On Fri, Dec 7, 2012 at 11:34 AM, Jakub Jelinek wrote: > On Fri, Dec 07, 2012 at 11:25:38AM +0100, Steven Bosscher wrote: >> Perhaps somewhere during the development of ree.c struct ext_cand was >> GGC-allocated, in which case TODO_ggc_collect would make sense, to >> collect the ext_cands (there can be many of them). But since ext_cands >> are not GGC-allocated, the only garbage "produced" by ree.c is when it >> removes redundant extensions (via delete_insn). This is typically only >> a very small percentage of the instructions, so there isn't a lot of >> garbage produced. > > That isn't the only garbage produced, it also updates the PATTERNs of > various instructions with something different. Have you done any > measurement on what kind of percentage of the instructions is modified, > or is "very small percentage" just a guess?
I almost never guess, and try to measure the impact of my patches. In this case, I couldn't even get the garbage collector to trigger without bringing the collection threshold down by a factor 10 or so. Ciao! Steven
