Commit Graph

3211 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith
f1c527b5c1 AsmPrinter: Don't emit empty .debug_loc entries
If we don't know how to represent a .debug_loc entry, skip the entry
entirely rather than emitting an empty one.  Similarly, if a .debug_loc
list has no entries, don't create the list.

We still want to create the variables, just in an optimized-out form
that doesn't have a DW_AT_location.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240244 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-21 16:54:56 +00:00
Duncan P. N. Exon Smith
01a8dc8ca6 AsmPrinter: Rewrite initialization of DbgVariable, NFC
There are three types of `DbgVariable`:
  - alloca variables, created based on the MMI table,
  - register variables, created based on DBG_VALUE instructions, and
  - optimized-out variables.

This commit reconfigures `DbgVariable` to make it easier to tell which
kind we have, and make initialization a little clearer.

For MMI/alloca variables, `FrameIndex.size()` must always equal
`Expr.size()`, and there shouldn't be an `MInsn`.  For register
variables (with a `MInsn`), `FrameIndex` must be empty, and `Expr`
should have 0 or 1 element depending on whether it has a complex
expression (registers with multiple locations use `DebugLocListIndex`).
Optimized-out variables shouldn't have any of these fields.

Moreover, this separates DBG_VALUE initialization until after the
variable is created, simplifying logic in a future commit that changes
`collectVariableInfo()` to stop creating empty .debug_loc entries/lists.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240243 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-21 16:50:43 +00:00
Alexander Kornienko
cf0db29df2 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240137 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-19 15:57:42 +00:00
David Majnemer
6d136d7300 [CodeGen] Don't emit a random reference to the personality function
This should fix issues we've been seeing with Darwin.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240036 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-18 18:31:46 +00:00
Benjamin Kramer
24e04b80a5 [AsmPrinter] Make isRepeatedByteSequence smarter about odd integer types
- zext the value to alloc size first, then check if the value repeats
  with zero padding included. If so we can still emit a .space
- Do the checking with APInt.isSplat(8), which handles non-pow2 types
- Also handle large constants (bit width > 64)
- In a ConstantArray all elements have the same type, so it's sufficient
  to check the first constant recursively and then just compare if all
  following constants are the same by pointer compare

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239977 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-17 23:55:17 +00:00
David Majnemer
cc714e2142 Move the personality function from LandingPadInst to Function
The personality routine currently lives in the LandingPadInst.

This isn't desirable because:
- All LandingPadInsts in the same function must have the same
  personality routine.  This means that each LandingPadInst beyond the
  first has an operand which produces no additional information.

- There is ongoing work to introduce EH IR constructs other than
  LandingPadInst.  Moving the personality routine off of any one
  particular Instruction and onto the parent function seems a lot better
  than have N different places a personality function can sneak onto an
  exceptional function.

Differential Revision: http://reviews.llvm.org/D10429

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239940 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-17 20:52:32 +00:00
Rafael Espindola
3fea1651f6 Rename and improve emitSectionOffset.
Different object formats represent references from dwarf in different ways.

ELF uses a relocation to the referenced point (except for .dwo) and
COFF/MachO use the offset of the referenced point inside its section.

This patch renames emitSectionOffset because

* It doesn't produce an offset on ELF.
* It changes behavior depending on how DWARF is represented, so adding
dwarf to its name is probably a good thing.

The patch also adds an option to force the use of offsets.That avoids
funny looking code like

  if (!UseOffsets)
    Asm->emitSectionOffset....

It was correct, but read as if the ! was inverted.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239866 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-16 23:22:02 +00:00
Daniel Sanders
7f5b833aa3 Replace string GNU Triples with llvm::Triple in TargetMachine::getTargetTriple(). NFC.
Summary:
This continues the patch series to eliminate StringRef forms of GNU triples
from the internals of LLVM that began in r239036.

Reviewers: rengolin

Reviewed By: rengolin

Subscribers: llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D10381


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239815 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-16 13:15:50 +00:00
Adrian Prantl
0f80e47db3 Debug Info IR: Switch DIObjCProperty to use DITypeRef.
This is a prerequisite for turning on ODR type uniquing for ObjC++.

rdar://problem/21377883

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239780 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 23:18:03 +00:00
NAKAMURA Takumi
145cdc632a AsmPrinter.cpp: Avoid crashes for targeting like "arm-mingw32". CurrentFnSym might not be <MCSymbolELF> here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239692 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-14 00:23:40 +00:00
NAKAMURA Takumi
82b72bed60 Reformat.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239691 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-14 00:23:33 +00:00
Reid Kleckner
2bd0221fa4 [WinEH] Put finally pointers in the handler scope table field
We were putting them in the filter field, which is correct for 64-bit
but wrong for 32-bit.

Also switch the order of scope table entry emission so outermost entries
are emitted first, and fix an obvious state assignment bug.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239574 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 23:37:18 +00:00
Reid Kleckner
3e16bd3aaf [WinEH] Create an llvm.x86.seh.exceptioninfo intrinsic
This intrinsic is like framerecover plus a load. It recovers the EH
registration stack allocation from the parent frame and loads the
exception information field out of it, giving back a pointer to an
EXCEPTION_POINTERS struct. It's designed for clang to use in SEH filter
expressions instead of accessing the EXCEPTION_POINTERS parameter that
is available on x64.

This required a minor change to MC to allow defining a label variable to
another absolute framerecover label variable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239567 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 22:32:23 +00:00
Rafael Espindola
6c56decee0 Generalize emitAbsoluteSymbolDiff.
This makes emitAbsoluteSymbolDiff always succeed and moves logic from the asm
printer to it.

The object one now also works on ELF. If two symbols are in the same fragment,
we will never move them apart.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239552 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 18:58:08 +00:00
Pete Cooper
5a118340dd Remove MachineModuleInfo::UsedFunctions as it has no users.
It hasn't been used since r130964.

This also removes MachineModuleInfo::isUsedFunction and
MachineModuleInfo::AnalyzeModule, both of which were only
there to support UsedFunctions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239501 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 01:04:56 +00:00
Reid Kleckner
3de99b70aa [WinEH] _except_handlerN uses 0 instead of 1 to indicate catch-all
Our usage of 1 was a holdover from __C_specific_handler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239482 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-10 18:14:07 +00:00
Reid Kleckner
6d7e69b227 Remove safeseh debug print and remove extra braces
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239449 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-10 01:13:44 +00:00
Reid Kleckner
c8e72e9126 [WinEH] Emit .safeseh directives for all 32-bit exception handlers
Use a "safeseh" string attribute to do this. You would think we chould
just accumulate the set of personalities like we do on dwarf, but this
fails to account for the LSDA-loading thunks we use for
__CxxFrameHandler3. Each of those needs to make it into .sxdata as well.
The string attribute seemed like the most straightforward approach.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239448 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-10 01:02:30 +00:00
Reid Kleckner
a8c0a9b042 Fix -Wsign-compare warning in WinException.cpp
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239445 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-10 00:04:53 +00:00
Reid Kleckner
bdcbc426af [WinEH] Add 32-bit SEH state table emission prototype
This gets all the handler info through to the asm printer and we can
look at the .xdata tables now. I've convinced one small catch-all test
case to work, but other than that, it would be a stretch to say this is
functional.

The state numbering algorithm avoids doing any scope reconstruction as
we do for C++ to simplify the implementation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239433 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-09 21:42:19 +00:00
David Blaikie
6eee2375d9 Revert "[DWARF] Fix a few corner cases in expression emission"
This reverts commit r239380 due to apparently GDB regressions:
http://lab.llvm.org:8011/builders/clang-x86_64-ubuntu-gdb-75/builds/22562

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239420 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-09 18:01:51 +00:00
Keno Fischer
b4863a99c9 [DWARF] Fix a few corner cases in expression emission
Summary: I noticed an object file with `DW_OP_reg4 DW_OP_breg4 0` as a DWARF expression,
which I traced to a missing break (and `++I`) in this code snippet.
While I was at it, I also added support for a few other corner cases
along the same lines that I could think of.

Test Plan: Hand-crafted test case to exercises these cases is included.

Reviewers: echristo, dblaikie, aprantl

Reviewed By: aprantl

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10302

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239380 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-09 01:53:59 +00:00
Matt Arsenault
d99ce2f630 MC: Add target hook to control symbol quoting
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239370 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-09 00:31:39 +00:00
Rafael Espindola
f7e0685b9a Create a MCSymbolELF.
This create a MCSymbolELF class and moves SymbolSize since only ELF
needs a size expression.

This reduces the size of MCSymbol from 56 to 48 bytes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238801 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-02 00:25:12 +00:00
Jim Grosbach
586c0042da MC: Clean up MCExpr naming. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238634 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-30 01:25:56 +00:00
Reid Kleckner
16e4a624c4 [WinEH] Emit EH tables for __CxxFrameHandler3 on 32-bit x86
Small (really small!) C++ exception handling examples work on 32-bit x86
now.

This change disables the use of .seh_* directives in WinException when
CFI is not in use. It also uses absolute symbol references in the tables
instead of imagerel32 relocations.

Also fixes a cache invalidation bug in MMI personality classification.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238575 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-29 17:00:57 +00:00
Reid Kleckner
178db50629 Rename Win64Exception.(cpp|h) to WinException.(cpp|h)
This is in preparation for reusing this for 32-bit x86 EH table
emission.  Also updates the type name for consistency. NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238521 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-28 22:47:01 +00:00
Duncan P. N. Exon Smith
2c7cce70cd AsmPrinter: Stop exposing underlying DIE children list, NFC
Update `DIE` API to hide the implementation of `DIE::Children` so we can
swap it out.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238468 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-28 19:56:34 +00:00
Duncan P. N. Exon Smith
bfecc6bdee AsmPrinter: Rename begin_values() => values_begin(), NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238456 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-28 18:55:38 +00:00
Benjamin Kramer
331b719b2b [AsmPrinter] Destroy allocated DIEAbbrevs on teardown.
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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238418 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-28 12:55:43 +00:00
Duncan P. N. Exon Smith
2c46a37b03 AsmPrinter: Avoid a warning in NDEBUG, NFC
Should fix the -Werror release build:
http://lab.llvm.org:8011/builders/lld-x86_64-darwin13/builds/11113

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238375 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 23:02:36 +00:00
Duncan P. N. Exon Smith
59be554de4 AsmPrinter: Return added DIE from DIE::addChild()
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`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238372 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 22:59:03 +00:00
Duncan P. N. Exon Smith
636aba5bd1 AsmPrinter: Stop exposing underlying DIEValue list, NFC
Change the `DIE` API to hide the implementation of the list of
`DIEValue`s.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238369 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 22:44:06 +00:00
Duncan P. N. Exon Smith
95afdd3a07 AsmPrinter: Remove DIEHash::AttrEntry, NFC
Remove "the most boring struct ever" (thanks to review by Eric).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238366 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 22:36:37 +00:00
Duncan P. N. Exon Smith
611a2f2322 AsmPrinter: Store abbreviation data directly in DIE and DIEValue
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
2015-05-27 22:31:41 +00:00
Duncan P. N. Exon Smith
09fe4bf794 Reapply "AsmPrinter: Change DIEValue to be stored by value"
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
2015-05-27 22:14:58 +00:00
Duncan P. N. Exon Smith
344593ce6c AsmPrinter: Introduce DIEValue.def, NFC
Use a .def macro file to iterate through the various subclasses of
`DIEValue`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238359 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 21:15:43 +00:00
Duncan P. N. Exon Smith
3c41ae83f2 Revert "AsmPrinter: Change DIEValue to be stored by value"
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
2015-05-27 19:30:27 +00:00
Duncan P. N. Exon Smith
b9d92c6a8d AsmPrinter: Change DIEValue to be stored by value
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
2015-05-27 19:22:50 +00:00
Rafael Espindola
eac1f66427 Use operator<< instead of print in a few more places.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238315 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 13:05:42 +00:00
Adrian Prantl
2cc3e0a5ec Use "auto &" in range-based for-loop and remove the extra braces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238243 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 20:06:51 +00:00
Adrian Prantl
74f44b6c69 Fix a use-after-free in a DEBUG output.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238242 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 20:06:48 +00:00
Duncan P. N. Exon Smith
518dcb905e AsmPrinter: Avoid creating symbols in DwarfStringPool
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.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238122 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-24 16:58:59 +00:00
Duncan P. N. Exon Smith
b976cabda3 AsmPrinter: Prune an include, NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238121 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-24 16:54:59 +00:00
Duncan P. N. Exon Smith
6c44d1fc4e AsmPrinter: Remove dead code, NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238120 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-24 16:51:29 +00:00
Duncan P. N. Exon Smith
9ec6380779 AsmPrinter: Avoid EmitLabelDifference() in DwarfAccelTable
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.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238119 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-24 16:48:54 +00:00
Duncan P. N. Exon Smith
3755781deb AsmPrinter: Use DwarfStringPoolEntry in DwarfAccelTable, NFC
This is just an API change, but it prepares to stop using
`EmitLabelDifference()` when possible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238118 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-24 16:44:32 +00:00
Duncan P. N. Exon Smith
24ad5c9e05 AsmPrinter: Make DIEString small
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
2015-05-24 16:40:47 +00:00
Duncan P. N. Exon Smith
1717728066 AsmPrinter: Extract DwarfStringPoolEntry from DwarfStringPool, NFC
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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238116 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-24 16:33:33 +00:00
Duncan P. N. Exon Smith
e3ae958f94 AsmPrinter: Emit the DwarfStringPool offset directly when possible
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.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238114 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-24 16:14:59 +00:00