In FreeBSD, rtld expects .ctors containing -1 (0xffffffff), and a
.ctors section containing the correct bits is provided to the linker as
input (/usr/lib/crtbegin.o).
Contents of section .ctors:
0000 ffffffff ffffffff ........
This section is not stripped even if not referenced or empty, also in
gold or ld.bfd. It would be nice to strip it when not needed but
since existing object files rely on that we can't do better to keep it
around.
Differential Revision: http://reviews.llvm.org/D15767
llvm-svn: 256373
The patterns that set a mask register to 0/1
KXOR %kn, %kn, %kn / KXNOR %kn, %kn, %kn
are replaced with
KXOR %k0, %k0, %kn / KXNOR %k0, %k0, %kn - AVX-512 targets optimization.
KNL does not recognize dependency-breaking idioms for mask registers,
so kxnor %k1, %k1, %k2 has a RAW dependence on %k1.
Using %k0 as the undef input register is a performance heuristic based
on the assumption that %k0 is used less frequently than the other mask
registers, since it is not usable as a write mask.
Differential Revision: http://reviews.llvm.org/D15739
llvm-svn: 256365
Doing so required separating them so that the former doesn't inherit
from the latter anymore. Investigating that, it became clear that the
inheritance wasn't actually providing real value in any case.
So also:
- Remove a bunch of redundant functions (getExplicitTemplateArgs,
getOptionalExplicitTemplateArgs) on various Expr subclasses which
depended on the inheritance relationship.
- Switched external callers to use pre-existing accessors that return the
data they're actually interested in (getTemplateArgs,
getNumTemplateArgs, etc).
- Switched internal callers to use pre-existing getTemplateKWAndArgsInfo.
llvm-svn: 256359
Summary: Linker testing was sad at seeing an unresolved external symbol. For now don't do that: it's valid but we're not playing with multi-file linking yet, and the LLVM tests are used as hacky sanity tests for single-file linking (the GCC torture tests are much better for this purpose). Another solution would be to use '.extern' to make the intent explicit (don't simple-file link this, there's an unresolved symbol), some assemblers use '.extern' while others ignore it, so we wouldn't really be inventing anything new.
Reviewers: sunfish, kripken
Subscribers: jfb, llvm-commits, dschuff
Differential Revision: http://reviews.llvm.org/D15753
llvm-svn: 256353
Teach the statepoint lowering code to emit Indirect stackmap entries for spill inserted by StatepointLowering (i.e. SelectionDAG), but Direct stackmap entries for in-IR allocas which represent manual stack slots. This is what the docs call for (http://llvm.org/docs/StackMaps.html#stack-map-format), but we've been emitting both as Direct. This was pointed out recently on the mailing list as a bug. It also blocks http://reviews.llvm.org/D15632 which extends the lowering to handle vector-of-pointers since only Indirect references can encode a variable sized slot.
To implement this, I introduced a new flag on the StackObject class used to maintian information about stack slots. I original considered (and prototyped in http://reviews.llvm.org/D15632), the idea of using the existing isSpillSlot flag, but end up deciding that was a bit too risky and that the cost of adding a new flag was low. Having the new flag will also allow us - in the future - to emit better comments in verbose assembly which indicate where a particular stack spill around a call comes from. (deopt, gc, regalloc).
Differential Revision: http://reviews.llvm.org/D15759
llvm-svn: 256352
This replicates the logic of Darwin dwarfdump for manually opening up
.dSYM bundles without introducing any new dependencies.
<rdar://problem/20491670>
llvm-svn: 256350
Clarify a comment about what it means to drop memory operands from an instruction. While I'm adding change the name of the method slightly to make it a bit more clear what's going on when reading calling code.
llvm-svn: 256346
Summary:
We need to actually remove the use of the personality function,
otherwise we can run into trouble if we want to e.g. delete
the personality function because ther's no way to get rid of
its uses. Do this by resetting to ConstantPointerNull value
that the operands are set to when first allocated.
Reviewers: vsk, dexonsmith
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15752
llvm-svn: 256345
The way `getLoopBackedgeTakenCounts` is written right now isn't
correct. It will try to compute and store the BE counts of a Loop
#{child loop} number of times (which may be zero).
llvm-svn: 256338
Move several checks into isLegalStores. Also, delineate between those stores
that are memset-able and those that are memcpy-able.
http://reviews.llvm.org/D15683
Patch by Haicheng Wu <haicheng@codeaurora.org>!
llvm-svn: 256336
As far as I can tell, the correct interpretation of an empty memoperands list is that we didn't have sufficient room to store information about the MachineInstr, NOT that the MachineInstr doesn't access any particular bit of memory. This appears to be fairly consistent in a number of places, but I'm not 100% sure of this interpretation. I'd really appreciate someone more knowledgeable confirming my reading of the code.
This patch fixes two latent bugs in MachineLICM - given the above assumption - and adds comments to document the meaning and required handling. I don't have test cases; these were noticed by inspection.
Differential Revision: http://reviews.llvm.org/D15730
llvm-svn: 256335
Before this patch sections that go after relro sequence were placed at
the same memory page with relro ones. It caused segmentation fault on
freebsd.
Fixes PR25790.
Patch by George Rimar with some tweaks by myself.
llvm-svn: 256334
First step towards making better use of AVX's implicit zeroing of the upper half of a 256-bit vector by instructions that only act on the lower 128-bit vector - discussed on D14151.
As well as the fact that 128-bit shuffle instructions are generally more capable, this can be performant for older CPUs with 128-bit ALUs (e.g. Jaguar, Sandy Bridge) that must treat 256-bit vectors as multiple micro-ops.
Moved the similar subvector extraction shuffle combines from PerformShuffleCombine256 to lowerVectorShuffle as well.
Note: I've avoided combining shuffles that reference elements from the upper halves of the input vectors - this may be reviewed in future work as well (AVX1 would probably always gain, but AVX2 does have some cross-lane shuffle instructions).
Differential Revision: http://reviews.llvm.org/D15477
llvm-svn: 256332
OpenMP 4.5 adds 'depend(sink:vec)' in 'ordered' directive for doacross loop synchronization. Patch adds parsing and semantic analysis for this clause.
llvm-svn: 256330
Marina Yatsina