[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

Michael Meissner  changed:

   What|Removed |Added

 Status|ASSIGNED|RESOLVED
 Resolution|--- |FIXED

--- Comment #24 from Michael Meissner  ---
Fixed in the trunk subversion id 246508, and on the GCC 6.x branch in
subversion id 246509.

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #23 from Michael Meissner  ---
Author: meissner
Date: Mon Mar 27 19:35:35 2017
New Revision: 246509

URL: https://gcc.gnu.org/viewcvs?rev=246509=gcc=rev
Log:
[gcc]
2017-03-27  Michael Meissner  

Back port from trunk
2017-03-27  Michael Meissner  

PR target/78543
* config/rs6000/rs6000.md (bswaphi2_extenddi): Combine bswap
HImode and SImode with zero extend to DImode to one insn.
(bswap2_extenddi): Likewise.
(bswapsi2_extenddi): Likewise.
(bswaphi2_extendsi): Likewise.
(bswaphi2): Combine bswap HImode and SImode into one insn.
Separate memory insns from swapping register.
(bswapsi2): Likewise.
(bswap2): Likewise.
(bswaphi2_internal): Delete, no longer used.
(bswapsi2_internal): Likewise.
(bswap2_load): Split bswap HImode/SImode into separate load,
store, and gpr<-gpr swap insns.
(bswap2_store): Likewise.
(bswaphi2_reg): Register only splitter, combine with the splitter.
(bswaphi2 splitter): Likewise.
(bswapsi2_reg): Likewise.
(bswapsi2 splitter): Likewise.
(bswapdi2): If we have the LDBRX and STDBRX instructions, split
the insns into load, store, and register/register insns.
(bswapdi2_ldbrx): Likewise.
(bswapdi2_load): Likewise.
(bswapdi2_store): Likewise.
(bswapdi2_reg): Likewise.

[gcc/testsuite]
2017-03-27  Michael Meissner  

Back port from trunk
2017-03-27  Michael Meissner  

PR target/78543
* gcc.target/powerpc/pr78543.c: New test.


Added:
branches/gcc-6-branch/gcc/testsuite/gcc.target/powerpc/pr78543.c
  - copied unchanged from r246508,
trunk/gcc/testsuite/gcc.target/powerpc/pr78543.c
Modified:
branches/gcc-6-branch/gcc/ChangeLog
branches/gcc-6-branch/gcc/config/rs6000/rs6000.md
branches/gcc-6-branch/gcc/testsuite/ChangeLog

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #22 from Michael Meissner  ---
Author: meissner
Date: Mon Mar 27 19:19:00 2017
New Revision: 246508

URL: https://gcc.gnu.org/viewcvs?rev=246508=gcc=rev
Log:
[gcc]
2017-03-27  Michael Meissner  

PR target/78543
* config/rs6000/rs6000.md (bswaphi2_extenddi): Combine bswap
HImode and SImode with zero extend to DImode to one insn.
(bswap2_extenddi): Likewise.
(bswapsi2_extenddi): Likewise.
(bswaphi2_extendsi): Likewise.
(bswaphi2): Combine bswap HImode and SImode into one insn.
Separate memory insns from swapping register.
(bswapsi2): Likewise.
(bswap2): Likewise.
(bswaphi2_internal): Delete, no longer used.
(bswapsi2_internal): Likewise.
(bswap2_load): Split bswap HImode/SImode into separate load,
store, and gpr<-gpr swap insns.
(bswap2_store): Likewise.
(bswaphi2_reg): Register only splitter, combine with the splitter.
(bswaphi2 splitter): Likewise.
(bswapsi2_reg): Likewise.
(bswapsi2 splitter): Likewise.
(bswapdi2): If we have the LDBRX and STDBRX instructions, split
the insns into load, store, and register/register insns.
(bswapdi2_ldbrx): Likewise.
(bswapdi2_load): Likewise.
(bswapdi2_store): Likewise.
(bswapdi2_reg): Likewise.

[gcc/testsuite]
2017-03-27  Michael Meissner  

PR target/78543
* gcc.target/powerpc/pr78543.c: New test.


Added:
trunk/gcc/testsuite/gcc.target/powerpc/pr78543.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/config/rs6000/rs6000.md
trunk/gcc/testsuite/ChangeLog

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #21 from Michael Meissner  ---
The backport to GCC 6 also succeeded with no regressions on a little endian
power8 system.

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

Michael Meissner  changed:

   What|Removed |Added

  Attachment #41035|0   |1
is obsolete||

--- Comment #20 from Michael Meissner  ---
Created attachment 41050
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41050=edit
Proposed patch to fix the problem (rework)

This patch reworks the original patch I submitted, to try and make it less
hacky.  It separates the bswap insns where there is hardware support into
separate read, write, and register swap instructions. This is because the
register allocators will try to push the bswap value in a register to the stack
and do the load based swap with reverse bytes.  Reload fumbles in certain
conditions.  LRA generates working code, but the store and the load with byte
reverse from the same location, can slow things down compared to the operation
on registers.

I only did this optimization where we had the hardware support (i.e. bswap for
HImode all of the time, bswap for SImode all of the time, and bswap for DImode
if we are executing 64-bit instructions and the machine has LDBRX/STDBRX --
power7 and newer/cell ppc).

I have done bootstrap builds on a little endian power8 system, on a big endian
power8 system, and a big endian power7 system (both 32/64-bit support on this
last system).  There were no regressions.

I am building the patches applied to gcc 6 right now.  The patches apply
cleanly to gcc 6.  I suspect it will also build on gcc 5.

I built spec 2006 benchmarks with the compiler.  There are 12 benchmarks that
generate one or more load/store with byte swap instructions (perlbench, gcc,
gamess, milc, zeusmp, calculix, h264ref, tonto, omnetpp, wrf, sphinx3,
xalancbmk).

I compared the instructions generated.  10 of the benchmarks generated the same
instructions.

Milc generated 1 less load with byte swap instruction and 1 more store with
byte swap instruction.

Sphinx3 generated 6 less load with byte swap instructions and 6 more store with
byte swap instructions.

So I count this as the same level of byte swapping is being generated.

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[meissner at linux dot vnet.ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #19 from Michael Meissner  ---
On Tue, Mar 21, 2017 at 09:00:37PM +, brenohl at br dot ibm.com wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543
> 
> --- Comment #16 from Breno Leitao  ---
> If it helps, the problem is reproducible on some other packages as well. Here
> is another example:
> 
> https://nopaste.linux-dev.org/?1122124

Note, the source is not complete.  Please attach the file as a text file to
this bug report.

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #18 from Michael Meissner  ---
Created attachment 41035
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41035=edit
Proposed patch to fix the problem

This patch does not allow SUBREG's in bswap functions, which confuses the
register allocators.  It has passed without regression on a little endian
power8 system, and I'm testing it on a big endian power8 system and big endian
power7 system.

I also will be testing the back port to gcc 6 (and later gcc 5).

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

Michael Meissner  changed:

   What|Removed |Added

   Assignee|bergner at gcc dot gnu.org |meissner at gcc dot 
gnu.org

--- Comment #17 from Michael Meissner  ---
While Peter is away, I looked into this.

The bug happens when the RELOAD register allocator tries to do a bswap
operation.  I believe in the original test case, the compiler identifies the
case as something that could be optimized to __builtin_bswap16.  In the second
case, the code has an explicit __builtin_bswap32 call.

This bug shows up on little endian systems and not on big endian systems.  This
is due to the bswap instruction being called with a SUBREG.  Reload gets
confused with this, and LRA decides to do a store, so that it can then do a
LWBRX instruction.

If we copy the SUBREG to a new register, it works for the second case provided.
 I can't get the first case to fail.

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[brenohl at br dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #16 from Breno Leitao  ---
If it helps, the problem is reproducible on some other packages as well. Here
is another example:

https://nopaste.linux-dev.org/?1122124

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

Peter Bergner  changed:

   What|Removed |Added

 CC||uweigand at gcc dot gnu.org

--- Comment #15 from Peter Bergner  ---
(In reply to Peter Bergner from comment #14)
> Patch submitted.

Uli commented that the patch needs reworking, so I'm back to digging into this.

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

Peter Bergner  changed:

   What|Removed |Added

URL||https://gcc.gnu.org/ml/gcc-
   ||patches/2017-03/msg00264.ht
   ||ml

--- Comment #14 from Peter Bergner  ---
Patch submitted.

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

Peter Bergner  changed:

   What|Removed |Added

 Status|UNCONFIRMED |ASSIGNED
   Last reconfirmed||2017-03-06
 Ever confirmed|0   |1

--- Comment #13 from Peter Bergner  ---
(In reply to Matthias Klose from comment #10)
> here is one more build failure seen with 20170221, with -O1 (works with
> -O0), seen in the gtk-gnutella package:

I have a patch that fixes this and the original test case.

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #12 from Matthias Klose  ---
still reproducible with r245899 on the gcc-6-branch

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #11 from Matthias Klose  ---
Created attachment 40883
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40883=edit
preprocessed source (fileinfo.i)

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #10 from Matthias Klose  ---
here is one more build failure seen with 20170221, with -O1 (works with -O0),
seen in the gtk-gnutella package:

$ gcc-6 -c -O1 -msecure-plt -mcpu=power8 fileinfo.i
fileinfo.c: In function 'file_info_retrieve_binary':
fileinfo.c:2113:1: internal compiler error: in push_reload, at reload.c:1349
Please submit a full bug report,
with preprocessed source if appropriate.

$ cat fileinfo.i
typedef long a;
enum c { e, f, g, h, i, ab } j();
int l, n, o, p;
a q, r;
void *memcpy();
void b();
static int k(int *s) {
  int m;
  if (j())
*s = m;
  return !0;
}
void d(char s) {
  int af[4];
  int ag;
  enum c ah;
  char ai[24 << 11];
  unsigned aj;
  if (!k())
goto ak;
  for (;;) {
if (!k())
  goto ak;
switch (ah) {
case e:
  b("");
  b("bad length %d for GUID in fileinfo v%u for \"%s\"");
case i:
  b("bad length %d for TTH in fileinfo v%u for \"%s\"", aj);
case ab:
  if (ag % 24)
b("for \"%s\"", s);
case f:
  if (20 == ag)
  case h:
if (20 == ag)
  o = 0;
  break;
case g:
  memcpy(af, ai, sizeof af);
  b();
  if (p) {
a al, am;
r = al << 2 | am;
n = af[2];
al = n;
l = __builtin_bswap32(af[3]);
am = q = n | l;
  }
default:
  b("%s0 unhandled field ID %u 0", __func__);
}
  }
ak:;
}

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

Jakub Jelinek  changed:

   What|Removed |Added

   Target Milestone|6.3 |6.4

--- Comment #9 from Jakub Jelinek  ---
GCC 6.3 is being released, adjusting target milestone.

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #8 from Peter Bergner  ---
(In reply to Breno Leitao from comment #7)
> Created attachment 40182 [details]
> gcc dump with pre processed file

Ok, this on I have recreated.  I'll dig into it.

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[brenohl at br dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #7 from Breno Leitao  ---
Created attachment 40182
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40182=edit
gcc dump with pre processed file

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #6 from Peter Bergner  ---
(In reply to Breno Leitao from comment #5)
> I can reproduce this (or a very similar version of this) bug on my system. 
> 
> I am seeing this failure when compiling package yadifa-2.2.2 on Debian
> testing with (Debian 6.2.1-4) 6.2.1 20161119.
> 
> If I use -O2 instead of -O3, I see no failure.

Can you attach the preprocessed source of the file that is failing?

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[brenohl at br dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

Breno Leitao  changed:

   What|Removed |Added

 CC||brenohl at br dot ibm.com

--- Comment #5 from Breno Leitao  ---
I can reproduce this (or a very similar version of this) bug on my system. 

I am seeing this failure when compiling package yadifa-2.2.2 on Debian testing
with (Debian 6.2.1-4) 6.2.1 20161119.

If I use -O2 instead of -O3, I see no failure.

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #4 from Matthias Klose  ---
that was binutils 2.27.51.20161124, and the Debian GCC version (unstable),
configured with
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 6.2.1-5ubuntu1'
--with-bugurl=file:///usr/share/doc/gcc-6/README.Bugs
--enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-6 --program-prefix=powerpc64le-linux-gnu- --enable-shared
--enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/
--enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-libquadmath --enable-objc-gc --enable-secureplt --with-cpu=power8
--enable-targets=powerpcle-linux --disable-multilib --enable-multiarch
--disable-werror --with-long-double-128 --enable-checking=release
--build=powerpc64le-linux-gnu --host=powerpc64le-linux-gnu
--target=powerpc64le-linux-gnu

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

--- Comment #3 from Peter Bergner  ---
I cannot recreate this using r242827 of the FSF 6 branch.  What configure
options are you using?   ...and in case it makes a difference (it can), what
binutils version?

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

Peter Bergner  changed:

   What|Removed |Added

   Assignee|unassigned at gcc dot gnu.org  |bergner at gcc dot 
gnu.org

--- Comment #2 from Peter Bergner  ---
I'll have a look.

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

Arseny Solokha  changed:

   What|Removed |Added

 CC||asolokha at gmx dot com

--- Comment #1 from Arseny Solokha  ---
*** Bug 77346 has been marked as a duplicate of this bug. ***

[Bug target/78543] [6 Regression] ICE in push_reload, at reload.c:1349 on powerpc64le-linux-gnu

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543

Andrew Pinski  changed:

   What|Removed |Added

   Target Milestone|--- |6.3