Re: Fix handling of stores in modref_summary::useful_p
The 10/05/2020 23:45, Jan Hubicka wrote:
> > The 10/05/2020 17:28, Szabolcs Nagy via Gcc-patches wrote:
> > minimal reproducer:
> >
> > #include
> > int main()
> > {
> > int r,t;
> > r = sscanf("01", "%2x", &t);
> > printf("scanf: %d %02x\n", r, t);
> > return 0;
> > }
> >
> > should print
> >
> > scanf: 1 01
> >
> > but when glibc is compiled with gcc trunk on aarch64 it prints
> >
> > scanf: 0 00
> >
> > i will continute the debugging from here tomorrow.
>
> There is a report on glibc issue here
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97264
> it turned out to be a latent glibc bug type punning const char * and
> const unsigned char *.
>
> I wonder if it is same as problem you are seeing?
thanks, that indeed looks very similar, i'll comment on the glibc bug.
Re: Fix handling of stores in modref_summary::useful_p
> The 10/05/2020 17:28, Szabolcs Nagy via Gcc-patches wrote:
> > The 10/05/2020 12:52, Vaseeharan Vinayagamoorthy wrote:
> > > Hi,
> > >
> > > After this patch, I am noticing that some glibc crypto tests get stuck in
> > > scanf which goes into busy loop.
> > >
> > > My build/host/target setup is:
> > > Build: aarch64-none-linux-gnu
> > > Host: aarch64-none-linux-gnu
> > > Target: aarch64-none-linux-gnu
> >
> > i can reproduce this on aarch64, i'm looking at it:
> >
> > if i compile glibc with gcc trunk after this commit i see
> >
> > $ ./testrun.sh crypt/cert < $glibcsrc/crypt/cert.input
> > K: P: C: Encrypt FAIL
> > K: P: C: Encrypt FAIL
> > K: P: C: Encrypt FAIL
> > K: P: C: Encrypt FAIL
> > K: P: C: Encrypt FAIL
> > K: P: C: Encrypt FAIL
> > ...
> >
> > it just keeps printing this.
> >
> > same test binary with glibc code compiled with an
> > older gcc works, so something in glibc gets miscompiled.
> >
> > i will have to do more digging to figure out what.
>
> minimal reproducer:
>
> #include
> int main()
> {
> int r,t;
> r = sscanf("01", "%2x", &t);
> printf("scanf: %d %02x\n", r, t);
> return 0;
> }
>
> should print
>
> scanf: 1 01
>
> but when glibc is compiled with gcc trunk on aarch64 it prints
>
> scanf: 0 00
>
> i will continute the debugging from here tomorrow.
There is a report on glibc issue here
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97264
it turned out to be a latent glibc bug type punning const char * and
const unsigned char *.
I wonder if it is same as problem you are seeing?
Honza
>
>
> > > On 27/09/2020, 22:46, "Gcc-patches on behalf of Jan Hubicka"
> > > wrote:
> > >
> > > Hi,
> > > this patch fixes a pasto in modref_summary::useful_p that made
> > > ipa-modref to give up on tracking stores when all load info got lost.
> > >
> > > Bootstrapped/regtested x86_64-linux, comitted.
> > >
> > > gcc/ChangeLog:
> > >
> > > 2020-09-27 Jan Hubicka
> > >
> > > * ipa-modref.c (modref_summary::useful_p): Fix testing of stores.
> > >
> > > diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c
> > > index 728c6c1523d..6225552e41a 100644
> > > --- a/gcc/ipa-modref.c
> > > +++ b/gcc/ipa-modref.c
> > > @@ -135,7 +135,7 @@ modref_summary::useful_p (int ecf_flags)
> > > return true;
> > >if (ecf_flags & ECF_PURE)
> > > return false;
> > > - return stores && !loads->every_base;
> > > + return stores && !stores->every_base;
> > > }
> > >
> > > /* Dump A to OUT. */
> > >
Re: Fix handling of stores in modref_summary::useful_p
The 10/05/2020 17:28, Szabolcs Nagy via Gcc-patches wrote:
> The 10/05/2020 12:52, Vaseeharan Vinayagamoorthy wrote:
> > Hi,
> >
> > After this patch, I am noticing that some glibc crypto tests get stuck in
> > scanf which goes into busy loop.
> >
> > My build/host/target setup is:
> > Build: aarch64-none-linux-gnu
> > Host: aarch64-none-linux-gnu
> > Target: aarch64-none-linux-gnu
>
> i can reproduce this on aarch64, i'm looking at it:
>
> if i compile glibc with gcc trunk after this commit i see
>
> $ ./testrun.sh crypt/cert < $glibcsrc/crypt/cert.input
> K: P: C: Encrypt FAIL
> K: P: C: Encrypt FAIL
> K: P: C: Encrypt FAIL
> K: P: C: Encrypt FAIL
> K: P: C: Encrypt FAIL
> K: P: C: Encrypt FAIL
> ...
>
> it just keeps printing this.
>
> same test binary with glibc code compiled with an
> older gcc works, so something in glibc gets miscompiled.
>
> i will have to do more digging to figure out what.
minimal reproducer:
#include
int main()
{
int r,t;
r = sscanf("01", "%2x", &t);
printf("scanf: %d %02x\n", r, t);
return 0;
}
should print
scanf: 1 01
but when glibc is compiled with gcc trunk on aarch64 it prints
scanf: 0 00
i will continute the debugging from here tomorrow.
> > On 27/09/2020, 22:46, "Gcc-patches on behalf of Jan Hubicka"
> > wrote:
> >
> > Hi,
> > this patch fixes a pasto in modref_summary::useful_p that made
> > ipa-modref to give up on tracking stores when all load info got lost.
> >
> > Bootstrapped/regtested x86_64-linux, comitted.
> >
> > gcc/ChangeLog:
> >
> > 2020-09-27 Jan Hubicka
> >
> > * ipa-modref.c (modref_summary::useful_p): Fix testing of stores.
> >
> > diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c
> > index 728c6c1523d..6225552e41a 100644
> > --- a/gcc/ipa-modref.c
> > +++ b/gcc/ipa-modref.c
> > @@ -135,7 +135,7 @@ modref_summary::useful_p (int ecf_flags)
> > return true;
> >if (ecf_flags & ECF_PURE)
> > return false;
> > - return stores && !loads->every_base;
> > + return stores && !stores->every_base;
> > }
> >
> > /* Dump A to OUT. */
> >
Re: Fix handling of stores in modref_summary::useful_p
The 10/05/2020 12:52, Vaseeharan Vinayagamoorthy wrote: > Hi, > > After this patch, I am noticing that some glibc crypto tests get stuck in > scanf which goes into busy loop. > > My build/host/target setup is: > Build: aarch64-none-linux-gnu > Host: aarch64-none-linux-gnu > Target: aarch64-none-linux-gnu i can reproduce this on aarch64, i'm looking at it: if i compile glibc with gcc trunk after this commit i see $ ./testrun.sh crypt/cert < $glibcsrc/crypt/cert.input K: P: C: Encrypt FAIL K: P: C: Encrypt FAIL K: P: C: Encrypt FAIL K: P: C: Encrypt FAIL K: P: C: Encrypt FAIL K: P: C: Encrypt FAIL ... it just keeps printing this. same test binary with glibc code compiled with an older gcc works, so something in glibc gets miscompiled. i will have to do more digging to figure out what. > > > > Kind regards > Vasee > > > On 27/09/2020, 22:46, "Gcc-patches on behalf of Jan Hubicka" > wrote: > > Hi, > this patch fixes a pasto in modref_summary::useful_p that made > ipa-modref to give up on tracking stores when all load info got lost. > > Bootstrapped/regtested x86_64-linux, comitted. > > gcc/ChangeLog: > > 2020-09-27 Jan Hubicka > > * ipa-modref.c (modref_summary::useful_p): Fix testing of stores. > > diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c > index 728c6c1523d..6225552e41a 100644 > --- a/gcc/ipa-modref.c > +++ b/gcc/ipa-modref.c > @@ -135,7 +135,7 @@ modref_summary::useful_p (int ecf_flags) > return true; >if (ecf_flags & ECF_PURE) > return false; > - return stores && !loads->every_base; > + return stores && !stores->every_base; > } > > /* Dump A to OUT. */ > --
Re: Fix handling of stores in modref_summary::useful_p
Hi, After this patch, I am noticing that some glibc crypto tests get stuck in scanf which goes into busy loop. My build/host/target setup is: Build: aarch64-none-linux-gnu Host: aarch64-none-linux-gnu Target: aarch64-none-linux-gnu Kind regards Vasee On 27/09/2020, 22:46, "Gcc-patches on behalf of Jan Hubicka" wrote: Hi, this patch fixes a pasto in modref_summary::useful_p that made ipa-modref to give up on tracking stores when all load info got lost. Bootstrapped/regtested x86_64-linux, comitted. gcc/ChangeLog: 2020-09-27 Jan Hubicka * ipa-modref.c (modref_summary::useful_p): Fix testing of stores. diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c index 728c6c1523d..6225552e41a 100644 --- a/gcc/ipa-modref.c +++ b/gcc/ipa-modref.c @@ -135,7 +135,7 @@ modref_summary::useful_p (int ecf_flags) return true; if (ecf_flags & ECF_PURE) return false; - return stores && !loads->every_base; + return stores && !stores->every_base; } /* Dump A to OUT. */
Fix handling of stores in modref_summary::useful_p
Hi, this patch fixes a pasto in modref_summary::useful_p that made ipa-modref to give up on tracking stores when all load info got lost. Bootstrapped/regtested x86_64-linux, comitted. gcc/ChangeLog: 2020-09-27 Jan Hubicka * ipa-modref.c (modref_summary::useful_p): Fix testing of stores. diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c index 728c6c1523d..6225552e41a 100644 --- a/gcc/ipa-modref.c +++ b/gcc/ipa-modref.c @@ -135,7 +135,7 @@ modref_summary::useful_p (int ecf_flags) return true; if (ecf_flags & ECF_PURE) return false; - return stores && !loads->every_base; + return stores && !stores->every_base; } /* Dump A to OUT. */
