------- Comment #52 from seongbae dot park at gmail dot com 2008-01-17 22:31 ------- Subject: Re: [4.3 regression] bad interaction between DF and SJLJ exceptions
I just talked to Kenny on the phone, and my suggestion is wrong since it changes the return value - doing my naive suggestion would lead to infinite loop, as the transfer function will almost always return true, even when the out set didn't change. Can you add a comment to that effect there ? Also please add a comment above df_live_scratch definition that this is an optimization to reduce memory allocation overhead for the scratch. Can you explain why the hunk in df_live_bb_local_compute() is correct ? As this seems to change what DF_REF_AT_TOP means for artificial defs... Seongbae On Jan 17, 2008 1:31 PM, Seongbae Park (¹Ú¼º¹è, ÚÓà÷ÛÆ) <[EMAIL PROTECTED]> wrote: > In df_live_transfer_function: > > Doesn't look like we need df_live_scratch - can't we do: > > bitmap_and (out, gen, bb_lr_info->out); > bitmap_and_into (in, bb_lr_info->in); > return bitmap_ior_and_compl_into (out, in, kill); > > ? > > Seongbae > > > On Jan 17, 2008 1:05 PM, Kenneth Zadeck <[EMAIL PROTECTED]> wrote: > > This is the second of three patches to fix 34400. This patch also makes > > some progress on 26854 but more work is required that is not going to be > > done in 4.3 to fix the problems here. > > > > This patch uses the output of the df_lr problem to make the df_live > > problem converge faster. > > This not only saves time but also space since the size of the df_live > > bitmaps never grows and the space of our bitmaps is proportional to the > > number of 1 bits. > > > > This has been tested on several platforms and along with the patch just > > committed cuts the time on the 34400 problems significantly. I believe > > that this patch also has some modest improvement on bootstrap time, i.e > > regular programs. > > > > The change to df_live_reset is a slightly related latent bug fix. > > > > Ok to commit? > > > > Kenny > > > > > > 2008-01-17 Kenneth Zadeck <[EMAIL PROTECTED]> > > Steven Bosscher <[EMAIL PROTECTED]> > > > > PR rtl-optimization/26854 > > PR rtl-optimization/34400 > > * df-problems.c (df_live_scratch): New scratch bitmap. > > (df_live_alloc): Allocate df_live_scratch when doing df_live. > > (df_live_reset): Clear the proper bitmaps. > > (df_live_bb_local_compute): Only process the artificial defs once > > since the order is not important. > > (df_live_init): Init the df_live sets only with the variables > > found live by df_lr. > > (df_live_transfer_function): Use the df_lr sets to prune the > > df_live sets as they are being computed. > > (df_live_free): Free df_live_scratch. > > > > > > > > -- > #pragma ident "Seongbae Park, compiler, http://seongbae.blogspot.com"; > -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34400
