[Bug regression/93009] AVX512 FMA - wrong code generation

[matthias.hochsteger at tuwien dot ac.at]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93009

Matthias Hochsteger  changed:

   What|Removed |Added

 Status|RESOLVED|UNCONFIRMED
 Resolution|INVALID |---

--- Comment #5 from Matthias Hochsteger  ---
Thanks for the fast replies. Anyway, I think there was a misunderstanding. The
issue is not about accuracy of fma vs. mult+add.

The attached code should clarify the issue (I still couldn't simplify it much
though). It basically boils down to a single call of multiplyAndAdd:

template
T multiplyAndAdd(T a, T b, T c)
{
  return a*b+c;
}

  template 
  __attribute__ ((__always_inline__)) inline S P1(S x) const 
  {
cout << "a = " << S(coefsal[1][0]) << endl; 
cout << "b = " << S(x) << endl; 
cout << "c = " << S(coefsal[1][1]) << endl; 
auto res = multiplyAndAdd (S(coefsal[1][0]),S(x),S(coefsal[1][1]));
cout << "res: " << res << endl; 
return res;
  }

The data type is "AutoDiffRec<3, SIMD>", which basically contains 4
_m128d values.

>$ g++ -std=c++17 -march=skylake-avx512 -O1 test_fma.ii && ./a.out
> a = 1 1, D = 0 0 0 0 0 0 
> b = 3 4, D = 0 0 0 0 0 0 
> c = 2 2, D = 0 0 0 0 0 0 
> res: 5 6, D = 0 0 0 0 0 0 


>$ g++ -std=c++17 -march=skylake-avx512 -O1 -fexpensive-optimizations 
>test_fma.ii && ./a.out
> a = 1 1, D = 0 0 0 0 0 0 
> b = 3 4, D = 0 0 0 0 0 0 
> c = 2 2, D = 0 0 0 0 0 0 
> res: 3 3, D = 0 0 0 0 0 0

[Bug regression/93009] AVX512 FMA - wrong code generation

[matthias.hochsteger at tuwien dot ac.at]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93009

--- Comment #4 from Matthias Hochsteger  ---
Created attachment 47534
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47534=edit
new code, cout results

[Bug regression/93009] New: AVX512 FMA - wrong code generation

[matthias.hochsteger at tuwien dot ac.at]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93009

Bug ID: 93009
   Summary: AVX512 FMA - wrong code generation
   Product: gcc
   Version: 9.2.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: regression
  Assignee: unassigned at gcc dot gnu.org
  Reporter: matthias.hochsteger at tuwien dot ac.at
  Target Milestone: ---

Created attachment 47526
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47526=edit
preprocessed code

Hello,

gcc 9.2 produces wrong output when compiling for AVX512 targets, depending on
the optimization level. The preprocessed source file is attached.

Correct output:
> g++ -std=c++17 -march=skylake-avx512 -O1 test_fma.ii
> g++ -std=c++17 -march=skylake-avx512 -O2 -fno-expensive-optimizations 
> test_fma.ii
> 7.95851e-06

Wrong output:
> g++ -std=c++17 -march=skylake-avx512 -O1 -fexpensive-optimizations test_fma.ii
> g++ -std=c++17 -march=skylake-avx512 -O2 test_fma.ii
> 1e-10

All four cases work if the (non-preprocessed) source file is compiled with gcc
8.3, or the target is "skylake" instead of "skylake-avx512".

gcc -v

Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC) 

Best,
Matthias

[Bug c++/84091] [8 Regression] ICE on valid C++ code: Segmentation fault

[matthias.hochsteger at tuwien dot ac.at]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84091

Matthias Hochsteger  changed:

   What|Removed |Added

 CC||matthias.hochsteger@tuwien.
   ||ac.at

--- Comment #1 from Matthias Hochsteger  ---
Introduced with

commit fa01d4a50ef3115a509c67af897c854001597ea7 (HEAD)
Author: jason 
Date:   Fri Jan 26 15:25:23 2018 +

PR c++/82514 - ICE with local class in generic lambda.

* pt.c (regenerated_lambda_fn_p): Remove.
(enclosing_instantiation_of): Don't use it.
(tsubst_function_decl): Call enclosing_instantiation_of.

* pt.c (lookup_template_class_1): Add sanity check.
* name-lookup.c (do_pushtag): Don't add closures to local_classes.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@257093
138bc75d-0d04-0410-961f-82ee72b054a4

[Bug c++/82148] ICE in assign_temp, at function.c:968

[matthias.hochsteger at tuwien dot ac.at]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82148

--- Comment #1 from Matthias Hochsteger  ---
Same on latest trunk (git commit 520b78be6e5b448ae4341960acc5706ae561c974):

 ~/local/gcc7/bin/c++ -v -save-temps -std=c++17 -c code.cpp
Using built-in specs.
COLLECT_GCC=/home/matthias/local/gcc7/bin/c++
Target: x86_64-pc-linux-gnu
Configured with: ../configure --prefix=/home/matthias/local/gcc7
--enable-languages=c,c++ --disable-multilib
Thread model: posix
gcc version 8.0.0 20170908 (experimental) (GCC) 
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++1z' '-c' '-shared-libgcc'
'-mtune=generic' '-march=x86-64'
 /home/matthias/local/gcc7/libexec/gcc/x86_64-pc-linux-gnu/8.0.0/cc1plus -E
-quiet -v -D_GNU_SOURCE code.cpp -mtune=generic -march=x86-64 -std=c++1z
-fpch-preprocess -o code.ii
ignoring nonexistent directory
"/home/matthias/local/gcc7/lib/gcc/x86_64-pc-linux-gnu/8.0.0/../../../../x86_64-pc-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:

/home/matthias/local/gcc7/lib/gcc/x86_64-pc-linux-gnu/8.0.0/../../../../include/c++/8.0.0

/home/matthias/local/gcc7/lib/gcc/x86_64-pc-linux-gnu/8.0.0/../../../../include/c++/8.0.0/x86_64-pc-linux-gnu

/home/matthias/local/gcc7/lib/gcc/x86_64-pc-linux-gnu/8.0.0/../../../../include/c++/8.0.0/backward
 /home/matthias/local/gcc7/lib/gcc/x86_64-pc-linux-gnu/8.0.0/include
 /usr/local/include
 /home/matthias/local/gcc7/include
 /home/matthias/local/gcc7/lib/gcc/x86_64-pc-linux-gnu/8.0.0/include-fixed
 /usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++1z' '-c' '-shared-libgcc'
'-mtune=generic' '-march=x86-64'
 /home/matthias/local/gcc7/libexec/gcc/x86_64-pc-linux-gnu/8.0.0/cc1plus
-fpreprocessed code.ii -quiet -dumpbase code.cpp -mtune=generic -march=x86-64
-auxbase code -std=c++1z -version -o code.s
GNU C++14 (GCC) version 8.0.0 20170908 (experimental) (x86_64-pc-linux-gnu)
compiled by GNU C version 8.0.0 20170908 (experimental), GMP version
6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.16.1-GMP

GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
GNU C++14 (GCC) version 8.0.0 20170908 (experimental) (x86_64-pc-linux-gnu)
compiled by GNU C version 8.0.0 20170908 (experimental), GMP version
6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.16.1-GMP

GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
Compiler executable checksum: 34f3776a4b4b0480fb19303c453a2e50
during RTL pass: expand
code.cpp: In function ‘void bar()’:
code.cpp:17:8: internal compiler error: in assign_temp, at function.c:970
 foo(Derived{0});
 ~~~^~~~
0x6cef41 assign_temp(tree_node*, int, int)
../../gcc/function.c:970
0xb80dd3 initialize_argument_information
../../gcc/calls.c:1830
0xb818df expand_call(tree_node*, rtx_def*, int)
../../gcc/calls.c:3279
0xc8ea1d expand_expr_real_1(tree_node*, rtx_def*, machine_mode,
expand_modifier, rtx_def**, bool)
../../gcc/expr.c:10860
0xb957e0 expand_expr
../../gcc/expr.h:276
0xb957e0 expand_call_stmt
../../gcc/cfgexpand.c:2666
0xb957e0 expand_gimple_stmt_1
../../gcc/cfgexpand.c:3585
0xb957e0 expand_gimple_stmt
../../gcc/cfgexpand.c:3751
0xb96721 expand_gimple_basic_block
../../gcc/cfgexpand.c:5750
0xb9b12e execute
../../gcc/cfgexpand.c:6357

[Bug c++/82148] New: ICE in assign_temp, at function.c:968

[matthias.hochsteger at tuwien dot ac.at]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82148

Bug ID: 82148
   Summary: ICE in assign_temp, at function.c:968
   Product: gcc
   Version: 7.2.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: matthias.hochsteger at tuwien dot ac.at
  Target Milestone: ---

Created attachment 42141
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42141=edit
Preprocessed source file

The code below fails to compile with -std=c++17, but compiles with -std=c++14.
A work-around is to add a constructor to 'Base'.

The code (code.ii is attached):

///
#include 

struct Base {
// Working with the follwing line
// ~Base() {}
};

struct Derived : public Base
{
  Derived (std::initializer_list list) { }
  ~Derived() { }
};

void foo(Base a) { }

void bar() {
foo(Derived{0});
}
///

The compiler call:

> c++ -v -save-temps -std=c++17 -c code.cpp

Using built-in specs.
COLLECT_GCC=c++
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared
--enable-threads=posix --enable-libmpx --with-system-zlib --with-isl
--enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu
--disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object
--enable-linker-build-id --enable-lto --enable-plugin
--enable-install-libiberty --with-linker-hash-style=gnu
--enable-gnu-indirect-function --disable-multilib --disable-werror
--enable-checking=release --enable-default-pie --enable-default-ssp
Thread model: posix
gcc version 7.2.0 (GCC) 
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++1z' '-c' '-shared-libgcc'
'-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/cc1plus -E -quiet -v -D_GNU_SOURCE
code.cpp -mtune=generic -march=x86-64 -std=c++1z -fpch-preprocess -o code.ii
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/../../../../x86_64-pc-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/../../../../include/c++/7.2.0

/usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/../../../../include/c++/7.2.0/x86_64-pc-linux-gnu
 /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/../../../../include/c++/7.2.0/backward
 /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/include
 /usr/local/include
 /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/include-fixed
 /usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++1z' '-c' '-shared-libgcc'
'-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/cc1plus -fpreprocessed code.ii -quiet
-dumpbase code.cpp -mtune=generic -march=x86-64 -auxbase code -std=c++1z
-version -o code.s
GNU C++14 (GCC) version 7.2.0 (x86_64-pc-linux-gnu)
compiled by GNU C version 7.2.0, GMP version 6.1.2, MPFR version
3.1.5-p2, MPC version 1.0.3, isl version isl-0.18-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C++14 (GCC) version 7.2.0 (x86_64-pc-linux-gnu)
compiled by GNU C version 7.2.0, GMP version 6.1.2, MPFR version
3.1.5-p2, MPC version 1.0.3, isl version isl-0.18-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: f3b185e2b85ecd352b4699fa98d9eb0f
code.cpp: In function ‘void bar()’:
code.cpp:17:8: internal compiler error: in assign_temp, at function.c:968
 foo(Derived{0});
 ~~~^~~~
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://bugs.archlinux.org/> for instructions.



Thanks,
Matthias

[Bug tree-optimization/70499] internal compiler error: in make_ssa_name_fn, at tree-ssanames.c:266

[matthias.hochsteger at tuwien dot ac.at]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70499

--- Comment #6 from Matthias Hochsteger  ---
Oh, now I get it, sorry for the misunderstanding.

[Bug tree-optimization/70499] internal compiler error: in make_ssa_name_fn, at tree-ssanames.c:266

[matthias.hochsteger at tuwien dot ac.at]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70499

--- Comment #4 from Matthias Hochsteger  ---
This testcase is just a very striped-down version of the actual code to
reproduce the error, so it may seem useless at some spots, like the missing
initialization.
We already have a workaround by adding additional
__attribute__((__always_inline__)) 
to the methods of SIMD, in this sense it's no critical bug.
This code is part of a cross-platform project. We are including immintrin.h
since it is supplied by all used compilers. I am not sure how
typedef double v4df __attribute__((vector_size (32)));
behaves on others, but we will give it a try.

Thanks,
Matthias

[Bug c++/70499] New: internal compiler error: in make_ssa_name_fn, at tree-ssanames.c:266

[matthias.hochsteger at tuwien dot ac.at]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70499

Bug ID: 70499
   Summary: internal compiler error: in make_ssa_name_fn, at
tree-ssanames.c:266
   Product: gcc
   Version: 6.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: matthias.hochsteger at tuwien dot ac.at
  Target Milestone: ---

The compiler crashes with the given code. Multiple (in fact probably all)
versions are affected. Tested versions are 4.7, 4.8, 4.9, 5.1, 5.3 and 6.0 (4.6
and earlier don't accept -mavx2). Exact versions and abort messages are given
below.

Thanks!

The code:
//
#include 

struct SIMD {
  __m256d data;
  SIMD() {};
  SIMD (double val) { }
  SIMD(__m256d _data) { data = _data; }
  SIMD operator* (SIMD a) { return a; }
};

struct Foo {
  SIMD val;
  SIMD dval[2];
  __attribute__((__always_inline__)) SIMD & Value() throw() { return val; }
  __attribute__((__always_inline__)) Foo operator* ( const Foo & y) throw() 
{
  Foo res;
  SIMD hx;
  SIMD hy;
  res.Value() = hx*hy;
  res.dval[0] = hx*hy;
  return res;
}
};

template  
__attribute__((__always_inline__)) void inlineFunc(Tx hx[]) {
Tx x = hx[0], y = hx[1];
Tx lam[1] = (x*y);
}

void FooBarFunc () {
  Foo adp[2];
  inlineFunc (adp);
}
//

Abort messages:
=
g++-4.7 -v
Using built-in specs.
COLLECT_GCC=g++-4.7
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.7.3-12ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs
--enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.7 --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.7 --libdir=/usr/lib --enable-nls
--with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug
--enable-gnu-unique-object --disable-libmudflap --enable-plugin
--with-system-zlib --enable-objc-gc --with-cloog --enable-cloog-backend=ppl
--disable-cloog-version-check --disable-ppl-version-check --enable-multiarch
--disable-werror --with-arch-32=i686 --with-abi=m64
--with-multilib-list=m32,m64,mx32 --with-tune=generic --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-12ubuntu1) 

g++-4.7 -mavx2 -O2 -c simd.cpp
simd.cpp:27:41: warning: always_inline function might not be inlinable
[-Wattributes]
simd.cpp: In function ‘void inlineFunc(Tx*) [with Tx = Foo]’:
simd.cpp:35:1: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See  for instructions.
Preprocessed source stored into /tmp/cc7UN6UV.out file, please attach this to
your bugreport.
ERROR: Cannot create report: [Errno 17] File exists:
'/var/crash/_usr_lib_gcc_x86_64-linux-gnu_4.7_cc1plus.1028.crash'
=
g++-4.8 -v
Using built-in specs.
COLLECT_GCC=g++-4.8
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.8.2-19ubuntu1'
--with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs
--enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.8 --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.8 --libdir=/usr/lib --enable-nls
--with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-libmudflap
--enable-plugin --with-system-zlib --disable-browser-plugin
--enable-java-awt=gtk --enable-gtk-cairo
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/jre --enable-java-home
--with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-amd64
--with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
--enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686
--with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) 

g++-4.8 -mavx2 -O2 -c simd.cpp
simd.cpp:27:41: warning: always_inline function might not be inlinable
[-Wattributes]
 __attribute__((__always_inline__)) void inlineFunc(Tx hx[]) {
 ^
simd.cpp: In function ‘void Fo

[Bug c++/70271] New: internal compiler error: in dwarf2out_finish, at dwarf2out.c:27346

[matthias.hochsteger at tuwien dot ac.at]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70271

Bug ID: 70271
   Summary: internal compiler error: in dwarf2out_finish, at
dwarf2out.c:27346
   Product: gcc
   Version: 6.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: matthias.hochsteger at tuwien dot ac.at
  Target Milestone: ---

The compiler crashes when creating debug symbols for the given code.

command line:
g++ -c -g testfile.cpp

compiler version: g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/home/matthias/local/libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../configure --prefix=/usr --disable-multilib
--disable-bootstrap --with-system-zlib --prefix=/home/matthias/local
--enable-languages=c,c++,lto --no-create --no-recursion
Thread model: posix
gcc version 6.0.0 20160317 (experimental) (GCC) 



/// Utility functions to convert capture-less lambdas to function pointers
template 
struct function_traits
: public function_traits<decltype(::operator())> 
{ };

template 
struct function_traits<ReturnType(ClassType::*)(Args...) const> 
{
  typedef ReturnType (*pointer)(Args...);
  typedef ReturnType return_type;
};

template 
typename function_traits::pointer
FunctionPointer (const Function& lambda) 
{
  return static_cast::pointer>(lambda);
}

template 
typename function_traits::return_type
GetReturnValue (Function func) 
{
  typename function_traits::return_type *dummy;
  return *dummy;
}


template  class ClassFoo {};
template  void FuncBar () { }

template <> inline void FuncBar ()
{
  typedef void (*func_type)(ClassFoo &);

  // this code fails with
  // internal compiler error: in dwarf2out_finish, at dwarf2out.c:27346
  //   0x9ec27b dwarf2out_finish
  //   ../../gcc/dwarf2out.c:27346
  func_type f1 = FunctionPointer ([](ClassFoo & ref) { });

  // this code is working fine
//   func_type f2 = static_cast([](ClassFoo  & self) { });
}

[Bug debug/70271] [6 Regression] internal compiler error: in dwarf2out_finish, at dwarf2out.c:27346

[matthias.hochsteger at tuwien dot ac.at]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70271

--- Comment #2 from Matthias Hochsteger  ---
Looks like the following commit introduced this behavior:

commit b309adc8ef90cd7c7ecc46124707a51a53cfb205
Author: rguenth 
Date:   Fri Sep 18 12:59:32 2015 +

2015-09-18  Richard Biener  

* dwarf2out.c (append_entry_to_tmpl_value_parm_die_table): Assert
we're in early phase.
(schedule_generic_params_dies_gen): Likewise.
(gen_remaining_tmpl_value_param_die_attribute): Do only as much
work as possible, retaining unhandled cases.
(gen_scheduled_generic_parms_dies): Set early-dwarf flag and
clear out generic_type_instances at the end.
(dwarf2out_finish): Move call to gen_scheduled_generic_parms_dies...
(dwarf2out_early_finish): ... here.  Do most of
gen_remaining_tmpl_value_param_die_attribute here.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@227905
138bc75d-0d04-0410-961f-82ee72b054a4

[Bug c++/64487] New: internal compiler error: in fold_offsetof_1, at c-family/c-common.c:9857

[matthias.hochsteger at tuwien dot ac.at]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64487

Bug ID: 64487
   Summary: internal compiler error: in fold_offsetof_1, at
c-family/c-common.c:9857
   Product: gcc
   Version: 4.9.1
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: matthias.hochsteger at tuwien dot ac.at

The C++ file:
#include stddef.h  

struct foo {
  int member;
};

template  int N
struct bar {};

template int N
struct qux {
static barN+offsetof(foo,member) static_member;
};

template int N
barN+offsetof(foo,member) quxN::static_member;

int main() { }

g++ -c foo.cpp

Error message:
foo.cpp:16:6: internal compiler error: in fold_offsetof_1, at
c-family/c-common.c:9857

The code compiles with GCC 4.4.7, but fails to compile with all other tested
versions (4.6, 4.7, 4.8, 4.9, 5.0).

Tested versions:

- GCC 4.4.7
=
Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.4.7-8ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs
--enable-languages=c,c++,fortran --prefix=/usr --program-suffix=-4.4
--enable-shared --enable-linker-build-id --with-system-zlib
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.4 --libdir=/usr/lib --enable-nls
--with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug
--disable-libmudflap --disable-werror --with-arch-32=i686 --with-tune=generic
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 4.4.7 (Ubuntu/Linaro 4.4.7-8ubuntu1) 

- GCC 4.6.4
=
Using built-in specs.
COLLECT_GCC=g++-4.6
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.6/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.6.4-6ubuntu2' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.6 --enable-shared --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-gnu-unique-object --disable-libmudflap
--enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686
--with-tune=generic --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.6.4 (Ubuntu/Linaro 4.6.4-6ubuntu2) 

- GCC 4.7.4
=
Using built-in specs.
COLLECT_GCC=g++-4.7
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.7.4-2ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs
--enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.7 --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.7 --libdir=/usr/lib --enable-nls
--with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug
--enable-gnu-unique-object --disable-libmudflap --enable-plugin
--with-system-zlib --enable-objc-gc --with-cloog --enable-cloog-backend=ppl
--disable-cloog-version-check --disable-ppl-version-check --enable-multiarch
--disable-werror --with-arch-32=i686 --with-abi=m64
--with-multilib-list=m32,m64,mx32 --with-tune=generic --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.4 (Ubuntu/Linaro 4.7.4-2ubuntu1) 

- GCC 4.8.3
=
Using built-in specs.
COLLECT_GCC=g++-4.8
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.8.3-12ubuntu3'
--with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs
--enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.8 --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.8 --libdir=/usr/lib --enable-nls
--with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-libmudflap
--enable-plugin --with-system-zlib --disable-browser-plugin
--enable-java-awt=gtk --enable-gtk-cairo
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/jre --enable-java-home
--with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64
--with-jvm-jar-dir=/usr