Most processors have carry flags which they set on addition overflow, so
it's a good idea to access them whenever possible. Most of them also
have widening multiply instructions that can be used to detect overflow
of the non-widening version.
Tested to compile on:
Architecture Compiler
x86 GCC 4.9, GCC 5*, Clang 3.6*, ICC 16 beta
x86-64 GCC 4.9, GCC 5*, Clang 3.6*, ICC 16 beta
x86-64 ILP32 GCC 4.9, GCC 5*, Clang 3.6*
IA-64 LP64 GCC 4.8
ARMv7-A GCC 4.9, Clang 3.6*
AArch64 Clang 3.6*
MIPS GCC 4.9, Clang 3.6*
MIPS64 GCC 4.9, Clang 3.6*
PowerPC GCC 4.9, Clang 3.6*
PowerPC 64 GCC 4.9, Clang 3.6*
SPARC Clang 3.6*
SPARCv9 Clang 3.6*
[*] supports the intrinsics
If the compiler does not offer a way to detect an overflow, we do it by
hand. For unsigned additions, that's easy, since the C++ language
specifies the behavior of the overflow. That's also the reason why this
code is implemented only for unsigned integers.
For the multiplication, if the compiler does not support widening
multiplications, we do it with a division instead. This is necessary for
GCC < 4.5 and compilers not compatible with GCC or MSVC.
Change-Id: I049a653beeb5454c9539ffff13e637de0f1338c1
Reviewed-by: Ulf Hermann <ulf.hermann@theqtcompany.com>
Reviewed-by: Alex Trotsenko <alex1973tr@gmail.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
The keyword no longer has a meaning for the new CI.
Change-Id: Ibcea4c7a82fb7f982cf4569fdff19f82066543d1
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>
The Intel compiler defaults to "fast math" mode, which is why those
tests had been failing. So for the test that is trying to check whether
we conform to IEEE strict requirements, turn on strict requirements.
Change-Id: I02f8426b1c8e4241ac10ffff13e8efa224f313b2
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Qt 5.0 beta requires changing the default to the 5.0 API, disabling
the deprecated code. However, tests should test (and often do) the
compatibility API too, so turn it back on.
Task-number: QTBUG-25053
Change-Id: I8129c3ef3cb58541c95a32d083850d9e7f768927
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
qttest_p4.prf was added as a convenience for Qt's own autotests in Qt4.
It enables various crufty undocumented magic, of dubious value.
Stop using it, and explicitly enable the things from it which we want.
Change-Id: I7c1ffe9c8c294dbdc988e1582e580b1ed3f4593e
Reviewed-by: Jason McDonald <jason.mcdonald@nokia.com>
Liang Qi
Thiago Macieira
Friedemann Kleint
Jason McDonald
Rohan McGovern
Holger Ihrig