On January 29, 2015 6:25:35 PM CET, Jakub Jelinek <ja...@redhat.com> wrote: >On Thu, Jan 29, 2015 at 06:19:45PM +0100, Tom de Vries wrote: >> consider attached patch, which adds pass_lim after fre1 (a >simplification of >> my oacc kernels patch series). >> >> The included testcase lim-before-stdarg.c fails. >> >> The first sign of trouble is in lim-before-stdarg.c.088t.stdarg >(attached): >> ... >> gen_rtvec: va_list escapes 0, needs to save 0 GPR units and 0 FPR >units. >> ... >> >> Because of the 'need to save 0 GPRs units', at expand no prologue is >> generated to dump the varargs in registers onto stack. > >The stdarg pass can't grok too heavy optimizations, so if at all >possible, >don't schedule such passes early, and if you for some reason do, avoid >optimizing in there the va_list related accesses. I'm afraid that is >the >only recommendation I can give here for that.
The other possibility (Matz has patches for that) is to delay vaarg lowering currently done by gimplification and combine it with the stdarg pass. Richard. > Jakub
