execution might be messing up your > measurements, too. -- ↙↙↙ uǝlƃ - .... . -..-. . -. -.. -..-. .. ... -..-. .... . .-. . FRIAM Applied Complexity Group listserv Zoom Fridays 9:30a-12p Mtn GMT-6 bit.ly/virtualfriam un/subscribe http://redfish.com/mailman/listinfo/friam_redfish.com archives: http://friam.471366.n2.nabble.com/ FRIAM-COMIC http://friam-comic.blogspot.com/
