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.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238364 91177308-0d34-0410-b5e6-96231b3b80d8
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.)
--
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238362 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238350 91177308-0d34-0410-b5e6-96231b3b80d8
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.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238349 91177308-0d34-0410-b5e6-96231b3b80d8
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.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238117 91177308-0d34-0410-b5e6-96231b3b80d8
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.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238084 91177308-0d34-0410-b5e6-96231b3b80d8
AsmPrinter owns the OutStreamer, so an owning pointer makes sense here. Using a
reference for this is crufty.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235752 91177308-0d34-0410-b5e6-96231b3b80d8
This commit removes `DebugLocList` and replaces it with
`DebugLocStream`.
- `DebugLocEntry` no longer contains its byte/comment streams.
- The `DebugLocEntry` list for a variable/inlined-at pair is allocated
on the stack, and released right after `DebugLocEntry::finalize()`
(possible because of the refactoring in r231023). Now, only one
list is in memory at a time now.
- There's a single unified stream for the `.debug_loc` section that
persists, stored in the new `DebugLocStream` data structure.
The last point is important: this collapses the nested `SmallVector<>`s
from `DebugLocList` into unified streams. We previously had something
like the following:
vec<tuple<Label, CU,
vec<tuple<BeginSym, EndSym,
vec<Value>,
vec<char>,
vec<string>>>>>
A `SmallVector` can avoid allocations, but is statically fairly large
for a vector: three pointers plus the size of the small storage, which
is the number of elements in small mode times the element size).
Nesting these is expensive, since an inner vector's size contributes to
the element size of an outer one. (Nesting any vector is expensive...)
In the old data structure, the outer vector's *element* size was 632B,
excluding allocation costs for when the middle and inner vectors
exceeded their small sizes. 312B of this was for the "three" pointers
in the vector-tree beneath it. If you assume 1M functions with an
average of 10 variable/inlined-at pairs each (in an LTO scenario),
that's almost 6GB (besides inner allocations), with almost 3GB for the
"three" pointers.
This came up in a heap profile a little while ago of a `clang -flto -g`
bootstrap, with `DwarfDebug::collectVariableInfo()` using something like
10-15% of the total memory.
With this commit, we have:
tuple<vec<tuple<Label, CU, Offset>>,
vec<tuple<BeginSym, EndSym, Offset, Offset>>,
vec<char>,
vec<string>>
The offsets are used to create `ArrayRef` slices of adjacent
`SmallVector`s. This reduces the number of vectors to four (unrelated
to the number of variable/inlined-at pairs), and caps the number of
allocations at the same number.
Besides saving memory and limiting allocations, this is NFC.
I don't know my way around this code very well yet, but I wonder if we
could go further: why stream to a side-table, instead of directly to the
output stream?
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235229 91177308-0d34-0410-b5e6-96231b3b80d8
We were creating an expression of the form (S+C)-S which is just C.
Patch by Frédéric Riss. I just added the testcase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232549 91177308-0d34-0410-b5e6-96231b3b80d8
This makes code that uses section relative expressions (debug info) simpler and
less brittle.
This is still a bit awkward as the symbol is created late and has to be
stored in a mutable field.
I will move the symbol creation earlier in the next patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231802 91177308-0d34-0410-b5e6-96231b3b80d8
To be used/tested by llvm-dsymutil. (llvm-dsymutil does a 'static' link,
no need for relocations for most things, so it'll just emit raw integers
for most attributes)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231298 91177308-0d34-0410-b5e6-96231b3b80d8
utils/sort_includes.py.
I clearly haven't done this in a while, so more changed than usual. This
even uncovered a missing include from the InstrProf library that I've
added. No functionality changed here, just mechanical cleanup of the
include order.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225974 91177308-0d34-0410-b5e6-96231b3b80d8
dsymutil would like to use all the AsmPrinter/MCStreamer infrastructure
to stream out the DWARF. In order to do so, it will reuse the DIE object
and so this header needs to be public.
The interface exposed here has some corners that cannot be used without a
DwarfDebug object, but clients that want to stream Dwarf can just avoid
these.
Differential Revision: http://reviews.llvm.org/D6695
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225208 91177308-0d34-0410-b5e6-96231b3b80d8
In preparation for sinking all the subprogram emission code down from
DwarfDebug into DwarfCompileUnit, this will avoid bloating
DwarfUnit.h/cpp greatly and make concerns a bit more clear/isolated.
(sinking this handling down is part of the work to handle emitting
minimal subprograms for -gmlt-like data into the skeleton CU under
fission)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219057 91177308-0d34-0410-b5e6-96231b3b80d8
Makes some more cases (the unit tests, specifically), lexically
compatible with a change to unique_ptr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207261 91177308-0d34-0410-b5e6-96231b3b80d8
Got bored, removed some manual memory management.
Pushed references (rather than pointers) through a few APIs rather than
replacing *x with x.get().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206222 91177308-0d34-0410-b5e6-96231b3b80d8
This removes the magic-number-esque code creating/retrieving the same
label for a debug_loc entry from two places and removes the last small
piece of reusable logic from emitDebugLoc so that there will be less
duplication when refactoring it into two functions (one for debug_loc,
the other for debug_loc.dwo).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205382 91177308-0d34-0410-b5e6-96231b3b80d8
Implement debug_loc.dwo, as well as llvm-dwarfdump support for dumping
this section.
Outlined in the DWARF5 spec and http://gcc.gnu.org/wiki/DebugFission the
debug_loc.dwo section has more variation than the standard debug_loc,
allowing 3 different forms of entry (plus the end of list entry). GCC
seems to, and Clang certainly, only use one form, so I've just
implemented dumping support for that for now.
It wasn't immediately obvious that there was a good refactoring to share
the implementation of dumping support between debug_loc and
debug_loc.dwo, so they're separate for now - ideas welcome or I may come
back to it at some point.
As per a comment in the code, we could choose different forms that may
reduce the number of debug_addr entries we emit, but that will require
further study.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204697 91177308-0d34-0410-b5e6-96231b3b80d8
This works by moving the existing code into the DIEValue hierarchy
and using the DwarfDebug pointer off of the AsmPrinter to access
any global information we need.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203033 91177308-0d34-0410-b5e6-96231b3b80d8
This enables us to figure out where in the debug_loc section our
locations are so that we can eventually hash them. It also helps
remove some special case code in emission. No functional change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203018 91177308-0d34-0410-b5e6-96231b3b80d8
using a full uint16_t with the flag value... which happens to be
0 or 1. Update the class for bool values and rename functions slightly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202921 91177308-0d34-0410-b5e6-96231b3b80d8
This commit moves getSLEB128Size() and getULEB128Size() from
MCAsmInfo to LEB128.h and removes some copy-and-paste code.
Besides, this commit also adds some unit tests for the LEB128
functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201937 91177308-0d34-0410-b5e6-96231b3b80d8
alongside DIEBlock and replace uses accordingly. Use DW_FORM_exprloc
in DWARF4 and later code. Update testcases.
Adding a DIELoc instead of using extra forms inside DIEBlock so
that we can keep location expressions separate from other uses. No
direct use at the moment, however, it's not a lot of code and
using a separately named class keeps it somewhat more obvious
what's going on in various locations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201481 91177308-0d34-0410-b5e6-96231b3b80d8
This simplifies type unit and type unit reference creation as well as
setting the stage for inter-type hashing across type unit boundaries.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197539 91177308-0d34-0410-b5e6-96231b3b80d8
section use the form DW_FORM_data4 whilst in Dwarf 4 and later they
use the form DW_FORM_sec_offset.
This patch updates the places where such attributes are generated to
use the appropriate form depending on the Dwarf version. The DIE entries
affected have the following tags:
DW_AT_stmt_list, DW_AT_ranges, DW_AT_location, DW_AT_GNU_pubnames,
DW_AT_GNU_pubtypes, DW_AT_GNU_addr_base, DW_AT_GNU_ranges_base
It also adds a hidden command line option "--dwarf-version=<uint>"
to llc which allows the version of Dwarf to be generated to override
what is specified in the metadata; this makes it possible to update
existing tests to check the debugging information generated for both
Dwarf 4 (the default) and Dwarf 3 using the same metadata.
Patch (slightly modified) by Keith Walker!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195391 91177308-0d34-0410-b5e6-96231b3b80d8
Emit DW_TAG_type_units into the debug_info section using compile unit
headers. This is bogus/unusable by debuggers, but testable and provides
more isolated review.
Subsequent patches will include support for type unit headers and
emission into the debug_types section, as well as comdat grouping the
types based on their hash. Also the CompileUnit type will be renamed
'Unit' and relevant portions pulled out into respective CompileUnit and
TypeUnit types.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195166 91177308-0d34-0410-b5e6-96231b3b80d8
We add a map in DwarfDebug to map MDNodes that are shareable across CUs to the
corresponding DIEs: MDTypeNodeToDieMap. These DIEs can be shared across CUs,
that is why we keep the maps in DwarfDebug instead of CompileUnit.
We make the assumption that if a DIE is not added to an owner yet, we assume
it belongs to the current CU. Since DIEs for the type system are added to
their owners immediately after creation, and other DIEs belong to the current
CU, the assumption should be true.
A testing case is added to show that we only create a single DIE for a type
MDNode and we use ref_addr to refer to the type DIE.
We also add a testing case to show ref_addr relocations for non-darwin
platforms.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193779 91177308-0d34-0410-b5e6-96231b3b80d8
To support ref_addr, we calculate the section offset of a DIE (i.e. offset
of a DIE from beginning of the debug info section). The Offset field in DIE
is currently CU-relative. To calculate the section offset, we add a
DebugInfoOffset field in CompileUnit to store the offset of a CU from beginning
of the debug info section. We set the value in DwarfUnits::computeSizeAndOffset
for each CompileUnit.
A helper function DIE::getCompileUnit is added to return the CU DIE that
the input DIE belongs to. We also add a map CUDieMap in DwarfDebug to help
finding the CU for a given CU DIE.
For a cross-referenced DIE, we first find the CU DIE it belongs to with
getCompileUnit, then we use CUDieMap to get the corresponding CU for the CU DIE.
Adding the section offset of the CU with the CU-relative offset of a DIE gives
us the seciton offset of the DIE.
We correctly emit ref_addr with relocation using EmitLabelPlusOffset when
doesDwarfUseRelocationsAcrossSections is true.
This commit handles the emission of DW_FORM_ref_addr when we have an attribute
with FORM_ref_addr. A follow-on patch will start using ref_addr when adding a
DIEEntry. This commit will be tested and verified in the follow-on patch.
Reviewed off-list by Eric, Thanks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193658 91177308-0d34-0410-b5e6-96231b3b80d8
Also improve the implementation of EmitRawText(Twine) so it doesn't
bother using the SmallString buffer if the Twine is a simple StringRef
anyway.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193378 91177308-0d34-0410-b5e6-96231b3b80d8
