diff options
| author | Thiago Macieira <thiago.macieira@intel.com> | 2024-02-22 16:53:51 -0600 |
|---|---|---|
| committer | Thiago Macieira <thiago.macieira@intel.com> | 2024-02-25 18:29:38 -0600 |
| commit | 08349ef0fe3902504987d12ebe0ed9674ed1e486 (patch) | |
| tree | d882c08aa69e0fab7fbd892865fcff1af6b73aed /src/corelib/thread/qthread.h | |
| parent | 90a6415bedfc4ce1a934c3a36271b20c1a6a606a (diff) | |
QThread::currentThreadId: fix build on x32 (ILP32) ABI
On this ABI, pointers are 32-bit, so Qt::HANDLE (void *) is a 32-bit
variable and the "movq" instruction is inappropriate.
There's a GCC extended inline assembler modifier for the instruction
size suffix (%z0) but Clang seems not to understand it. Instead, I just
removed the suffix: we can do that because this is a memory load
instruction, which implies the destination is a general purpose register
(also required by the "=r" constraint) and therefore the assembler can
determine the size of the memory load from the name of the selected
register.
Note: I did not verify this compiles on x32 at all, much less that it
loads the right thing from memory.
Fixes: QTBUG-122674
Pick-to: 6.5 6.6 6.7
Change-Id: I01ec3c774d9943adb903fffd17b6513d146e89ce
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Diffstat (limited to 'src/corelib/thread/qthread.h')
| -rw-r--r-- | src/corelib/thread/qthread.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/src/corelib/thread/qthread.h b/src/corelib/thread/qthread.h index 32a0bb703e..a4b7183b5a 100644 --- a/src/corelib/thread/qthread.h +++ b/src/corelib/thread/qthread.h @@ -151,13 +151,13 @@ inline Qt::HANDLE QThread::currentThreadId() noexcept static_assert(sizeof(tid) == sizeof(void*)); // See https://akkadia.org/drepper/tls.pdf for x86 ABI #if defined(Q_PROCESSOR_X86_32) && ((defined(Q_OS_LINUX) && defined(__GLIBC__)) || defined(Q_OS_FREEBSD)) // x86 32-bit always uses GS - __asm__("movl %%gs:%c1, %0" : "=r" (tid) : "i" (2 * sizeof(void*)) : ); + __asm__("mov %%gs:%c1, %0" : "=r" (tid) : "i" (2 * sizeof(void*)) : ); #elif defined(Q_PROCESSOR_X86_64) && defined(Q_OS_DARWIN) // 64bit macOS uses GS, see https://github.com/apple/darwin-xnu/blob/master/libsyscall/os/tsd.h - __asm__("movq %%gs:0, %0" : "=r" (tid) : : ); + __asm__("mov %%gs:0, %0" : "=r" (tid) : : ); #elif defined(Q_PROCESSOR_X86_64) && ((defined(Q_OS_LINUX) && defined(__GLIBC__)) || defined(Q_OS_FREEBSD)) // x86_64 Linux, BSD uses FS - __asm__("movq %%fs:%c1, %0" : "=r" (tid) : "i" (2 * sizeof(void*)) : ); + __asm__("mov %%fs:%c1, %0" : "=r" (tid) : "i" (2 * sizeof(void*)) : ); #elif defined(Q_PROCESSOR_X86_64) && defined(Q_OS_WIN) // See https://en.wikipedia.org/wiki/Win32_Thread_Information_Block // First get the pointer to the TIB |