Thx! I guess we'll live with that for now, knowing dce and cprop is dependent for some ASM stmts Sun
On Tue, Jan 10, 2012 at 7:28 PM, Rao, Shivarama <shivarama....@amd.com> wrote: > It passes at -O0 and at -O1. Fails at -O2. > > Regards, > Shivaram > > -----Original Message----- > From: Sun Chan [mailto:sun.c...@gmail.com] > Sent: Tuesday, January 10, 2012 6:00 AM > To: Ye, Mei > Cc: open64-devel > Subject: Re: [Open64-devel] Review request for fix bug787[WOPT] > > I wonder what the behavior at O0 for this bug? > Sun > > On Tue, Jan 10, 2012 at 8:28 AM, Sun Chan <sun.c...@gmail.com> wrote: >> thx for pointing this out, it could cause problem for automatic bug >> triaging. >> Sun >> >> On Tue, Jan 10, 2012 at 1:34 AM, Ye, Mei <mei...@amd.com> wrote: >>> I don't have objection to this fix. But this bug exposes a design problem >>> in DCE, i.e., >>> DCE can't handle a situation where copy prop is disabled upstream. >>> >>> -Mei >>> >>> -----Original Message----- >>> From: Sun Chan [mailto:sun.c...@gmail.com] >>> Sent: Friday, January 06, 2012 9:55 PM >>> To: Gang Yu >>> Cc: open64-devel >>> Subject: Re: [Open64-devel] Review request for fix bug787[WOPT] >>> >>> this fix looks better. i am still a bit worry about regressions >>> (performance). Have you checked perf regression with this change? >>> Sun >>> >>> On Sat, Jan 7, 2012 at 1:36 PM, Gang Yu <yugang...@gmail.com> wrote: >>>> Hi, >>>> >>>> I have a new fix for the bug787, the cut-down case from Rao(thanks) is as >>>> follows: >>>> >>>> extern int main(int argc) >>>> { >>>> int res1; >>>> int val0,val1; >>>> val1=100; >>>> if(1) >>>> { >>>> asm("bswapl %0" : "=r" (val0) : "0" (val1)); >>>> res1=val0; >>>> } >>>> val0=res1; >>>> asm("bswapl %0" : "=r" (val1) : "0" (val0)); >>>> } /* main */ >>>> analysis: >>>> >>>> Current open64 disallows copy propagation into ASM_INPUT for the var and >>>> ivar cases, this is reasonable since some constraints do only allow the >>>> parameter in specific form. >>>> >>>> If we fix following Rao's suggested way, i.e, mark some identity assignment >>>> undeletable for DCE, then we need special marking work for the identity >>>> assignment. >>>> >>>> a sound way as RAO suggested is say if the LHS of the identity assignment >>>> has flag CR_DONT_PROP, we disable deleting this identiy assign. However, >>>> this triggers the problem that other identity assign also undeletable only >>>> if its LHS has CR_DONT_PROP, so bug882 thrown out and it is hard to patch >>>> again for this special handling, this changes the default verifycation >>>> and DCE behavior. >>>> >>>> My suggested way is that we try propagate to a var inside ASM_INPUT, if the >>>> propagated expr is also a var, we allow this propagation. in the above case >>>> >>>>>LINE 13___ >>>>> LDID I4 I4 sym5v3 0 ty=402 <u=2 cr13> flags:0x8 b=-1 #res1 >>>>>OPR_STID I4 I4 sym4v4 0 <u=0 cr15> b=-1 flags:0x2 pj2 Sid-1 >>>> chi <> 0x0x80e1e40 >>>>>LINE 14___ >>>> mu<9/cr14 > >>>>> LDID I4 I4 sym4v4 0 ty=402 <u=0 cr15> flags:0x0 b=-1 #val0 >>>>> ASM_INPUT opnd:1 <u=0 cr16> isop_flags:0xc0000 flags:0x0 b=E1 >>>>> ASM_STMT <u=0 cr17> isop_flags:0xc0000 flags:0x0 b=-1 >>>>>OPR_ASM_STMT b=-1 flags:0x2 pj2 Sid-1 >>>> sym5v3 is propagated into OPR_ASMINPUT. >>>> >>>> The patch below: >>>> >>>> --- a/osprey/be/opt/opt_prop.cxx >>>> +++ b/osprey/be/opt/opt_prop.cxx >>>> @@ -1504,9 +1504,23 @@ COPYPROP::Copy_propagate_cr(CODEREP *x, BB_NODE >>>> *curbb, >>>> expr = Copy_propagate_cr(x->Opnd(i), curbb, inside_cse, >>>> in_array); >>>> else { >>>> // OSP_384 >>>> - if(opr == OPR_ASM_INPUT) >>>> - x->Opnd(i)->Set_flag(CF_DONT_PROP); >>>> - expr = NULL; >>>> + if(opr == OPR_ASM_INPUT) { >>>> + // open64.net bug787. Try propagate for VAR first, if the >>>> propagated expr is the same >>>> + // kind to the original one,i.e, also a VAR. we allow this >>>> propagation. otherwise, disable it. >>>> + if ( x->Opnd(i)->Kind() == CK_VAR ) { >>>> + CODEREP *possible_prop = Copy_propagate_cr(x->Opnd(i), >>>> curbb, >>>> inside_cse, in_array); >>>> + if (possible_prop && possible_prop->Kind() == >>>> x->Opnd(i)->Kind()) >>>> + expr = possible_prop; >>>> + else { >>>> + x->Opnd(i)->Set_flag(CF_DONT_PROP); >>>> + expr = NULL; >>>> + } >>>> + } >>>> + else { >>>> + x->Opnd(i)->Set_flag(CF_DONT_PROP); >>>> + expr = NULL; >>>> + } >>>> + } >>>> } >>>> #else >>>> please gatekeeper help a review >>>> >>>> Thanks. >>>> >>>> Regards >>>> Gang >>>> >>>> ------------------------------------------------------------------------------ >>>> Ridiculously easy VDI. With Citrix VDI-in-a-Box, you don't need a complex >>>> infrastructure or vast IT resources to deliver seamless, secure access to >>>> virtual desktops. With this all-in-one solution, easily deploy virtual >>>> desktops for less than the cost of PCs and save 60% on VDI infrastructure >>>> costs. Try it free! http://p.sf.net/sfu/Citrix-VDIinabox >>>> _______________________________________________ >>>> Open64-devel mailing list >>>> Open64-devel@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/open64-devel >>>> >>> >>> ------------------------------------------------------------------------------ >>> Ridiculously easy VDI. With Citrix VDI-in-a-Box, you don't need a complex >>> infrastructure or vast IT resources to deliver seamless, secure access to >>> virtual desktops. With this all-in-one solution, easily deploy virtual >>> desktops for less than the cost of PCs and save 60% on VDI infrastructure >>> costs. Try it free! http://p.sf.net/sfu/Citrix-VDIinabox >>> _______________________________________________ >>> Open64-devel mailing list >>> Open64-devel@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/open64-devel >>> >>> > > ------------------------------------------------------------------------------ > Write once. Port to many. > Get the SDK and tools to simplify cross-platform app development. Create > new or port existing apps to sell to consumers worldwide. Explore the > Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join > http://p.sf.net/sfu/intel-appdev > _______________________________________________ > Open64-devel mailing list > Open64-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/open64-devel > > ------------------------------------------------------------------------------ Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev _______________________________________________ Open64-devel mailing list Open64-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/open64-devel
