@CopperheadSec @RichFelker Why would -fwrapv have a performance cost period?
@CopperheadSec @cr1901 Indeed, most UB is undetectable by the compiler without explicit runtime checks since extern acts as compiler barrier
-
-
@CopperheadSec@cr1901 LTO is completely game-changing here. I'm proactively trying to find anything in@musllibc assuming extern-as-barrierThanks. Twitter will use this to make your timeline better. UndoUndo
-
-
-
@cr1901@RichFelker Functions from other files (other than inline in headers) are opaque to the compiler without link-time optimization. -
@cr1901@RichFelker But with LTO, the compiler can optimize the program as a whole and that makes subtle cases of UB much more dangerous. -
@cr1901@RichFelker Without LTO, issues are usually confined to a single source file if there's no memory corruption. -
@CopperheadSec@RichFelker Oh, you're assuming the compiler can prove that signed overflow can't occur if it knows all the places >> -
@CopperheadSec@RichFelker where side effects to an extern signed int occurs globally? -
@cr1901@RichFelker For example, a call to foo(a, b). Lets say it does a + b internally. Now foo(a, b) is a guarantee to the compiler. -
@cr1901@RichFelker Without LTO, these kinds of assumptions can't be made across source files. It greatly limits the potential for breakage. - 1 more reply
New conversation
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.