[Bug tree-optimization/52969] New: ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[Bug tree-optimization/52969] New: ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[vincenzo.innocente at cern dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

             Bug #: 52969
           Summary: ICE in in get_expr_operands, at
                    tree-ssa-operands.c:1035 with
                    -ftree-loop-if-convert-stores
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: vincenzo.innocente@cern.ch


Created attachment 27147
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27147
source code (generated with -E)

compiling the attached "real-life" code I get

c++ -v -O3 -std=c++0x -ftree-loop-if-convert-stores -c buggy.i
Using built-in specs.
COLLECT_GCC=c++
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-apple-darwin11.3.0/4.7.0/lto-wrapper
Target: x86_64-apple-darwin11.3.0
Configured with: ./configure --enable-languages=c,c++,fortran
--disable-multilib --disable-bootstrap --enable-lto -disable-libitm
Thread model: posix
gcc version 4.7.0 20120205 (experimental) (GCC) 
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.7.3' '-v' '-O3' '-std=c++11'
'-ftree-loop-if-convert-stores' '-c' '-shared-libgcc' '-mtune=core2'
 /usr/local/libexec/gcc/x86_64-apple-darwin11.3.0/4.7.0/cc1plus -fpreprocessed
buggy.i -fPIC -quiet -dumpbase buggy.i -mmacosx-version-min=10.7.3 -mtune=core2
-auxbase buggy -O3 -std=c++11 -version -ftree-loop-if-convert-stores -o
/var/folders/hd/vml6pgj48xjfkp006s6djxf80000gq/T//ccT2Uqbf.s
GNU C++ (GCC) version 4.7.0 20120205 (experimental) (x86_64-apple-darwin11.3.0)
    compiled by GNU C version 4.7.0 20111201 (experimental), GMP version 4.3.1,
MPFR version 2.4.1, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
GNU C++ (GCC) version 4.7.0 20120205 (experimental) (x86_64-apple-darwin11.3.0)
    compiled by GNU C version 4.7.0 20111201 (experimental), GMP version 4.3.1,
MPFR version 2.4.1, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
Compiler executable checksum: 3c7081ac5da07d4d6f6ca789c3e35f66
unhandled expression in get_expr_operands():
 <truth_not_expr 0x1050e00a0
    type <boolean_type 0x141b1bb28 bool sizes-gimplified public unsigned type_6
QI
        size <integer_cst 0x141b0cba0 constant 8>
        unit size <integer_cst 0x141b0cbc0 constant 1>
        align 8 symtab 0 alias set 14 canonical type 0x141b1bb28 precision 1
min <integer_cst 0x141b0cfa0 0> max <integer_cst 0x141b0cfe0 1>
        pointer_to_this <pointer_type 0x1013bfe70> reference_to_this
<reference_type 0x1013bff18>>

    arg 0 <lt_expr 0x104f9d900 type <boolean_type 0x141b1bb28 bool>

        arg 0 <ssa_name 0x105523550 type <real_type 0x141b1be70 float>
            visited var <var_decl 0x104fb0aa0 maxpix>def_stmt maxpix_135 =
MEM[(struct SiStripTemplate *)templ_76(D) + 40B];

            version 135>
        arg 1 <ssa_name 0x105523820 type <real_type 0x141b1be70 float>
            visited var <var_decl 0x105475b40 D.104278>def_stmt D.104278_144 =
qscale_123 * D.104277_143;

            version 144>
        SiStripTemplateReco.cc:160:5>
    SiStripTemplateReco.cc:160:5>

SiStripTemplateReco.cc: In function ‘int
SiStripTemplateReco::StripTempReco1D(int, float, float, float,
std::vector<float>&, SiStripTemplate&, float&, float&, float&, int&, int,
float&)’:
SiStripTemplateReco.cc:79:5: internal compiler error: in get_expr_operands, at
tree-ssa-operands.c:1035
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
pb-d-128-141-131-26:bugs48 innocent$ c++ -v -O3 -std=c++0x  -c buggy.i
Using built-in specs.
COLLECT_GCC=c++
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-apple-darwin11.3.0/4.7.0/lto-wrapper
Target: x86_64-apple-darwin11.3.0
Configured with: ./configure --enable-languages=c,c++,fortran
--disable-multilib --disable-bootstrap --enable-lto -disable-libitm
Thread model: posix
gcc version 4.7.0 20120205 (experimental) (GCC) 
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.7.3' '-v' '-O3' '-std=c++11' '-c'
'-shared-libgcc' '-mtune=core2'
 /usr/local/libexec/gcc/x86_64-apple-darwin11.3.0/4.7.0/cc1plus -fpreprocessed
buggy.i -fPIC -quiet -dumpbase buggy.i -mmacosx-version-min=10.7.3 -mtune=core2
-auxbase buggy -O3 -std=c++11 -version -o
/var/folders/hd/vml6pgj48xjfkp006s6djxf80000gq/T//ccLlzfNR.s
GNU C++ (GCC) version 4.7.0 20120205 (experimental) (x86_64-apple-darwin11.3.0)
    compiled by GNU C version 4.7.0 20111201 (experimental), GMP version 4.3.1,
MPFR version 2.4.1, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
GNU C++ (GCC) version 4.7.0 20120205 (experimental) (x86_64-apple-darwin11.3.0)
    compiled by GNU C version 4.7.0 20111201 (experimental), GMP version 4.3.1,
MPFR version 2.4.1, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
Compiler executable checksum: 3c7081ac5da07d4d6f6ca789c3e35f66
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.7.3' '-v' '-O3' '-std=c++11' '-c'
'-shared-libgcc' '-mtune=core2'
 as -arch x86_64 -force_cpusubtype_ALL -o buggy.o
/var/folders/hd/vml6pgj48xjfkp006s6djxf80000gq/T//ccLlzfNR.s
COMPILER_PATH=/usr/local/libexec/gcc/x86_64-apple-darwin11.3.0/4.7.0/:/usr/local/libexec/gcc/x86_64-apple-darwin11.3.0/4.7.0/:/usr/local/libexec/gcc/x86_64-apple-darwin11.3.0/:/usr/local/lib/gcc/x86_64-apple-darwin11.3.0/4.7.0/:/usr/local/lib/gcc/x86_64-apple-darwin11.3.0/
LIBRARY_PATH=/usr/local/lib/gcc/x86_64-apple-darwin11.3.0/4.7.0/:/usr/local/lib/gcc/x86_64-apple-darwin11.3.0/4.7.0/../../../:/usr/lib/
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.7.3' '-v' '-O3' '-std=c++11' '-c'
'-shared-libgcc' '-mtune=core2'


same on linux with 4.7.0

c++ -O3 -std=c++0x -ftree-loop-if-convert-stores -c buggy.i -v
Using built-in specs.
COLLECT_GCC=/afs/cern.ch/cms/slc5_amd64_gcc470/external/gcc/4.7.0/bin/c++
Target: x86_64-unknown-linux-gnu
Configured with: ../configure
--prefix=/build/da/build-BOOTSTRAP_slc5_amd64_gcc470/b/tmp/BUILDROOT/de8f21fa6a50f532872e71e7ff72a173/opt/cmssw/slc5_amd64_gcc470/external/gcc/4.7.0
--disable-multilib --disable-nls --enable-languages=c,c++,fortran
--enable-gold=yes --enable-lto
--with-gmp=/build/da/build-BOOTSTRAP_slc5_amd64_gcc470/b/tmp/BUILDROOT/de8f21fa6a50f532872e71e7ff72a173/opt/cmssw/slc5_amd64_gcc470/external/gcc/4.7.0
--with-mpfr=/build/da/build-BOOTSTRAP_slc5_amd64_gcc470/b/tmp/BUILDROOT/de8f21fa6a50f532872e71e7ff72a173/opt/cmssw/slc5_amd64_gcc470/external/gcc/4.7.0
--with-mpc=/build/da/build-BOOTSTRAP_slc5_amd64_gcc470/b/tmp/BUILDROOT/de8f21fa6a50f532872e71e7ff72a173/opt/cmssw/slc5_amd64_gcc470/external/gcc/4.7.0
--with-ppl=/build/da/build-BOOTSTRAP_slc5_amd64_gcc470/b/tmp/BUILDROOT/de8f21fa6a50f532872e71e7ff72a173/opt/cmssw/slc5_amd64_gcc470/external/gcc/4.7.0
--with-cloog=/build/da/build-BOOTSTRAP_slc5_amd64_gcc470/b/tmp/BUILDROOT/de8f21fa6a50f532872e71e7ff72a173/opt/cmssw/slc5_amd64_gcc470/external/gcc/4.7.0
--enable-cloog-backend=isl --enable-shared CC='gcc -fPIC' CXX='c++ -fPIC'
CPP=cpp CXXCPP='c++ -E'
Thread model: posix
gcc version 4.7.0 20120302 (prerelease) (GCC) 
COLLECT_GCC_OPTIONS='-O3' '-std=c++11' '-ftree-loop-if-convert-stores' '-c'
'-v' '-shared-libgcc' '-mtune=generic' '-march=x86-64'

/afs/cern.ch/cms/slc5_amd64_gcc470/external/gcc/4.7.0/bin/../libexec/gcc/x86_64-unknown-linux-gnu/4.7.0/cc1plus
-fpreprocessed buggy.i -quiet -dumpbase buggy.i -mtune=generic -march=x86-64
-auxbase buggy -O3 -std=c++11 -version -ftree-loop-if-convert-stores -o
/tmp/innocent/ccEsHv8G.s
GNU C++ (GCC) version 4.7.0 20120302 (prerelease) (x86_64-unknown-linux-gnu)
    compiled by GNU C version 4.7.0 20120302 (prerelease), GMP version 5.0.2,
MPFR version 3.0.1, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C++ (GCC) version 4.7.0 20120302 (prerelease) (x86_64-unknown-linux-gnu)
    compiled by GNU C version 4.7.0 20120302 (prerelease), GMP version 5.0.2,
MPFR version 3.0.1, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 69c1686c229166b95e41aad94dc9fb81
SiStripTemplateReco.cc: In function 'int
SiStripTemplateReco::StripTempReco1D(int, float, float, float,
std::vector<float>&, SiStripTemplate&, float&, float&, float&, int&, int,
float&)':
SiStripTemplateReco.cc:79:5: internal compiler error: in get_expr_operands, at
tree-ssa-operands.c:1035
Please submit a full bug report,
with preprocessed source if appropriate.

[Bug tree-optimization/52969] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[markus at trippelsdorf dot de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

Markus Trippelsdorf <markus at trippelsdorf dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |markus at trippelsdorf dot
                   |                            |de

--- Comment #1 from Markus Trippelsdorf <markus at trippelsdorf dot de> 2012-04-13 09:37:05 UTC ---
markus@x4 tmp % cat test.cpp
#include <vector>
int a, b;
void foo (std::vector<float> &cluster) {
  int j;
  float xsum[0];
  for (; a ; ++j) {
    xsum[j] = cluster[j];
    if (xsum[j] > 0)
      xsum[j] = 0;
  }
  if (xsum[0])
    b = 0;
}
markus@x4 tmp % gcc test.cpp -std=c++0x -ftree-loop-if-convert-stores -O1
test.cpp: In function ‘void foo(std::vector<float>&)’:
test.cpp:3:6: internal compiler error: in get_expr_operands, at
tree-ssa-operands.c:1035
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

[Bug tree-optimization/52969] [4.7/4.8 Regression] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2012-04-13
         AssignedTo|unassigned at gcc dot       |rguenth at gcc dot gnu.org
                   |gnu.org                     |
   Target Milestone|---                         |4.7.1
            Summary|ICE in in                   |[4.7/4.8 Regression] ICE in
                   |get_expr_operands, at       |in get_expr_operands, at
                   |tree-ssa-operands.c:1035    |tree-ssa-operands.c:1035
                   |with                        |with
                   |-ftree-loop-if-convert-stor |-ftree-loop-if-convert-stor
                   |es                          |es
     Ever Confirmed|0                           |1

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-04-13 10:01:06 UTC ---
Mine.

[Bug tree-optimization/52969] [4.7/4.8 Regression] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

--- Comment #3 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-04-13 10:39:35 UTC ---
(gdb) call debug_gimple_stmt (stmt)
_ifc_.9_27 = !(D.11217_6 > 0.0) ? _ifc_.8_26 : _ifc_.7_20;

the negate is spurious.  I have a patch.  if-conversion is also incredibly
stupid, transforming

  if (cond)
    x = a;
  else
    x = b;

to

  x = cond ? a : x;
  x = !cond ? b : x;

and only DSE removes the first dead store.  But we keep both conditionals
as nothing even tries to optimize them:

  D.1966_8 = *D.1965_7;
  _ifc_.3_12 = xsum[j_21];
  _ifc_.5_19 = D.1966_8 > 0.0 ? 0.0 : _ifc_.3_12;
  D.1983_25 = D.1966_8 > 0.0;
  D.1984_26 = ~D.1983_25;
  _ifc_.8_27 = D.1983_25 ? _ifc_.5_19 : D.1966_8;
  xsum[j_21] = _ifc_.8_27;


Reduced testcase:

int a, b;
float xsum[100];
void foo (float *cluster)
{
  int j;
  for (; a ; ++j) {
      xsum[j] = cluster[j];
      if (xsum[j] > 0)
        xsum[j] = 0;
  }
  if (xsum[0])
    b = 0;
}

I have a patch.

[Bug tree-optimization/52969] [4.7/4.8 Regression] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[vincenzo.innocente at cern dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

--- Comment #4 from vincenzo Innocente <vincenzo.innocente at cern dot ch> 2012-04-13 11:31:37 UTC ---
Ready to test the patch.
I've another code that produces the same ICE in stl_algo.h:3264
not easy to reproduce in a small example...

[Bug tree-optimization/52969] [4.7/4.8 Regression] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

--- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-04-13 11:39:27 UTC ---
Created attachment 27151
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27151
patch

[Bug tree-optimization/52969] [4.7/4.8 Regression] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[vincenzo.innocente at cern dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

--- Comment #6 from vincenzo Innocente <vincenzo.innocente at cern dot ch> 2012-04-13 11:59:59 UTC ---
patch applied to latest trunk.
success on both cases.
thanks.
  v.

p.s. optimizing the if-conversion to produce a single comparison will be
appreciated as well

[Bug tree-optimization/52969] [4.7/4.8 Regression] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[rguenther at suse dot de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

--- Comment #7 from rguenther at suse dot de <rguenther at suse dot de> 2012-04-13 12:04:38 UTC ---
On Fri, 13 Apr 2012, vincenzo.innocente at cern dot ch wrote:

> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969
> 
> --- Comment #6 from vincenzo Innocente <vincenzo.innocente at cern dot ch> 2012-04-13 11:59:59 UTC ---
> patch applied to latest trunk.
> success on both cases.
> thanks.
>   v.
> 
> p.s. optimizing the if-conversion to produce a single comparison will be
> appreciated as well

It looks like RTL optimization is able to get rid of the redundant
one for the testcase.  Do you have a testcase where this obviously
not happens?  I do have a patch that should address this.

Richard.

[Bug tree-optimization/52969] [4.7/4.8 Regression] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

--- Comment #8 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-04-13 12:22:25 UTC ---
Author: rguenth
Date: Fri Apr 13 12:22:16 2012
New Revision: 186416

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=186416
Log:
2012-04-13  Richard Guenther  <rguenther@suse.de>

    PR tree-optimization/52969
    * tree-if-conv.c (predicate_mem_writes): Properly gimplify
    the condition for the COND_EXPR and handle predicate negation
    by swapping the COND_EXPR arms.

    * gcc.dg/torture/pr52969.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr52969.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-if-conv.c

[Bug tree-optimization/52969] [4.7/4.8 Regression] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

--- Comment #9 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-04-13 12:27:11 UTC ---
Author: rguenth
Date: Fri Apr 13 12:27:02 2012
New Revision: 186417

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=186417
Log:
2012-04-13  Richard Guenther  <rguenther@suse.de>

    PR tree-optimization/52969
    * tree-if-conv.c (predicate_mem_writes): Properly gimplify
    the condition for the COND_EXPR and handle predicate negation
    by swapping the COND_EXPR arms.

    * gcc.dg/torture/pr52969.c: New testcase.

Added:
    branches/gcc-4_7-branch/gcc/testsuite/gcc.dg/torture/pr52969.c
Modified:
    branches/gcc-4_7-branch/gcc/ChangeLog
    branches/gcc-4_7-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_7-branch/gcc/tree-if-conv.c

[Bug tree-optimization/52969] [4.7/4.8 Regression] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

--- Comment #10 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-04-13 12:34:43 UTC ---
Fixed.

[Bug tree-optimization/52969] [4.7/4.8 Regression] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[vincenzo.innocente at cern dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

--- Comment #11 from vincenzo Innocente <vincenzo.innocente at cern dot ch> 2012-04-13 13:03:48 UTC ---
I do not have a clear case in hand with evidence of "double" compare
I will have a closer look to "real life" code.

btw 
I just noticed that your test case does not vectorize even if
I rewrite as
 for (; a ; ++j) 
       xsum[j] = (cluster[j] > 0.) ? 0. : cluster[j];

any idea why?

c++ -O3 -c ifconv.cc -ftree-loop-if-convert-stores -ftree-vectorizer-verbose=9

Analyzing loop at ifconv.cc:10

10: ===== analyze_loop_nest =====
10: === vect_analyze_loop_form ===
10: not vectorized: control flow in loop.
10: bad loop form.
ifconv.cc:3: note: vectorized 0 loops in function.
pb-d-128-141-131-26:bugs48 innocent$ c++ -O3 -c ifconv.cc
-ftree-loop-if-convert-stores -ftree-vectorizer-verbose=9

Analyzing loop at ifconv.cc:10

10: ===== analyze_loop_nest =====
10: === vect_analyze_loop_form ===
10: not vectorized: control flow in loop.
10: bad loop form.
ifconv.cc:3: note: vectorized 0 loops in function.
pb-d-128-141-131-26:bugs48 innocent$ c++ -Ofast -c ifconv.cc
-ftree-loop-if-convert-stores -ftree-vectorizer-verbose=9

Analyzing loop at ifconv.cc:10

10: ===== analyze_loop_nest =====
10: === vect_analyze_loop_form ===
10: not vectorized: multiple exits.
10: bad loop form.
ifconv.cc:3: note: vectorized 0 loops in function.
pb-d-128-141-131-26:bugs48 innocent$ c++ -Ofast -c ifconv.cc 
-ftree-vectorizer-verbose=9

Analyzing loop at ifconv.cc:10

10: ===== analyze_loop_nest =====
10: === vect_analyze_loop_form ===
10: not vectorized: multiple exits.
10: bad loop form.
ifconv.cc:3: note: vectorized 0 loops in function.

[Bug tree-optimization/52969] [4.7/4.8 Regression] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

--- Comment #12 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-04-13 13:26:59 UTC ---
(In reply to comment #11)
> I do not have a clear case in hand with evidence of "double" compare
> I will have a closer look to "real life" code.
> 
> btw 
> I just noticed that your test case does not vectorize even if
> I rewrite as
>  for (; a ; ++j) 
>        xsum[j] = (cluster[j] > 0.) ? 0. : cluster[j];
> 
> any idea why?

It's because of the loop exit condition which we realize makes the loop
execute at most once.  If you rewrite it to for (; j < a; ++j) then it works.

[Bug tree-optimization/52969] [4.7/4.8 Regression] ICE in in get_expr_operands, at tree-ssa-operands.c:1035 with -ftree-loop-if-convert-stores

[vincenzo.innocente at cern dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52969

--- Comment #13 from vincenzo Innocente <vincenzo.innocente at cern dot ch> 2012-04-13 13:35:19 UTC ---
Richard, please,  look at PR59275.
I think your testcase CAN produce not optimized code.