[Bug tree-optimization/55748] New: compile eror when -fprefetch-loop-arrays is added , while everything goes well without the option.

[chx319 at mail dot ustc.edu.cn]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55748

             Bug #: 55748
           Summary: compile eror when -fprefetch-loop-arrays is added ,
                    while everything goes well without the option.
    Classification: Unclassified
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: chx...@mail.ustc.edu.cn


I use gcc-4.4.0 to compile qt-everywhere-opensource-src-4.7.2, and a compiler
inner error comes out.
the steps of compiling qt:
> 1)export CFLAGS="-O3 -pipe -Wall -march=loongson3a -ftree-vectorize
> -fprefetch-loop-arrays -Wp,-D_FORTIFY_SOURCE=2 -fexceptions
> --param=ssp-buffer-size=4"
> 2)export CXXFLAGS="-O3 -pipe -Wall -march=loongson3a -ftree-vectorize
> -fprefetch-loop-arrays -Wp,-D_FORTIFY_SOURCE=2 -fexceptions
> --param=ssp-buffer-size=4"
> 3)./configure
> 4)gmake
However when I strike out the -fprefetch-loop-arrays option, the compilation
goes right.
The -fprefetch-loop-arrays option is only related to the ssa optimization
pass(struct gimple_opt_pass pass_ssa_prefetch). 
I made a test. I rewrite the gate function of pass_ssa_prefetch, and let the
function do nothing but return 0. The compilation was OK , using the original
options.

•the  version of GCC : gcc-4.4.0
•the system type : mips64-linux
•the options given when GCC was configured/built:
  ../gcc-4.4.0/configure --prefix=/opt/toolchain/ --with-system-zlib \
        --enable-threads=posix --enable-shared --enable-long-long \
        --enable-disable-libjava-multilib --disable-ssp --disable-libssp \
        --with-local-prefix=/opt/toolchain --with-abi=32 --disable-multilib \
        --with-binutils=/opt/toolchain \
        --enable-languages=c,c++,fortran,objc,obj-c++ \
•the complete command line that triggers the bug:
  g++ -O3  -Wall -march=loongson3a -ftree-vectorize -fprefetch-loop-arrays
-save-temps -fexceptions  -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include 
-I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include -I/usr/include/atk-1.0
-I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/glib-2.0
-I/usr/lib/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2
-I/usr/include/libpng12 -O2 -fvisibility=hidden -fvisibility-inlines-hidden
-Wall -W -D_REENTRANT -I/usr/include/freetype2 -fPIC -DQT_SHARED
-DQT_BUILD_GUI_LIB -DQT_NO_USING_NAMESPACE -DQT_NO_CAST_TO_ASCII
-DQT_ASCII_CAST_WARNINGS -DQT3_SUPPORT -DQT_MOC_COMPAT
-DQT_USE_FAST_OPERATOR_PLUS -DQT_USE_FAST_CONCATENATION -DQT_NO_OPENTYPE
-DQT_NO_STYLE_MAC -DQT_NO_STYLE_WINDOWSVISTA -DQT_NO_STYLE_WINDOWSXP
-DQT_NO_STYLE_WINDOWSCE -DQT_NO_STYLE_WINDOWSMOBILE -DQT_NO_STYLE_S60
-DQ_INTERNAL_QAPP_SRC -DQT_NO_DEBUG -DQT_CORE_LIB -D_LARGEFILE64_SOURCE
-D_LARGEFILE_SOURCE -I../../mkspecs/linux-g++ -I. -I../../include/QtCore
-I../../include -I../../include/QtGui -I.rcc/release-shared -I../3rdparty/xorg
-Iimage -I/usr/include/freetype2 -I../3rdparty/harfbuzz/src -Idialogs
-I.moc/release-shared -I/usr/X11R6/include -I.uic/release-shared -o
.obj/release-shared/qtoolbararealayout.o widgets/qtoolbararealayout.cpp
•the compiler output :
  widgets/qtoolbararealayout.cpp: In member function ‘QList<int>
QToolBarAreaLayout::currentGapIndex() const’:
widgets/qtoolbararealayout.cpp:1058: 警告：此函数中的‘k’在使用前未初始化
widgets/qtoolbararealayout.cpp: In member function ‘QList<int>
QToolBarAreaLayout::gapIndex(const QPoint&) const’:
widgets/qtoolbararealayout.cpp:1029: 编译器内部错误：在 expand_expr_addr_expr_1 中，于
expr.c:6990
请提交一份完整的错误报告，
如有可能请附上经预处理后的源文件。
具体步骤请参见 <http://gcc.gnu.org/bugs.html>。
•the preprocessed file: the file is update as the attachment.