http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57866
Bug ID: 57866
Summary: Erroneous constant folding of SSE intrinsics
Product: gcc
Version: 4.7.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: other
Assignee: unassigned at gcc dot gnu.org
Reporter: artem.alimarin at gmail dot com
Created attachment 30484
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30484&action=edit
Tiny C++ bug reproducer
The expected output of the resulting program:
ok = 1
The real output with -O3:
ok = 0
When compiled with -O0 the output is as expected.
With -O3 the ADDSD instruction is not generated. As the result the MXCSR flags
are not set correctly.
Apparently the optimizer performs incorrect constant folding with SSE
built-ins.
Compilation:
[artem@desktop ~]$ g++ -v -O3 -o sse sse.cpp
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 4.4.7-3) (GCC)
COLLECT_GCC_OPTIONS='-v' '-O3' '-o' 'sse' '-shared-libgcc' '-mtune=generic'
/usr/libexec/gcc/x86_64-redhat-linux/4.4.7/cc1plus -quiet -v -D_GNU_SOURCE
sse.cpp -quiet -dumpbase sse.cpp -mtune=generic -auxbase sse -O3 -version -o
/tmp/cchr9Wzi.s
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-redhat-linux/4.4.7/include-fixed"
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../x86_64-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../include/c++/4.4.7
/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../include/c++/4.4.7/x86_64-redhat-linux
/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../include/c++/4.4.7/backward
/usr/local/include
/usr/lib/gcc/x86_64-redhat-linux/4.4.7/include
/usr/include
End of search list.
GNU C++ (GCC) version 4.4.7 20120313 (Red Hat 4.4.7-3) (x86_64-redhat-linux)
compiled by GNU C version 4.4.7 20120313 (Red Hat 4.4.7-3), GMP version
4.3.1, MPFR version 2.4.1.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 223f8a064e7bf286655580f46ccd9b7c
COLLECT_GCC_OPTIONS='-v' '-O3' '-o' 'sse' '-shared-libgcc' '-mtune=generic'
as -V -Qy -o /tmp/ccZ96kdM.o /tmp/cchr9Wzi.s
GNU assembler version 2.20.51.0.2 (x86_64-redhat-linux) using BFD version
version 2.20.51.0.2-5.36.el6 20100205
COMPILER_PATH=/usr/libexec/gcc/x86_64-redhat-linux/4.4.7/:/usr/libexec/gcc/x86_64-redhat-linux/4.4.7/:/usr/libexec/gcc/x86_64-redhat-linux/:/usr/lib/gcc/x86_64-redhat-linux/4.4.7/:/usr/lib/gcc/x86_64-redhat-linux/:/usr/libexec/gcc/x86_64-redhat-linux/4.4.7/:/usr/libexec/gcc/x86_64-redhat-linux/:/usr/lib/gcc/x86_64-redhat-linux/4.4.7/:/usr/lib/gcc/x86_64-redhat-linux/
LIBRARY_PATH=/usr/lib/gcc/x86_64-redhat-linux/4.4.7/:/usr/lib/gcc/x86_64-redhat-linux/4.4.7/:/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/:/lib/../lib64/:/usr/lib/../lib64/:/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-O3' '-o' 'sse' '-shared-libgcc' '-mtune=generic'
/usr/libexec/gcc/x86_64-redhat-linux/4.4.7/collect2 --eh-frame-hdr --build-id
-m elf_x86_64 --hash-style=gnu -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o
sse /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/crt1.o
/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/crti.o
/usr/lib/gcc/x86_64-redhat-linux/4.4.7/crtbegin.o
-L/usr/lib/gcc/x86_64-redhat-linux/4.4.7
-L/usr/lib/gcc/x86_64-redhat-linux/4.4.7
-L/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64 -L/lib/../lib64
-L/usr/lib/../lib64 -L/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../..
/tmp/ccZ96kdM.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc
/usr/lib/gcc/x86_64-redhat-linux/4.4.7/crtend.o
/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/crtn.o
