It is optimal at least up to 7 bits (I've tested all such cases)
This change to truncate() allows a little simplification to the multiplication code,
and it also makes multiplication optimal :)
llvm-svn: 160512
when run on an Intel Atom processor. The failures have arisen due
to changes elsewhere in the trunk over the past 8 weeks or so.
These failures were not detected by the Atom buildbot because the
CPU on the Atom buildbot was not being detected as an Atom CPU.
The fix for this problem is in Host.cpp and X86Subtarget.cpp, but
shall remain commented out until the current set of Atom test failures
are fixed.
Patch by Andy Zhang and Tyler Nowicki!
llvm-svn: 160451
file buffer is null-terminated.
If the file is smaller than we thought, mmap will not allow dereferencing
past the pages that are enough to cover the actual file size,
even though we asked for a larger address range.
rdar://11612916
llvm-svn: 160075
The cpuid registers are only available in privileged mode so we don't have
an OS-independent way of implementing this. ARM doesn't provide a list of
processor IDs so the list is somewhat incomplete.
llvm-svn: 159228
Fix 'sys::IdentifyFileType' to work with big and little endian byte orderings
when reading the ELF object file type.
Initial patch by Stefan Hepp.
llvm-svn: 159138
llvm::RawMemoryObject handles empty ranges just fine, and the assert can
be triggered in the wild by e.g. invoking clang with a file that
included an empty pre-compiled header file when clang has been built
with assertions enabled. Without assertions enabled, clang will properly
report that the empty file is not a valid PCH.
llvm-svn: 158769
StringMap suffered from the same bug as DenseMap: when you explicitly
construct it with a small number of buckets, you can arrange for the
tombstone-based growth path to be followed when the number of buckets
was less than '8'. In that case, even with a full map, it would compare
'0' as not less than '0', and refuse to grow the table, leading to
inf-loops trying to find an empty bucket on the next insertion. The fix
is very simple: use '<=' as the comparison. The same fix was applied to
DenseMap as well during its recent refactoring.
Thanks to Alex Bolz for the great report and test case. =]
llvm-svn: 158725
This is likely only the tip of the ice berg, but this particular bug
caused any double-free on a glibc system to turn into a deadlock! It is
not generally safe to either allocate or release heap memory from within
the signal handler. The 'pop_back()' in RemoveFilesToRemove was deleting
memory and causing the deadlock. What's worse, eraseFromDisk in PathV1
has lots of allocation and deallocation paths. We even passed 'true' in
a place that would have caused the *signal handler* to try to run the
'system' system call and shell out to 'rm -rf'. That was never going to
work...
This patch switches the file removal to use a vector of strings so that
the exact text needed for the 'unlink' system call can be stored there.
It switches the loop to be a boring indexed loop, and directly calls
unlink without looking at the error. It also works quite hard to ensure
that calling 'c_str()' is safe, by ensuring that the non-signal-handling
code path that manipulates the vector always leaves it in a state where
every element has already had 'c_str()' called at least once.
I dunno exactly how overkill this is, but it fixes the
deadlock-on-double free issue, and seems likely to prevent any other
issues from sneaking up.
Sorry for not having a test case, but I *really* don't know how to test
signal handling code easily....
llvm-svn: 158580
POWER4 is a 64-bit CPU (better matched to the 970).
The g3 is really the 750 (no altivec), the g4+ is the 74xx (not the 750).
Patch by Andreas Tobler.
llvm-svn: 158363
Original commit message:
Move PPC host-CPU detection logic from PPCSubtarget into sys::getHostCPUName().
Both the new Linux functionality and the old Darwin functions have been moved.
This change also allows this information to be queried directly by clang and
other frontends (clang, for example, will now have real -mcpu=native support).
llvm-svn: 158349
thread local data, embed them in the class using a uint64_t and make sure
we get compiler errors if there's a platform where this is not big enough.
This makes ThreadLocal more safe for using it in conjunction with CrashRecoveryContext.
Related to crash in rdar://11434201.
llvm-svn: 158342
Both the new Linux functionality and the old Darwin functions have been moved.
This change also allows this information to be queried directly by clang and
other frontends (clang, for example, will now have real -mcpu=native support).
llvm-svn: 158337
Apart from being slightly cheaper, this fixes a real bug that hits 32 bit
linux systems. When passing a file larger than 2G to be linked (which isn't
that uncommon with large projects such as WebKit), clang's driver checks
if the file exists but the file size doesn't fit in an off_t and stat(2)
fails with EOVERFLOW. Clang then says that the file doesn't exist instead
of passing it to the linker.
llvm-svn: 157891
Nuno Lopes