[Bug target/59874] Missing builtin (__builtin_clzs) when compiling with g++

[manuel.lauss at googlemail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59874

Manuel Lauss <manuel.lauss at googlemail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |manuel.lauss at googlemail dot com

--- Comment #2 from Manuel Lauss <manuel.lauss at googlemail dot com> ---
Hello,

I've run into this issue with current gcc-6-branch while building for example
qt-5.7.  gcc-5-branch can build this source just fine:

x86_64-pc-linux-gnu-g++ -c -o qmakeparser.o -O3 -march=haswell -mtune=haswell
-fno-lifetime-dse -fno-delete-null-pointer-checks -pipe -std=c++11
-ffunction-sections 
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake/library
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake/generators
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake/generators/unix
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake/generators/win32
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake/generators/mac
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake/generators/integrity
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/include
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/include/QtCore
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/include/QtCore/5.7.0
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/include/QtCore/5.7.0/QtCore
-I../src/corelib/global -DHAVE_QCONFIG_CPP
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/mkspecs/linux-g++
-I/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/tools/shared
-DQT_VERSION_STR=\"5.7.0\" -DQT_VERSION_MAJOR=5 -DQT_VERSION_MINOR=7
-DQT_VERSION_PATCH=0 -DQT_BUILD_QMAKE -DQT_BOOTSTRAPPED -DPROEVALUATOR_FULL
-DQT_NO_TEXTCODEC -DQT_NO_UNICODETABLES -DQT_NO_COMPONENT -DQT_NO_COMPRESS
-DQT_NO_THREAD -DQT_NO_QOBJECT -DQT_NO_GEOM_VARIANT -DQT_NO_DATASTREAM
-DQT_NO_FOREACH -DQT_CRYPTOGRAPHICHASH_ONLY_SHA1 -DQT_JSON_READONLY
-DQT_NO_STANDARDPATHS
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake/library/qmakeparser.cpp
In file included from
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/include/QtCore/qalgorithms.h:1:0,
                 from
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/include/QtCore/../../src/corelib/tools/qvector.h:43,
                 from
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/include/QtCore/qvector.h:1,
                 from
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake/library/proitems.h:35,
                 from
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake/library/qmakeparser.h:33,
                 from
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake/library/qmakeevaluator.h:36,
                 from
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake/project.h:32,
                 from
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/qmake/project.cpp:29:
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/include/QtCore/../../src/corelib/tools/qalgorithms.h:
In function 'uint qCountTrailingZeroBits(quint16)':
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/include/QtCore/../../src/corelib/tools/qalgorithms.h:630:32:
error: '__builtin_ctzs' was not declared in this scope
     return v ? __builtin_ctzs(v) : 16U;
                                ^
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/include/QtCore/../../src/corelib/tools/qalgorithms.h:
In function 'uint qCountLeadingZeroBits(quint16)':
/tmp-ram/portage/dev-qt/qtcore-5.7.0/work/qtbase-opensource-src-5.7.0/include/QtCore/../../src/corelib/tools/qalgorithms.h:693:32:
error: '__builtin_clzs' was not declared in this scope
     return v ? __builtin_clzs(v) : 16U;