[Bug c/64918] invalid (?) warning when initializing structure
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64918 --- Comment #2 from Øystein Schønning-Johansen --- Really insightful, Joseph. I do understand the warning a bit better now. I have not looked into the GCC parsing code, but based on your description and my (limited) understanding of the problem, I guess a fix is not trivial? Can I suppress this warning in any way? -Ø
[Bug c/64918] New: invalid (?) warning when initializing structure
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64918
Bug ID: 64918
Summary: invalid (?) warning when initializing structure
Product: gcc
Version: 4.9.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: oystein at gnubg dot org
Created attachment 34651
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34651&action=edit
Code that trigger the invalid warning.
Hi!
I'm initializing a complex structure with designated initialisers and
overriding an array element (intentionally), and I then get the error message:
sideffects.c:26:13: warning: initialized field with side-effects overwritten
[3] = { .func = thefunction, .args = &((char*[]){"foo4", "bar4",
"baz4"})},
^
sideffects.c:26:13: warning: (near initialization for 'myconfig.config[3]')
However I do believe my code is correct. It complains about initializing with
side-effects, but I think my code is legal c99. (Please tell me otherwise.)
I compile the attached code with:
gcc -std=gnu99 -Wall -Wextra -Wno-override-init sideeffects.c -o sideeffects
I have tried several different versions of GCC, and here is a short summary:
GCC 4.9.2 (Arch Linux x86_64) -> Warning generated.
GCC 4.9.2 (Mingw32-w64 x86_64) -> Warning generated.
GCC 4.8.0 (Linux x86_64) -> Warning generated.
GCC 4.4.7 (Red Hat 4.4.7-4)-> No warning.
GCC 4.1.2 (Red Hat 4.1.2-52) -> No warning.
clang 3.5.1 (Arch Linux) -> No warning.
Best regards,
-Øystein
Full info on compilers used (Those that generates warning):
[oystein@jupiter ~]$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: /build/gcc/src/gcc-4.9-20141224/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 --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-cloog-backend=isl --enable-lto --enable-plugin
--enable-install-libiberty --with-linker-hash-style=gnu --disable-multilib
--disable-werror --enable-checking=release
Thread model: posix
gcc version 4.9.2 20141224 (prerelease) (GCC)
[14:29:03,90 c:\APPL]# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=C:/Program\
Files/mingw-w64/x86_64-4.9.2-posix-seh-rt_v3-rev1/mingw64/bin/../libexec/gcc/x86_64-w64-mingw32/4.9.2/lto-wrapper.exe
Target: x86_64-w64-mingw32
Configured with: ../../../src/gcc-4.9.2/configure --host=x86_64-w64-mingw32
--build=x86_64-w64-mingw32 --target=x86_64-w64-mingw32 --prefix=/mingw64
--with-sysroot=/c/mingw492/x86_64-492-posix-seh-rt_v3-rev1/mingw64
--with-gxx-include-dir=/mingw64/x86_64-w64-mingw32/include/c++ --enable-shared
--enable-static --disable-multilib
--enable-languages=ada,c,c++,fortran,objc,obj-c++,lto
--enable-libstdcxx-time=yes --enable-threads=posix --enable-libgomp
--enable-libatomic --enable-lto --enable-graphite --enable-checking=release
--enable-fully-dynamic-string --enable-version-specific-runtime-libs
--disable-isl-version-check --disable-cloog-version-check
--disable-libstdcxx-pch --disable-libstdcxx-debug --enable-bootstrap
--disable-rpath --disable-win32-registry --disable-nls --disable-werror
--disable-symvers --with-gnu-as --with-gnu-ld --with-arch=nocona
--with-tune=core2 --with-libiconv --with-system-zlib
--with-gmp=/c/mingw492/prerequisites/x86_64-w64-mingw32-static
--with-mpfr=/c/mingw492/prerequisites/x86_64-w64-mingw32-static
--with-mpc=/c/mingw492/prerequisites/x86_64-w64-mingw32-static
--with-isl=/c/mingw492/prerequisites/x86_64-w64-mingw32-static
--with-cloog=/c/mingw492/prerequisites/x86_64-w64-mingw32-static
--enable-cloog-backend=isl --with-pkgversion='x86_64-posix-seh-rev1, Built by
MinGW-W64 project' --with-bugurl=http://sourceforge.net/projects/mingw-w64
CFLAGS='-O2 -pipe
-I/c/mingw492/x86_64-492-posix-seh-rt_v3-rev1/mingw64/opt/include
-I/c/mingw492/prerequisites/x86_64-zlib-static/include
-I/c/mingw492/prerequisites/x86_64-w64-mingw32-static/include' CXXFLAGS='-O2
-pipe -I/c/mingw492/x86_64-492-posix-seh-rt_v3-rev1/mingw64/opt/include
-I/c/mingw492/prerequisites/x86_64-zlib-static/include
-I/c/mingw492/prerequisites/x86_64-w64-mingw32-static/include' CPPFLAGS=
LDFLAGS='-pipe -L/c/mingw492/x86_64-492-posix-seh-rt_v3-rev1/mingw64/opt/lib
-L/c/mingw492/prerequisites/x86_64-zlib-static/lib
-L/c/mingw492/prerequisites/x86_64-w64-mingw32-static/lib '
Thread model: posix
gcc version 4.9.2 (x86_64-posix-seh-rev1, Built by
[Bug c/59697] Function attribute __target_(("no-avx)) work on Windows/mingw but fails on Linux.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59697 --- Comment #1 from Øystein Schønning-Johansen --- Follow up: I try the same code on a RedHat 6.5 64bit workstation with GCC4.4. st-lx794988(ojohans) -/ojohans 37> gcc -v Using built-in specs. Target: x86_64-redhat-linux Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk --disable-dssi --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre --enable-libgcj-multifile --enable-java-maintainer-mode --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib --with-ppl --with-cloog --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux Thread model: posix gcc version 4.4.7 20120313 (Red Hat 4.4.7-4) (GCC) On this system the sse function is also translated to avx instructions. :-( 004004f0 : 4004f0:c1 fe 02 sar$0x2,%esi 4004f3:85 f6test %esi,%esi 4004f5:74 2eje 400525 4004f7:83 ee 01 sub$0x1,%esi 4004fa:c5 f8 c6 c0 00 vshufps $0x0,%xmm0,%xmm0,%xmm0 4004ff:48 c1 e6 04 shl$0x4,%rsi 400503:48 8d 44 37 10 lea0x10(%rdi,%rsi,1),%rax 400508:0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1) 40050f:00 400510:c5 f8 28 0f vmovaps (%rdi),%xmm1 400514:c5 f0 59 c8 vmulps %xmm0,%xmm1,%xmm1 400518:c5 f8 29 0f vmovaps %xmm1,(%rdi) 40051c:48 83 c7 10 add$0x10,%rdi 400520:48 39 c7 cmp%rax,%rdi 400523:75 ebjne400510 400525:f3 c3repz retq 400527:66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) -Øystein
[Bug c/59697] New: Function attribute __target_(("no-avx)) work on Windows/mingw but fails on Linux.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59697
Bug ID: 59697
Summary: Function attribute __target_(("no-avx)) work on
Windows/mingw but fails on Linux.
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: oystein at gnubg dot org
Created attachment 31754
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31754&action=edit
Example source code file
Hi,
As I last week tried to compile a file with one function to sse instruction and
another to avx, (see invalid bug report #59657), I tried to solve this by using
function attributes.
static void calculate_sse(float *data, float scale, int size ) __attribute__
((__target__ ("no-avx")));
static void calculate_avx(float *data, float scale, int size );
(Full example code attached)
When I compile this as my mingw system, the produced code is as expected, and
the code runs good at my no-avx Windows-machine.
Compiled with:
gcc -Wall -O3 -g -mavx sse_test.c -o sse_test
[10:52:28,97 C:\APPL\ssetest]# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=c:/appl/mingw/bin/../libexec/gcc/mingw32/4.7.2/lto-wrapper.exe
Target: mingw32
Configured with: ../gcc-4.7.2/configure
--enable-languages=c,c++,ada,fortran,objc,obj-c++
--disable-sjlj-exceptions --wit
h-dwarf2 --enable-shared --enable-libgomp --disable-win32-registry
--enable-libstdcxx-debug --disable-build-poststage1-wi
th-cxx --enable-version-specific-runtime-libs --build=mingw32 --prefix=/mingw
Thread model: win32
gcc version 4.7.2 (GCC)
Disassembly of the calculate_sse functions looks like this:
(gdb) disassemble calculate_sse
Dump of assembler code for function calculate_sse:
0x0040138c <+0>: mov0xc(%esp),%eax
0x00401390 <+4>: sar$0x2,%eax
0x00401393 <+7>: lea-0x1(%eax),%edx
0x00401396 <+10>:test %eax,%eax
0x00401398 <+12>:je 0x4013be
0x0040139a <+14>:mov0x4(%esp),%eax
0x0040139e <+18>:movss 0x8(%esp),%xmm0
0x004013a4 <+24>:shufps $0x0,%xmm0,%xmm0
0x004013a8 <+28>:movaps %xmm0,%xmm1
0x004013ab <+31>:nop
0x004013ac <+32>:movaps (%eax),%xmm0
0x004013af <+35>:mulps %xmm1,%xmm0
0x004013b2 <+38>:movaps %xmm0,(%eax)
0x004013b5 <+41>:add$0x10,%eax
0x004013b8 <+44>:dec%edx
0x004013b9 <+45>:cmp$0x,%edx
0x004013bc <+48>:jne0x4013ac
0x004013be <+50>:ret
End of assembler dump.
All nice and as expected on Windows/mingw!
I then try the same code with the same function attribute on my Arch linux
laptop (also non-avx CPU). But on this system the calculate_sse functions is
compiled with avx instruction despite the function attribute.
I compile with the same command line:
gcc -Wall -O3 -g -mavx sse_test.c -o sse_test
[oystein@oysteins-laptop ~]$ gcc --version
gcc (GCC) 4.8.2 20131219 (prerelease)
Produced disassembly of calculate_sse function:
(gdb) disassemble
Dump of assembler code for function calculate_sse:
0x08048440 <+0>:mov0xc(%esp),%ecx
0x08048444 <+4>:mov0x4(%esp),%eax
0x08048448 <+8>:sar$0x2,%ecx
0x0804844b <+11>:test %ecx,%ecx
0x0804844d <+13>:lea-0x1(%ecx),%edx
0x08048450 <+16>:je 0x8048474
=> 0x08048452 <+18>:vbroadcastss 0x8(%esp),%xmm1
0x08048459 <+25>:lea0x0(%esi,%eiz,1),%esi
0x08048460 <+32>:vmulps (%eax),%xmm1,%xmm0
0x08048464 <+36>:sub$0x1,%edx
0x08048467 <+39>:add$0x10,%eax
0x0804846a <+42>:vmovaps %xmm0,-0x10(%eax)
0x0804846f <+47>:cmp$0x,%edx
0x08048472 <+50>:jne0x8048460
0x08048474 <+52>:repz ret
End of assembler dump.
I'm always unsure what to expect, but at least I did not the behavior to be
different on the two systems. Well, it might not be the Windows/Linux systems
that makes the difference but maybe rather the 4.7.x / 4.8.x gcc-version that
makes the difference. What do I know?
Thanks,
-Øystein
[Bug c/59657] New: SSE intrinsics translates to AVX instructions
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59657
Bug ID: 59657
Summary: SSE intrinsics translates to AVX instructions
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: oystein at gnubg dot org
Created attachment 31558
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31558&action=edit
Example source code file
Happy new year!
I writing code which should be running both on sse and avx machines. I have
manually vectorized the code for SSE and AVX in two different functions and
using a function pointer to set the right function according to CPU at startup.
The two functions are in the same translation unit.
(See attached code)
compiled with:
gcc -Wall -O3 -g -mavx sse_test.c -o sse_test
The problem is that the sse intisics in the sse function gets translated to AVX
instructions. This will of course give an illegal instruction on on all non-AVX
machines.
My gdb session:
Program received signal SIGILL, Illegal instruction.
0x08048452 in calculate_sse (data=data@entry=0xb5e0, scale=scale@entry=0.5,
size=size@entry=256)
at sse_test.c:33
33for ( ; count-- ; p += 4 ){
(gdb) list
28
29static void calculate_sse(float *data, float scale, int size )
30{
31int count = size >> 2;
32float *p = data;
33for ( ; count-- ; p += 4 ){
34__m128 d = _mm_load_ps( p );
35__m128 s = _mm_set1_ps( scale );
36_mm_store_ps( p, _mm_mul_ps( d, s ));
37}
(gdb) disassemble
Dump of assembler code for function calculate_sse:
0x08048440 <+0>:mov0xc(%esp),%ecx
0x08048444 <+4>:mov0x4(%esp),%eax
0x08048448 <+8>:sar$0x2,%ecx
0x0804844b <+11>:test %ecx,%ecx
0x0804844d <+13>:lea-0x1(%ecx),%edx
0x08048450 <+16>:je 0x8048474
=> 0x08048452 <+18>:vbroadcastss 0x8(%esp),%xmm1
0x08048459 <+25>:lea0x0(%esi,%eiz,1),%esi
0x08048460 <+32>:vmulps (%eax),%xmm1,%xmm0
0x08048464 <+36>:sub$0x1,%edx
0x08048467 <+39>:add$0x10,%eax
0x0804846a <+42>:vmovaps %xmm0,-0x10(%eax)
0x0804846f <+47>:cmp$0x,%edx
0x08048472 <+50>:jne0x8048460
0x08048474 <+52>:repz ret
End of assembler dump.
(Arch linux)
[oystein@oysteins-laptop ~]$ gcc --version
gcc (GCC) 4.8.2 20131219 (prerelease)
Bug or feature? I'm not sure if this is the expected way the intrisics should
translate, but it was not what I expected. If it is supposed to be like this,
can I get out of my problem without splitting the the two functions to two
translation units and use two different compile options?
Thanks,
Øystein
[Bug c/39194] New: options -O3 and -msse does not cooperate ?
Hi,
I try the following code:
#define MAX_N 40
#define MAX_R 25
#ifndef FALSE
#define FALSE 0
#define TRUE 1
#endif
static unsigned int bin_coeff_tab[ MAX_N ][ MAX_R ];
static int is_calculated = FALSE;
static void
bin_coeff_init( void )
{
int i, j;
for( i = 0; i < MAX_N; i++ )
bin_coeff_tab[ i ][ 0 ] = i + 1;
for( j = 1; j < MAX_R; j++ )
bin_coeff_tab[ 0 ][ j ] = 0;
for( i = 1; i < MAX_N; i++ )
for( j = 1; j < MAX_R; j++ )
bin_coeff_tab[ i ][ j ] = bin_coeff_tab[ i - 1 ][ j - 1 ] +
bin_coeff_tab[ i - 1 ][ j ];
is_calculated = TRUE;
}
int main()
{
bin_coeff_init();
return 0;
}
(There is no header file included, so I won't include the .i file)
If I try to compile this with both -O3 and -msse, I get a segmentation fault.
> gcc --version
gcc (GCC) 4.3.0 20080305 (alpha-testing) mingw-20080502
the assembler code file becomes:
.file "mytest.c"
.def___main;.scl2; .type 32; .endef
.text
.p2align 2,,3
.globl _main
.def_main; .scl2; .type 32; .endef
_main:
leal4(%esp), %ecx
andl$-16, %esp
pushl -4(%ecx)
pushl %ebp
movl%esp, %ebp
pushl %esi
pushl %ebx
pushl %ecx
subl$12, %esp
call___main
movl$_bin_coeff_tab, %edx
xorl%eax, %eax
.p2align 2,,3
L2:
incl%eax
movl%eax, (%edx)
addl$100, %edx
cmpl$40, %eax
jne L2
movl$0, _bin_coeff_tab+4
movl$0, _bin_coeff_tab+8
movl$0, _bin_coeff_tab+12
xorps %xmm0, %xmm0
movaps %xmm0, _bin_coeff_tab+16
movaps %xmm0, _bin_coeff_tab+32
movaps %xmm0, _bin_coeff_tab+48
movaps %xmm0, _bin_coeff_tab+64
movaps %xmm0, _bin_coeff_tab+80
movl$0, _bin_coeff_tab+96
movl$1, %esi
.p2align 2,,3
L3:
leal(%esi,%esi,4), %eax
leal(%eax,%eax,4), %eax
leal_bin_coeff_tab-100(,%eax,4), %edx
leal_bin_coeff_tab+4(,%eax,4), %ebx
movl$1, %ecx
.p2align 2,,3
L4:
movl4(%edx), %eax
addl(%edx), %eax
movl%eax, (%ebx)
incl%ecx
addl$4, %edx
addl$4, %ebx
cmpl$25, %ecx
jne L4
incl%esi
cmpl$40, %esi
jne L3
movl$1, _is_calculated
xorl%eax, %eax
addl$12, %esp
popl%ecx
popl%ebx
popl%esi
leave
leal-4(%ecx), %esp
ret
.lcomm _is_calculated,16
.lcomm _bin_coeff_tab,4000
Best regards,
-Øystein
--
Summary: options -O3 and -msse does not cooperate ?
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: oystein at gnubg dot org
GCC host triplet: windows (mingw)
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39194
[Bug target/21126] internal compiler error: in output_constant_pool_2, at varasm.c:3232
--- Additional Comments From oystein at gnubg dot org 2005-04-24 23:06 --- I've fetched the cvs sources today, and the code builds today. I don't know what's different, but it's not the source file that's changed. The snapshit tarball build fails in the same way as usual. Using built-in specs. Target: mingw32 Configured with: ../gcc/configure --with-gcc --with-gnu-ld --with-gnu-as --host=mingw32 --target=mingw32 --prefix=/gcc4.0 --enable-threads --disable-nls --enable-languages=c,c++ --disable-win32-registry --disable-shared Thread model: win32 gcc version 4.1.0 20050424 (experimental) I'm closing this bug! OK? -- What|Removed |Added Status|UNCONFIRMED |RESOLVED Resolution||WORKSFORME http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21126
[Bug target/21126] internal compiler error: in output_constant_pool_2, at varasm.c:3232
--- Additional Comments From oystein at gnubg dot org 2005-04-20 20:31 --- H I'm a bit skeptic to the compiler installation. I did a configure with --prefix=/home/mingw/. Then I did a 'make install'. I notice now that /home/mingw/include/ is empty. Should it be? (And which header files was then used in the compilation?) -Øystein -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21126
[Bug c/21126] New: internal compiler error: in output_constant_pool_2, at varasm.c:3232
gcc -v
Using built-in specs.
Target: mingw32
Configured with: ../gcc-4.1-20050410/configure --with-gcc --with-gnu-ld
--with-gnu-as --host=mingw32 --target=mingw32 --prefix=/home/mingw
--enable-threads --disable-nls --enable-languages=c,c++,treelang
--disable-win32-registry --disable-shared
Thread model: win32
gcc version 4.1.0 20050410 (experimental)
/msys/1.0/home/mingw/bin/gcc.exe -g -Wall -O3 -msse -mtune=pentium3 -DHAVE_CONFI
G_H -I. -I.. -c -o neuralnet.o neuralnet.c
neuralnet.c: In function 'Evaluate':
neuralnet.c:540: internal compiler error: in output_constant_pool_2, at varasm.c
:3232
Please submit a full bug report,
with preprocessed source if appropriate.
See http://gcc.gnu.org/bugs.html> for instructions.
make: *** [neuralnet.o] Error 1
Preprocessed files can be found here:
http://home.online.no/~oeysteij/neuralnet.i
http://home.online.no/~oeysteij/neuralnet.s
--
Summary: internal compiler error: in output_constant_pool_2, at
varasm.c:3232
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: oystein at gnubg dot org
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: 4.1.0 20050410 (built with msys 1.0.10)
GCC host triplet: i686-mingw
GCC target triplet: i686-mingw
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21126
