On 5/28/21 8:41 AM, Richard Biener wrote: > On Fri, 28 May 2021, Bernd Edlinger wrote: > >> >> >> On 5/28/21 6:42 AM, Bernd Edlinger wrote: >>> Hi, >>> >>> I was wondering, why gimple-match.c and generic-match.c >>> are not built early but always last, which slows down parallel >>> makes significantly. >>> >>> The reason seems to be that generated_files does not >>> mention gimple-match.c and generic-match.c. >>> >>> This comment in Makefile.in says it all: >>> >> >> Oh, dear, git commit did eliminate the comments >> starting with "#" >> the mentined comment is >> >> # Dependency information. >> >> # In order for parallel make to really start compiling the expensive >> # objects from $(OBJS) as early as possible, build all their >> # prerequisites strictly before all objects. >> >>> $(ALL_HOST_OBJS) : | $(generated_files) >>> >>> So this patch adds gimple-match.c generic-match.c to generated_files. >>> >>> >>> Tested on x86_64-pc-linux-gnu. >>> Is it OK for trunk? > > OK. Does it really help though? >
Yes, I guess so, at least a little bit. Prior to this patch the whole build stage was completed for everything then those two big files got generated, and then there are only two large files compiled in parallel for several minutes at least. So a make -j8 utilizes only 25 % cpu power and make -j16 only 12.5 % utilization. That can certainly be a bit annoying. Bernd. > Thanks, > Richard. > >>> >>> >>> Thanks >>> Bernd. >>> >>> >>> 2021-05-28 Bernd Edlinger <bernd.edlin...@hotmail.de> >>> >>> * Makefile.in (generated_files): Add gimple-match.c and >>> generic-match.c >>> >> >
