We were previously codegen'ing these as regular load/store operations and
hoping that the register allocator would allocate registers in ascending order
so that we could apply an LDM/STM combine after register allocation. According
to the commit that first introduced this code (r37179), we planned to teach
the register allocator to allocate the registers in ascending order. This
never got implemented, and up to now we've been stuck with very poor codegen.
A much simpler approach for achiveing better codegen is to create LDM/STM
instructions with identical sets of virtual registers, let the register
allocator pick arbitrary registers and order register lists when printing an
MCInst. This approach also avoids the need to repeatedly calculate offsets
which ultimately ought to be eliminated pre-RA in order to decrease register
pressure.
This is implemented by lowering the memcpy intrinsic to a series of SD-only
MCOPY pseudo-instructions which performs a memory copy using a given number
of registers. During SD->MI lowering, we lower MCOPY to LDM/STM. This is a
little unusual, but it avoids the need to encode register lists in the SD,
and we can take advantage of SD use lists to decide whether to use the _UPD
variant of the instructions.
Fixes PR9199.
Differential Revision: http://reviews.llvm.org/D9508
llvm-svn: 238473
BranchProbabilityInfo was leaking 3MB of memory when running 'opt -O2 verify-uselistorder.lto.bc'. This was due to the Weights member not being cleared once the pass is no longer needed.
This adds the releaseMemory override to clear that field. The other fields are cleared at the end of runOnFunction so can stay there.
llvm-svn: 238462
Currently we only fold a BitCast into a Load when the BitCast is its
only user.
Do the same for any no-op cast.
Differential Revision: http://reviews.llvm.org/D9152
llvm-svn: 238452
The fuzzer is very simple, but not quite useful at the moment: it's unable
to discover "interesting" examples, as LLVMObject library is terrible at
error recovery, calling "report_fatal_error()" far too often.
llvm-svn: 238451
GCC seems to have some overzealous warnings about strict aliasing.
Rafael reports that this patch suppresses them on GCC 4.9, and I'm
hoping this will work for GCC 4.7 as well. I'll watch [1] and iterate
if necessary.
[1]: http://bb.pgr.jp/builders/clang-3stage-x86_64-linux/builds/8597
llvm-svn: 238447
shrinking the Size and NumDefs fields to offset the size growth, and
reordering the fields to preserve a good packing.
This is necessary in the short term for adding a convergent flag, and
simultaneously future-proofs us against more flags being added in the
future.
llvm-svn: 238445
Octeon CPUs use dmtc2 rt,imm16 and dmfcp2 rt,imm16 for the crypto coprocessor.
E.g. dmtc2 rt,0x4057 starts calculation of sha-1.
I had to introduce a new deconding namespace to avoid a decoding conflict.
Reviewed By: dsanders
Differential Revision: http://reviews.llvm.org/D10083
llvm-svn: 238439
This adds support for the 64-bit DWARF format, but is still limited to
less than 4GB of debug data by the DataExtractor class. Some versions
of the GNU MIPS toolchain generate 64-Bit DWARF even though it isn't
actually necessary.
Differential Revision: http://reviews.llvm.org/D1988
llvm-svn: 238434
This was a bug for bug compatibility with gas that is completely unnecessary.
If a _GLOBAL_OFFSET_TABLE_ symbol is used, it will already be created by
the time we get to the ELF writer.
llvm-svn: 238432
Summary:
Following on from r209907 which made personality encodings indirect, do the
same for TType encodings. This fixes the case where a try/catch block needs
to generate references to, for example, std::exception in the
.gcc_except_table.
Reviewers: petarj
Reviewed By: petarj
Subscribers: srhines, joerg, tberghammer, llvm-commits
Differential Revision: http://reviews.llvm.org/D9669
llvm-svn: 238427
Add support for resolving MIPS64r2 and MIPS64r6 relocations in MCJIT.
Patch by Vladimir Radosavljevic.
Differential Revision: http://reviews.llvm.org/D9667
llvm-svn: 238424
DIEAbbrev contains a SmallVector that can leak for overly large abbrevs. They
used to be owned by the DIE, but after the recent refactoring DWARFFile
allocates its own abbrevs.
Leak found by asan.
llvm-svn: 238418
Canonicalizing 'x [+-] (-Constant * y)' is not a win if we don't *know*
we will open up CSE opportunities.
If the multiply was 'nsw', then negating 'y' requires us to clear the
'nsw' flag. If this is actually worth pursuing, it is probably more
appropriate to do so in GVN or EarlyCSE.
This fixes PR23675.
llvm-svn: 238397
Summary:
This patch made two improvements to NaryReassociate and the NVPTX pipeline
1. Run EarlyCSE/GVN after NaryReassociate to get rid of redundant common
expressions.
2. When adding an instruction to SeenExprs, maps both the SCEV before and after
reassociation to that instruction.
Test Plan: updated @reassociate_gep_nsw in nary-gep.ll
Reviewers: meheff, broune
Reviewed By: broune
Subscribers: dberlin, jholewinski, llvm-commits
Differential Revision: http://reviews.llvm.org/D9947
llvm-svn: 238396
Extracted from the D6531 patch by Bruno Cardoso Lopes, and re-generated
to reflect the current state of the world. This should let Bruno's D6531
actually show the delta between the approaches by running the x86 test
case update script after re-building.
llvm-svn: 238391
Change `DIE::addChild()` to return a reference to the just-added node,
and update consumers to use it directly. An upcoming commit will
abstract away (and eventually change) the underlying storage of
`DIE::Children`.
llvm-svn: 238372
Stop storing a `DIEAbbrev` in `DIE`, since the data fits neatly inside
the `DIEValue` list. Besides being a cleaner data structure (avoiding
the parallel arrays), this gives us more freedom to rearrange the
`DIEValue` list.
This fixes the temporary memory regression from 845 MB up to 879 MB, and
drops it further to 829 MB for a net memory decrease of around 1.9%
(incremental decrease around 5.7%).
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
llvm-svn: 238364
This reverts commit r238350, effectively reapplying r238349 after fixing
(all?) the problems, all somehow related to how I was using
`AlignedArrayCharUnion<>` inside `DIEValue`:
- MSVC can only handle `sizeof()` on types, not values. Change the
assert.
- GCC doesn't know the `is_trivially_copyable` type trait. Instead of
asserting it, add destructors.
- Call placement new even when constructing POD (i.e., the pointers).
- Instead of copying the char buffer, copy the casted classes.
I've left in a couple of `static_assert`s that I think both MSVC and GCC
know how to handle. If the bots disagree with me, I'll remove them.
- Check that the constructed type is either standard layout or a
pointer. This protects against a programming error: we really want
the "small" `DIEValue`s to be small and simple, so don't
accidentally change them not to be.
- Similarly, check that the size of the buffer is no bigger than a
`uint64_t` or a pointer. (I thought checking against
`sizeof(uint64_t)` would be good enough, but Chandler suggested that
pointers might sometimes be bigger than that in the context of
sanitizers.)
I've also committed r238359 in the meantime, which introduces a
DIEValue.def to simplify dispatching between the various types (thanks
to a review comment by David Blaikie). Without that, this commit would
be almost unintelligible.
Here's the original commit message:
--
Change `DIEValue` to be stored/passed/etc. by value, instead of
reference. It's now a discriminated union, with a `Val` field storing
the actual type. The classes that used to inherit from `DIEValue` no
longer do. There are two categories of these:
- Small values fit in a single pointer and are stored by value.
- Large values require auxiliary storage, and are stored by reference.
The only non-mechanical change is to tools/dsymutil/DwarfLinker.cpp. It
was relying on `DIEInteger`s being passed around by reference, so I
replaced that assumption with a `PatchLocation` type that stores a safe
reference to where the `DIEInteger` lives instead.
This commit causes a temporary regression in memory usage, since I've
left merging `DIEAbbrevData` into `DIEValue` for a follow-up commit. I
measured an increase from 845 MB to 879 MB, around 3.9%. The follow-up
drops it lower than the starting point, and I've only recently brought
the memory this low anyway, so I'm committing these changes separately
to keep them incremental. (I also considered swapping the commits, but
the other one first would cause a lot more code churn.)
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
--
llvm-svn: 238362
Both MCStreamer and MCObjectStreamer were maintaining a current section
variable and they were slightly out of sync. I don't think this was observable,
but was inefficient and error prone.
Changing this requires a few cascading changes:
* SwitchSection has to call ChangeSection earlier for ChangeSection to see
the old section.
* With that change, ChangeSection cannot call EmitLabel, since during
ChangeSection we are still in the old section.
* When the object streamer requires a begin label, just reused the existing
generic support for begin labels instead of calling EmitLabel directly.
llvm-svn: 238357
