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
This reverts commit r238349, since it caused some errors on bots:
- std::is_trivially_copyable isn't available until GCC 5.0.
- It was complaining about strict aliasing with my use of
ArrayCharUnion.
llvm-svn: 238350
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: 238349
This commit a 3rd attempt at comitting the initial MIR serialization patch.
The first commit (r237708) was reverted in 237730. Then the second commit
(r237954) was reverted in r238007, as the MIR library under CodeGen caused
a circular dependency where the CodeGen library depended on MIR and MIR
library depended on CodeGen.
This commit has fixed the dependencies between CodeGen and MIR by
reorganizing the MIR serialization code - the code that prints out
MIR has been moved to CodeGen, and the MIR library has been renamed
to MIRParser. Now the CodeGen library doesn't depend on the
MIRParser library, thus the circular dependency no longer exists.
--Original Commit Message--
MIR Serialization: print and parse LLVM IR using MIR format.
This commit is the initial commit for the MIR serialization project.
It creates a new library under CodeGen called 'MIR'. This new
library adds a new machine function pass that prints out the LLVM IR
using the MIR format. This pass is then added as a last pass when a
'stop-after' option is used in llc. The new library adds the initial
functionality for parsing of MIR files as well. This commit also
extends the llc tool so that it can recognize and parse MIR input files.
Reviewers: Duncan P. N. Exon Smith, Matthias Braun, Philip Reames
Differential Revision: http://reviews.llvm.org/D9616
llvm-svn: 238341
v2: TargetLoweringBase:: -> TargetLowering::
Use Ops array
v3: Explicitly use value 0 for ?DIV
Remove redundant newline
Differential revision: http://reviews.llvm.org/D7803
reviewer: ab
llvm-svn: 238336
- Clean documentation comment
- Change the API to accept an iterator so you can actually pass
MachineBasicBlock::end() now.
- Add more "const".
llvm-svn: 238288
remove ExecutionEngine's dependence on CodeGen. NFC.
This is a follow-up to r238080.
Differential Revision: http://reviews.llvm.org/D9830
llvm-svn: 238244
Stop creating symbols we don't need in `DwarfStringPool`. The consumers
only call `DwarfStringPoolEntryRef::getSymbol()` when DWARF is
relocatable, so this just stops creating the unused symbols when it's
not. This drops memory usage from 851 MB to 845 MB, around 0.7%.
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
llvm-svn: 238122
Mint a new function, `AsmPrinter::emitDwarfStringOffset()`, which takes
a `DwarfStringPoolEntryRef`. When DWARF is relocatable across sections,
this defers to `emitSectionOffset()` and emits the `MCSymbol`;
otherwise, just emit the offset directly, without using any intermediate
symbols.
`EmitLabelDifference()` is already optimized to emit absolute label
differences cheaply when possible, so there aren't any major memory
savings here (853 MB down to 851 MB, or 0.2%). However, it prepares for
making the `MCSymbol`s in the `DwarfStringPool` optional.
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
llvm-svn: 238119
Expose the `DwarfStringPool` entry in a header, and store a pointer to
it directly in `DIEString`. Instead of choosing at creation time how to
emit it, use the `dwarf::Form` to determine that at emission time.
Besides avoiding the other `DIEValue`, this shaves two pointers off of
`DIEString`; the data is now a single pointer. This is a nice cleanup
on its own -- and drops memory usage from 861 MB down to 853 MB, around
0.9% -- but it's also preparation for passing `DIEValue`s by value.
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
llvm-svn: 238117
Extract out `DwarfStringPoolEntry` and `DwarfStringPoolRef` from
`DwarfStringPool` so that downstream users can start using
`DwarfStringPool::getEntry()` directly. This will allow users to delay
the decision between emitting a symbol or an offset until later.
llvm-svn: 238116
Change `DwarfStringPool` to calculate byte offsets on-the-fly, and
update `DwarfUnit::getLocalString()` to use a `DIEInteger` instead of a
`DIEDelta` when Dwarf doesn't use relocations (i.e., Mach-O). This
eliminates another call to `EmitLabelDifference()`, and drops memory
usage from 865 MB down to 861 MB, around 0.5%.
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
llvm-svn: 238114
Move `DwarfStringPool`'s `getEntry()` to the header (and make it a
member function) in preparation for calculating symbol offsets
on-the-fly.
llvm-svn: 238112
On GPU targets, materializing constants is cheap and stores are
expensive, so only doing this for zero vectors was silly.
Most of the new testcases aren't optimally merged, and are for
later improvements.
llvm-svn: 238108
Remove all virtual functions from `DIEValue`, dropping the vtable
pointer from its layout. Instead, create "impl" functions on the
subclasses, and use the `DIEValue::Type` to implement the dynamic
dispatch.
This is necessary -- obviously not sufficient -- for passing `DIEValue`s
around by value. However, this change stands on its own: we make tons
of these. I measured a drop in memory usage from 888 MB down to 860 MB,
or around 3.2%.
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
llvm-svn: 238084
This is part of the work to remove TargetMachine::resetTargetOptions.
In this patch, instead of updating global variable NoFramePointerElim in
resetTargetOptions, its use in DisableFramePointerElim is replaced with a call
to TargetFrameLowering::noFramePointerElim. This function determines on a
per-function basis if frame pointer elimination should be disabled.
There is no change in functionality except that cl:opt option "disable-fp-elim"
can now override function attribute "no-frame-pointer-elim".
llvm-svn: 238080
The usual CodeGenPrepare trickery, on a target-specific intrinsic.
Without this, the expansion of atomics will usually have the zext
be hoisted out of the loop, defeating the various patterns we have
to catch this precise case.
Differential Revision: http://reviews.llvm.org/D9930
llvm-svn: 238054
This change to VirtRegRewriter::addMBBLiveIns adds live-in registers for each
MachineBasicBlock's LiveIns set without isLiveIn checks as they are being added
because doing so is expensive. After all live-in registers are added, the LiveIn
vectors are sorted and uniqued.
llvm-svn: 238008
Previously `SDDbgValue`s used the general allocator that lives for all
of `SelectionDAG`. Instead, give them their own allocator, and reset it
whenever `SDDbgInfo::clear()` is called, plugging a spiritual leak.
This drops `SelectionDAGBuilder::visitIntrinsicCall()` off of my heap
profile (was at around 2% of `llc` for codegen of `-flto -g`). Thanks
to Pete Cooper for spotting the problem and suggesting the fix.
llvm-svn: 237998
Cleanup how `SDDbgValue` is initialized, and rearrange the fields to
save two pointers in the struct layout. No real functionality change
though (and I doubt the memory savings would show up in a profile).
llvm-svn: 237997
Prior to this patch, we could update the operand of another MI in the same
bundle.
Longer version:
Before InlineSpiller rematerializes a vreg, it iterates over operands of each MI
in a bundle, collecting all (MI, OpNo) pairs that reference that vreg.
Then if it does rematerialize, it goes through the pair list and replaces the
operands with the new (rematerialized) vreg. The problem is, it tries to
replace all of these operands in the main MI ! This works fine for single MIs.
However, if we are processing a bundle of MIs and the list contains multiple
pairs - the rematerialization will either crash trying to access a non-existing
operand of the main MI, or silently corrupt one of the existing ones. It will
also ignore other MIs in the bundle.
The obvious fix is to use the MI pointers saved in collected (MI, OpNo) pairs.
This must have been the original intent of the pair list but somehow these
pointers got lost.
Patch by Dmitri Shtilman <dshtilman@icloud.com>!
Differential revision: http://reviews.llvm.org/D9904
<rdar://problem/21002163>
llvm-svn: 237964
This commit is a 2nd attempt at committing the initial MIR serialization patch.
The first commit (r237708) made the incremental buildbots unstable and was
reverted in r237730. The original commit didn't add a terminating null
character to the LLVM IR source which was passed to LLParser, and this
sometimes caused the test 'llvmIR.mir' to fail with a parsing error because
the LLVM IR source didn't have a null character immediately after the end
and thus LLLexer encountered some garbage characters that ultimately caused
the error.
This commit also includes the other test fixes I committed in
r237712 (llc path fix) and r237723 (remove target triple) which
also got reverted in r237730.
--Original Commit Message--
MIR Serialization: print and parse LLVM IR using MIR format.
This commit is the initial commit for the MIR serialization project.
It creates a new library under CodeGen called 'MIR'. This new
library adds a new machine function pass that prints out the LLVM IR
using the MIR format. This pass is then added as a last pass when a
'stop-after' option is used in llc. The new library adds the initial
functionality for parsing of MIR files as well. This commit also
extends the llc tool so that it can recognize and parse MIR input files.
Reviewers: Duncan P. N. Exon Smith, Matthias Braun, Philip Reames
Differential Revision: http://reviews.llvm.org/D9616
llvm-svn: 237954
This starts merging MCSection and MCSectionData.
There are a few issues with the current split between MCSection and
MCSectionData.
* It optimizes the the not as important case. We want the production
of .o files to be really fast, but the split puts the information used
for .o emission in a separate data structure.
* The ELF/COFF/MachO hierarchy is not represented in MCSectionData,
leading to some ad-hoc ways to represent the various flags.
* It makes it harder to remember where each item is.
The attached patch starts merging the two by moving the alignment from
MCSectionData to MCSection.
Most of the patch is actually just dropping 'const', since
MCSectionData is mutable, but MCSection was not.
llvm-svn: 237936
This patch improves support for sign extension of the lower lanes of vectors of integers by making use of the SSE41 pmovsx* sign extension instructions where possible, and optimizing the sign extension by shifts on pre-SSE41 targets (avoiding the use of i64 arithmetic shifts which require scalarization).
It converts SIGN_EXTEND nodes to SIGN_EXTEND_VECTOR_INREG where necessary, that more closely matches the pmovsx* instruction than the default approach of using SIGN_EXTEND_INREG which splits the operation (into an ANY_EXTEND lowered to a shuffle followed by shifts) making instruction matching difficult during lowering. Necessary support for SIGN_EXTEND_VECTOR_INREG has been added to the DAGCombiner.
Differential Revision: http://reviews.llvm.org/D9848
llvm-svn: 237885
Create a low-overhead path for `EmitLabelDifference()` that emits a
emits an absolute number when (1) the output is an object stream and (2)
the two symbols are in the same data fragment.
This drops memory usage on Mach-O from 975 MB down to 919 MB (5.8%).
The only call is when `!doesDwarfUseRelocationsAcrossSections()` --
i.e., on Mach-O -- since otherwise an absolute offset from the start of
the section needs a relocation. (`EmitLabelDifference()` is cheaper on
ELF anyway, since it creates 1 fewer temp symbol, and it gets called far
less often. It's not clear to me if this is even a bottleneck there.)
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
llvm-svn: 237876
Duncan P. N. Exon Smith