https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109154
--- Comment #37 from Andrew Macleod <amacleod at redhat dot com> --- Created attachment 54780 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54780&action=edit in progress patch Well call me a liar. It took me a while to understand why, but if we leave it to single dependencies only, the impact is relatively linear. I wrote a bunch of code, then deleted most of it as I found the engine was bypassing my code and doing it on its own. The attached patch is the core. It actually works to a depth of 5 recomputations. my sample of: int a = left * 2; int b = a - 4; int c = b % 7; func (a,b ,c); int d = c * 4; if (left == 20) { func (b,c,d); produces <bb 5> : func (36, 1, 4); IT also changes your program somewhat. Try applying it and see if it does what you want. It bootstraps, regression are running.. but based on the minimal code impact, I wouldn't expect incorrect failures. Performance impact on building GCC is barely half a percent in VRP, and 0.05% overall compile time. pretty minimal. Im still working with it to tweak it, I just wanted you to be able to see if it helps. I presume we dont want to add a new --param this late in the game. But it seems we can set a reasonable number and not run into much trouble.
